ORGANISATION OF THE HUMAN BODY

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ORGANISATION OF THE HUMAN BODY Powered By Docstoc
					INTRODUCTION
The early students of anatomy and physiology were most likely
concerned with treating illnesses and injuries. Early healers
relied on superstitions and magic. Later, herbs were used to
treat certain ailments. Eventually, after much controversy the
study of medicine with standardized terms in Greek and Latin
began.


ANATOMY AND PHYSIOLOGY
      Anatomy deals with the structure (morphology) of the body
and its parts, in other words, what are things called?
      Physiology studies the functions of these parts or asks the
question, “How do they work?
      The two disciplines are closely interrelated because the
functional role of a part depends on how it is constructed.
      Anatomists rely on observation and dissection, while
physiologists employ experimentation.
      It is more common to discover new information about
physiology but anatomical discoveries are being made as well.

CHARACTERISTICS OF LIFE
      Fundamental characteristics of life are traits shared by all
organisms. Characteristics of life include:
      1.    Movement (internal or gross)
      2.    Responsiveness (reaction to internal or external
change)
      3.    Growth (increase in size without change in shape)
      4.    Reproduction (new organisms or new cells)
      5.    Respiration (use of oxygen; removal of CO2)
6.    Digestion (breakdown of food into simpler forms)
      7.    Absorption (movement of substances through
membranes and into fluids)
      8.    Circulation (movement within body fluids)
      9.    Assimilation (changing nutrients into chemically
different forms)
      10. Excretion (removal of metabolic wastes)
Taken together, these 10 characteristics constitute metabolism.
REQUIREMENTS OF ORGANISMS
      Life depends on the availability of the following:
      a.    Water (required for metabolic reactions, for transport
of    substances, for temperature regulation)
      b.    Food (nutrients needed to supply energy and raw
materials for    building new living matter)
      c.    Oxygen (used in releasing energy from nutrients)
      d.    Heat (a byproduct of metabolism; its presence
governs the rate       at which reactions occur)
      e.    Pressure (force required to facilitate movement of air
or fluids)
      Both the quality and quantity of these factors are
important.
ORGANISATION OF THE BODY
OBJECTIVES
After studying this paperwork you should be able to:
   1) define common anatomical terms
   2) use the terms that describe relative positions, body sections,
      and body regions
   3) identify the principal bones of the axial skeleton and the
      appendicular skeleton
   4) state the boundaries of the four body cavities
   5) list the contents of the body cavities
   6) state the organs located in each of the body cavities
ANATOMICAL TERMS
It is a custom (usual behaviour) to use certain terms to describe the
relationship of body parts, imaginary planes and sections of the body,
various regions, and cavities of the body. It is essential to become
accustomed to these terms before the study of anatomy and
physiology begins. When these terms are used, it is assumed that the
body is in the anatomical position. In this position, the body is
standing erect (upright, vertical), the face is forward, and the arms
are at the sides with the palms and toes directed forward.




Figure 1 the levels of structural complexity.
Relative Positions of Body Part
The terms used in table 1 describe the location of a part in relation to
another part of the body.
Table 1 shows the directional terms in describing human body.

The terms used in figure 2, 4 & 5 describe the regional and directional
terms of human body.




Figure 2 Directional terms.
Planes and Sections of the Body
Planes – a 3-dimensional axis
Section – a slice parallel to a plane

In order to observe the internal body parts, it is necessary to section
(cut open) the body in some way. It is customary to describe these
sections in terms of imaginary planes that divide the body. (Fig. 3)
      A median (midsagittal) plane is a lengthwise cut that divides
the body into right and left portions. If the section passes exactly
through the midline it is called midsagittal cut.
      A transverse (horizontal) plane is a cut that divides the body
horizontally to give a cross section. A transverse cut divides the body
into superior (upper) and inferior (lower) portions.
      A frontal plane divides the body lengthwise into anterior and
posterior portions.
      The terms longitudinal section and cross section are often
applied to body parts that have been removed and cut either
lengthwise or straight across, respectively.




Figure 3 to observe internal parts, the body may be sectioned (cut)
along various imaginary planes.
Key Concept
Anatomical position – hands at sides, palms forward.
Supine – lying down, face up
Prone – lying down, face down

Regions of the Body
The human can be divided into the axial portion, which includes the
head, neck, trunk, and the appendicular portion, which includes the
arms and legs. The trunk, or torso, contains the thorax, abdomen,
and pelvis. Each of these portions has been further divided into the
specific regions mentioned.
Figure 4 Regional terms (anterior view).
Figure 5 Regional terms (posterior view).
Head
Cephalic (head)
Frontal (forehead)
Occipital (back of head)
Orbital (eye)
Nasal (nose)
Buccal (cheek)
Oral (mouth)


Neck
Cervical (neck)

