Chapter - Organization of the Body

© 2009 The McGraw-Hill Companies, Inc. All rights reserved

Organization of the BodyOrganization of the BodyThird Edition

Booth, Whicker, Wyman, Pugh, Thompson


Learning Outcomes

23.1 Describe body organization from simple to more complex levels.

23.2 List the body organ systems, their general functions, and the major organs contained in each.

23.3 Define the anatomical position and explain its importance.

23.4 Use anatomical terminology correctly.


Learning Outcomes (cont.)

23.5 Name the body cavities and the organs contained in each.

23.6 Explain the abdominal regions and quadrants.


Introduction Human body is

complex in its structure and function

The body is organized from the chemical level all the way up to the organ system level

You will also learn important terminology used in the clinical setting to describe body positions and parts.


Study of the Body Anatomy

Study of body structure Normal position of body

structures

Physiology Study of function

Anatomy of the body allows it to function


Study of the Body (cont.)

Homeostasis Relative consistency of the

body’s internal environment

Body conditions must remain stable


Structural and Functional Organization


Organization of the Body


Body Organs and Systems Organ

Structure formed by organization of two or more different tissue types that work together to carry out specific functions

Organ system Organs join together to carry out vital

functions


Body Organs and Systems (cont.)

For example The respiratory system

consists of the following organs: Nose Nasal cavity Pharynx Larynx Bronchi Lungs


6 Characteristics of Life Organization

Is the condition in which the parts of an organism have specific relationships to each other and the parts interact to perform specific functions.

Metabolism It includes an organism’s ability to break down food

molecules, which it uses as energy and raw materials to synthesize its own molecules

This is necessary for the vital functions, such as responsiveness, growth, development and reproduction.


6 Characteristics of Life Responsiveness

Is the ability of an organism to sense changes in its external or internal environment and make the adjustments that help maintain its life.

Growth Results in an increase in size of all part of the

organism It can result from an increase in cell number, cell

size or the amount of substance surrounding cells


6 Characteristics of Life Development

It includes the changes an organism undergoes through time; it begins with fertilization and ends at death.

Reproduction It is the formation of new cells or new

organsisms


Study of the Body (cont.)

Homeostasis Relative consistency of the

body’s internal environment

Body conditions must remain stable


Homeostasis Homeostasis

Equilibrium of the body’s internal environment produced by the interaction of organ systems and regulatory processes (feedback systems).

Homeostasis is a dynamic condition in response to changing conditions.

The two body systems that largely control the body’s homeostatic state:

1. Nervous system

2. Endocrine system


Control of Homeostasis

Homeostasis is continually being disrupted by external stimuli

intense heat, cold , and lack of oxygen internal stimuli

psychological stresses exercise

Disruptions are usually mild & temporary If homeostasis is not maintained, death may result


Control of Homeostasis

Homeostatic imbalances occur because of disruptions from the external or internal environments. Homeostasis is regulated by the nervous system and

endocrine system, acting together or independently. The nervous system detects changes and sends nerve

impulses to counteract the disruption. The endocrine system regulates homeostasis by

secreting hormones. Whereas nerve impulses cause rapid changes, hormones

usually work more slowly. Examples: CO2, O2, temperature, blood pressure, etc…


Components of Feedback Loop

Receptor monitors a controlled condition

Control center determines next action

Effector receives directions from the

control center produces a response that changes

the controlled condition


Basic Components of a Negative Feedback System


Basic Components of a Positive Feedback System




Anatomical Terminology Terms used to describe the location of body

parts and various body regions

Anatomical position Body is standing upright, facing forward, with

the arms at the sides and palms of hands facing forward


Body Organization The body can be divided into two

major sections:Axial portion

Head Neck Trunk

Appendicular portion Upper limbs (arms) Lower limbs (legs)


Body Cavities and Abdominal Regions

Dorsal cavity Cranial

Formed by the skull Contains the brain

Vertebral Formed by the

vertebrae of the spinal column

Contains the spinal cord


Body Cavities and Abdominal Regions (cont.)

