B13.2 - Hormones

Question 1

what are hormones?

Answer 1

chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs

Question 2

what hormone does ovaries produce?

Answer 2

oestrogen

Question 3

what hormone does testes produce?

Answer 3

testosterone

Question 4

what hormone does adrenal glands produce?

Answer 4

adrenaline

Question 5

what hormone does pancreas produce?

Answer 5

insulin & glucagon

Question 6

how do hormones find their target cells?

Answer 6

target cells’ receptors are specific to that hormone on the cell membrane so then the hormone binds to these receptors and a response is caused

Question 7

how do hormones get secreted?

Answer 7

glands = effectors
–> respond to an impulse that was initiated by a stimulus
–> gland secretes hormone into blood, hormone is carried around body until it finds a target cell

Question 8

difference of ‘speed of communication’ between nerves and hormones (CNS and endocrine / hormonal system)

Answer 8

nerves : very fast
hormones : slower

Question 9

difference of ‘method of transport / transmission’ between nerves and hormones (CNS and endocrine / hormonal system)

Answer 9

nerves : electrical impulse
hormones : in the blood

Question 10

difference of ‘duration of response’ between nerves and hormones (CNS and endocrine / hormonal system)

Answer 10

nerves : short acting
hormones : longer acting

Question 11

difference of ‘area targeted’ between nerves and hormones (CNS and endocrine / hormonal system)

Answer 11

nerves : very precise area
hormones : larger area

Question 12

what hormone is adrenaline?

Answer 12

fight or flight
–> triggers the ‘fight or flight’ response when an organism is in a dangerous situation

Question 13

when is adrenaline produced?

Answer 13

times of danger, stress, excitement

Question 14

how is adrenaline released?

Answer 14

1) brain detects danger / stressful / exciting situation
2) nerve impulses are sent to the adrenal glands
3) adrenal glands secret adrenaline into blood
4) adrenaline travels to target organs
5) body is ready for action

Question 15

what does adrenaline do? [3] [3] [1]

Answer 15

-increase breathing rate
-increase heart rate
-increase pupil diameter (pupils widen)

-heightens sensitivity
-makes person more alert
-causes liver to break down glycogen stores to release glucose

-diverting blood away from areas that don’t need it as much (pale skin due to this)

Question 16

4 target organs for adrenaline and their effects

Answer 16

heart –> increases heart rate
lungs –> increases breathing rate
eyes –> increases pupil diameter (pupils widen)
liver –> breaks down glycogen stores to release glucose

Question 17

how does increasing breathing and heart rate increase metabolic activity? [7]

Answer 17

1) adrenaline causes heart muscle to contract more (and with more force) so heart rate increase
2) blood flow to muscles increases
3) cells receive more oxygen and glucose
4) respirations is increased
5) liver breaks down glycogen stores to release glucose
6) blood glucose concentration is increased
7) there’s more glucose in the blood that can be transported to cells

Question 18

how is adrenaline different from other hormones?

Answer 18

its fast acting
its short lived

Question 19

4 features of hormones

Answer 19

-produced by glands
-carried by blood
-chemical substances
-change the activity of one or more target organs

Question 20

what does an endocrine system do?

Answer 20

coordinates the body’s response to changes in the environment using hormones

Question 21

what are endocrine glands?

Answer 21

groups of cells that produce hormones and secrete them into the bloodstream, where they travel to target organs

Question 22

4 endocrine glands

Answer 22

-testes
-ovaries
-adrenal gland
-pancreas