Chapter 1 Body

I.        The Human Body: An Orientation

1)   An overview of Anatomy and Physiology

a)    Introduction

b)   Definitions

i)     Anatomy- study of the structure and shape of the body and its parts

ii)    Physiology- study of  how the body and its parts work or function

c)    Topics of Anatomy

i)     Gross or macroscopic anatomy

(1)  Large structures

(2) Easily observable

(3) Studied through dissection

ii)    Microscopic anatomy

(1)  Very small structures

(2) Can only be view with a microscope

(3) Cytology- study of cells

(4) Histology- study of tissues

d)   Topics of Physiology

i)     Renal- kidney functions

ii)    Cardiovascular- heart and blood vessels functions

iii)  Neural- nervous system functions

iv)   **Close relationship between structure and function**

v)    Other organ system physiology

e)    Complementarity of structure and function

2)   Levels of structural organization

a)    Levels of structural hierarchy (See Fig. 1.1)

i)     Chemical level

(1)  Atoms

(2) Molecules

(3) Atoms combine to form molecules

ii)    Cellular level

(1)  Cells are made up of molecules

iii)  Tissue level

(1)  Tissues consist of similar types of cells

iv)   Organ level

(1)  Organs are made up of different types of tissues

v)    Organ system level

vi)   Organismal level

b)   Summary of the body’s organ systems (See Fig. 1.2)

i)     Integumentary System- forms the external body covering

-      Protects deeper tissue from injury

-      Helps regulate body temperature

-      Location of cutaneous nerve receptors

ii)    Skeletal System- protects and supports body organs

                                           -protects muscle attachment for movements

                                           -site of blood cell formation

                                           -stores minerals

iii)  Muscular System- produces movement

-maintains posture

-produces heat

iv)   Nervous System- fast-acting control system

          -responds to internal and external change

          -activates muscle and glands

v)    Endocrine System- secrets regulatory hormones

-growth

-reproduction

-metabolism

vi)   Cardiovascular System- transports materials in the body via blood                                                pumped by heart

-      Oxygen

-      Carbon dioxide

-      Nutrients

-      Wastes

vii) Lymphatic System / Immune System- returns fluids to blood vessels

                -cleanses the blood

                -involved in immunity

viii)        Respiratory System- keeps blood supplied with oxygen

-      Removes carbon dioxide

ix)  Digestive System- breaks down food

-allows for nutrient absorption into blood

-eliminates indigestible material

x)   Urinary System- eliminates nitrogenous wastes

        -maintains acid-base balance

        -regulates water and electrolytes

xi)  Reproductive System- produces offspring

3)  Necessary Life Functions

            a) maintain boundaries – gradients = differences

            b) movement

                        - locomotion- organism moves

                        - movement of substances – within or outside

            c) responsiveness –ability to sense changes and react

            d) digestion- break-down and absorption of nutrients

            e) metabolism: chemical reactions within the body

                        -produces energy from food

                        - makes body structures

            f) excretion- eliminates waste from metabolic reactions

            g) reproduction- produces future generation

            h) growth- increases cell size and number of cells

3)   Homeostasis

a)    Definition- maintain of a stable internal environment

     -a dynamic state of equilibrium

b)   Necessary for normal body function and to sustain life

c)    Homeostasis imbalance- a disturbance in homeostasis resulting in disease

d)   Homeostatic control mechanisms (See Fig. 1.4)

i)     Elements of a control system

(1)  Receptor-

(2) Control center

(3) Effector

ii)    Negative feedback mechanism (See Fig. 1.5)

(1)  Includes most homeostatic control mechanisms

(2) Shuts off the original stimulus or reduces its intensity

(3) Works like a household thermostat

(4) Opposite directional change

(5) Effector decreases original stimulus

iii)  Positive feedback mechanism (See Fig. 1.6)

(1)  Increases the original stimulus to push the variable farther

(2) In the body this only occurs in blood clotting and during the birth of a baby

