body planes directions and membranes by dxizRr


									                                                                           Anatomy and Physiology
    the study of the structure (morphology) and shape of the body parts and their relationships to one
      another; in other words, what are things called?
    from the Greek word cut (tomy) apart (ana)

          Gross Anatomy                – the study of large easily observable body structures
          Microscopic Anatomy          – the study of microscopic structures of the body

     studies the functions of these parts or asks the question, how do they work?
     nature (physio) and study of (ology)

          Subdivisions of Physiology
          1. Neurophysiology – explains the working of the nervous system
          2. Cardiac Physiology – studies the function of the heart, which acts as a muscular pump to keep
                                   blood flowing throughout the body

 The two disciplines are closely interrelated because the functional role of a part depends on how it is

Levels of Organization

The human body is the sum of its parts and these parts can be studied at a variety of levels of organization.

1. Atoms are the simplest level.
2. Two or more atoms comprise a molecule
3. Macromolecules are large, biologically important molecules inside cells.
4. Organelles are aggregates of macromolecules used to carry out a specific function in the cell.
5. Cells are the basic living unit.
6. Tissues are groups of cells functioning together.
7. Groups of tissues form organs
8. Groups of organs function together as organ systems
9. Organ systems functioning together make up an organism.

 Anatomical Position

 In order to avoid confusion when describing the body, it is always described in the anatomical position.
 In the anatomical position, a person stands erect, legs together and arms by their sides, with their head,
 eyes, toes and palms of the hands facing forward. It is important to remember that the palms face forward
 as their relaxed position is generally facing inwards.

 The anatomical position allows us to describe the position of structures in relation to their surroundings,
 e.g. ‘the heart lies above the diaphragm’. The anatomical position avoids confusion as to whether the
 body is lying down or standing up.

 You should also bear in mind that when looking at a person in the anatomical position, their right side
 will be on your left. The structures will always be described as they are to the subject rather than as they
 appear to you.

 Anatomical planes and directions


 When preparing to look at the structures of the body, medical students find if necessary to make a section
 or cut. When the section is made through the body wall or through an organ, it is made along an
 imaginary line called plane.

 A sagittal section is an imaginary plane that travels vertically from the top to the bottom of the body,
 dividing it into left and right portions.

 Language of Anatomy and Body Membranes
                                                                           Anatomy and Physiology
There are three major anatomical planes; axial, coronal, and sagittal.

Anatomical Position             Description
Axial                           This plane cuts the body horizontally, into superior (upper) and inferior
(transverse plane)              (lower) portions.
Coronal                         This plane cuts the body vertically, into anterior (front) and posterior
(frontal plane)                 (back) portions.
Sagittal                        This plane cuts the body vertically, into left and right portions.

If the body is cut in the sagittal plane, exactly along the middle of the body, it is known as the midsagittal,
and when the half of the midsagittal is further cut we call it parasagittal.


Direction is used, when the body is in the anatomical position to explain the location of a structure
relative to the structures surrounding it.

Direction             Description                                 Example
                      Towards the front of the body
Anterior (or ventral)                                             The breastbone area is anterior to the heart.
                      (in front of).
Posterior (or dorsal) Towards the back of the body (behind).      The heart is posterior the breastbone area.
Superior (or cranial) Above (on top of).                          The heart is superior to the diaphragm.
Inferior (or caudal) Below (underneath).                          The diaphragm is inferior to the heart.
                      Away from the mid line of the body
Lateral                                                           The arms are lateral to the chest.
                      (towards the sides).
                      Towards the mid line of the body
Medial                                                            The heart is medial to the arm.
                      (towards the middle).
                      Away from the body surface (towards
Deep                                                              The lungs are deep to the rib cage.
                      the inner body).
                      Towards the external surface of the
Superficial                                                       The skin is superficial to the skeleton.
Proximal              Nearer to the trunk of the body.            The shoulder is proximal to the elbow.
Distal                Furthest from the trunk of the body.        The elbow is distal to the shoulder.


The body is split up
into two main areas,
the      axial      and
appendicular regions.
The axial region
refers to the head,
vertebral column and
trunk,      and      the
appendicular region
refers to the pelvic
girdles and the upper
and lower limbs. Each
area is further divided
into         descriptive

Language of Anatomy and Body Membranes
                                                                           Anatomy and Physiology

                       Description (pertaining        Appendicular regions         Description (pertaining to)
Axial regions
                       to)                            Upper limb
Cephalic               Head                           Clavicular                   Clavicles
Frontal                Forehead                       Acromial                     Acromion of the shoulder
Facial                 Face                           Scapular                     Scapula
Occipital              Back of the head               Interscapular                Between the two scapulae
Orbital                Eye cavity                     Axillary                     Armpit
Buccal                 Cheek                          Brachial                     Arm
Thoracic               Chest                          Antebrachial                 Forearm
Sternal                Breastbone area                Cubital                      Elbow
Umbilical              Navel (belly button)           Carpal                       Wrist
Inguinal               Groin                          Digits                       Fingers
Pubic                  Mons pubis (pubic bone)        Pollicis                     Thumb
Genital                Reproductive organs            Palmar                       Palm of the hand
Perineal               Perineum                       Lower Limb
Dorsum                 Back                           Gluteal                      Buttocks
Vertebral              Spinal column                  Coxal                        Hip
Cervical               Neck                           Femoral                      Thigh
Lumbar                 Lower back                     Patellar                     Front of the knee
Sacral                 Sacrum                         Popliteal                    Back of the knee
                                                      Crural                       Leg
                                                      Tarsal                       Ankle
                                                      Calcaneal                    Heel
                                                      Pedal                        Foot
                                                      Plantar                      Sole of the foot

Body cavities

There are two main cavities within the body, the ventral and the dorsal cavities.

