Biology- The Hormonal System Flashcards
(89 cards)
1
Q
What does the pancreas make?
A
- makes insulin and glucagon
2
Q
What is the function of Insulin?
A
- lowers blood sugar by changing it into glycogen.
3
Q
What is the function of glycogen?
A
- increases blood sugar
4
Q
What is the function of the ovaries?
A
- make oestrogen and progesterone in females
- these control the menstrual cycle and develop female features during puberty
5
Q
What is the pituitary?
A
- gland at the base of the brain
-makes hormones and controls things like growth, water balance, sperm and egg production
-also makes hormones that control other hormonal glands
6
Q
What does the thyroid make?
A
- thyroxin
7
Q
What is the function of thyroxin?
A
- regulates the rate of metabolism, too little and our chemical reactions slow down
8
Q
When do your adrenal glands make adrenaline?
A
- when you are frightened or angry
-adrenaline helps your body cope with emergency
9
Q
What do the testes make?
A
- testosterone in males
- this develops male features during puberty
10
Q
Why is glucose needed by cells?
A
- for respiration
11
Q
What makes sure glucose level in the blood is kept at the correct level?
A
- homeostasis
12
Q
What continually monitors the level of glucose?
A
- the pancrease
13
Q
What are the two hormones that the pancreas produces?
A
-insulin
-glucagon
14
Q
Where are insulin and glucagon made?
A
- by the cells of the pancreas and then secreted into the blood
15
Q
After they are secreted in the blood, where do the hormones travel?
A
- to their target organ (the liver) where the response occurs
16
Q
What is the hormone secreted by the pancreas if glucose level is too high?
A
- insulin
17
Q
What is the hormone secreted by the pancreas if glucose level is too low?
A
- glucagon
18
Q
What is the effect of the liver when insulin is secreted by the pancreas?
A
- liver converts glucose into glycogen which is stored in the liver and skeletal muscles?
19
Q
What is the effect of the liver when glucagon is secreted by the pancreas?
A
- liver converts glycogen into glucose
20
Q
What is the effect on glucose level when insulin is secreted by the pancreas?
A
- goes down as glucose is removed from the blood
21
Q
What is the effect on glucose level when glucagon is secreted by the pancreas?
A
- goes up as glucose is released into the blood from the liver cells
22
Q
How is the quality of action and response different between the NS and the HS?
A
- NS may be involuntary or voluntary
- HS is always voluntary
23
Q
How long is the duration of affects different between the HS and the NS?
A
- HS is short lived or long lived
-NS is shortlived
24
Q
How are the forms of information different between the NS and the HS?
A
- NS involves nervous impulse
-HS involves hormones (chemical impulses)
25
What is the process if the normal blood glucose level is too high?
- stimulus- rising blood glucose level
-high blood glucose level detected by insulin secreting cells of pancreas
-insulin secreting cells of pancreas stimulated too release insulin into the blood
- either liver takes up glucose and stores it as glycogen
- or most body cells take up more glucose
-blood glucose level declines to a set point; stimulus for insulin release diminishes and body returns to homeostasis
26
What is the process if the normal blood glucose level is too low?
- stimulus- declining blood glucose level
-low blood glucose level detected by glucagon releasing cells of pancreas
-glucagon- releasing cells of pancreas stimulated to release glucagon into the blood; target is in the liver
-liver breaks down glycogen stores and releases glucose to the blood
-blood glucose level rises to set point ; stimulus for glucagon release diminishes and body returns to homeostasis
27
What is water taken into the body through?
-ingesting food and drink
28
How does water leave the body?
-via the lungs during exhalation
29
What is lost through the skin in sweat?
- water, ions, urea
30
What is removed via the kidneys in the urine?
- excess water, excess ions, urea
31
What is the main function of the kidney?
- maintain the water balance of the body
32
What do the kidneys produce urine by?