Abdomen
Sternal (breastbone)
Vertebral (spinal column)
Thoracic (chest)
Mammary (breast)
Dorsal (back)
Axillary (armpit)
Abdominal (abdomen)
Lumbar (loin)
Umbilical (navel)
Inguinal (groin)
Sacral (between the hips)
Pubic (genital region)
Gluteal (buttock)
Perineal (between the anus and the external genitalia)

Limbs (arms and legs)
Brachial (arm)
Antecubital (front of elbow)
Carpal (wrist)
Palmar (palm)
Digital (fingers)
Femoral (thigh)
Patellar (front of knee)
Crural (leg)
Popliteal (back of knee)
Tarsal (ankle)
Pedal (foot)
Calcaneal (heel)
Hallux (great toe)
Digital (toes)
Plantar (sole)

Other
Cutaneous (skin)


The skeleton
Functions
The skeleton has the following functions:

         1) the skeleton, notably the large heavy bones of the legs,
            supports the body against the pull of gravity
         2) The skeleton protects soft body parts. For example, the
            skull forms a protective encasement for the brain
         3) Flat bones such as those of the skull, ribs, and
            breastbone produce red blood cells in both adults and
            children
         4) bones are storage areas for inorganic calcium and
            phosphorus salts
         5) bones provide sites for muscle attachment and permit
            flexible body movement, especially the bones of the legs
            and arms

Bones of the Skeleton
The bones of the skeleton are not smooth; they have protuberances
(swelling) called processes and indentations called depressions
(dent).
      The skeleton is divided into the axial skeleton and the
appendicular skeleton. The axial skeleton lies in the midline of the
body and contains the bones of the skull, vertebral column, and
thoracic cage. The appendicular skeleton contains the bones of the
pectoral girdle, upper limbs (arms), pelvic girdle, and lower limbs
(legs).
Figure 6 Axial skeleton and appendicular skeleton.
Figure 7 Our Skeleton.


AXIAL SKELETON
The axial skeleton consists of the bones in the head and trunk of the
human body. It is composed of five parts; the human skull, the
ossicles of the inner ear, the hyoid bone of the throat, the chest, and
the vertebral column. The axial skeleton and the appendicular
skeleton together form the complete skeleton.

       Protective or flat bones house the brain spinal cord and other
vital organs. The purpose of the axial skeleton (among other things)
is to protect the body's most vital organs. All vertebrates have an
axial skeleton. This article mainly deals with the axial skeletons of
humans; however, it is important to understand the evolutionary
lineage of the axial skeleton. The axial skeleton has 80 bones in it. In
conclusion, Professor Sherman Leung in Brisbane discovered how
the axial skeleton affects a human's location or movement.

Human Skull
In humans, the adult skull is normally made up of 29 bones. Except
for the mandible, all of the bones of the skull are joined together by
sutures, semi-rigid articulations formed by bony ossification, the
presence of Sharpey's fibers permitting a little flexibility.

        Eight bones form the neurocranium (braincase), a protective
vault of bone surrounding the brain and brain stem medulla
oblongata. Fourteen bones form the splanchnocranium (facial bones),
the bones supporting the face. Encased within the temporal bones
are the six ear or auditory ossicles of the middle ear. The hyoid bone,
supporting the larynx, is usually not considered as part of the skull, as
it is the only bone that does not articulate with any other bones.

       The skull also contains the sinus cavities, which are air-filled
cavities lined with respiratory epithelium, which also lines the large
airways. The exact functions of the sinuses are debatable; they
contribute to lessening the weight of the skull with a minimal
reduction in strength, they contribute to resonance of the voice, and
assist in the warming and moistening of air drawn in through the
nasal cavities.

      The meninges are three layers of connective tissue, or
membranes, which surround the structures of the central nervous
system. They are known as the dura mater (outermost), the
arachnoid mater (middle) and the pia mater (innermost). Each layer
adds important protection functions.

      In humans, the anatomical position for the skull is the Frankfurt
plane, where the lower margins of the orbits and the upper borders of
the ear canals are all in a horizontal plane, or anatomical position.
This is the position where the subject is standing and looking directly
forward.
Skull (22)

   •   Cranial Bones (8)
         o Parietal (2)
         o Temporal (2)
         o Frontal (1)
         o Occipital (1)
         o Ethmoid (1)
         o Sphenoid (1)
   •   Facial Bones (14)
         o Maxilla (2)
         o Zygomatic (2)
         o Mandible (1)
         o Nasal (2)
         o Palatine (2)
         o Inferior nasal concha (2)
         o Lacrimal (2)
         o Vomer (1)


Ossicles
The ossicles (also called auditory ossicles) are the three
smallest bones in the human body. They are contained
within the middle ear space and serve to transmit sounds
from the air to the fluid-filled labyrinth (cochlea). The
absence of the auditory ossicles would constitute a
moderate-to-severe hearing loss.
Figure 8 the ossicles.

