HUMAN FUNCTIONAL ANATOMY by hcj

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									HUMAN FUNCTIONAL ANATOMY

     HEAD AND NECK

      LAB ANSWERS
Human Functional Anatomy 213
213: HUMAN FUNCTIONAL ANATOMY:
PRACTICAL CLASS 8 The Skull and Regions of the Head and Neck
Osteology of the Skull
Work in pairs to examine a skull. The skull consists of a cranium and a mandible. The cranium
can be thought of as having two major parts: The brain case enclosing and protecting the brain,
and the facial skeleton. You will notice that, while the brain case is composed of fairly strong
and thick bone, the parts of the facial skeleton are paper thin. For this reason great care must be
taken when handling the skulls - NEVER HOLD THE SKULL BY THE EYE SOCKETS OR
NASAL CAVITY. The safest way to handle a skull is which a finger in the foramen magnum.
The skull is normally described from its anterior, superior, posterior, lateral, inferior and internal
aspects (those features which you may be able to palpate are underlined).

There is a lot of information on the following pages. Do not try to memorise everything this
week. Over the following weeks you should return to these pages to consolidate and complete
your understanding of the Osteology of the skull

NORMA VERTICALIS
Examine a skull from the superior aspect. As you work through the list of features on the skull,
try to identify the structures on your own head or that of a partner.
Draw and label the following features on the outline
Frontal bone
         Coronal suture
         Bregma (anterior fontanelle in infants)
Parietal bones
         Sagittal suture
         Parietal foramen
Occipital bone (just visible posteriorly)
         Lambda
         Lambdoid suture

What soft tissues cover this part of the skull? SCALP

NORMA OCCIPITALIS
Examine a skull from the posterior aspect. As you work
through the list of features on the skull, try to identify the
structures on your own head or that of a partner. Draw the
posterior aspect of the skull and label the following features.
Parietal bones
Occipital bone
Lambdoid suture and lambda
Nuchal lines (what muscles attach here?)
External occipital protuberance (the inion)
Occipital condyles (for articulation with the vertebral column)
Temporal bone
        Mastoid process

What is the nuchal region              the back of the neck




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Human Functional Anatomy 213
NORMA FRONTALIS
Examine a skull from the anterior aspect. As you work through the list of features on the skull,
try to identify the structures on your own head or that of a partner. Label extra features on the
diagram of the norma frontalis.
Orbits
Nares
Frontal bone: (forms the forehead and the roofs of the orbits)
        Supraorbital foramen or notch (which do you have?)
        Glabella (prominence of bone just above the bridge of the nose)
        Superciliary ridges (prominences underlying the eyebrows)
Nasal bones:
        Feel the difference between the bony and cartilagenous parts of your own nose
Lachrymal bone has the naso-lachrymal canal on the medial side of the orbits
Zygomatic bone:
        These form your cheek bones:
        Temporal process (forms the anterior part of the zygomatic arch).
        Orbital margin (around the edge of the orbit the zygomatic bone joins the frontal bone
laterally, and the maxilla along the lower margin of the orbit)
Maxilla
        Forms the lower medial part of the orbital margin and articulates with the frontal bone
medially
        Forms most of the margin of the nares
        Anterior nasal spine
        Infraorbital foramen
        Alveolar process: forms the upper jaw and holds all the upper teeth
        Maxillary sinus (large air space situated in the bone above the upper teeth)
        Palatine      process
(forms most of the roof of
the mouth)
Mandible
        Mental
protuberance (chin)
        Mental foramen
        Body of mandible
        Genial tubercles
        Mylohyoid line
        Submandibular
fossa
        Angle of mandible

The regions of the head
seen in the frontal view
include:
    1. Scalp
    2. Face
    3. Nose
    4. Orbits
    5. Mouth
    6. Temporal region
Locate each region on the
skull, and an X-ray and mark them on the diagram….



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Human Functional Anatomy 213
NORMA LATERALIS
Examine a skull from the lateral aspect. As you work through the list of features on the skull, try
to identify the structures on your own head or that of a partner. Label extra features on the
diagram of the norma lateralis.
Parietal bone
       Temporal lines and Temporal fossa
Occipital bone
Frontal bone
       Coronal suture
       Pterion (junction of frontal, parietal, temporal and sphenoid bones)
               Notice how thin the bone is in this region
               What muscle covers this area?
Temporal bone
       Squamous part
       Petrous part
       Mastoid process
       Styloid process
       Tympanic plate
       External acoustic meatus
       Zygoma (zygomatic process of temporal bone)
       Temporomandibular joint
               (Mandibular fossa)
               (Articular eminence)

Sphenoid Bone
Greater wing
Pterygoid plates
Pterygomaxillary
fissure
Maxilla
Alveolar process
Nares
Maxillary sinus
Zygomatic bone
Orbital margin
Mandible
Angle
Body
Ramus
Coronoid process
Condyloid process
(head of mandible)




The regions of the head seen in the lateral view include all those seen from the front plus:
   1. Parotid region
   2. Nuchal region
Locate each region on the skull, and an X-ray and mark them on the diagram….




