Introduction to Anatomy and Physiology:

Directional Terms, Planes, Sections, and Body Cavities

Nestor T. Hilvano, M.D., M.P.H.

Learning Objectives You should be able to: 1. Define anatomy and physiology, and describe its

subdivisions. 2. Lists the levels of organization of the human structure.3. Identify the organ systems of the body and major

components, and describe a major function of each system.

4. Define homeostasis and explain its importance.5. Describe how negative feedback and positive feedback

are involved in homeostatic control.6. Describe the anatomical position, relative directional

terms, regions, planes, and sections of the body.7. Identify the major body cavities and their subdivisions.8. Discuss the techniques used in doing physical

examination.

Introduction • ______ “cutting up”, is the study of structures.

I. Gross anatomy

- large, visible structures

II. Microscopic anatomy

- minute structures seen by

use of instrument

_____ - is the study of cells.

_____ - is the study of tissues• _____ is the study of functions.

a. histology b. physiology c. anatomy d. cytology

Levels of Human Organization

• Molecule (Chemical)• Cell• Tissue• Organ • Organ System• Organism ___ What is the

simplest form of life?

___ What is the smallest chemical unit

a. tissue b. molecule c. organ d. cell e. atom

Organ Systems and it’s Functions ___ Integumentary system

___ Skeletal system

___ Muscular system

___ Nervous system

___ Endocrine system

a) Long term changes in metabolic activities

b) Coordinate sensation and motor control, immediate response to stimuli

c) Movement, control of body opening, generate heat

d) Support, protect enclosed organ, stores calcium, forms blood cells

e) Protection against environmental hazards and thermoregulation

Organ Systems and it’s Functions ___ Cardiovascular system

___ Lymphoid system

___ Respiratory system

___ Digestive system

___ Urinary system

___ Reproductive system

a) Produce sex cells (sperms and oocytes) and hormones

b) Distribute blood cells and dissolved materials

c) Excrete waste products from the blood, urine elimination

d) Absorb nutrients and breakdown dietary products

e) Defend against infection and disease

f) Delivers air to alveoli and provides oxygen to bloodstream

Homeostasis • What is homeostasis? ___________________

• 2 mechanisms involved:

a) Autoregulation - intrinsic regulation, immediate and automatic response to environmental change.

ex. if blood flow falls, arterial resistance falls as the vessels dilate, which increases blood flow to supply the organ (myogenic and endothelial mechanisms).

b) Extrinsic regulation – nervous or endocrine systems activation, mostly controlled via negative feedback.

ex. if blood calcium is high, calcitonin (hormone) is released to decrease it within normal level.

Positive Feedback

• Negative feedback- Negates the stimulus; beneficial to maintain health

• Positive feedback- Enhances the change; Beneficial effects (ex. blood clotting); Harmful effects (ex. Fever)

Exercises: State the type of feedback mechanism involved:1. ___ hormonal regulation to lower blood sugar within normal level.2. ___ increasing uterine contraction for child’s birth.a. positive feedback b. negative feedback

Anatomical Position• Describe the anatomical position.

body posture is _____

hands are at the ____

palms facing _______

feet are ___________

a. sides b. anterior c. together d. erect

Directional Terms • Anterior (ventral)- front

• Posterior (dorsal)- back

• Superior (cranial)- head/above

• Inferior (caudal)- tail/below

• Medial- toward the body’s longitudinal axis

• Lateral- away from the body’s longitudinal axis

• Proximal- toward an attached base

• Distal- away from an attached base

• Superficial- close to body surface

• Deep- farther from body surface

Exercises:

The breast is on the ___ surface of the trunk. (anterior; posterior)

The abdomen is ___ to the thighs. (cranial; caudal)

The nose is ___ to the ears. (lateral; medial)

The fingers are ___ to the wrist. (proximal; distal)

The skin is ___ to the skeletal muscles. (superficial; deep)

Abdominopelvic Quadrants and Regions

• 4 Quadrants: RUQ, LUQ, RLQ, LLQ• 9 Regions: R hypochondriac, epigastric, L hypochondriac, R lumbar, umbilical, L

lumbar, R inguinal, hypogastric, L inguinal • Significance of body’s quadrants and regions- clinical localization of diseases

organs

• Exercises: Pain at the right upper quadrant can be caused by infection of ___. Hypogastric region contains what organ? ___.

Pain localized at the right inguinal region can be due to inflammation of ___.

a. urinary bladder b. liver and gallbladder c. appendix d. spleen

Body Planes and Sections

a. sagittal b. frontal (coronal) c. transverse (horizontal)

Exercise: What planes (sections)

1. separates right and left portions of the body? ___

2. separates anterior and posterior portions of the body? ___

3. separates superior and inferior portions of the body? ___

Body Cavities • Closed, lined with serosal membranes that secrete serous

fluid; 2 main cavities

I. Ventral (anterior) body cavity

a) Thoracic cavity = pleural cavity and pericardial cavity

b) Abdominopelvic cavity = abdominal cavity and pelvic cavity

II. Dorsal (posterior) body cavity

a) cranial cavity

b) vertebral (spinal) cavity

Exercises: Name specific body cavity where the following organs are found?

1. spinal cord 2. urinary bladder 3. heart

4. brain 5. stomach 6. lungs

Physical Examination• Inspection – Observe surface

structures/body regions• Palpation – feeling structures using

the fingers/hands• Percussion – tapping structures using

fingers/hands• Auscultation – hearing sounds using

stetoscope

Homework (Self-Review) 1. Define terms: anatomy, physiology,

cytology, histology, cell, tissue, organ system, palpation, percussion, auscultation, proximal, distal, deep, superficial, lateral, coronal, sagittal, transverse, ventral, dorsal, medial

2. Discuss the negative feedback and positive mechanisms by citing an example.

3. Describe the anatomic position. 4. Identify body cavities and their

subdivisions and give its contents.