Homeostasis - Unit 5

Question 1

Enzymes and cells cannon work well to carry out necessary bodily functions if the conditions around it are not _________?

Answer 1

Optimum

Question 2

Homeostasis is the r_______ of the i______ conditions of a cell or ___________ to m________ o________ conditions for function in response to i_________ and e________ changes

Answer 2

Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

Question 3

examples of co-ordination centres

Answer 3

Brain, spine, pancreas

Question 4

How would a long distance runner’s body regulate itself?

Answer 4

Sweating (Lowers body temperature)

Question 4

what are the 5 stages of an automatic control system?

Answer 4

Stimulus (change to environment)
Receptor (Detects changes in environment)
Co-ordination centre (processes from
receptors + sends instructions to
effector)
Effector (carry out responses)
Response

Question 4

What are neurons

Answer 4

nerve cells

Question 5

Receptors detect stimulus, then send e_____ i_____ down n______ to CNS

Answer 5

Receptors detect stimulus, then send electrical impulses down neurones to CNS

Question 6

State how a scenario of touching a hot object uses a reflex arc.

Answer 6

• Stiulus is detected by receptor (heat + skin)
• electrical impulses pass from receptors along a sensory neurone to CNS
• at the end of a sensory neurone, there is a junction called a synapse, which is where a chemical releases
• The chemical diffuses across to a relay neurones in CNS, triggering an electrical impulse
  -electrical impulse passes across the relay neurones, reaching another synapse
• A chemical is once again released, triggering an electrical impulse in a motor neurone
• electrical impulse now passes down the motor neurones to an effector (muscle in hand)
  -Muscle contracts and hand is pulled away from the heat

Question 7

Order of neurones in a reflex arc?

Answer 7

sensory, relay, motor

Question 8

why are some actions reflexes?

Answer 8

no decision making in the CONCIOUS PART of the brain

Question 9

what do reflexes do?

Answer 9

protect us from danger

Question 10

What is the dependant variable of the ruler reaction time practical?

Answer 10

reaction time

Question 10

What is the independant variable of the ruler reaction time practical?

Answer 10

person having reaction time tested

Question 10

Ruler practical on reaction time

Answer 10

-Person 1 sits on stool with good upright posture, placing their dominant arm across the table, hang overhanging
- Person two hold a ruler vertically, the 0cm mark of the ruler should be between 1’s thumb and 1st finger, 2 tells 1 to be ready to catch the ruler
- 2 drops ruler at a random time, then person 1 must catch the ruler as fast as possible with thumb and 1st finger
- 2 records measurement on a ruler that is level with the top of person 1’s thumb
- test is repeated several times + a mean is calculated
- we can then determine a reaction time using a conversion table
- 1+ 2 can also swtch

Question 11

What is the control variable of the ruler reaction time practical?

Answer 11

starting distabce, lighting, background noise

Question 12

what does the endocrine system do?

Answer 12

it has glands which secrete hormones into the bloodstream, which carries the hormones around the body, each hormone will only act on specific target organs

Question 13

6 glands we you to know

Answer 13

• Pituitary
• Thyroid
• Panceas
• Adrenal
• Testes
• Ovaries

Question 14

type 1 diabeties

Answer 14

pancreas does not produce enough/sufficient insulin

Question 14

How does the pancreas regulate blood glucose levels?

Answer 14

After a meal, the pancreas will sense an increase, so it prduces insulin which travels alla roynd the body in the bloodstream, this triggers body cells to take up glucose from the blood, insulin also triggers liver and muscle cells to store excess glucose as a storage molecule called glycogen, glucose is now being taken out of the blood and stored thus meaning it goes back to normal

Question 14

purpose of Pituitary gland (also known as master gland)?

Answer 14

releawse a number of different hormones (I.e FSH) into the blood depending on conditionsm these hormones act on other glands, causing other hormones

Question 14

when would glucose levels rise?

Answer 14

after a carbohydrate-rich meal

Question 14

what is the basal metabolic rate?

Answer 14

how rapidly body’s reactions take place

Question 15

purpose of thyroid gland

Answer 15

produces thyroxine, integral to growth, regulates the body’s basal metabolic rate

Question 16

how do type 1 diabetics monitor their blood glucose levels?

Answer 16

injections of insulin

Question 17

type 2 diabeties

Answer 17

body cells stop responding to insulin produced by pancreas

Question 18

how do you treat type 2 diabeties

Answer 18

- a diet which controls intake of carbohydrates - excercise

Question 19

glucagon

Answer 19

glucagon is a hormone released to raise blood concentration levels when they are low

Question 20

How does glucagon work

Answer 20

it triggers liver cells to convert glycogen stores back to glucose, which are then released into the blood

Question 21

where are the adrenal glands located?

