T5 hormonal coordination in humans Flashcards Preview

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Flashcards in T5 hormonal coordination in humans Deck (58)
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1
Q

name of the body’s coordination system which involves hormones

A

endocrine system

2
Q

what is a hormone

A

chemical messenger secreted by a gland

travels in the blood to a target organ, where it causes a response

3
Q

which gland controls many other glands in the body

A

pituitary gland

4
Q

why is the pituitary gland considered a master gland

A

secretes a wide range of hormones, some of which may stimulate other endocrine glands

5
Q

what is the role of the pituitary gland in the endocrine system

A

secretes HGH - controls human growth

stimulates the thyroid gland

stimulates ovulation and production of oestrogen in the ovaries

stimulates the production of sperm and testosterone in the testes

6
Q

what is the role of the thyroid gland in the endocrine system

A

secretes thyroxine - controls metabolism, heart rate and body temperature

7
Q

what is the role of the pancreas in the endocrine system

A

secretes insulin - controls blood glucose levels

8
Q

what is the role of the adrenal gland in the endocrine system

A

secretes adrenaline - controls the body’s fight or flight response and is secreted during times of stress

9
Q

role of the ovaries in the endocrine system

A

secretes oestrogen which coordinates the menstrual cycle and the development of female secondary sexual characteristics

10
Q

role of the testes in the endocrine system

A

secrete testosterone which coordinates the production of sperm and the development of male secondary sexual characteristics

11
Q

how does the pancreas respond when blood glucose levels are too high

A

pancreas secretes insulin

insulin binds to receptors on the liver and muscles, causing excess glucose to be converted into glycogen and stored

12
Q

how does the pancreas respond when blood glucose levels are too low

A

pancreas secretes glucagon

glucagon binds to liver cells, causing glycogen to be converted into glucose and released into the blood

13
Q

how is blood glucose concentration controlled using a negative feedback loop

A

when the conc rises or falls below the optimum, a hormone is secreted by the pancreas

action of either hormone helps bring back the conc to the correct level

14
Q

what is type 1 diabetes

A

autoimmune disorder in which the pancreas doesn’t produce enough insulin to control the blood glucose conc

as a result, blood glucose levels are often very high, leading to excessive urination, tiredness and weight loss

15
Q

how can type 1 diabetes be treated

A

insulin injections before meals - allows glucose to be converted into glycogen

limiting carbohydrate intake

attempts using pancreas and pancreatic cell transplants; investigations into genetic engineering of pancreatic cells

16
Q

what is type 2 diabetes

A

disorder in which body’s cells stop responding to insulin, leading to an uncontrolled blood glucose conc

its onset is linked with increasing age and obesity

17
Q

how can type 2 diabetes be treated

A

following a carefully-controlled diet

doing regular exercise

losing weight

use of drugs which increase insulin production and effectiveness

18
Q

what is osmosis

A

movement of water from a dilute solution to a concentrated solution through a partially permeable membrane

19
Q

in what ways is water lost from the body

A

during exhalation via the lungs

sweating

urine (some reabsorbed in the kidney)

20
Q

in what ways are ions lost from the body

A

sweating

urine

21
Q

how are excess amino acids excreted from the body

A

excess amino acids are deaminated in the liver to form ammonia

ammonia is toxic, therefore converted into urea

urea is excreted from the body via sweat and urine

22
Q

how do kidneys maintain the balance of water and other substances in the body

A

filter blood in order to remove waste products

selectively reabsorb useful molecules

23
Q

full name of ADH hormone

A

Anti-diuretic hormone

24
Q

where is ADH secreted in the body

A

pituitary gland of the brain

25
Q

how does ADH affect the reabsorption of water in the kidneys

A

when the blood is too concentrated, the pituitary gland secretes more ADH

ADH travels in the bloodstream to the kidney and increases the permeability of kidney tubules to water

more water is reabsorbed in the kidneys, resulting in a smaller volume of more concentrated urine

26
Q

why is kidney failure dangerous

A

when damaged, unable to filter the blood properly

a build-up of toxic molecules in the body

uncontrolled ion and water balance and cells being damaged as a result of osmosis

27
Q

two main ways of treating kidney failure

A

dialysis

transplant

28
Q

what is kidney dialysis

A

use of a specialist machine to carry out the same function of kidneys

dialysis fluid contains the same concentration of glucose and ions as healthy blood

as a result, only excess and waste molecules are lost from the blood, and glucose and ions remain

29
Q

function of reproductive hormones during puberty

A

M: cause the development of secondary sexual characteristics

F: cause the development of secondary sexual characteristics and maturation of eggs

