SB7 Flashcards
1
Q
What is a Hormone?
A
Organic Chemical Messenges produced and secreted by an endocrine cell.
Released by endocrine glands
2
Q
Describe what is an Endocrine system?
A
A system made up of various endocrien glands, which controls body functions throug hormones.
Releases hormones into the blood which then these hormones reach the target organs.
3
Q
Features of the Endocrine System
A
- Ductless
- Rich Supply of blood
- Hormones produced by the endocrine glands are secreted into the bloodstream.
- Hormones travel in the blood to target cells close by or faraway from point of secretion.
- Hormone receptors have specific binding sites on to the target cells
4
Q
Define Exocrine Glands
A
Secretes and releases substances through openings onto your body’s surface.
Such as sweat, enzymes mucus and sebum
5
Q
Organs used in exocrine system
A
- Sweat glands which produce sweat in sweat ducts for thermoregulation
- Liver through bile ducts producing bile dor emulsificiation.
- Pancrease which secretes pencreatic juices contsining digestic enzyme from pancreatic ducts.
- Memory glands which through a memory duct release milk to nourish the body
6
Q
Dfferent Endocrine Organs
A
- Anterior Pituitary Gland
- Posterior Pituitary Gland
- Kidney
- Thyroid Gland
- Hypothalamus
- Pineal Gland
7
Q
Name several hormones produced in the Anterior Pituitary Gland?
A
- Growth Hormone(GH)
-Promotes growth of tissues (if hypersecretion then gigantism, if undersecretion then dwarfism) - Prolactin (Promotes milk production)
- Thyroid-Stimulating Hormome (TSH)
-(Stimulates thyroid to release thyroxine)
4.ACTH (stimulates adrenaline)
- Follicle Stimulating Hormome(FSH)
-(Stimulates gamete production) - Luteinizing Hormone(LH)
-(Stiumates the ovary to release oestrogen and progrstrone in females)
-(Stimulates testes which releases Testosterone in males)
8
Q
Hormones produced in Posterior Pituitary
A
- Antidiuretuc Hormone(ADH)
-Stinulates water reabsorption by kidneys - Oxytocin
-Stimulates uterine contraction during childbirth
9
Q
Describe Thyroid in Endocrine Organ and effects of hypo and hyper secretions of thyroxine
A
Produces Thyroxine and Calcitonin and Parathyroid Hormone
1) Thyroxine Stimulates metabolism(all the reactions taking place within a cell)
2) Calcitonin Reduces blood Ca levels
3)Patathyroid Hormone increases blood Calcium levels
(calcium is used for bones and teeth)
Hyposecretion of Thyroxine results in Goitre, enlargement of thyroid. which occurs due to a lack of iodine from iodine salts.
Hypersecretion of thyroxine increases BMR
10
Q
Describe Different Endocrine Glands in the kidney
A
1) Adrenal Cortex Glands
2) Adrenal Medulla Gland
3) Pancreas
11
Q
What does adrenal cortext gland release?
A
1) Aldosterone-increases blood sodium levels
2) Cortico Steroids-increases blood glucose levels
12
Q
Describe the hormone produced in the adrenal medulla gland?
A
Adrenaline which stimulates fight or flight reaction
13
Q
Describe the Pancreas
A
The pancreas contains both endocrien and exocrine glsnds. Found below the stomache and shaped similar to a leaf like organ.
Releases Insulin and Glucagon Hormones which target the organ the liver.
Glucagon is produced by Alpha cells, Beta cells produce insulin and Delta cells producd stomatostatin
14
Q
Describe Glucoregulation
A
Glucoregulation refers to the body’s homeostasis/balance of glucose levels in the blood.
If glucose levels are too high, the pancreas releases insulin which goes to the liver, which converts glucose into glycogen and storing glucose, reducing glucose blood levels.
If glucose levels are too low the pancreas releases glucagon which goes to the liver which converts glycogen to glucose increasing glucose blood levels.