(3)  Same directional change

(4) Effector enhances original stimulus

4)   The Language of Anatomy

a)    Special terminology is used to prevent misunderstanding

b)   Exact terms are used for:

i)     Position

ii)    Direction

iii)  Regions

iv)   Structures

c)    Anatomical position

i)     Human body erect

ii)    Arms at sides

iii)  Palms forward

iv)   Feet together

d)   Directional terms (See Table 1.1)

i)     Definition:  Directional terms allow us to explain where one body structure is in relation to another.

ii)    Superior- toward the head end or upper part of a structure or the body, above

(1)  Inferior- away from the head end or toward the lower part of a structure  of the body, below

iii)  Anterior (ventral)- toward or at the backside of the body, behind

(1)  Posterior (dorsal)- toward or at the midline of the body, on the inner side of the body

iv)   Proximal- close to the origin of the body part or the point of attachment of a limb to the body trunk

(1)  Distal- farther from the origin of a body part or the point of attachment of a limb to the body trunk

v)    Lateral- away from the midline of the body, on the outer side of

(1)  Intermediate- (between lateral and medial) in the middle

(2) Medial- toward or at the midline of the body, on the inner side of

vi)   Superficial (external)- toward or at the body surface

(1)  Deep (internal)- away from the body surface, more internal

e)    Body Planes and Sections

i)     A sagittal section divides the body (or organ) into left and right parts

ii)    A median, or midsagittal, section divides the body (or organ) into left and right parts

iii)  A frontal, or coronal, divides the body (or organ) into anterior or posterior parts

iv)   A transverse, or cross, section divides the body or organ into superior or inferior parts

f)    Body Cavities

i)     Dorsal body cavity

(1)  Cranial cavity houses the brain

(2) Spinal cavity houses the spinal cord

ii)    Ventral body cavity

(1)  Thoracic cavity houses the heart, lungs, and others

(2) Abdominopelvic cavity houses digestive system and most urinary system organs

g)    Regional terms (See Fig. 1.7)

i)     Definition: Regional terms are used to designate specific areas within the major body divisions

(1)  Axial part = head, neck and trunk

(2) Appendicular part = appendages or limbs

ii)    Anterior body landmarks

·         Nasal (nose)

·        Oral (mouth)

·        Cervical (neck)

·        Axillary (armpit)

·        Frontal (forehead)

·        Orbital (eye)

·        Buccal (cheek)

·        Sternal (breastbone)

·        Thoracic (chest)

·        Mammary (breast)

·        Abdominal (abdomen)

·        Brachial (arm)

·        Umbilical (navel)

·        Pelvic (pelvis)

·        Femoral (thigh)

·        Carpal (wrist)

·        Digital (fingers)

·        Coxal (hip)

·        Pubic (genital region)

·        Patellar (anterior knee)

·        Pedal (foot)

iii)  Posterior body landmarks

·        Cephalic (head)

·        Otic (ear)

·        Sacral (between hips)

·        Occipital (base of the skull)

·        Vertebral (spinal column)

·        Scapular (shoulder blade)

·        Dorsal (back)

·        Gluteal (buttock)

·        Calcaneal (heel)

·        Plantar (sole)

·        Acromial (point of shoulder)

·        Popliteal (back of the knee)

Body planes (See Fig. 1.8)

iv)   Sagittal plane

(1)  Midsagittal = median plane

(2) Parasagittal

v)    Transverse plane = horizontal plane

vi)   Oblique

(1) 

vii) Frontal plane

h)   Body cavities (See Fig. 1.9)

i)     Dorsal body cavity

(1)  Cranial cavity

(2) Vertebral cavity

ii)    Ventral body cavity

(1)  Thoracic cavity

(a)  Pleural cavities

(b) Pericardial cavity

(2) Abdominopelvic cavity

(a)  Abdominal cavity

(b) Pelvic cavity

i)     Membranes in the ventral body cavity (See Fig. 1.10)

i)     Serous membrane = Serosa

(1)  Parietal serosa

(2) Visceral serosa

ii)     Serous fluid

(1)  Location

(2) Functions

iii)  Examples of serous membranes

(1)  Pericardium

(2) Pleura

(3) Peritoneum

j)    Quadrants