next Flashcards
(31 cards)
1
Q
what is a hormone?
A
- chemical substance produced by a gland + carried in bloodstream - which alters activity of particular cells in particular organs - target organs
- they control things in organs and cells that need constant adjustment
- produced in (+ secreted by) various glands - endocrine glands - make up endocrine system
- once hormone has been used - destroyed by liver
- hormones can control the body - effects much slower than nervous system - but last longer
2
Q
list example of glands:
A
- pituitary gland
- thyroid
- ovaries
- adrenal gland
- testes
- the pancreas
3
Q
what is the pituitary gland?
A
- located in brain
- produces many hormones that regulate body conditions
- sometimes called the ‘master gland’ because these hormones act on other glands - directing them to release hormones that bring about change
4
Q
what is the thyroid?
A
- near throat
- produces thyroxine - which is involved in regulating things like rate of metabolism, heart rate, and temp
5
Q
what are the ovaries?
A
- below belly button
- produce oestrogen - which involved in menstrual cycle
6
Q
what is the adrenal gland?
A
- below pancreas - centre of body - produces adrenaline
- used to prepare body for a ‘flight or fight’ response
7
Q
what are the testes?
A
produce testosterone - controls puberty + sperm production in males
8
Q
what is the pancreas?
A
- above adrenal glands
- produces insulin - which used to regulate the blood glucose level
9
Q
differences between hormones and nerves?
A
nerves:
- very fast action
- act for very short time
- act on very precise area
hormones:
- slower action
- act for long time
- act in a more general way
10
Q
what is glucose and insulin?
A
- insulin - hormone that regulates glucose concentrations in blood
- level in glucose in blood must be kept steady - changes monitored and controlled by pancreas using hormone insulin + glucagon in a negative feedback cycle
11
Q
what if blood glucose conc too high?
A
- pancreas produces insulin that causes glucose to move from the blood into the cells
- in liver and muscle cells excess glucose converted to glycogen for storage -will be used at a later date
12
Q
action of insulin if low glucose?
A
- effect on pancreas - insulin not secreted into blood
- effect on liver - does not convert glucose into glycogen
- effect on blood glucose level - increases
13
Q
what is diabetes?
A
a condition where the blood glucose levels remain too high - can be treated by injecting insulin
14
Q
what is type 1 diabetes?
A
- pancreas fails to produce sufficient insulin
- characterised by uncontrolled high BGLs + normally treated with insulin injections
- people with it have to monitor blood sugar levels throughout day - level of physical activity + diet affect amount of insulin needed
- help control blood glucose level by being careful with diet - not eat foods which will cause large increases in BSL + exercising - can lower BGL due to increased respiration in muscles
15
Q
what is type 2 diabetes?
A
- the body resistant to its own insulin
- cause BSL to rise to a dangerous level
- carbohydrate controlled diet and an exercise regime are common treatments
- obesity is a risk factor for Type 2 diabetes
16
Q
what do hormones do in puberty?
A
- body starts releasing sex hormones at puberty that trigger off secondary sexual characteristics (ex breasts) + cause eggs to mature in women
- men - main reproductive hormone: testosterone produced by the testes - stimulates sperm production
- women - main reproductive hormone: oestrogen - produced by ovaries - bring about physical changes - also involved in menstrual cycle
17
Q
what are the four stages of the menstrual cycle?
A
- stage 1 - day 1 - menstruation starts. uterus lining breaks down for about 4 days
- stage 2 - uterus lining builds up again, from day 4 to day 14, into thick spongy layer full of blood vessels ready to receive fertilised egg
- stage 3 - an egg develops and is released from ovary at day 14 - called ovulation
- stage 4 - wall is then maintained until day 28 - if no fertilised egg landed on the uterus wall by day 28 - spongy lining starts to break down + whole cycle starts again
18
Q
what four hormones controls
the menstrual cycle?
A
- Follicle-stimulating Hormone (FSH)
- Oestrogen
- Progesterone
- Luteinising Hormone (LH)
19
Q
what is FSH?
A
- produced in the pituitary gland
- causes an egg to mature in an ovary
- stimulates the ovaries to produce oestrogen
20
Q
what is oestrogen?
A
- produced in the ovaries
- causes the lining of the uterus to grow
- stimulates the release of LH and inhibits release of FSH
21
Q
what is LH?
A
- produced by the pituitary gland
- stimulates the release of an egg at day 14 (ovulation)
22
Q
what is progesterone?
A
- produced in the ovaries
- maintains lining of uterus during middle part of menstrual cycle + during preg
- when level of progesterone falls - lining breaks down
23
Q
what is the contraceptive pill?
A
- oral contraceptive
- contain hormones - oestrogen + progesterone) which prevent body from producing hormone FSH (causes egg to mature)
- highly effective
- but must be taken everyday
- side effects - headaches + nausea
- does not protect against STDs
24
Q
more hormonal forms of contraception?
A
- implant, skin patch or injection - all contain progesterone
- progesterone stops eggs from maturing or being released
- these more convenient than taking daily pill
- none prevent against STDs
25
how do barriers act as contraception (non-hormonal)?
- stop sperm reaching egg
| - because don't use hormones don't have side effects
26
what are good non-hormonal contraceptions?
- condoms
- diaphragm
- spermicide
- IUD
27
what does a condom do?
only form of contraception that will protect against STDs - but can break or slip off
28
what does a diaphragm do?
shallow plastic cup that fits over cervix to form barrier - has to be used with spermicide
29
what does spermicide do?
spermicide alone can be used as form of contraception - not as effective
30
what is IUD?
many women use intrauterine devices - prevent the implantation of an embryo or release a hormone to reduce chances of fertilisation
31
what are more drastic ways to avoid pregnancy?
- sterilisation - for women, prevents egg from reaching uterus - for men, prevents sperm leaving penis
- permanent procedure
- do not protect against STI's
- natural ways: avoiding days when woman most fertile + abstinence - not have intercourse