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Human Functional Anatomy 213
NORMA BASALIS The main features on the inferior aspect of the skull are the palate the
choana (posterior nasal aperture), the foramen magnum and other foramina on the base of the
skull.
Occipital bone
Foramen magnum
Squamous part
Basiocciput
Occipital condyles
Jugular foramen
Hypoglossal canal
Temporal bone
Petrous part
Tympanic part
Zygoma
Styloid process
Mastoid process
Stylomastoid
foramen
Carotid canal
Sphenoid bone
Greater wing
Foramen ovale
For. spinosum
Foramen lacerum
Pterygoid plates
Pterygoid
hamulus (2 small
hooks of bone at
the back of the
hard palate)
Palatine bone
        Posterior part of the palate
        Greater and lesser palatine foramina
Maxilla
        Palatine plates
        Dental arch of the alveolar processes
        Incisive canal




Look at a lateral and an anterior X-ray of the skull – You should be able to find all the underlined
features.
Look some CT scans as well – see how many features and regions you can identify




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Human Functional Anatomy 213
INSIDE THE CRANIAL CAVITY
The floor of the cranial cavity is divided into three levels or cranial fossae:
1. Anterior cranial fossa
Orbital plates of the frontal bone
Ethmoid bone
        Cribriform plate
        Crista galli
Lesser wings of the sphenoid bone
2. Middle cranial fossa
Sphenoid bone
Body of sphenoid
        Pituitary fossa (sella turcica)
        Dorsum sellae
        Tuberculum sellae
        Anterior clinoid processes
        Posterior clinoid processes
Greater wing of the sphenoid bone
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
Carotid canal
Temporal bone
Petrous temporal
(middle and inner ear)
3. Posterior cranial
fossa
Occipital bone
Clivus = Basiocciput +
basisphenoid
Squamous part of
occipital bone
Foramen magnum
Hypoglossal canal
Temporal bone
Internal acoustic meatus


Look at a lateral and an anterior X-ray of the skull – You should be able to find all the underlined
features
Look some CT scans as well – see how many features and regions you can identify




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Human Functional Anatomy 213
THE NECK
Superficially the neck can be described in
anterior and posterior triangles which are
separated by the sternomastoid muscle

TRIANGLES OF THE NECK
Revise the posterior triangle of the neck:
Boundaries:
Trapezius, sternomastoid and the clavicle
Muscles in the floor
Semispinalis
Splenius
Levator scapulae
Scalenus medius and posterior
Scalenus anterior

Brachial plexus
Which muscles does it emerge between?    Scalenus medius & posterior and Scalenus anterior
Subclavian artery and vein
Accessory nerve
What does it supply Trapezius and sternomastoid

The anterior triangle
Use the diagram and a wet specimen to outline
the boundaries of the anterior triangle (midline,
mandible, and the anterior border of the
sternocleidomastoid). The anterior triangle is
further subdivided into three smaller triangles by
three muscles:
    1. Anterior belly of digastric
    2. Posterior belly of digastric
    3. Superior belly of omohyoid.
A) Submandibular or digastric triangle
(Between the mandible and the two bellies of
digastric) contains the submandibular gland and
the facial artery.
Feel the submandibular gland and lymph nodes
below the body of the mandible. You can feel
the facial artery pulse as it crosses about
halfway along the body of the mandible.
Find the attachments of the digastric muscle on
the mandible and temporal bone.
B) Carotid triangle
(between the sternomastoid muscle, posterior belly of digastric and the omohyoid) contains the
carotid sheath (carotid artery, internal jugular vein, vagus nerve)
In the upper lateral part of the anterior triangle you’ll be able to feel the carotid artery pulse in the
hollow in front of SCM.
C) Muscular triangle
(between the midline and the omohyoid muscle) contains the infrahyoid strap muscles
(sternothyroid, sternohyoid, thyrohyoid, omohyoid)

Surface anatomy
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Human Functional Anatomy 213
Find your sternomastoid and trapezius muscles, and the anterior and posterior triangles
Feel down the midline at the front of your neck and locate the: hyoid bone thyroid cartilage,
cricoid cartilage, and the tracheal rings. The thyroid gland is the soft mass beside and below the
lower half of the thyroid cartilage.

BONES AND CARTILAGES IN THE NECK
Examine models of the larynx and loose examples of
these bones and cartilages to identify the following
(many of which can also be felt in your neck).
Hyoid bone
       Body
       Greater horns
       Lesser horns
Feel the hyoid bone in your own neck (just below the
mandible). Move your tongue and feel how the hyoid
moves

Thyroid cartilage
      Laminae
      Prominence
      Notch
      Superior horns
      Inferior horns

Cricoid cartilage
        Arch
        Lamina
Feel the small gap between the thyroid and cricoid
cartilages filled by the cricothyroid membrane. This gap
can be opened (by qualified people) to provide an
emergency airway.


Fascia in the neck
Use the diagram to identify the layers of fascia in
the neck:
    1. Prevertebral fascia surrounds the vertebral
       column and its muscles
    2. The carotid sheath surrounds the carotid
       artery, internal jugular vein and vagus nerve
    3. Visceral fascia surrounds the pharynx,
       larynx, trachea, oesophagus and thyroid
       gland
    4. The deep/investing fascial of the neck
       surrounds the whole neck and contains the
       sternomastoid and trapezius muscles.




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Human Functional Anatomy 213
Homework/Tutorial sheet               REGIONS OF THE HEAD
Using a skull, X-rays and CT scans to locate each of the following regions of the skull.
Label these regions and parts of the head on their respective diagrams.
SAGITTAL SECTION - Midline regions
   1. Cranial cavity
           a. Anterior cranial fossa
           b. Middle cranial fossa
           c. Posterior cranial fossa
   2. Scalp – Top of skull (Skin, CT,
       Aponeurosis, Loose CT, Periosteum)                                                  A
   3. Face
   4. Nose – Nasal cavity
   5. Palate
   6. Mouth – Oral cavity
   7. Pharynx – Behind the nose and mouth
   8. Suboccipital / nuchal

Bilateral regions
    9. Orbit – Eye socket                                     B
    10. Temporal region – side of skull where
        temporalis muscle is
               Temporalis
    11. Infratemporal – Lateral to the pharynx, medial to the mandibular ramus
               Pterygoid muscles (of mastication)
    12. Petrous temporal – Middle and inner ear

HORIZONTAL SECTION
Posterior cranial fossa
Pharynx
                                                                                               A
Nose
Face
Maxillary sinus
Temporal
Body of sphenoid
Petroustemporal
Infratemporal
       Auditory tube


CORONAL SECTION                                                                                B
Anterior cranial fossa
Nose
Palate
Mouth
Orbits
Face
Sinuses
    1. ethmoid
    2. maxillary




