Homeostasis/Excretory System Flashcards
Homeostasis
The physiological state of the body in which internal physical and chemical conditions are kept within a range that is suitable for life processes
Internal environment
The extracellular fluid, which consists of the fluid that surrounds the cells and tissues in the body and the plasma portion of the blood
Interstitial fluid
The fluid that surrounds the body cells
Homeostatic mechanism
A system that monitors internal and external conditions and changes bodily functions to maintain homeostasis
Negative feedback
The response of a system that acts to maintain equilibrium by compensating for any changes made to the system
Ex. water balance or blood pressure
Sensor
The element of a feedback system that detects changes in the environment
Ex. free nerve ending in the skin
Integrator
The element of a feedback system that compares existing conditions with ideal conditions
Ex. the brain
Effector
The element (or elements) of a feedback system that acts to return the system to its optimal state Ex. a muscle or gland
Positive feedback
The response of a system that acts to increase the effect of any changes made to the system
Ex. body releases adrenaline into the blood when attacked that trigger “fight or flight” reactions that make the person more fit to survive
Thermoregulation
The regulation of internal temperature by negative feedback mechanisms
Osmotic pressure
The pressure that results from a difference in solute concentration between the two sides of a selectively permeable membrane
Hyperosmotic
The property of the solution on one side of a selectively permeable membrane that has the lower concentration of water
Hypoosmotic
The property of the solution on one side of a selectively permeable membrane that has a higher concentration of water
Isoosmotic
The property of two solutions that have equal water concentrations
Osmoregulation
The process of actively regulating the osmotic pressure of bodily fluids and cells
Nephron
The tiny functional unit of the kidney that filters wastes from the blood
Bowman’s capsule
A small folded structure in the human kidney that encircles the glomerulus
Glomerulus
A network of capillaries within the Bowman’s capsule that performs the first step in the filtration of blood
Afferent arteriole
A vessel that supplies blood to the nephrons in the human kidney
Efferent arteriole
A vessel that carries away filtered blood from the nephrons in the human kidney
Peritubular capillaries
A net of capillaries in the nephrons that reasborn essential ions and minerals from filtered blood
Proximal convoluted tubule
The duct portion of a nephron that connects the Bowman’s capsule to the loop of Henle
Loop of Henle
The U-shaped part of the duct that connects the proximal convoluted tubule to the distal convoluted tubule
Distal convoluted tubule
The duct portion of a nephron that connects the loop of Henle to the ducts that lead to the renal pelvis
Filtration
The process in which blood and fluid pass through a selectively permeable membrane
Reabsorption
The transfer of water, ions, and nutrients back to the interstitial fluid via passive and active transport
Secretion
The removal of waste materials from the blood and intercellular fluid
