Coach fortier class resources


The Human Body: An Orientation

The Human Body—An Orientation


  • Study of the structure and shape of the body and its parts


  • Study of how the body and its parts work or function

Anatomy—Levels of Study

  • Gross anatomy

  • Large structures

  • Easily observable

Anatomy—Levels of Study

  • Microscopic anatomy

  • Structures cannot be seen with the naked eye

  • Structures can only be viewed with a microscope

Organ System Overview

  • Integumentary

  • Forms the external body covering

  • Protects deeper tissue from injury

  • Helps regulate body temperature

  • Location of cutaneous nerve receptors

Organ System Overview

  • Skeletal

  • Protects and supports body organs

  • Provides muscle attachment for movement

  • Site of blood cell formation

  • Stores minerals

Organ System Overview

  • Muscular

  • Produces movement

  • Maintains posture

  • Produces heat

Organ System Overview

  • Nervous

  • Fast-acting control system

  • Responds to internal and external change

  • Activates muscles and glands

Organ System Overview

  • Endocrine

  • Secretes regulatory hormones

  • Growth

  • Reproduction

  • Metabolism

Organ System Overview

  • Cardiovascular

  • Transports materials in body via blood pumped by heart

  • Oxygen

  • Carbon dioxide

  • Nutrients

  • Wastes

Organ System Overview

  • Lymphatic

  • Returns fluids to blood vessels

  • Cleanses the blood

  • Involved in immunity

Organ System Overview

  • Respiratory

  • Keeps blood supplied with oxygen

  • Removes carbon dioxide

Organ System Overview

  • Digestive

  • Breaks down food

  • Allows for nutrient absorption into blood

  • Eliminates indigestible material as feces

Organ System Overview

  • Urinary

  • Eliminates nitrogenous wastes

  • Maintains acid-base balance

  • Regulates water and electrolytes

Organ System Overview

  • Reproductive

  • Produces offspring

  • Testes produce sperm and male hormone

  • Ovaries produce eggs and female hormones

Necessary Life Functions

  • Maintain boundaries

  • Movement

  • Locomotion

  • Movement of substances

  • Responsiveness

  • Ability to sense changes and react

  • Digestion

  • Breakdown and absorption of nutrients

Necessary Life Functions

  • Metabolism—chemical reactions within the body

  • Break down complex molecules into smaller ones

  • Build larger molecules from smaller ones

  • Produces energy

  • Regulated by hormones

  • Excretion

  • Eliminates waste from metabolic reactions

  • Wastes may be removed in urine or feces

Necessary Life Functions

  • Reproduction

  • Occurs on cellular level or organismal level

  • Produces future generation

  • Growth

  • Increases cell size and number of cells

Survival Needs

  • Nutrients

  • Chemicals for energy and cell building

  • Includes carbohydrates, proteins, lipids, vitamins, and minerals

  • Oxygen

  • Required for chemical reactions

Survival Needs

  • Water

  • 60 to 80 percent of body weight

  • Most abundant chemical in the human body

  • Provides for metabolic reaction

  • Stable body temperature

  • 37°C (98°F)

  • Atmospheric pressure

  • Must be appropriate for gas exchange


  • Homeostasis—maintenance of a stable internal environment

  • A dynamic state of equilibrium

  • Necessary for normal body functioning and to sustain life

  • Homeostatic imbalance

  • A disturbance in homeostasis resulting in disease

Maintaining Homeostasis

  • The body communicates through neural and hormonal control systems

  • Receptor

  • Responds to changes in the environment (stimuli)

  • Sends information to control center

Maintaining Homeostasis

  • Control center

  • Determines set point

  • Analyzes information

  • Determines appropriate response

  • Effector

  • Provides a means for response to the stimulus

Feedback Mechanisms

  • Negative feedback

  • Includes most homeostatic control mechanisms

  • Shuts off the original stimulus, or reduces its intensity

  • Works like a household thermostat

Feedback Mechanisms

  • Positive feedback

  • Increases the original stimulus to push the variable farther

  • In the body this only occurs in blood clotting and during the birth of a baby

The Language of Anatomy

  • Special terminology is used to prevent misunderstanding

  • Exact terms are used for

  • Position

  • Direction

  • Regions

  • Structures

Body Planes and Sections

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

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

  • A frontal, or coronal, section divides the body (or organ) into anterior and posterior parts.

  • A transverse, or cross, section divides the body (or organ) into superior and inferior parts.

Body Cavities

  • Dorsal body cavity

  • Cranial cavity houses the brain

  • Spinal cavity houses the spinal cord

  • Ventral body cavity

  • Thoracic cavity houses heart, lungs, and others

  • Abdominopelvic cavity houses digestive system and most urinary system organs