Homeostasis and endocrine signaling Flashcards
What is epithelial tissue?
Form active interfaces on external and internal surfaces . Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin.
What is connective tissue?
Binds and supports other tissue.
What is muscle tissue?
Contracts, moving body parts.
What is nerve tissue?
Transmits nerve impulses throughout the body.
Animals _____ certain internal variables while allowing other internal variables to ______
regulate, conform
What is homeostasis?
The maintenance of a steady state despite internal and external changes
What acts as the thermostat in mammalian regulation of body temperature?
The hypothalamus.
What does the endocrine system do?
Broadcasts signaling molecules called hormones via the bloodstream. Only certain cells are responsive to each hormone.
What is a negative feedback in an organism?
A process that dampens a stimulus.
What is osmoregulation?
The process of balancing of water gain and loss with controlled movement of solutes between internal and external environments, and on the movement of water flow through osmosis.
Metabolism of ____ and _____ generates ammonia
proteins, nucleic acids
What are the roles of most excretory systems?
Filtration, reabsorption, secretion and excretion
What are structures in the mammalian kidney?
Nephrons, collecting ducts, and blood vessels.
Describe the mammalian kidney.
Within the nephron, selective secretion and reabsorption in the proximal tubule alter filtrate volume and composition. The descending limb of the loop of henle is permeable to water but not salt, whereas the ascending limb is permeable to salt but not water. The distal tubule regulates potassium and sodium chloride levels in body fluids.
What involving the loop of henle maintains the gradient of salt concentration in the kidney interior? What causes the urine to be collected in the collecting duct?
a countercurrent multiplier system, hormone signaling