Ossicles (6)

   •   Malleus (2)
   •   Incus (2)
   •   Stapes (2)




Figure 9 Anterior view of the Skull.
Figure 10 Side view of the Skull

Thoracic Cage
The thoracic cavity (or chest cavity) is the chamber of the human
body (and other animal bodies) that is protected by the thoracic wall
(thoracic cage and associated skin, muscle, and fascia).

Components of the Thoracic Cage
Structures within the thoracic cavity include:

   •   the heart,
   •   the great vessels, which include the thoracic aorta, the
       pulmonary artery and its branches, the superior and inferior
       vena cava, and the pulmonary veins
   •   other vascular structures such as the azygos vein,
   •   the trachea, bronchi and lungs
   •   the oesophagus,
   •   the thymus gland,
  •   structures of the nervous system including the paired vagus
      nerves, and the paired sympathetic chains,
  •   Structures of the lymphatic system, especially the thoracic duct.

It contains three potential spaces lined with mesothelium: the paired
pleural cavities and the pericardial cavity. The mediastinum
comprises those organs which lie in the centre of the chest between
the lungs.




Fig 11 Thoracic cavity
Vertebral Column
In human anatomy, the vertebral column (backbone or spine) is a
column of vertebrae situated in the dorsal aspect of the torso. It
houses the spinal cord in its spinal canal.

Components of the Vertebral Column
Individual vertebrae named according to region and position, from
superior to inferior

Cervical – 7 vertebrae (C1-C7)

  •   Often possess bifid spinous processes

Thoracic – 12 vertebrae (T1-T12)

Lumbar – 5 vertebrae (L1-L5)

Sacral – 5 (fused) vertebrae (S1-S5)

Coccygeal – 3-5 vertebrae (Co1-Co5)




Figure 12 the vertebral column (lateral view).
APPENDICULAR SKELETON
The appendicular skeleton is the part of the skeleton that includes
the pectoral girdle, the upper limbs, the pelvic girdle, and the lower
limbs. The appendicular skeleton and the axial skeleton together form
the complete skeleton.

     The appendicular skeleton, consisting of 126 bones, makes
body movement possible and protects the organs of digestion,
excretion, and reproduction. The word appendicular means referring
to an appendage or anything attached to a major part of the body,
such as the upper and lower extremities.

Components of the Appendicular Skeleton
   •   Shoulder girdle
   •   Arm
   •   Hand
   •   Pelvic girdle
   •   Leg
   •   Foot

Cavities of the Body
The internal organs, called the visceral organs, are located within
specific cavities. The two main cavities are the dorsal cavities and the
larger ventral cavity. The dorsal cavity can be subdivided into two
parts: the cranial cavity within the skull contains the brain; and the
spinal cavity, protected by vertebrae, contains the spinal cord.

      The ventral cavity is subdivided into the thoracic cavity and
the abdominopelvic cavity. The lungs, heart, oesophagus, trachea,
and thymus gland are located in the thoracic cavity. This cavity
separated from the abdominopelvic cavity by a horizontal muscle
called the diaphragm.

       The abdominopelvic cavity has two portions: the upper
abdominal portion and the lower pelvic portion. The stomach, liver,
spleen, gallbladder, and most of the small and large intestine are in
the abdominal cavity. The pelvic cavity contains the rest of the large
intestine, the rectum, the urinary bladder, and the internal
reproductive organs. In males, there is an external extension of the
abdominal wall called the scrotum where the testes are found.

      Since the abdominopelvic cavity is quite large, it is sometimes
divided into four sections by running a transverse plane across the
midsagittal plane at the point of the navel. The abdominal cavity can
also be divided into a greater number of sections as is done in figure
20.




Figure 13 Cavities of the Body.

The Ventral Body Cavity – divided by the diaphragm into the thoracic
cavity and the abdominopelvic cavity.


Dorsal Cavity
Consists of cranial cavity, enclosed by the Skull and contains the
brain, eyes, and ears and spinal canal, enclosed by the spine and
contains the spinal cord.

Cranial Cavity
The cranial cavity is the relatively large space formed inside the
skull. The brain occupies the cranial cavity, which is lined by the
meninges and which contains fluid to cushion blows.
Eight cranial bones together form the cranial cavity: the frontal and
occipital bones, and two each of the parietal, temporal, sphenoid and
ethmoid bones (Martini et al., 2001).




Figure 14 Bones forming the right half of the cranium and the face
(viewed from the left).

Spinal Cavity
The spinal canal (or vertebral canal or spinal cavity) is the space
in vertebrae through which the spinal cord passes. It is a process of
the dorsal human body cavity. This canal is enclosed within the
vertebral foramen of the vertebrae. In the intervertebral spaces, the
canal is protected by the ligamentum flavum posteriorly and the
posterior longitudinal ligament anteriorly.

