Chapter 7

Question 1

Where are hormones produced

Answer 1

The pituitary gland

Question 2

How are hormones transported

Answer 2

From endocrine glands to their target organs through the blood stream

Question 3

What does the thyroid gland produce, what’s its target organ and what’s the effect?

Answer 3

Produces thyroxine which controls rate of metabolism

Question 4

What does the pancreas produce, what’s its target organ and what’s the effect?

Answer 4

Produces insulin which controls blood sugar levels, its target organ is the uterus and its effects are it maintains the lining of the womb- which stops FSH production in the pituitary gland

Question 5

What does the adrenal gland produce, what’s its target organ and what’s the effect?

Answer 5

Produces adrenaline which prepares the body for rapid activity by increasing the heart rate and diverting blood to muscles and brain, the target organs are vital organs liver and heart and the effect is to prepare the body for fight or flight

Question 6

What does the ovaries produce, what’s its target organ and what’s the effect?
2

Answer 6

Produces hormone oestrogen which controls puberty and the menstrual cycle in Females; it stimulates the production of LH and suppresses the production of FSH in ThE pituitary gland and its target organs are the ovaries, uterus and pituitary gland.
Produces hormone progesterone which maintains lining of the womb- stops FSH Production in the pituitary gland and its target organ is the uterus

Question 7

What does the testes produce, what’s its target organ and what’s the effect?

Answer 7

Produces testosterone which controls puberty in males and its target organs are the male reproductive organs

Question 8

What is fight or flight

Answer 8

Several responses that prepare the body for sudden action, including increased heart rate, increased blood flow to muscles and release of glucose into the blood

Question 9

adrenaline produces by the adrenal glands to prepare the body for fight the effects are…

Answer 9

Increased heart rate
Increased blood pressure
Increased blood flow to the muscles
Raider blood sugar levels by stimulating the liver to change glycogen into glucose

Question 10

Explain Steps on how thyroxine controls metabolic rate as an example of negative feedback

Answer 10

Low levels of thyroxine stimulates production of TRH in the hypothalamus
This causes release of TSH from the pituitary gland
TSH acts on the thyroid to produce thyroxine
When thyroxine levels are normal thyroxine inhibits the release of TRH and the production of TSH

Question 11

Stages of menstruation

Answer 11

1) Follicular phase- first day of bleeding where the follicles develop in the ovaries. At the start the lining of the uterus is thick for embryo, if no embryo is present the oestrogen and progesterone levels are low this causes lining of uterus to shed.
2) Ovulatory phase- LH surge and decrease in FSH, causes egg to release (ovulation) egg travels down Fallopian tube ready for fertilisation (egg can survive for 12-24 hours after.
3) Luteal phase- ends before menstrual period unless fertilisation occurs. The egg travels along the Fallopian tube, Corpus luteum secretes P and O prepares the uterus for fertilisation

Question 12

Explain the interactions of oestrogen

Answer 12

Oestrogen is secreted by the ovaries and stops FSH being produced so that only one egg matures in a cycle, it stimulates the pituitary gland to release luteinising hormone (LH) which triggers ovulation (release of mature egg from ovary)

Question 13

What does hormonal contraception do

Answer 13

Influences menstrual cycle and prevents pregnancy and works by preventing the ovary from releasing an egg by thickening the cervical mucus making it difficult for the sperm to reach the egg and changing the lining of the uterus which makes implantation difficult

Question 14

Evaluate hormonal and barrier methods of contraception

Answer 14

Barrier methods include that of condom and cervical cap which don’t require hormones but physically stop sperm being released into woman’s body.
Hormonal methods such as the pill reduces chance of mature egg being produced. The pill contains Oestrogen or/ and progesterone. These hormones inhibit the production of FSH, which in turn stops egg maturing in the ovaries

Question 15

Explain use of hormones in assisted reproductive technology (ART) including IVF and clomifene therapy

Answer 15

women who have difficulty becoming pregnant don’t produce enough FSH to allow their eggs to mature. Fertility drugs contain FSH and LH which stimulates eggs to mature in the ovary

Question 16

Evaluate the advantages and disadvantages of assisted reproductive technology (ART) including IVF and clomifene therapy

Answer 16

A= increase chance of woman's chance of becoming pregnant and boosts production of women's mature eggs 
D= may not always work, multiple conceptions sometimes occur, with twins or triplets being expected. Which increases risk of complications in pregnancy and childbirth, which may lead to premature or underweight babies