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Human Functional Anatomy 213
                             Practical anatomy checklist

Osteology
The skull
Don’t try to know all the parts of the skull this week. But learn some of it and build up you
detailed knowledge over the next few weeks – There will be a viva on the osteology of the skull
next week

Triangles of the neck
Posterior
Anterior
Submandibular
Carotid
Muscular

Bones and cartilages of the neck
Hyoid
Thyroid
Cricoid
Trachea



Regions of the head and neck
Have a general idea about the names and locations of the regions




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Human Functional Anatomy 213
213: HUMAN FUNCTIONAL ANATOMY:
PRACTICAL CLASS 9 Face & Surface anatomy of the head & neck
Look at someone's face and make sure you can locate the following features – draw diagrams and
add labels to the figures below:
Nose:
Nostrils
Nasal septum
Alae
Bridge

Mouth:
Lips (labia)
Philtrum of the lip
Vestibule of the mouth
Teeth (incisors, canines, premolars, molars)
        Buccal, labial, lingual and occlusal surfaces
Gums
Tongue
Hard and soft palate

Eye:
Palpebrae
Medial and lateral canthus
Palpebral fissure

Lachrymal caruncle and puncta
Lachrymal gland
Medial and lateral canthus

Ear:
External acoustic meatus
The auricle
Tragus
Antitragus
Intertragateric notch
Concha
Helix
Antihelix
Tubercle
Lobule.

The Scalp
Is composed of 5 layers: the skin, dense
connective tissue, and the flat tendon of
occipitofrontalis, which can slide forwards and
backwards on a loose connective tissue layer over                                         the
periosteum of the skull



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Human Functional Anatomy 213
FACIAL MUSCLES
Look at the prosections of the face. Identify and draw in the space provided, each of the
following muscles, try to use that muscle on your own face, while watching a friend doing the
same. Spend some time at home testing these muscles in front of the mirror
Platysma
Draws up the skin on the
neck
Orbicularis oris
purses the lips.
Orbicularis oculi
(palpebral part) - blink.
(orbital part) - screws up
the eyes.
Occipitofrontalis
raises the eyebrows
(horizontal lines on the
forehead)
occipital part retracts the
hair
Corrugator supercilii
pulls the eyebrows
medially
 (vertical lines on the
forehead)
Procerus
wrinkles skin on the bridge of the nose.
Zygomaticus major and minor
pulls the corner of the mouth up and out.
Levator labii alaque nasi
flares the nostrils and bares the canines.
Depressor anguli oris
pulls the corners of the mouth down.
Levator anguli oris
lifts corners of the mouth.
Mentalis
puckers the skin on the chin.
Buccinator
muscle in the cheek used for blowing.

Find motor branches of the facial nerve (temporal, zygomatic, buccal, mandibular, and
cervical) coming out of the parotid gland between the ear and the back of the mandible, and
radiating out to supply the muscles of facial expression.


Identify the facial artery and vein crossing the face. Why is the facial artery tortuous?
        The face is very mobile (mastication and facial expression)




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Human Functional Anatomy 213
ARTERIES AND VEINS OF THE HEAD

Find the common carotid artery in the neck                and
follow it until it divides into internal and
external carotid arteries.
The internal carotid artery goes directly to the
brain.
The Internal jugular vein runs back down the              neck
inside the carotid sheath with the internal and
common carotid arteries and the vagus nerve.
The external carotid artery gives 6 collateral
branches:
    1. Superior thyroid
    2. Lingual
    3. Facial
    4. Occipital
    5. Posterior auricular
    6. Ascending pharyngeal
The external carotid artery ends by dividing into:
    1. Maxillary
    2. Superficial temporal arteries
The external carotid arteries branches are distributed   to the
face scalp and neck.




Superficial veins
On superficial dissection of the
head and neck identify the
retromandibular vein, in the parotid
gland, behind the mandible.
The retromandibular vein divides,
just below the mandible, into
anterior and posterior branches.
The posterior branch joins the
posterior auricular vein to form the
external jugular vein which lies on
top and sternomastoid as it travels
down the neck to join the
subclavian vein.
The anterior branch of the
retromandibular vein joins the
facial vein and these go deep to
join the internal jugular vein.


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Human Functional Anatomy 213
THE TRIGEMINAL NERVE
Look inside the cranial cavity (middle cranial fossa) of a skull and a wet specimen. Use a piece
of wire, and a skull,
to trace the course
of each of the three
divisions of the
trigeminal    nerve,
identifying      the
bony landmarks as
you go. Start at the
trigeminal
ganglion, which lies
in a fossa near the
carotid canal at the
apex of the petrous
temporal bone.
First, what kind of
ganglion is the
trigeminal ganglion?

The ophthalmic division passes through the superior orbital fissure, the supraorbital and
      supratrochlear branches (together known as the frontal nerve) continue through the orbit
      and emerge onto the forehead at the supraorbital and supratrochlear notches (or foramen).
      The ophthalmic division also sends branches to the front of the eye (nasociliary), and into
      the ethmoid and frontal sinuses through ethmoid foramina in the medial wall of the orbit.
The maxillary division passes through the foramen rotundum into the pterygopalatine fossa. The
      infraorbital branch goes through the
      inferior orbital fissure into the orbit,
      before sinking into the floor and
      emerging on the face through the
      infraorbital foramen. In the orbit the
      infraorbital nerve gives off a
      zygomatic branch which goes through
      foramina in the zygomatic bone on its
      way to the cheek (zygomaticofacial
      and zygomaticotemporal nerves).
      Other branches of the maxillary nerve
      go through the pterygopalatine fossa
      into the nasal cavity via
      sphenopalatine foramen, and to the
      palate via the greater and lesser
      palatine canals. The maxillary nerve
      also supplies the upper teeth by tiny
      posterior superior alveolar branches
      that stream over the back of the
      mandible, and anterior superior
      alveolar branches of the infraorbital
      nerve.