15
Q
Describe different Hormones found in
1) Ovary 2) Testes
A
Ovary
1) Oestrogen which thickens the uterine wall and controls secondary sexual characteristics
2) Progesterone maintains the thickening of uterine wall
Testes
1) Testosterone which controls the production of sperm and secondary sexual characteristics in males
16
Q
Describe a Positive Feedback Loop
A
Positive feedback loop is in which a process by which a stimulus causes a response which will increase the stimulation
EG) Oxytocin in childbirth and Adrenaline
Least common Hormone Action
17
Q
Describe a Negative feedback loop
A
Negative feedback loop tries to maintain a median.(Homeostasis)
It achieves this through receptors detecting a change and initiating a response that will counter that change
EG) Blood Glucose Levels, Temperature, Blood Oxygen levels and CO2 Levels
18
Q
Describe the negative feedback loop of Thyroxine
A
Occurs in the hypothalamus and Anterior Pituitary
Hypothalamus>TRH> Anterior Pituitary>TSH>Thyroid>Thyroxine>
Hypothalamus
Hypersecretion of Thyoxine
If thyroxine is in high amounts then it inhibits the hypthoalamus which lowrrs production of TRHs which decreases anterior pituitarys production of TSH increasing thyroid production which decreases thyoxine.
Hyposecretion of Thyroxine
If thyroid levels is less it stimulates hypothalamus which increases TRH increasing production of TSH in pituitary hland stimulating production of thyroid so thyroxine levels increase
19
Q
What stimulates Adrenaline
A
Things that stimulate adrenaline
-Public speaking
-Slydiving
-a jumpscare
-talking to someone you have a crush on
20
Q
Effects of adrenaline to organs
A
1) Heart increases heartrate to increase bloodflow so more oxygen and glucose is available in our cells
2) Lungs increase in breathing rate so more oxygen reaches into cell muscles so aerobic respiration increases so more energy
3) Blood vessels in the lungs dilate more so more glucose and oxygen are available while some other vessels contract to decrease glucose and oxygen levels in those areas such as the digestive system
4) Liver stores glycogen, adrenaline favours the breakdown of glycogen to glucose to increase rate of respiration so more energy in the body
21
Q
other effects of adrenaline
A
dilation of pupil so more light reaches rods and cones
dry mouth as salivary glands dexrease
faster brearhinf
heart pounding
tense muscles
slow difestion
decrease in sensitivity of pain
22
Q
What is the menstral cycle?
A
A cycle of changes in the woman’s reproductive system that takes about 28 Days.
Prepares the womans body for the fertilidatoon of an egg cell leading to pregnancy
Cycle continues from puberty(around12yrs) to menopause(early 50s)
23
Q
Organs involved in the menstral cycle and hormones produced
A
Ovary releases
FSH(follicle stimulating hormone)
-causes the mutation of an egg in the ovary
LH(luteinizing hormone)
- stimulates the release of the eggcell
Anterior Pituitary releases
oestrogen
-involved in repairing and thickening the uterus lining
progestrone
-maintains the uterus lining
24
Q
What is Primary and secondary sexual characteristics?
A
Primary Sexual Characteristics
-Enable human beings to reproduce.
-Characteristics when we are born in(occurs in birth)
Secondary sexual characteristics
-occurs in puberty
-men 13-15(lower voice, developed muscles and alot of facial and body hair)
-women 11-14 (higher voice, breasts,wider hips, little body hair)
25
What is the importance of the menstral cycle
-Bodys way of preparing for pregnancy
-occurs only in females
-controlled by chemicals called hormones
26
Describe the parts of the female reproductive system and their functions
vagina: known as the birth anal, joind the cervix to the outside of the body
cervix: opening into the uterus
ovary: development of the follicles containing egg cells
fallopian tube: it collect the eggcell released during ovulation.
fusion of dperm + eggcell > fertilisation
27
Describe the main events in the menstrual cycle
1) Menstruation- uterus lining breaks down, blood and cells are lost
2) proliferation- repair of uterus lining
3) ovulation-release of an egg from the ovary
28
describe menstruation in detail
- from day 1-6
- pituitary glands release FSH, oestrogen levels become low.