Ventral cavity Thoracic – lungs, heart, esophagus,

and trachea

Diaphragm – muscle separating these two sections

Abdominopelvic Abdominal cavity – organs of

digestion (stomach, liver, small and large intestines….)

Pelvic cavity – bladder and internal reproductive organs


Two Principal

Body Cavities and

their Subdivisions


Trunk Cavities



Directional Terms Exercise Lateral/Medial

The ear is __ to the nose The cheekbone is __ to the ear The sternum is __ to the nipple The shoulder is __ to the sternum

Distal/Proximal The knee is __ to the ankle The toes are __ to the ankle The wrist is __ to the fingers The elbow is __ to the wrist


Directional Terms Exercise Superior/Inferior

The nose is __ to the chin The mouth is __ to the chin Nipples are __ to the umbilicus The hips are __ to the shoulders The chin is __ to the eyes The heart is __ to the diaphragm The liver is __ to the heart


Directional Terms Exercise Anterior/Posterior

The heart is __ to the sternum The heart is __ to the spinal cord

Superficial/Deep The skin is __ to the muscles The heart is __ to the spinal cord


Body Cavities Some key words and informationViscera: organs found within the body cavityDiaphragm: muscle that separates the thoracic and abdomino-pelvic cavities used for breathing

Curves upward into the thoracic cavity when relaxed When contracting, pushes down into the abdominal

cavity

Mediastinum: area in the thoracic cavity that divides its right and left sides


Serous Membranes Secrete a slippery fluid that separates the layer coving the walls from the layer covering the organsParietal layer

Thin lining of the walls of the thoracic and abdomino-pelvic cavities

Visceral layer Covers the organs within the cavities


Thoracic Membranes Pleural MembranesVisceral Pleura

Serous membrane that covers the lungs

Parietal Pleura Serous membrane that lines the walls of the

thoracic membrane


Thoracic Membranes Pericardial MembranesVisceral Pericardium

Serous membrane that covers the heart

Parietal Pericardium Serous membrane that lines a small area of the

wall of the thoracic membrane


Thoracic Membranes


Thoracic Membranes


Abdominopelvic Membranes Peritoneal MembranesVisceral Peritoneum

Serous membrane that covers the each organ of the abdominopelvic cavity

Parietal Peritoneum Serous membrane that lines the walls of the

abdominopelvic cavity


Abdominopelvic Membranes


Major Tissue Types Epithelial tissue

Covering, lining, or gland Tissue that covers the body and most organs

Glandular epithelium is composed of cells that make and secrete substances Exocrine gland – secretes product into duct Endocrine gland – secretes product directly into tissue

fluid or blood

Lacks blood vessels, has a nerve supply, divides constantly

Function based on location


Major Tissue Types (cont.)

Connective tissue Most abundant

Matrix separates the cells Matter between cells of connective tissue Components vary Generally has a rich blood supply, except for

cartilage


Major Tissue Types (cont.) Connective tissue

Blood Plasma is matrix Transports substances throughout the body

Osseous tissue (bone) Matrix of mineral salts Metabolically active

Cartilage Matrix rigid Gives shape to structures, protects ends of long bones,

and forms discs between the vertebrae



Connective tissue Dense connective tissue

Ligaments, tendons, and joint capsules Dermis of skin

Adipose tissue Adipocytes (fat cells) store fats Stores energy Insulates body



Muscle tissue Shortens and elongates Contracts and relaxes Includes skeletal, smooth, and cardiac

Skeletal Muscle Tissue



Nervous tissue Brain, spinal cord, and peripheral nerves Specializes to send impulses to neurons, muscles, and glands Neurons – largest cells, transmit impulses Neuroglial cells – smaller, more abundant, and act as support

for neurons

Nervous Tissue


In Summary The body is divided into levels of organization from

simplest to most complex Anatomy and physiology are the study of structure

and function of the human body Using directional anatomical terms enables you to

describe specific locations It is important to understand

The relationship between body levels The basics of the organization of the body The relationships found within each organization


Our history begins before we are born. We represent the hereditary influences of our race, and our ancestors virtually live in us.

~ James Nasmyth

Education

Chapter - Organization of the Body