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Human Functional Anatomy 213
The mandibular division of the trigeminal nerve passes out of the cranial cavity through foramen
      ovale, it immediately gives of sensory branches to the side of the head (auriculotemporal),
      tongue (lingual), cheeks and gums (buccal), and to the lower teeth and chin (inferior
      alveolar and mental nerves). The inferior alveolar nerve goes into the mandibular
      foramen and emerges at the mental foramen, after supplying the lower teeth, as the mental
      nerve to the chin. The mandibular nerve is also motor to the muscles of mastication
      (derived from the 1st pharyngeal arch)

Meninges
All three divisions of the trigeminal nerve also send
recurrent meningeal branches to the cranial dura.




Skin
Use the outline of the head to indicate the areas of skin
supplied by the three divisions of the trigeminal nerve.:
Ophthalmic
Maxillary
Mandibular


What nerves supply the neck and the back of the head?


Nose and mouth
Use the outline of the hemisected head, to indicate the
distribution of the trigeminal nerve to the regions of
mucous membrane in the nose, nasal sinuses and mouth,
and dura in the cranial cavity.
    1. Ophthalmic
    2. Maxillary
    3. Mandibular




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Human Functional Anatomy 213
OPENINGS (foramina, fissures and canals)
Each of the following openings in the skull connects two regions. Identify each opening and
name the regions connected, and indicate the contents of the foramen
Opening                             region 1       region 2           contents
Cribriform plate                  Ant cranial fossa (ACF) Nose                     Olfactory nerves I

Superior orbital fissure                  ACF               Orbit                  III, IV, V1, VI

Supraorbital foramen or notch             Orbit             forehead               supraorbital nerve

Optic canal                               middle CF         orbit                  Optic nerve II

Foramen rotundum                          MCF               pterygopalatine fossa V2 maxillary

Foramen ovale                     infratemporal fossa       MCF                    V3 mandibular

Foramen spinosum                          MCF infratemporal fossa          middle meningeal artery

Foramen lacerum                           MCF               infratemporal fossa    nothing

Carotid canal                     infratemporal fossa       MCF            Internal carotid artery

Internal acoustic meatus                  Posterior CF temporal bone               VII & VIII

Auditory canal (eustation tube)           Pharynx           middle ear             Air

Petrotympanic fissure             temporal bone             infratemporal fossa    chorda tympani

Jugular foramen                   PCF              Neck internal jugular vein + IX, X & XI

Hypoglossal canal                 PCF              Neck                    hypoglossal nerve XII

Stylomastoid foramen              temporal bone             infratemporal fossa    facial nerve VII

Inferior orbital fissure          Orbit            infratemporal fossa             veins

Infraorbital foramen              Orbit            face             infraorbital nerve

Sphenopalatine foramen            Pterygopalatine fossa             Nose nasal nerves

Nasolacrimal canal                Eye (lachrymal sac)       nose           Nasolachrymal duct

Pterygoid canal            Foramen lacerum         Pterygopalatine fossa Great petrosal nerve

Palatine canals            Pterygopalatine fossa            Palate palatine nerves

Incisive canal             Nose           anterior palate           nasopalatine nerve

Mandibular canal           infratemporal fossa     mandible/mental foramen         inf alveolar nerve




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Human Functional Anatomy 213
                            Practical anatomy checklist

Osteology
The skull
By now you should know most of the features of the skull outlined in week 8

Surface anatomy of the face
Eye
Nose
Mouth
Ear

Muscles of facial expression

Vessels of the head and neck

Trigeminal nerve
The three divisions and their main branches

Foraminae of the head and their contents




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Human Functional Anatomy 213
213: HUMAN FUNCTIONAL ANATOMY:
PRACTICAL CLASS 10 Mouth and mastication

OSTEOLOGY
Study a skull and identify bony features associated with the mouth and mastication:
Mandible
Ramus
Angle
Body
Head
Notch
Coronoid process
Genial tubercles
Digastric fossae
Mylohyoid line

Locate the areas of attachment of:
temporalis, masseter, medial
pterygoid, lateral pterygoid,
mylohyoid, genioglossus, geniohyoid and digastric.
Maxilla
Alveolar margin
Maxillary tuberosity
Palate
Incisive foramen.
Palatine bone
Palate
Palatine foraminae
Temporal bone
Mandibular fossa
Articular eminence
Post-glenoid tubercle
Styloid process
Stylomastoid foramen
Mastoid process
Sphenoid bone
Foramen ovale
Spine of the sphenoid
Lateral pterygoid plate
Medial pterygoid plate
Pterygoid hamulus.

MUSCLES OF MASTICATION AND THE TEMPOROMANDIBULAR JOINT
Surface Anatomy
With your mouth closed, feel the head of the mandible, just in front of the tragus of your auricle.
Open and close your mouth, and feel the head of mandible slip forwards, out from under your
finger. Feel your temporalis and masseter muscles while; clenching and unclenching your teeth;
and protracting and retracting your jaw.

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Human Functional Anatomy 213
Use the wet specimens to examine the TMJ (temporomandibular joint) and the muscles of
mastication. There is also a bottle which shows each muscle of mastication, but be sure to
identify them on a specimen as well.

On superficial dissections of the side of the face identify the temporalis and masseter muscles and
the TMJ.

On deeper dissections in the infratemporal fossa identify the medial and lateral pterygoid
muscles. Identify the intra-articular disc of the TMJ, and the insertion of the lateral pterygoid
muscle to this disc and the neck of the mandible.


All these muscles are supplied by the mandibular division of the trigeminal nerve. Two other
muscles associated with movements of the mandible are supplied by the mandibular nerve (nerve
to mylohyoid). Find mylohyoid muscle and the anterior belly of digastric under the chin.