Question 17

Explain the importance of maintaining a constant internal environment in response to internal and external change

Answer 17

X

Question 18

Explain the importance of homeostasis X2

Answer 18

Thermoregulation- the effect on enzyme activity

Osmoregulation- the effect on animal cells

Question 19

What is homeostasis

Answer 19

Maintaining a constant internal environment. The nervous system and hormones are responsible for this

Question 20

How is the internal condition of the body’s blood sugar levels

Answer 20

It is controlled to provide cells with a constant supply of energy. The blood sugar levels is controlled by the release and storage of glucose, which is in turn controlled by a hormone called insulin

Question 21

How is the internal condition of the body’s temperature

Answer 21

It's controlled to maintain the high enzymes work best, which is 37* 
Body temp is controlled by:
Controlling blood flow to the skin 
Sweating 
Shivering

Question 22

How is the internal condition of the body’s water content controlled

Answer 22

Controlled to protect cells by stopping too much water from entering or leaving them- this process is called osmoregulation.
Water is controlled by water loss from the lungs when we exhale, skin by swearing and body in urine produced by kidneys

Question 23

How does thermoregulation take place in the skin In cold conditions

Answer 23

Hair shafts on the surface of the epidermis layer will have a piloerection as the erector muscle from the dermis contracts and pulls the base of the hair making the hair stand up, this forms convection pockets to reduce heat loss.

Question 24

How does thermoregulation take place in the skin in hot conditions

Answer 24

Sweat gland travels through the dermis and into the epidermis where a pore is found, the glands secrete sweat onto surface of the skin (dermis layer) to increase Heat loss by evaporation, sweat secretion stops when the body temperature returns to normal

Question 25

How does thermoregulation take place in relation to shivering

Answer 25

The shivering reflex is triggered to maintain homeostasis. Skeletal muscles begin to shake in small movements which create warmth by expanding energy Rapid contraction and relaxation of muscles that cause body to warm

Question 26

How does thermoregulation take place by vasoconstriction

Answer 26

Blood vessel becomes narrower and deeper in cold conditions where is stops radiation by vasoconstriction Blood flow in capillaries decreases

Question 27

How does thermoregulation take place by vasodilation

Answer 27

The blood vessels widen which allow more blood to flow through nearer to the surface

Question 28

How does the hormone insulin control blood glucose concentration

Answer 28

Glucose is a sugar needed by cells for respiration. Insulin, a hormone produced by the pancreas, controls blood sugar levels in the body. It travels from the pancreas to the liver in the bloodstream.

Question 29

What happens when glucose levels In the blood become too high or low

Answer 29

If the glucose level becomes too high the pancreas would secrete insulin into blood where the liver converts glucose into glycogen and the glucose level goes down. If the glucose levels become too low the pancreas doesn't secrete insulin so the liver doesn't convert glucose to glycogen so the glucose levels go up

Question 30

How is blood glucose concentration regulated by glucagon

Answer 30

Pancreas releases another hormone called glucagon, when the blood sugar levels fall. This causes the cells in the liver to turn glycogen back into glucose which can then be released into the blood. The blood sugar levels when rise

Question 31

What's the hypothalamus

Answer 31

Part of the brain that monitors and controls the bodys temperature through nerves

Question 32

Cause of type 1 diabetes and how it's controlled

Answer 32

Pancreas stops making enough insulin, is controlled by daily injections of insulin for life and a healthy diet

Question 33

Cause of type 2 diabetes and how it's controlled

Answer 33

The body no longer responds to its insulin and is controlled by exercise and appropriate diet

Question 34

What's the BMI equation

Answer 34

Mass (kg) / BMI= height (m2)

Question 35

How is the structure of the nephron related to its function in filtering blood and forming urine

Answer 35

Each nephron contains multiple sub-structures. Filtration occurs in the glomerulus (dense network of capillaries which are under very high pressure and filter out small molecules from the blood into the bow mans capsule via ultrafiltration. At the proximal convoluted tubule glucose and water are reabsorbed.

