Homeostasis and Hormones

Question 1

Definition of homeostasis

Answer 1

maintenance of a constant internal environment within set limits

Question 2

Define hormones (2)

Answer 2

chemical substance produced by gland

alters activity of one or more target organs

Question 3

Where are hormones produced

Answer 3

endocrine glands

Question 4

How are hormones transported (2)

Answer 4

secreted into blood

carried around the body dissolved in plasma

Question 5

Effects of adrenaline (4)

Answer 5

increased pulse rate

increased depth of breathing

dilate pupils

causes liver and muscle cells to release glucose

Question 6

Where is adrenaline produced

Answer 6

adrenal glands above kidneys

Question 7

Functions of adrenaline

Answer 7

released in crucial moments during flight/fight response

Question 8

Hormones vs Nervous Systems form of transmission (2)

Answer 8

hormones is chemical

neurons = electrical impulses

Question 9

Where is glucagon secreted

Answer 9

pancreas

Question 10

Hormones vs Nervous Systems transmission pathway (2)

Answer 10

nervous = nerves

hormones = blood

Question 11

Hormones vs Nervous speed (2)

Answer 11

nervous faster

hormones slower

Question 12

Hormones vs Nervous duration (2)

Answer 12

nervous shorter

hormones longer (until hormone broken down)

Question 13

Hormones vs Nervous location of response (2)

Answer 13

nervous = specific

hormones = widespread though target organ may be specific

Question 14

Hormones vs Nervous what they consist of (2)

Answer 14

Nervous = neurons

hormones = glands

Question 15

Define the endocrine system

Answer 15

series of glands that produce/secrete hormones

Question 16

Define a gland

Answer 16

organ/tissue which produces/secretes chemical substances/hormones

Question 17

Glucoregulation steps for lack of glucose (4)

Answer 17

brain detects low blood glucose level

pancreas releases glucagon hormone into bloodstream

liver converts glycogen to glucose and releases to blood stream

blood glucose level rises

Question 18

Effect of increased pulse rate on adrenaline (2)

Answer 18

circulate blood more rapidly

deliver glucose and oxygen to muscle cells for more rapid contraction

Question 19

Effect of increased depth of breathing on adrenaline (2)

Answer 19

take more oxygen quicker

remove more CO2 quicker

Question 20

Effect of dilated pupils for adrenaline

Answer 20

better vision

Question 21

Effect of releasing glucose for adrenaline (3)

Answer 21

increase blood glucose concentration

more glucose for muscle respiration

release more energy for muscle contraction

Question 22

Glucoregulation steps for excess glucose (4)

Answer 22

brain detects high glucose blood levels

pancreas releases insulin hormone into bloodstream to liver

insulin causes liver to store glucose as glycogen

blood glucose level decreases

Question 23

Examples of homeostasis in sweat (3)

Answer 23

body temperature too high

sweat released from sweat glands

evaporation releases energy

Question 24

Examples of homeostasis in vasodilation (4)

Answer 24

arterioles near surface of skin dilate (widen)

more blood flows through capillaries

easier for heat to be transferred to skin

heat to environment by radiation and conduction

Question 25

Define negative feedback

Answer 25

stimulus change causes response which produces opposite change

Question 26

Homeostasis in vasoconstriction (4)

Answer 26

if body temperature too low arterioles near surface of skin constrict (narrower)

reduces amount of blood flowing through capillaries

warm blood kept deeper in skin

reduces heat loss by conduction

Question 27

Homeostasis reactions to low body temperature (2)

Answer 27

body hair raised by muscles in skin –> trap air as an insulator

muscles shiver - muscle contraction used to produce contractions which release energy and warm the body

Question 28

Which gland secretes testosterone

Answer 28

testes

Question 29

Which gland secretes insulin

Answer 29

pancreas

Question 30

Which gland secretes oestrogen

Answer 30

ovaries

Question 31

Example of positive feedback (childbirth) (5)

Answer 31

baby head pushes cervix

nerve impulses from cervix transmitted to brain

brain causes pituitary gland to produce oxytocin

oxytocin carried in blood to uterus

oxytocin causes uterus contractions and pushes baby to cervix

Question 32

Example of positive feedback in blood clotting (4)

Answer 32

break in blood vessel wall

clotting - platelets adhere to damage and release chemicals

clotting continues until break sealed

released chemicals attract more platelets