Make sure you understand the movements of the TMJ, and the muscles involved in each case:

Elevation
       Temporalis, masseter, medial pterygoid
Protraction
       Lateral pterygoid, anterior temporalis
Retraction
       Posterior temporalis, digastric
Depression
       Gravity, digastric
What is the function of bilateral protraction of both TMJs?
       Necessary prior to depress (opening) of the mandible
What is the function of unilateral protraction and retraction?
       Sideways movement – needed for chewing

Also in the infratemporal fossa, find the mandibular division of the trigeminal nerve emerging
from the foramen ovale, and the maxillary artery. Identify the lingual and inferior alveolar
nerves, and the nerve to mylohyoid. You may also be able to see the chorda tympani; this branch
of the facial nerve (carrying taste and parasympathetic fibres) emerges from the petrotympanic
fissure just medial to the TMJ, and joins the lingual nerve.




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Human Functional Anatomy 213
ORAL CAVITY
Look into a partner's mouth and, with the tongue depressed and protracted, identify and
draw:
   1. Teeth - Incisors (2), canines (1), premolars (2) and molars (3); (determine which teeth are
       missing from the adult complement).
   2. Dorsum of the tongue with small papillae all over, you may be able to see a row of large
       (vallate papillae) at the back of the anterior two thirds of the tongue.
   3. Palate, soft palate and uvula
   4. palatoglossal and palatopharyngeal folds
   5. Tonsils may be visible between those two folds
   6. Posterior pharyngeal wall




With the tongue elevated, identify and draw
   1. Frenulum of the tongue with papillae of the submandibular ducts
   2. Sublingual glands in the floor of the mouth




Find these structures on a hemisected head.


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Human Functional Anatomy 213
THE SALIVARY GLANDS AND PARASYMPATHETIC NERVE SUPPLIES
There are three main salivary glands (parotid, sublingual and submandibular), However the whole
lining of the mouth, nose and pharynx is a mucus membrane, with many tiny glands in the
mucosa.

On a superficial prosection of the face identify the parotid gland, with its duct passing forwards
across the masseter muscle. The parotid duct enters the mouth by piercing buccinator adjacent to
the 2nd upper molar.

Study a superficial prosection of the submandibular region; the submandibular gland is
obvious below the body of the mandible. The facial artery hooks over the submandibular gland
before coming onto the face. The submandibular gland is folded over the posterior edge of the
mylohyoid muscle, so that its duct passes over the muscle into the floor of the mouth. The
submandibular duct is accompanied by the lingual nerve, and as it passes the gland, you should
be able to see the submandibular ganglion hanging off the nerve. Also in this region identify the
hypoglossal nerve.

The parasympathetic nerves to the glands of the head:
Parasympathetic Origin               Ganglion         Distributed with        Glands
nerve
Chorda tympani  Facial (CNVII)       Submandibular Lingual (V1)            Submandibular
                                                                           Sublingual
                                                                     2
Greater   petrosal Facial (CNVII)       Pterygopalatine   Maxillary(V )    Nasal, palatine
nerve                                                                      and lachrymal
Lesser    petrosal Glossopharyngea      Otic              Auriculotemporal Parotid
nerve              l (CNIX)                               (V3)

Use colour to trace the Taste and Parasympathetic branches of the Facial and Glossopharyngeal
nerves on the diagram below. Also identify the parasympathetic ganglia and the branches of the
trigeminal nerve that carry some of these fibres




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Human Functional Anatomy 213
MUSCLES OF THE TONGUE
On the lateral view of the tongue, indicate all the extrinsic muscles (and nerve supplies):
Styloglossus (XII)
Palatoglossus (X)
Genioglossus (XII)
Hyoglossus (XII)

Add the accessory muscles of the tongue;
Digastric (VII+V)
Geniohyoid (XII)
Mylohyoid (V).

Consider what extrinsic muscles would be involved in
the movements of the tongue:
Protraction   genioglossus
Retraction    styloglossus
Elevation     palatoglossus & styloglossus
Depression    Hyoglossus & genioglossus

What muscles would perform movements like rolling the tongue?
      Intrinsic muscles, in this case the transverse muscles in the upper part of the tongue




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Human Functional Anatomy 213
THE DENTIST AND THE TRIGEMINAL NERVE

Consider which branches of the trigeminal nerve, the dentist needs to anaesthetise in order to
work on:

Lower teeth    inferior alveolar nerve

Upper front teeth     anterior superior alveolar nerve

Upper back teeth      posterior superior alveolar nerve

Palate and internal aspect of the gums       Upper :Palatine nerves (greater, lesser and
nasopalatine)                         Lower :Lingual nerve

Cheeks and outer aspect of the gums          Buccal and superior alveolar nerves




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Human Functional Anatomy 213
                            Practical anatomy checklist

Osteology
The skull and mandible
You should know all the features of the skull (from week 8) and especially the mandible and
features associated with mastication.

Temporomandibular joint
Muscles of mastication

The Mouth
The Oral cavity
Salivary glands
Muscles and movements of the tongue




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Human Functional Anatomy 213
213: HUMAN FUNCTIONAL ANATOMY:

PRACTICAL CLASS 11 Pharynx and swallowing

OSTEOLOGY
On the base of the skull identify the pharyngeal tubercle, auditory tube and styloid process. At
the inferior end of the medial pterygoid plate is a small hook called the pterygoid hamulus, which
forms a pulley for the tensor palati muscle.

Behind the last molar on the mandible, and the
maxilla are the anchoring points of the
pterygomandibular ligament (or raphe). The
pterygomandibular ligament gives attachment
to two muscles; the buccinator muscle passes
forwards into the cheek, and the superior
constrictor wraps around the pharynx
posteriorly.

Examine a hyoid bone, identify its body, and
greater and lesser horns. The lesser horn
receives the stylohyoid ligament and muscle;
the intermediate tendon of the digastric muscle
passes through a sling in the stylohyoid
ligament. The angle between the greater and
lesser horns gives attachment to the middle
constrictor of the pharynx.

