9.1 Flashcards
Homeostasis
The physiological state of the body in which internal physical and chemical conditions are kept within a range suitable for life processes.
-Not a constant condition.
-Continuously adjusts according to internal and external conditions.
Internal Environment
The extracellular fluid consists of the interstitial fluid and the plasma portion of the blood. A typical adult has ~15 L of extracellular fluid. The extracellular fluid is a medium for delivering energy, transporting chemicals, and eliminating waste. The volume, temperature, and chemical composition of the internal environment can change quickly.
Interstitial fluid
Fluid found in the spaces around cells. It comes from substances that leak out of blood capillaries (the smallest type of blood vessel). It helps bring oxygen and nutrients to cells and to remove waste products from them.
Nervous system
Receives sensory data from the environment which informs the body of external conditions. Transmits signals throughout the body to regulate homeostasis.
-Brain
-Spinal cord
-Peripheral nerves
-Sensory organs
Excretory system
Works to get rid of the body of waste and maintain a clean internal environment.
-Kidneys
-Bladder
-Ureter
-Urethra
Endocrine system
Regulates the levels of various hormones that are essential to life processes.
-Pituitary gland
-Thyroid
-Adrenal glands
-Pancreas
Muscular system
Gives the body structure, protects organs, allows for locomotion, and main organs.
-Skeletal muscle
-Cardiac muscle
-Smooth muscle
Integumentary system
Important for maintaining a constant body temperature.
-Skin
-Sweat glands
-Nails
-Hair
Reproductive system
Allows for the sexual reproduction of organisms.
-Ovaries
-Oviducts
-Uterus
-Vagina
-Mammary glands
Homeostatic mechanism
Systems that monitor internal and external conditions and change bodily functions to maintain homeostasis.
-When the internal temperature is too high, we sweat.
-When the internal temperature is too low, we shiver.
-Hunger and thirst are mechanisms that ensure adequate nutrition and hydration.