-FSH causes immature follicles to mature
-Oestrogen is low so breakdown of uterus lining occurs
29
describe proliferation in detail
-at day 6-13
- oestrogen from follicle cells released so oestrogen levels increase.
-uterus lining is repaired
-oestroven lowers levels of FSH so levels of LH increases
30
descrive ovulation in detail
at day 14
-graafian follicle contaisn the eggcell
-progretrone levels increase from corpus luteum
-presence of LH causes graafian follicle to burst
31
What happens after day 14?
progestrone maintains thickening of uterus
negative feedback loop is favoured by progestrone because corpus lutuum forms which declines levels of both FSH LH
32
What happens if the egg cell is feetilised and when the egg cell is not fertilised
If fertilised by sperm fell then
-oestrogen and progrstrone remains at high levels. these hormones maintain the uterus lining so menstruation does not occur
If the egg is not fertilised then
-follicle forms a yellow body and the egg dies
-hormone production stops
-low progestrone causes uterus lining to break, the next menstruation starts and the cycle contines.
33
order of hormones present in menstral cycle
1. FSH
2. Oestrogen
3. LH
4. Progestrone
34
Describe contraception
a method taken to prevent fertilisation
35
characteristics of ideal Contraception
-safe
-100% effective
-free of sideeffects
-easily obtainable
-affordable
-acceptablevto the user
-free of effects on future pregnancies
36
types of birthcontrol
1) hormonal
2) barrier
3) IUD
4) Permanent Steralization control
37
hormonal methods in detail
Inncludes oral contraceptives(birth pills and injections)
===
Birth Pills
How do birth control pills work?
pill contains high progestrone so
1)lowers fsh
-so no maturation of follicle
-low levels of oestrogen
-uterus lining is thin
-prevents implantation
2) low LH
-so no ovulation
take the pill once a day at the sametime everyday
Advantages
overall 99% effective
eases menstral cramps
shortens period
regulates period
offers protection from STDs
disadvantages
breast tenderness
nausea
increases in headaches
moodiness
weight change
===
Injections(depo provera)
-bidth control shot given once every 3 month to prevent pregnancy
-99.7% effective preventing pregnanct
-no daily pills
-extremely irregular menstral bleeding and spotting for 3-6 months
38
Describe natural contraception
a method of which fertilisation is avoided by avoiding sexual contact from days 14-16
Norplant
- can control fertility for years therefore considered long term control
-99% effective
-made of s combination of oestrogen and progestrone
39
Describe mechanical Contraception
-prevents pregnancy by blocking sperms and egg from ferilisation
short term barrier methods
1) spermicides(chemicals that kill sperm in vagina)
2) male comdom(prevent enttry of sperm and transmission of STDS)
3) female condom
4) vaginal ring (commonly used with spermicide)
5) diapraghm
6) cervical cap
long term barrier methods
1) IUD (intrauterine devices)
-prevente the process of implantation placed in the uterus
i) copper T, 10 years and 99.2% effective
copper acts as spermicide blocking egg from implantation
ii) progestasert
1 year 98% effective
-t shaped plastic that releases hormones over a year which thickens muchs blocking the egg.
40
Surgical Contraception
1) Sterilization
2) Tubal ligation
3. Vasectomy
41
Infertility described
The inability to concieve after 12months of having sexual intercoarse without the use of any form of birth control
42
how does infertility occur in males and females?