Next, look at the thyroid cartilage, it has two
flat plates (laminae) which join at the front.
Posteriorly each lamina has a long superior
horn, and a short inferior horn which
articulates with the cricoid cartilage. The
upper edge of the thyroid cartilage is attached
to the lower edge of the hyoid bone by the
thyrohyoid membrane. On the outside of each
lamina is an oblique line which gives
attachment to the inferior constrictor of the
pharynx.




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Human Functional Anatomy 213
THE PHARYNX
On a hemisected head identify the parts of the pharynx:
In the nasopharynx - the opening
      of the auditory tube; and
      the salpingo-pharyngeal
      fold, and a fold covering
      the levator palati
      descending from the tube.
The soft palate has five muscles,
      four of which are supplied
      by the vagus nerve and can
      be seen on the hemisected
      head: levator palati,
      palatoglossus,
      palatopharyngeus and
      musculae uvulae (in the
      uvula); the fifth is the
      tensor palati, which is
      supplied by the mandibular
      division of the trigeminal
      nerve.
In the oropharynx - the palato-
      glossal and palato-
      pharyngeal folds with the
      palatine tonsil between; the
      posterior 1/3 of the tongue
      is studded with lingual
      tonsils (lymphoid tissue).
In the laryngopharynx - the
      opening of the larynx
      surrounded by the
      epiglottis, arytenoid cartilages and aryepiglottic folds. Above the epiglottis is a pair of
      small recesses behind the tongue (valleculae), and beside the epiglottis is the pyriform
      recess.
The pharynx becomes continuous with the oesophagus at the level of the cricoid cartilage.




26
Human Functional Anatomy 213
On deep dissections identify the three
constrictors of the pharynx in relation to their
bony and cartilaginous attachments mentioned
above. Identify the common/internal carotid
artery, internal jugular vein and the vagus
nerve running up and down on either side of
the pharynx. Note that the pharynx is
separated from the vertebral column by loose
connective tissue - the retropharyngeal space.

The constrictors of the pharynx can also be
seen on special dissections which show the
posterior aspect of the pharynx. These
special dissections are also good for finding
the glossopharyngeal        nerve on the
stylopharyngeus muscle, entering the pharynx
between the superior and middle constrictor.
You can also see the vagus nerve running
with the internal carotid artery and the
internal jugular vein. The vagus nerve gives
off pharyngeal and superior laryngeal
branches. The sympathetic trunk can also be
seen on this prosection, identify its superior
ganglion and branches to the pharynx and
blood vessels. Remember that, in life, the
sympathetic trunk is stuck on to the vertebral
column and is separated from the pharynx by
the retropharyngeal space.

Open the posterior wall of the pharynx and re-
identify the internal features of the pharynx
which you saw on a hemisected head.
Posterior part of the tongue
Epiglottis and the opening of the larynx

The longitudinal muscle coat of the pharynx
consists of: stylo-pharyngeus (IX), salpingo-
pharyngeus (X) and palato-pharyngeus (X).
These muscles lie inside the circular muscle
(constrictors) in the pharynx. Salpingopharyngeus and palatopharyngeus can be seen as bulges
on the inside of the pharynx; while stylopharyngeus can be seen arising from the styloid process
and passing into the pharynx between the superior and middle constrictors.




                                                                                             27
Human Functional Anatomy 213
Watch a video on deglutition.
Feel your larynx while swallowing, why do you think it rises?
       Longitudinal pharyngeal muscles pull the pharynx (and larynx) up during swallowing)

How does swallowing help to equalise pressure in the middle ear (like when driving up a
mountain or taking off in a plane)?
       The action of the longitudinal muscles (especially salpingpharyngeus) – pulls the auditory
tube open

At the beginning of the swallow be aware of what your tongue is doing. What role does your
tongue play in swallowing.
       It pushes the bolus backwards and closes the oropharyngeal isthmus

What role do the epiglottis and soft palate play in the swallowing process
Epiglottis     Protects the larynx from food entering
Soft palate    Prevents food entering the nasopharynx

If you reach into your mouth and touch some part of your oropharynx, you will initiate the gag
reflex. What nerves are involved in the sensory and motor parts of this reflex, and how does this
reflex assist you in swallowing.
Motor           Vagus – pharyngeal branch
Sensory         Glossopharyngeal
Function        Triggers the reflex pharyngeal phase of swallowing




28
Human Functional Anatomy 213
Saliva
Identify the three main salivary glands and their openings in the mouth
What is the function of saliva? What effect do sympathetic and parasympathetic nerves have on
the secretion of saliva? How do these nerves reach the:
a) parotid gland        IX (lesser petrosal) – Otic ganglion – auriculotemporal nerve (V3)

b) submandibular gland         VII chordtympani – lingual nerve – submandibular ganglion –
lingual nerve

c) sublingual gland            same as for submandibular gland

On the midsagittal section of the
head, note the areas supplied with
sensory innervation from the: vagus,
facial, glossopharyngeal, and the
mandibular and maxillary divisions
of the trigeminal nerves.




What areas are covered with
stratified squamous epithelium, and which have respiratory epithelium?
Stratified squamous anywhere food normally passes (mouth, oro and laryngopharynx) also the
vocal folds (friction)
Respiratory            anywhere food doesn’t pass (larynx and nasopharynx)

Also indicate the areas receiving special sensory innervation from:
The olfactory (smell)
Facial (Taste - greater petrosal nerve)
Facial (Taste - chorda tympani)
Glossopharyngeal nerves (taste).

