Intro to Structure and Function

Question 1

How is homeostasis maintained?

Answer 1

Organ systems work together to maintain

Question 2

homeostasis-

Answer 2

maintenance of stable internal conditions

Question 3

Negative feedback-

Answer 3

reduces or shuts off certain stimulus. Receptor senses a change, Control center (brain) evaluates the change, Effector corrects the condition. ex–muscle
look up at light and pupils constrict

Question 4

Positive feedback-

Answer 4

intensifies a stimulus. ex–childbirth, lactation,

Question 5

Ectotherms/ poikilotherms-

Answer 5

cold-blooded. obtain body heat from environment, therefore, their body temperature changes with a changing environment. fish, amphibians, reptiles.

Question 6

Endotherms/ homeotherms-

Answer 6

warm-blooded. generate their own body heat and are able to maintain stable internal temperature

Question 7

hypothalamus

Answer 7

The hypothalamus is a section of the mammalian brain that contains centers that help control the body temperature

Question 8

Peripheral vasodilation-

Answer 8

diameter of blood vessels in skin increases, bringing more heat to the skin that can be given up to surroundings

Question 9

Heat stress causes the following

Answer 9

Peripheral vasodilation, Evaporative heat loss, panting

Question 10

Evaporative heat loss-

Answer 10

sweating produces liquid on the surface of the skin that uses heat to cause its evaporation, cooling the body

Question 11

Panting-

Answer 11

shallow, rapid breathing that causes evaporative heat loss from the mouth, respiratory tract, and
nasal cavity

Question 12

Peripheral vasoconstriction-

Answer 12

hypothalamus signals arterioles in skin to contract, causing less blood (with less metabolic heat) to reach the body surfaces

Question 13

cold stress causes the following

Answer 13

Peripheral vasoconstriction, Pilomotor response, shivering

Question 14

Pilomotor response-

Answer 14

hair or feather stand up, creating a layer of still air next to skin. This reduces heat loss

Question 15

shivering

Answer 15

hypothalamus tells skeletal muscles to contract ten to twenty times each second, increasing heat production as a waste product