Organ System Overview
Integumentary
 Forms the external body covering
 Protects deeper tissue from injury
 Helps regulate body temperature
 Location of cutaneous nerve receptors
Skeletal
 Protects and supports body organs
 Provides muscle attachment for movement
 Site of blood cell formation
 Stores minerals
Muscular
 Produces movement
 Maintains posture
 Produces heat
Nervous
 Fast-acting control system
 Responds to internal and external change
 Activates muscles and glands
Endocrine
 Secretes regulatory hormones
 Growth
 Reproduction
 Metabolism
Cardiovascular

Transports materials in body via blood pumped by heart

Oxygen

Carbon dioxide

Nutrients

Wastes
Lymphatic

Returns fluids to blood vessels

Cleanses the blood

Involved in immunity
Respiratory

Keeps blood supplied with oxygen

Removes carbon dioxide
Digestive

Breaks down food

Allows for nutrient absorption into blood

Eliminates indigestible material
Urinary

Eliminates nitrogenous wastes

Maintains acid-base balance

Regulates water and electrolytes
Reproductive

Produces offspring
Homeostasis



________________—maintenance of a stable internal environment

A dynamic state of equilibrium
Homeostasis is necessary for normal body ________________ and to sustain life
Homeostatic imbalance - A disturbance in homeostasis resulting in ________________
Maintaining Homeostasis

The body communicates through ________________ and ________________ control systems (nervous
and endocrine)

There are three parts
1. ________________
2. ________________
3. ________________

Receptor

Responds to changes in the ________________ (stimuli)

Sends information to control center

Information flows from the receptor to the control center along the __________ pathway

Control center

Determines ________________

Analyzes information

Determines appropriate ________________

Effector

Provides a means for ________________ to the stimulus

Information flows from the control center to the effector along the __________ pathway.
Feedback Mechanisms

Negative feedback

Includes most homeostatic control mechanisms

________________ the original stimulus, or reduces its intensity

Works like a household thermostat

Ex. Mechanisms that regulate ___________, blood pressure, _____________, and blood levels
of glucose, oxygen, carbon dioxide, and minerals.
 Household Thermostat
 Thermostat set at 70°F
 Stimulus – temperature of house drops to 68°F
 Receptor – the thermometer detects a cool temp.
 Tells the heater thermostat the change through the afferent pathway
 Control Center – thermostat turns on the heater.
 Once the house temperature rises to 70° the thermostat turns the heater off

Positive feedback

________________ the original stimulus to push the variable farther

Typically control ________________ events and do not require continuous adjustments.

In the body this only occurs in ________________ and during the birth of a baby