How do the taste fibres reach:
a) the anterior 2/3 of the tongue            chordotympani VII, joins the lingual nerve

b) the posterior 1/3 of the tongue           Glossopharyngeal nerve

c) the palate.         Greater petrosal nerve joins palatinenerves (V2)


                                                                                          29
Human Functional Anatomy 213
                            Practical anatomy checklist

Osteology
The skeleton of the Pharynx

Internal features of the pharynx on a sagittal section

Constrictors and longitudinal muscles of the pharynx

Salivary glands

Nerve supplies of the mouth, pharynx, and salivary glands




30
Human Functional Anatomy 213
213: HUMAN FUNCTIONAL ANATOMY:
PRACTICAL CLASS 12 Cranial cavity, eye and orbit

OSTEOLOGY
Identify the bones which comprise the walls of the orbit: maxilla, zygomatic, ethmoid, lachrymal,
frontal, and the greater and lesser wings of the sphenoid. Revise the openings of the orbit:
superior orbital fissure, inferior orbital fissure, optic canal, nasolachrymal canal, anterior and
posterior ethmoidal foramina, zygomatic foramina, infraorbital canal, supraorbital notch or
foramen.




In the middle cranial fossa
identify the superior orbital
fissure,     optic     canal,
pituitary fossa, and carotid
canal. Trace the carotid
canal through the temporal
bone. Identify the foramen
spinosum and follow the
groove for the middle
meningeal artery, which
comes from the foramen
and spreads out on the sides
of the cranial cavity.
Notice how deeply the
anterior branch of the artery
grooves the bone on the inside of the temple. What would be the result of a fracture of the bone
in this region?



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Human Functional Anatomy 213
DURAL VENOUS SINUSES OF THE CRANIAL CAVITY
Study the preparations of the cranial cavity with the dura intact. Identify the dural sinuses, which
are the venous drainage system of the brain: superior sagittal sinus, inferior sagittal sinus, straight
sinus, transverse sinus, sigmoid sinus, inferior and superior petrosal sinuses, and the cavernous
sinus.

Superior sagittal
sinus

Inferior sagittal
sinus

Straight sinus

Transverse sinus

Sigmoid sinus

Cavernous sinus

Superior petrosal sinus

Inferior petrosal sinus

What vessels can drain into the cavernous sinus      cerebral veins and also emissary veins from
outside the cranial cavity eg. superior ophthalmic veins from the face, (these can carry infection
from the region around the eyes into the brain – you shouldn’t scratch pimples in this region!)
Apart from the internal jugular vein, what other paths can blood take to leave the cranial cavity?
Can blood enter the cranial cavity through these alternative routes?

Compare the cranial cavity with dura, to a skull without the dura, you can see most of the sinuses
as grooves in the bone on a skull. Identify the internal carotid artery as it enters the cranial
cavity, compare this with the opening of the carotid canal on the skull, trace the course that the
carotid artery takes before it emerges from the dura.




32
Human Functional Anatomy 213
CRANIAL NERVES
Locate the cranial nerves as they pierce the
dura:
The olfactory and optic nerves pierce the
       dura in front of the cavernous sinus.
The oculomotor, trochlear, ophthalmic
       division of the trigeminal, and the
       abducent nerves all pierce the dura
       behind the cavernous sinus on their
       way to the superior orbital fissure.
       These nerves run forwards in the
       walls of the cavernous sinus.
The facial and vestibulocochlear nerves go
       into the internal acoustic meatus.
The glossopharyngeal, vagus, spinal
       accessory and hypoglossal nerves
       pierce the dura in the floor of the
       posterior cranial fossa.

CAVEROUS SINUS
Examine some glass slides and diagrams of coronal sections through the pituitary gland and
cavernous sinuses. Identify the carotid artery, and the oculomotor, trochlear, ophthalmic
division of the trigeminal, and abducent nerves running through the cavernous sinuses. Draw a
diagram a coronal section through the cavernous sinus and pituitary gland, including all the
structures listed above.

Pituitary

Cavernous sinus

Internal carotid artery

Oculomotor nerve

Trochlea nerve

Ophthalmic nerve

Maxillary nerve

Abducens nerve

The oculomotor, trochlea, ophthalmic (frontal, lachrymal, nasociliary branches) and abducens
nerves all pass through the superior orbital fissure.
       The nasociliary, occulomotor and abducens nerves pass through the fibrous ring of origin
       for the extraocular muscles.
       The lachrymal, frontal and trochlear nerves pass outside the cone of extraocular muscles.



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Human Functional Anatomy 213
EXTRA-OCULAR MUSCLES
Study a specimen with the roof of the orbit opened up. Notice how five of the six extra-ocular
muscles form a cone, arising from a tendinous ring posteriorly. Consider how the obliquity of
this cone affects the actions of the muscles.
Identify the levator palpebrae
superioris, and the six extra-
ocular muscles (medial rectus,
lateral rectus, superior rectus,
inferior rectus, superior oblique
and inferior oblique) on models
of the orbit. Notice that the
rectus muscles insert in front of
the equator of the eyeball, and
that the oblique muscles insert
behind the equator.


What action does each extra-
ocular muscle have on the
eyeball. Consider the action of
each muscle about: a vertical
axis (adduction - abduction), a
transverse axis (elevation -
depression),       and       an
anteroposterior axis (medial
and lateral rotation) Tabulate
your results below.




                       Transverse axis        Vertical axis          Anteroposterior axis
                       Elevate - depress      Adduct - abduct        Med & Lat Rotate
                                              Adduct
Medial rectus
                                              Abduct
Lateral rectus
                       Elevate                Adduct                 intort
Superior rectus
                       Elevate                Abduct                 extort
Inferior oblique
                       Depress                Adduct                 extort
Inferior rectus
                       Depress                Abduct                 intort
Superior oblique

Remember that because of the obliquity of the orbital axis, the superior and inferior rectus
muscles have adduction/abduction, and medial/lateral rotation effects. Remember also that, in


34
Human Functional Anatomy 213
health, there are no appreciable rotations of the eyeball, so the rotary effects of these muscles
must cancel opposite rotary effects.

Consider the superior rectus and inferior oblique. They
both elevate the eye, but they have opposite actions
about the anteroposterior and vertical axes. Therefore
together they can elevate the eye and balance each
others tendency to cause unwanted movements. If the
eye is adducted which muscle will be the best elevator?
What if the eye is abducted?