The dorsal body cavity is at the back of the body and is the smaller of the two cavities. It can be further
divided into the upper and lower portions, the cranial cavity and the vertebral canal respectively.

The ventral body cavity is at the front of the body and is the larger of the two cavities. It can be further
divided into three cavities, the thoracic cavity, abdominal cavity and pelvic cavity also called as the
abdominopelvic cavity. The thoracic and abdominal cavities are divided by the diaphragm and the
abdominal and pelvic cavities are continuous with each other.

Name            Description          Boundaries                                Contain
Dorsal cavity (Small cavity at the back of the body.)
Cranial         Upper portion.        Bounded by the skull.                    Brain and meninges.
Vertebral       Lower portion.        Bounded by the vertebral column,         Spinal cord, spinal nerve
canal                                 intervertebral discs and surrounding     roots.
Ventral cavity (Large cavity at the front of the body)
Thoracic        Large cavity           It is bound laterally by the ribs       Heart, lungs, trachea,
cavity          above the              (covered by costal pleura) and the      oesophagus, large blood
                diaphragm.             diaphragm inferiorly (covered by        vessels and nerves.
                                       diaphragmatic pleura)
Abdominal       Large cavity           It is bound superiorly by the           Gastrointestinal tract, spleen,

Language of Anatomy and Body Membranes
                                                                           Anatomy and Physiology
cavity          below the             diaphragm, laterally by the body     kidneys and adrenal glands.
                diaphragm.            wall, and inferiorly by the pelvic
Pelvic cavity   Small cavity          It is bounded superiorly by the      Urinary bladder, genitals,
                below the brim of     abdominal cavity, posteriorly by the sigmoid colon and rectum.
                the pelvis.           sacrum, and laterally by the pelvis

Quadrants and regions of the abdomen

The abdomen can be divided by two lines into 4 quadrants or by 4 lines into 9 regions.

The two lines that divide the abdomen into quadrants form a cross, the centre of which is positioned over
the umbilicus (belly button). These quadrants are often used to indicate the location of pain.

Quadrant Name        Contains
Right upper          Liver, gallbladder, right kidney, duodenum, a portion of the ascending and transverse
quadrant             colons and the small intestine.
Left upper           Stomach, spleen, left kidney, pancreas, a portion of the descending and transverse
quadrant             colons and the small intestine.
Right lower
                     Appendix, caecum, a potion of the ascending colon and the small intestine.
Left lower
                     A portion of the descending and transverse colons and the small intestine.


There are two vertical lines and two horizontal lines that divide the abdomen into a grid. The vertical lines
also known as lateral lines are positioned using the middle of each clavicle as a reference. The upper
horizontal line (also known as the transpyloric or subcostal line) is positioned at the level of the pylorus of
the stomach close to the subcostal margin of the ribs. The lower horizontal line (also known as
transtubercular line) is positioned at the level of the anterior superior iliac spines of the coxal (hip) bone.

Language of Anatomy and Body Membranes
                                                                       Anatomy and Physiology

Body Membrane

   A thin, flexible layer of tissue covering surfaces or separating or connecting regions, structures, or
   Covers the body surface.
   Line the body cavities.
   Forms protective sheets around the organs.

Types of Body Membrane

    Epithelial (covering & lining membranes)
         Cutaneous Membrane
         Mucous Membrane
         Serous Membrane
    Connective Tissue Membrane (line the fibrous capsules in the joints)
         Synovial Membrane

Cutaneous Membrane
    Composed of keratinizing stratified squamous epithelium.
    Underlying dermis is dense (fibrous) connective tissue.
    Exposed to air and is dry.

Mucous Membrane
   Composed of epithelium resting on a loose connective tissue membrane called a lamina propria.
   Lines all the cavities such as respiratory, digestive, urinary, and reproductive tracts.
   Always moist because they are continually bathed in secretions.
   Absorption and secretion.
   Most secretes mucus but not all times.

Language of Anatomy and Body Membranes
                                                                         Anatomy and Physiology
Serous Membrane
    Layer of simple squamous epithelium resting on a thin layer of areolar connective tissue.
    Line the body cavities that are closed to the exterior separated by a clear fluid called serous fluid.
    Important to decrease friction by moving organs (heart, stomach)
    Occur in pairs :
            parietal layer lines    (covers inside)
            viseral layer lines     (covers outside)

     Types of Serous Membrane:
          1. Peritoneum   – abdominal Cavity
          2. Pluera       – surrounding the lungs
          3. Pericardium – surrounding the heart

Connective Tissue Membrane

                                        Synovial Membrane

                                             Composed of soft areolar connective tissue and contain no
                                              epithelial cells at all.
                                             Line the fibrous capsules surrounding joints where they
                                              provide a smooth surface and secrete a lubricating fluid.

Language of Anatomy and Body Membranes

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