- filtration of the blood and selective re absorption of useful substances such as glucose, some ion and water
33
What does the urea do with the kidney?
- filters urea out the blood
- urea is then excreted in the urine
34
What do Ions do with the kidney?
- reabsorbs some ions
- kidney filters excess ions out the blood and excretes them in the urine
35
What does water do with the kidney?
- kidney filters out excess water from the blood
-excess water is excreted in the urine
36
What does glucose do with the kidney?
- the kidney selectively reabsorbs all the glucose to return it to the plasma.
37
What happens to the ammonia in the urea?
- its toxic
- so its immediately converted to urea for safe excretion by the kidney in the urine
38
Why is water regulation essential?
- to prevent cells rupturing or crenating
39
Where do ions enter through?
- ingestion of food
40
What are the two functions of the nephron?
- filtering the blood
- reabsorbing any useful substances
41
During filtration, where is blood brought? What does it contain a lot of?
- to each kidney in the renal artery
- the blood contains a lot of urea
42
What happens when the renal artery branches?
- each branch ends in a bunch of capillaries called a glomerulus
43
Where is the glomerulus?
- inside part of the nephron called the Bowens capsule
44
What happens as blood passes through each glomerulus?
- it is filtered
45
Why are molecules like glucose, ions, water and urea filtered out of the blood in to the nephrons but proteins are not?
- small molecules
- proteins are too big
- under pressure only small molecules are passed out
46
What is the process where useful substances by the body are reabsorbed back into the blood?
- selective reabsorption
47
What is the water level in the body controlled by?
- by hormones ADH which acts on the kidney tubules
48
What do receptors in the brain detect?
- detect changes in the water content of the blood plasma
49
What would happen if the water content of the plasma is too low?
-ADH is produced and secreted by the pituitary gland when the blood is too concentrated
-increases permeability of the kidney tubules to water
-this causes more water to be absorbed back into the blood plasma from kidney tubules
-lower volume of urine is produced
-makes urine more concentrated
50
What would happen if the water content of the plasma is too high?
-Less/No ADH is produced or secreted when the blood is too dilute
-decreases permeability of the kidney tubules to water
-this causes less water to be reabsorbed back into the blood plasma from kidney tubules
-greater volume of urine is produced
-makes urine more dilute
51
Why can kidney damage occur?
- kidney infection, genetic disease, road traffic accident
52
What can kidney failure result in?
- death as toxins, such as urea build up in the blood
53
What is Dialysis treatment?
- one method of artificially filtering the blood
54
The Dialysis machine carries out the same role as the kidneys- What are these roles?
- remove excess water, remove excess ions, remove urea
55
What does the kidney machine consist of?
- partially permeable membrane that separates the arterial blood from a dialysis fluid
56
How does Dialysis work?
1- blood leaves arm through artery
2- blood is passed through a pump to maintain the pressure to ensure the blood continues to flow through the system
3- anticoagulants are added to blood to prevent clogging
4-thinned blood enters dialysis machine
5-blood passes over dialysis membrane
6-fluid passes the other side of dialysis membrane and flows in the opposite direction to the blood
7 waste materials remove (urea, excess ions, water)
8- glucose not removed as conc is kept at level
9-filtered blood flows
10-filtered blood returned to patients vein
57
Who can donate a kidney?
- living donors (close relative or stranger)
- cadavers (road traffic incident, stroke)
-Xenotransplants (genetically engineered pigs)
58
What happens to the diseased/damaged kidney?
- remain in the body of the person
59
Why may the donor kidney be rejected?
- antigens on the surface of the donor kidney cells are recognised as foreign and causes the immune system to attack the donor kidney
60
What happens when an organ is rejected?
- antibodies of the recipient attack the antigens on the donor kidney causing kidney cell death and kidney tissue death
61
How can the risks of rejection be reduced?
- take immunosuppressants for life- these reduce the risk of rejection and recipients ability to cope with all infectious diseases
- tissue match the organ to be donated
62
What situation result in no risk of rejection?