       The outermost layer of the meninges, the dura mater, is closely
associated with the arachnoid which in turn is loosely connected to
the innermost layer of the meninges, the pia mater. The meninges
divide the spinal canal into the epidural space and the subarachnoid
space. The pia mater is closely attached to the spinal cord. A
subdural space is generally only present due to trauma and/or
pathological situations. The subarachnoid space is filled with
cerebrospinal fluid and contains the vessels that supply the spinal
cord, namely the anterior spinal artery and the paired posterior spinal
arteries, accompanied by corresponding spinal veins. The spinal
arteries form anastomoses known as the vasocorona of the spinal
cord. The epidural space contains loose fatty tissue, and a network of
large, thin-walled blood vessels called the anterior vertebral venous
plexus and the posterior vertebral venous plexus.




Figure 15 Spinal cavity


Ventral Cavity
The ventral cavity is a human body cavity that is in the anterior
(front) aspect of the human body. It is made up of the thoracic cavity,
and the abdominopelvic cavity. The abdominopelvic cavity is further
separated into the abdominal cavity and pelvic cavity, but there is no
physical barrier between the two. The abdominal cavity contains
digestive organs; the pelvic cavity contains the urinary bladder,
internal reproductive organs, and rectum.

Thoracic Cavity
The thoracic cavity (or chest cavity) is the chamber of the human
body (and other animal bodies) that is protected by the thoracic wall
(thoracic cage and associated skin, muscle, and fascia).
Figure 16 the structures forming the walls of the thoracic cage.
Figure 17 some of the main structures in the thoracic cavity and the
root of the neck.


Abdominopelvic Cavity
Abdominal Cavity
Abdominal cavity is the cavity of the human body (and other animal
bodies) that holds the bulk of the viscera and which is located below
(or inferior to) the thoracic cavity.

Organs of the abdominal cavity include the stomach, liver,
gallbladder, spleen, pancreas, urinary bladder, small intestine and
large intestine. (The kidneys are located not in the abdominal cavity
but behind it, in the retroperitoneum.)
The abdominal cavity is lined with a protective membrane termed the
peritoneum. The viscera are also covered, in the front, with a fatty
layer called the omentum (or omental apron).




Figure 18 Organs occupying the anterior part of the abdominal cavity
and the diaphragm.




Figure 19 Organs occupying the posterior part of the abdominal and
pelvic cavities. The broken line shows the position of the stomach.
Figure 20 Isolating the Organs - serous membranes consist of
parietal layer and visceral layer.




Figure 21 Dividing the Cavities - thoracic cavity is divided by the
mediastinum into 2 pleural cavities.
Figure 22(a, b, c) Regions of the abdominal cavity

Pelvic Cavity
The pelvic cavity is a body cavity that is bounded by the bones of
the pelvis and which primarily contains reproductive organs, the
urinary bladder, and the rectum.




Figure 23 Female reproductive organs and other structures in the
pelvic cavity.
Figure 24 the pelvic cavity and reproductive structures in the male.
CONCLUSION

      As a nurse, we must know certain anatomy terms and parts that
lead to easiness in our practice conduct as a professional body. We
need to instil all this core knowledge of human body as described as
“anatomy and physiology of human being”.

      We, as a professional body must practise all our knowledge in
making all our works done. As such, we must use anatomical terms &
region to refer to the parts of client’s body. It can be area of fracture,
area of aches, or signs and symptoms showed as client develop a
health problem. That knowledge of human body also will be use all
the times in making research conduct, filing nursing diagnosis and
also for the professional jargon language between colleagues of
health care paramedics.

      To be fully respected in not practising malpractice and
negligence e.g. putting IV drip on wrong body parts, we must learn
the concept and essentials of anatomy of human body to be a good
and competent nurse. So that, we won’t do such destruction that will
be a bad dream for the patient and also to his/her relatives member.
Worst, it may affect our job only because of our unawareness of this
side of knowledge as it has to be happening in conducting our
nursing practice.
REFERENCES
Elaine, M. N. 2006, Essentials of Human Anatomy & Physiology.
     8th ed, Pearson, San Francisco.
Sembulingam, K. & Sembulingam, P. 2001, Essentials of Medical
     Physiology 2nd ed, Jaypee Brothers, New Delhi.
Shier, D., Butler, J. & Lewis, R. 2003, Hole’s Essential of Human
     Anatomy and Physiology. 8th ed, Mc Graw Hill : New York.
Saladin, K. S. 2005. Human Anatomy, Mc Graw Hill, USA.
Tortora, G. J. & Derrickson, B. 2006, Principles of Anatomy and
     Physiology 11th ed, John Wiley Sons, Inc. USA.

				
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