Inferior rectus and superior oblique form a similar
couple, which coordinate depression of the eye.

NERVES OF THE ORBIT
Study the prosections where the roof of the orbit has been removed, and identify the branches of
the ophthalmic division of the trigeminal nerve: lacrimal, frontal (supraorbital and supratrochlear)
and the trochlear nerve going to superior oblique. Below these nerves is the levator palpebrae
superioris, and the superior rectus muscles. The nasociliary branch of the ophthalmic nerve lies
below superior rectus and sends branches through the ethmoidal foramina on the medial side of
the orbit. Deeper in the orbit the medial and lateral rectus muscles can be seen on their respective
sides. In some specimens the abducens nerve can be seen lying on the lateral rectus.

Deep in the middle of the orbit is the eyeball and the
optic nerve, plus branches of the oculomotor nerve. The
ciliary ganglion is sometimes visible on the lateral side of
the optic nerve. It is a tiny brown structure with many
small nerves radiating from it (short ciliary nerves). The
ciliary ganglion is the parasympathetic cell station for the
fibres of the oculomotor nerve which supply intraocular
smooth muscle (ciliary muscle and sphincter pupillae).

The dilator pupillae muscle is innervated by sympathetic
nerves, which travel with the nasociliary nerve (long
ciliary nerves).

There is also some extraocular smooth muscle supplied by
sympathetic nerves. This can be found in the levator
palpebrae superioris muscle, and there is also supposed to be
some smooth muscle stretching across behind the eyeball
which acts to protrude the eye. These sympathetic innervated
smooth muscles explain two of the symptoms of syndrome
(damage to the cervical sympathetic trunk), ptosis (droopy
eyelids) and enophthalmia (sunken eyes).

Use the diagram that shows nerves II,III, IV and VI to add the
other nerves found in the orbit (Lacrimal, frontal, nasociliary)



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Human Functional Anatomy 213
THE EYE BALL (BULBUS OCULI)
Watch a video on the dissection of the ox eye. There are fresh cow eyes and dissection tools
available in the lab if you want to dissect one yourself.

In particular you should understand that the eye ball has three layers
        a) A tough while fibrous layer (sclera),
represented in front by the transparent cornea
        b) A vascular layer (choroid) which is
pigmented so as to absorb light and make the
eye dark inside. The choroid is represented in
front by the iris, which controls the size of the
pupil by circular (sphincter pupillae) and radial
(dilator pupillae) smooth muscle.
        c) A neural layer (retina) contains the
receptors and nerve cells which do some early
processing of visual information. The retina has
its own blood supply quite separate from the
vessels in the choroid, and these vessels can be
seen     through     the     pupil    using    an
ophthalmoscope. Anteriorly this layer is represented by the lens.

The centre of the eye, behind the lens, is filled with a transparent jelly called the vitreous humour.
In front of the lens and behind the cornea is a space which extends through the pupil, this space is
filled with aqueous humour, aqueous humour is produced by the ciliary body at the periphery of
the lens and flows slowly through the pupil to the irido-corneal angle where it is reabsorbed into
the blood stream.




36
Human Functional Anatomy 213
SURFACE ANATOMY AND LACRIMAL APPARATUS
Look into a
partner's eye and
identify the
palpebrae,
palpebral fissure,
eye lashes (cilia).
Lift an eyelid
away from the eye
and note the
conjunctival sac;
you may be able
to see the
openings of
lachrymal ducts
under the lateral
side of the upper
eyelid. Where the
eyelids meet at the
medial angle is the lachrymal caruncle, on the end
of each eyelid above and below the caruncle is a
lachrymal puncta (tiny hole) which collects tears
and conducts them to a lachrymal sac deep to the
caruncle. Tears drain from the lachrymal sac into
the nasolachrymal duct and into the nasal cavity.

Feel in your upper eyelid for a cartilage plate
(tarsal plate), this is what enables people to invert
their eyelid.

Shine a light into a partners eye and watch the
pupil constrict, this is the light reflex. Explain the afferent and efferent limbs of the neural
pathway for the light reflex (do not worry about what occurs inside the brain, although some of
you should be able to describe the pathway in full).

If you touch the surface of the eye, it blinks; can you explain the nerves involved in this reflex
pathway?

What is the function of tears? What kinds of things stimulate the flow of tears? What nerves
control the secretion of tears? Can you describe their pathway to the lachrymal gland?




                                                                                               37
Human Functional Anatomy 213
                           Practical anatomy checklist

Osteology
The orbit and middle cranial fossa

The cranial cavity
Dural venous sinuses
The cranial nerves and there relations to the dura and cavernous sinus

The Orbit
Extra ocular muscles
Nerves of the Orbit

The eyeball
Lachrymal apparatus




38
Human Functional Anatomy 213
ANATOMY AND HUMAN BIOLOGY 213
MAJOR TOPICS - WEEK BY WEEK

WEEK 1
Clavicle, Axilla and Brachial plexus.
Pelvis and lower limb nerves

WEEK 2
Describe the movements at the shoulder (Scapular and glenohumeral).
Dorsal and ventral nerves and muscle groups

WEEK 3
Uniarticular muscles
The hip in posture and locomotion

WEEK 4
Biarticular muscles
The knee joint

WEEK 5
Extensor expansion, and finger movements
The Knee and Ankle in locomotion

WEEK 6
Nerve lesions
Grips and the small muscles of the hand

WEEK 7
Compare the muscle compartments and nerve supplies in the upper and lower limbs.

WEEK 8
Development and osteology of the skull
Regions of the head and triangles of the neck

WEEK 9
Muscles of facial expression
Cranial nerves (especially Trigeminal nerve and facial)

WEEK 10
Mouth and Mastication
Tongue and salivary glands

WEEK 11
Pharynx and Autonomic nerves of the head

WEEK 12
Action of eye muscles
Contents of the orbit

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