Answer 21

top of the kidneys

Question 22

one effect of adrenaline

Answer 22

increases in heart rate

Question 22

what does a heart rate's increase with adrenaline help your body?

Answer 22

more oxygen + glucose transported to cells in blood to brain + muscles

Question 22

where is the thyroid gland located?

Answer 22

back of the neck

Question 23

what does thyroxine do?

Answer 23

stimulates boyd's basal metabolic rate Makes body's chemical reactions happens faster

Question 23

what hormone does the thyroid gland release?

Answer 23

thyroxine

Question 24

metabolism

Answer 24

sum of all reactions in body or cell

Question 24

what happens if you have low thyroxine?

Answer 24

Pituitary gland releases the hormone TSH into the bloodstream, which triggers the thyroid gland to release more thyroxine

Question 24

what is negative feedback?

Answer 24

a balance of hormones to keep a certain state level by an increase in two opposite hromones

Question 25

during puberty, reporductive hormones produce s______ s_____ c________

Answer 25

secondary sexual characteristics

Question 25

overies produce _______ at the start of puberty

Answer 25

oestrogen

Question 25

secondary sexual characteristics

Answer 25

pubic hair armpit hair etc

Question 26

what is ovulation

Answer 26

the release of an egg every 28 dayd from the ovary to the uterus

Question 27

how does the uterus lining pperpare for ovulation?

Answer 27

becomes thick and spongy

Question 28

FSH (follicle stimulating hormone) function?

Answer 28

causes an egg to mature in the ovary

Question 28

LH (lutenising hormone) function?

Answer 28

causes ovulation/egg release

Question 29

adv + dis of implants/skinpatches/injections contraception

Answer 29

A - Convienience D - doesn't protect from STI

Question 29

menstrual cycle

Answer 29

--FSH released in pituitary gland - Travls in blood to ovaries where is causes to an egg to mature + causes oestrogen production - oestrogen thickens uterus lining and stops Pituitary gland from releasing any more FSH - instead, the pituitary gland now releases LH, triggering ovulation - once the egg is released, the ovary now produces progestrone - progestrone stops Pituitary gland from releasing FSH +LH, to prevent any more eggs maturing + releasing - if fertilisation does not take place, the level of progesterone calls and a woman has a period

Question 29

oral contraceptions

Answer 29

prevent body producing FSH

Question 29

Side effects of oral contraception

Answer 29

increased risk in breast cancer + blood clots

Question 29

function of oestrogen and progestrone?

Answer 29

maintain uterus lining Incase fertilisation happens

Question 29

adv + dis of barrier method (Condoms + diaphragms)

Answer 29

A - no side effects - reduced risk of STI D - can break/slip off

Question 29

adv + dis of oral contraception

Answer 29

A - highly effective if taken correctly D - must be taken daily

Question 29

what hormone do implants/skinpatches/injections contain

Answer 29

progestrone which stops eggs from maturing

Question 29

Condoms + diaphragms are more effective if s______ g___ is also used

Answer 29

spermicide gel

Question 30

hat does an intrauterine device (IUD) do

Answer 30

prevents embryo from impanting + sometimes reduce changes or fertilisation (hormones released)

Question 31

adv + dis of IUD

Answer 31

A - effective - long lasting (10 years) - few side ffects D - no STI protection

Question 32

sterilisation in men

Answer 32

prevents sperm from leaving penis

Question 32

sterilisation

Answer 32

surgery to stop baby making

Question 33

sterilisation In women?

Answer 33

prevents egg from reaching uterus

Question 34

adv + dis of sterilisation

Answer 34

A - effective D - hard to reverse

Question 34

what is the "natural" way to not get pregnant

Answer 34

abstaining from sex during time after ovulation

Question 35

disadvantages of adstaining from sex after ovulation?

Answer 35

- hard to tell if woman is ovulating - no STI protection

Question 36

What are the fertility drugs

Answer 36

FSH + LH - given to women in infertility clinics

Question 37

What is in-vitro fertilisation (IVF)

Answer 37

fertilisation takes place outside the body)

Question 38

how does IVF work

Answer 38

-Mother treated with LH + FSH causing several eggs to mature - eggs then collected from mother - sperm from father collected, used to fertilize eggs in labatory - fertilized eggs develop into embryos -n embryos develop into women (Inserted back in)

Question 39

adv + dis of IVF

Answer 39

A - allows women to have babies on their own - helps infertile couples D - success rates low - stressful physically demanding on mother - can lead to multiple births - not all embryos that are created will be transferred in mother ( some embryos are destroyed) meaning it is unetheical - expensive