- an identical twin as they have the same antigens on the surface of their cell membranes
63
What are the advantages of kidney transplants?
- live a normal life with no regular trips to the hospital
- long term cost is low
-good success rate
64
What are the disadvantages of kidney transplants?
- need to take immunosuppressants for life
-needs to be repeated after 10 years
-tissue matching is essential
-shortage of suitable donor organs
65
What is the oestrogen only pill?
- sustained high levels of oestrogen inhibits the release of FSH
- prevents egg from maturing, so prevents release of egg
66
What is the progesterone only pill?
- stimulates mucus at the neck of the uterus to thicken
-therefore, prevents sperm from entering uterus and reaching the egg
67
What is the combined oestrogen and progesterone pill?
- prevents production of FSH
-causes mucus in neck of uterus to thicken making it harder for sperm to reach uterus
-thin lining on uterus makes it harder for the zygote to implant
68
What are patches?
- combined oestrogen and progesterone
-typically last one week
69
What is the implant?
- progesterone
-typically last three years
70
What is the injection?
- progesterone
-last 2-3 months
71
What are the barrier methods of contraception?
- condoms, femidoms, diaphragm
-non hormonal method
-prevent STDS and sperm reaching the egg
72
What are intrauterine devices?
- progesterone, copper
- release hormones that prevent implantation of an embryo
73
What are spermicidal agents?
- contra gel
- kill or disable sperm
74
What is tubal ligation?
- cutting and trying of fallopian tubes prevents the passage of an egg to the uterus
75
What is vasectomy?
- sperm ducts can be cut and tied to prevent the ejaculation of sperm in the semen
76
What can hormones be used for?
- increase fertility in women, sometimes when they have low natural fertility levels
77
What is the treatment of low fertility levels?
- FSH and LH are given to women with low fertility to stimulate ovulation
78
What are the advantages of hormone treatment?
- increase chance of female getting pregnant
79
What are the disadvantages of hormone treatment?
- not always successful, women may need more than once which gets expensive
-lead women releasing more than one egg at ovulation- leads to multiple births (triplets)
80
What is IVF?
- when the women has blocked fallopian tubes
-male sperm count or motility low
81
What is the process of IVF?
- women given hormones to increase production of raw eggs
-mature eggs collected from the ovary
-sperm collected from male partner
-sperm injected into the mature egg in a laboratory technique
-fertilised eggs develop into a ball of cells called an embryo
- after 5 days they are transferred to a women's uterus
82
What are the advantages of IVF?
- Increase chance of infertile couple
83
What are the disadvantages of IVF?
- multiple births
-success rate is slow
-stressful/emotional procedure for the couple
84
What are the roles of the thyroxine?
- hormone produced by thyroid gland
-transported around the body in the blood plasma
-controls cells metabolism
85
What are the controls of the thyroxine levels?
- negative feedback controls levels of thyroxine
-negative feedback ensure any changes are reversed and returned back to normal level
86
What are the disorders affecting the thyroid gland? Hypothyroidism?
- underactive thyroid gland- which can cause tiredness, weight gain
-successfully treated by taking daily hormone tablets
- what happens when the thyroid gland is overreactive (producing too much thyroid hormone)
-more common in women
-treatment varies
87
What is the role of adrenaline?
- produced in the adrenal glands
-in times of fear/stress
-targets vital organs, increases heart rate
-prepares body for flight or fright
88
What is the control of thyroxine levels?
- positive feedback controls levels of adrenaline
-ensures any changes are enhanced
-as levels of adrenaline increase in the bloodstream more thyroxine is released
89
What are the effects of adrenaline?
- when adrenaline is released into the bloodstream the effects are: increased pulse rate, increased depth of breathing
-effects allow body to prepare for action in situations where a quick response may be essential
-is converted into a less active compound by the liver