Question 36

What is urea produced from

Answer 36

Breakdown of excess amino acids in the liver

Question 37

Explain the effect on ADH on the permeability of the collecting duct in regulating water content of blood

Answer 37

Increase because of aquaporins

Question 38

Treatments for kidney failure | Kidney dialysis

Answer 38

Blood (high in urea) is taken from a blood vessel in the arm, mixed with blood thinners to prevent clotting, and pumped into a machine. Inside the machine- separated by a partially permeable membrane the blood flows in the opposite direction to dialysis fluid, allowing exchange to occur between the two where a concentration gradient exists

Question 39

What does the dialysis fluid contain

Answer 39

Same concentration of glucose and mineral ions as normal blood plasma so there is no net movement of glucose out of the blood

Question 40

Treatments for kidney failure | Organ donation

Answer 40

Implanting a kidney from an organ donor into the patients body to replace the damaged kidney, the kidney would have specific protein antigens on it therefore when receiving the implant the patients immune system would quickly form antibodies against kidney cell antigens which would destroy the kidney which is known as Oban rejection

Question 41

Explain interaction of follicle stimulating hormone (FSH)

Answer 41

Secreted by pituitary gland and causes an egg to mature in an ovary and stimulates ovary to release hormone oestrogen

Question 42

Explain interaction of progesterone

Answer 42

Hormone secreted by ovaries. Maintains lining of the uterus during the middle part of the menstrual cycle during pregnancy

Question 43

Explain interaction of LH (luteinising hormone)

Answer 43

Causes mature egg to be released from the ovary

Question 44

recall 4 steps for process of IVF

Answer 44

Many eggs are produced at once and removed from the ovary Eggs are placed in a solution in a petri dish and mixed with sperm Embryos develop from fertilised eggs in the petri dish A couple of embryos are implanted in the mothers uterus

Question 45

In fertility treatments, what is FSH (follicle stimulating hormone) used for?

Answer 45

To trigger Oestrogen production and produce ripe egg cells

Question 46

What do kidneys do and why would someone need dialysis

Answer 46

Filters blood, they stop working toxic waste build up Kidney dialysis restores concentration of chemicals in blood to normal levels Kidney dialysis is needed every 3 days, or can be more frequent, it lasts 3 hours and the patient cannot move during that time- restrictive

Question 47

What is osmoregulation

Answer 47

Organism regulates water levels in body fluids by altering concentration of salts

Question 48

Explain how negative feedback is used to control the urinary system

Answer 48

If there is Too much water in blood the kidney will remove water, the urine will become more dilute and volume of urine increases Too little water in blood- chemical message from brain to kidney- changes the permeability of membranes in kidney- water now passes back into blood Osmosis is used to regulate water level

Question 49

What happens if there is to much water in your body

Answer 49

It dilutes reactants which causes slower reactions

Question 50

When your dehydrated what does your body do

Answer 50

Reabsorb water from urine

Question 51

What effect can food high in salts have on you

Answer 51

Make you lose more water as body tries to remove excess salt in urine

Question 52

What is negative feedback

Answer 52

A control mechanism in which a change in condition, such as temperature, causes the opposite change to happen so brings the condition back to a normal level

Question 53

What is the corpus luteum

Answer 53

A structure formed from the egg follicle after an egg cell is released from an ovary. It produces progesterone

Question 54

What is an egg follicle

Answer 54

Cells in the ovary that surround a developing egg. The follicle produces hormones such as oestrogen

Question 55

What is the bowmans capsule

Answer 55

The start of the nephron where filtration occurs

Question 56

What is the collecting duct

Answer 56

Final part of a nephron

Question 57

What is the first convoluted tubule

Answer 57

Part of a nephron where selective reabsorption of glucose and some Mineral ions takes place

Question 58

What is the loop of henle

Answer 58

A long loop of a nephron involved in osmoregulation

Question 59

What is selective reabsorption

Answer 59

Taking back particular (useful) substances, such as glucose and some mineral ions, into the nephron

Question 60

What is ADH

Answer 60

Antidiuretic hormone. Hormone produced by the pituitary gland that increases the permeability of the collecting duct in a nephron to water

Question 61

Explain how the increase in number insulin units injected would affect blood glucose concentration

Answer 61

An increase of insulin concentration would cause more glucose to be converted to glycogen leading to the blood glucose levels falling to low

Question 62

Explain how the blood entering the nephron of an organism is filtered to remove excess sodium ions and water

Answer 62

Ultrafiltration occurs in the glomerulus where the liquid part of the blood passes into the bowmans capsule. Reabsorption takes place as it travels through rthe proximal convoluted tubule into the loop of henle. Finally urine production occurs in the collecting duct where excess fluid & sodium ions are removed.