Topic 9 - Hormones and Fertility

Question 1

what are hormones

Answer 1

chemical messengers which travel in the blood to activate cells in target organs

Question 2

where are hormones produced

Answer 2

endocrine glands which are part of the endocrine system

Question 3

pituitary gland

Answer 3

produces many hormones that regulate body conditions. sometimes these hormones act on other glands

Question 4

thyroid gland

Answer 4

produces thyroxine which regulates body temp, metabolism, etc

Question 5

pancreas

Answer 5

produces insulin which regulates blood glucose level

Question 6

adrenal glands

Answer 6

produces adrenaline which triggers fight or flight response

Question 7

ovaries

Answer 7

produces oestrogen which is involved in female menstrual cycle

Question 8

testes

Answer 8

produces testosterone whcih controls sperm production in males

Question 9

3 differences between nerves and hormones

Answer 9

• nerves are faster action compared to hormones
• nerves act for a short time, compared to hormones
• nerves act on localised area but hormones act in more general way

Question 10

role of adrenaline

Answer 10

• released in response to scary or stressful situations
• this gets your body ready for fight ot flight

Question 11

how does adrenaline acheive this ( P1)

Answer 11

• binds to specific receptors in heart
• causes heart muscles to contract more frequently with more force
• increases blood flow to muscles so cells recieve more glucose + o2 for increased respiration
• releases energy for muscle contraction allowing you to fight/flight

Question 12

how does adrenaline acheive this ( P1)

Answer 12

• binds to specific receptors in liver
• causes liver to break down glycogen stores to release more glucose
• increases blood glucose level so more in blood to be transported to cells
• increased glucose used to fuel muscle contraction

Question 13

negative feedback

Answer 13

• when levels of certain substance go above/below a normal level
• body triggers responses that help bring these levels back to normal

Question 14

role of thyroxine

Answer 14

• regulates the basal metabolic rate which is the speed at which chemical reactions in body occur at rest

Question 15

decrease from normal thryoxine level

Answer 15

• low levels of thyroxine stimulates production of TRH in hypothalamus
  -this causes release of TSH from the pituitary gland
• TSH acts on the thyroid to produce thyroxine

Question 16

increase from normal thryoxine level

Answer 16

• when thyroxine levels are higher normal thyroxine, release of TRH is and the production of TSH is inhibited
• reduces amnt of thyroxine produced so falls back towards normal

Question 17

homeostasis

Answer 17

• regulation of the conditions inside the body to maintain a constant internal environment
• in response to changes in both internal and external conditions

Question 18

why is maintaining homeostasis important

Answer 18

• cells and enzymes need right conditions to function properly, to keep you alive

Question 19

which two hormones are produced by pancrease to regulate blood glucose level?

Answer 19

• insulin
• glycagon

Question 20

how to decrease blood glucose level when it becomes rises ( after eating carbs or sugary sweets )

Answer 20

• rise detected by pancreas : produces insulin which is secreted into blood
• insulin causes body cells to take up more glucose in blood
• cells in liver and muscle take glucose and convert into glycogen, reducing glucose level

Question 21

how to increase blood glucose level when it becomes decrease (

Answer 21

• fall detected by pancreas : produces glygacon which is secreted into blood
• glycagon causes glycogen stored in liver and muscles to be converted back into glucose
• causes blood glucose level to rise

Question 22

type 1 diabetes cause

Answer 22

• when the pancrease produces little to no insulin which means blood glucose level can rise to fatal level

Question 23

controlling type 1

Answer 23

• insulin injections into subcutaneous tissue, several times a day during meals
• makes sure glucose has been removed quickly after digestion
• limiting intake of carbs
• taking regular exercise

Question 24

type 2 diabetes cause

Answer 24

• same as type 1 OR they become resistant to own insluin and cells stop responding to it

Question 25

controlling type 2

Answer 25

- healthy diet - getting regular exercise - losing weight ( being obese is risk factor )

Question 26

why is thermoregulation important

Answer 26

- body temp needs to be kept at 37 - optimum temp for enzyme activity - above this temperature and enzymes start to denature

Question 27

where is the thermoregulatory centre located?

Answer 27

- in the hypothalamus

Question 28

what different receptors are there

Answer 28

- receptors in thermoregulatory centre sensitive to body blood temp - receptors that send info about skin temp via nervous impulses

Question 29

how does hypothalamus co-ordinate responses to temp change

Answer 29

- these receptors detect changes in temp and send nervous impulses to H - hypothalamus send impulses to effectors which respond

Question 30

how does body respond to high temp to cool it down

Answer 30

- erector muscles in dermis relax - sweat is produced by sweat glands in dermis - vasodilation

Question 31

erector muscles in dermis relax

Answer 31

- makes hairs on skin lie flat - less air trapped near surface of skin so no insulating air surrounding skin - more heat can be transferred to environment more easily

Question 32

sweat produced by sweat glands

Answer 32

- released into surface through pores of epidermis - when sweat evaporates it transfers thermal energy to environment - reducing body temp

Question 33

vasodilation

Answer 33

- blood vessels dilate (widen) - more blood flows close to surface of skin which helps transfer energy from skin to environment

Question 34

how does body respond to cold temp to warm it up

Answer 34

- erector muscles contract - very little sweat produced - vasoconstriction - shivering

Question 35

shivering

Answer 35

- muscles contract automatically - increases rate of respiration which transfers more energy to warm the body

Question 36

stage 1 menstrual cycle ( 1- 4 )

Answer 36

- menstruation ( bleeding ) occurs. - uterus lining breaks down and released

Question 37

stage 2 menstrual cycle ( 4 - 14 )

Answer 37

- lining of uterus is repaired - into thick spongy layer full of blood vessels

Question 38

stage 3 menstrual cycle ( 14 )

Answer 38

ovulation - egg released from one of ovaries

Question 39

stage 4 menstrual cycle ( 14 - 28 )

Answer 39

- lining maintained for 14 days until day 28. if no fertilized egg lands on uterus by 28, - lining breaks down again, cycle restarted

Question 40

FSH

Answer 40

- produced in pituitary gland - causes one of follicles in ovary to mature - stimulates oestrogen production in ovary

Question 41

Oestrogen

Answer 41

- causes lining of uterus to thicken and grow - stimulates LH surge - inhibits production of FSH

Question 42

LH

Answer 42

- produced by pituitary gland - causes follicle to rupture and egg to be released - stimulates remains of follicle to develop into corpus luteum

Question 43

Progesterone

Answer 43

- produced by corpus luteum - maintains lining of uterus lining - inhibits release of FSH and LH