30
Q

main male reproductive hormone

A

testosterone, which is produced by the testes and controls sperm production

31
Q

main female reproductive hormone

A

oestrogen, produced by ovaries and is involved in the menstrual cycle

32
Q

what is the menstrual cycle

A

monthly cycle of physiological changes, involving the shedding of the uterus lining and ovulation

33
Q

describe the events of the menstrual cycle

A

uterus lining thickens and eggs begin to mature in the ovaries

egg is released from one of the ovaries (ovulation) - uterus lining remains thick

if fertilised, pregnancy may occur

if not, both the egg and uterus lining are shed during menstruation

34
Q

what is ovulation

A

release of a mature egg from the ovaries, which occurs approximately every 28 days

35
Q

name the 4 main hormones involved in the menstrual cycle

A

oestrogen
progesterone
follicle stimulating hormone (FSH)
luteinising hormone (LH)

36
Q

role of FSH in the menstrual cycle

A

secreted by pituitary gland

controls the maturation of eggs within the ovaries (inside a follicle) and triggers the production of oestrogen by the ovaries

37
Q

role of oestrogen in the menstrual cycle

A

produced by the ovaries and released due to the action of FSH - it causes the regrowth of the uterus lining

triggers the production of LH and restricts the release of more FSH

38
Q

role of LH in the menstrual cycle

A

produced in the pituitary gland as a result of oestrogen

release triggers ovulation

39
Q

role of progesterone in the menstrual cycle

A

secreted from the follicle of the ovary

sustains the uterus lining and inhibits FSH and LH

40
Q

two types of oral contraceptives

A

combined contraceptive pill (O and P)

mini pill (only progesterone)

41
Q

how does the contraceptive pill prevent pregnancy

A

inhibits FSH - eggs don’t mature

prevents the development of the uterus lining - eggs can’t implant

increases the thickness of cervical mucus - immobilises sperm cells

42
Q

what is the contraceptive patch

A

contains both O and P

patch placed on skin for 7 days at a time

43
Q

what is the contraceptive implant

A

small rod inserted under the skin which releases progesterone - lasts for 3 years

44
Q

what is the contraceptive injection

A

injection containing progesterone - lasts for 3 months

45
Q

what is the IUS

A

intrauterine system - small plastic device that is inserted into the uterus

releases progesterone which thickens cervical mucus and prevents the build-up of the uterine lining

46
Q

what is the IUD

A

intrauterine device - small copper-containing device inserted into the uterus which prevents the implantation of embryos

47
Q

what is a spermicide

A

chemical that kills or immobilises sperm cells however not very effective and work better when combined with barrier methods

48
Q

what is a barrier method of contraception

A

involves a physical separation between the sperm and egg

condoms - thin sheath worn on the penis or inside the vagina - protects against STIs but may tear/break

diaphragms - thin cap placed over the cervix, prevents entry of sperm

49
Q

what surgical methods of contraception are available

A

sterilisation - in males, sperm ducts are tied (vasectomy) and in females, oviducts are tied

50
Q

what is abstinence

A

practice of not having sex, which avoids pregnancy

some people abstain around the time of ovulation (rhythm method) but is quite unreliable

51
Q

how do fertility drugs increase the chance of pregnancy

A

many contain FSH which stimulates O production and the maturation of eggs in the ovary

also contain LH which triggers ovulation

52
Q

what is IVF

A

mother is given FSH and LH - stimulates maturation of eggs and ovulation

eggs are fertilised using sperm in lab - develop into embryos

1 or 2 are inserted into the mother’s womb

53
Q

advantages of fertility treatment

A

allows infertile couples to have children

can store a woman’s eggs for later

54
Q

disadvantages of fertility treatment

A

can be very expensive

low success rate

increases change of multiple pregnancies

side effects - mental & physical

55
Q

what is negative feedback

A

type of control where the body responds to an increase or decrease in a factor by returning it to the optimum level

56
Q

what is thyroxine

A

hormone released by thyroid gland

release is triggered by the thyroid stimulating hormone (TSH)

controls the body’s metabolic rate, growth and development

57
Q

how is the release of thyroxine controlled by negative feedback

A

levels of blood thyroxine falls - detected by receptors in the brain

pituitary gland releases more TSH

more thyroxine produced and released by the thyroid gland

blood thyroxine level returns to normal

58
Q

what are the effects of adrenaline

A

increase in H&BR - delivers oxygen and glucose to the body

stored glycogen converted to glucose

dilation of pupils

increased mental awareness

blood diverted away from digestive system to muscles