males
1) hormone imbalance, low levels of testosterone
2) no of sperm produced is less or abnormal sperms produced
3) blockage of sperm duct
females
1) hormone imbalance low levels of FSH & LH
2) abnormal egg cells or eggcells are not released/matured
3) blockage of oviduct
4) uterus lining is either too thick or too thin due to hormonal imbalance of progestrone or oestrogen
43
types of infertility
1) primary infertility
-couple had never produced a pregnancy
2) secondary infertility
-woman has previously been pregnant regardless of the outcoem and is now unable to concieve
44
Factors affecting fertility
1) Timing of intercourse
sperm survives for 5 days
ovum life is about 1 day if not fertilized
sperm shoudl be available in the genital tract shortly before ovulation
2) requirements of male infertility
spermatogenisis- process in the testes for development and maturation of sperm
notmal spermatogensis in order to fertillise egg is sperm count motility biological structure and function
3) requirements of female fertility
-adequate sexual drive and sexual function
-normal immunologic response to accomodate sperm
-adequate nutritional and health statues to maintsin nutrition and oxygen to the placenta and fetus
4) STIs and other infections
gonorrhea and chlamdyja can cause pelvic inflammatory disease and cervicts to females and csuse urethritis, epididymitis, accessory gland infection in males
5) agr
women- after 40 fertility rate decreases by 50% while the risk of miscarriage increases
men- increased age affects cortal frequency and seceral functions
6) lifestyle
smoking alcohol and pesticides
in women may cause reduced contraceptions and increased risk of fetal waste
in men reduced sex drive and sperm count
45
explain what is polysaccharide and monoaaccharide
glucose is monosaccharide
glycogen is polysaccharide (a storage substance made of glucose)
46
when is insulin and glucagon used?
insulin is used in hyperglycemia,
in hyperglycemia anabolism occurs(making of amino acids into proteins, glucose into starch/glycogen)
glucagon is used in hypoglycemia
in hypoglycemia catabolism occurs(the breaking down of substances such as glycogen to glucose or fat into fatty acids and glycerol)
47
when is insulin and glucagon used?
insulin is used in hyperglycemia,
in hyperglycemia anabolism occurs(making of amino acids into proteins, glucose into starch/glycogen)
glucagon is used in hypoglycemia
in hypoglycemia catabolism occurs(the breaking down of substances such as glycogen to glucose or fat into fatty acids and glycerol)
48
effects of blood glucose being too high tr too low (not referring to glucoreg)
when blood glucose is too high
- severe dehydration occurs as it alters water potential in blood creating dangerous osmotic gradients
when blood glucose is too low
-cells are deprived of glucose needed for respiration and then they may die
49
Types of diabetes expplained
Type 1 (Insulin Dependent)
- pancreas does not produce enough insulin. can lead to high levels of glucose in the blood which can be fatal
-mainly younng ppl
Cause;
-autoimmune attack on pancreas therefore body doesnt produce insulin and glucose cant be taken into the cell
Treatment:
-regular insulin ijs tions
-regular monitoring of blood sugsr levels needed to ensure correct dose administered
Type 2 (glucose independent)
-the body(receptors) no longer responds to its insulin and has been linked very closely to obesity
-occurs in mainly adults
causes
-receptors is less responsive to insulin hormones that is produced
treatment:
-healthy diet+regular exercise
-possible option of takinv drugs to reduce rate at which glucose is absorbed into the body
50
Body organs used in glucose regulation
1) Pancreas:
Releases hormones insulin and glucagon which control blood glucose levels.
2) Liver:
takes up glucose when levels are too high, converts into glucagon to be stored
3) Muscles:
our muscles take up and store lots of glucose when insulin is present
4) fat cells
made up of adipose tissue
acts as insulator
5) brain
takes up glucose whenever it needs enerfy
does not require insulin
brain is maxe up of neurons, ATP
is required got transmission of impulses
51
Tests for glucose
1)fasting glucose test
2) oral glucose tolerance test
3) A1C test
4) glucose test strips-qualitative test strip
52
Type 2 diabetes in more detail
liver would have extra fat lining so less glucose enters the liver so less glucose is converted into glycogen
beta cells can be damaged over time when pancreas works hard, once beta cells are damaged diabetes bexomes a long life infector
53
What are the roles of the skin
1) temperature regulation
2) protection of underlying tissues
3) slowing the rate of water loss
4) housing sensory receptors
5) syntgesizing certain chemicals
6) exceting waste
54
In brief describe layers of the skin
1) Epidermis
the role of protection
layered into "stratum corneum(cornified layer, stratum grabulosum(granular layer), stratum basale(basal layer)"
2) Dermis
role of thermoregulation
3) Hypodermis
role of insulation
55
in depth describe the epidermis
Epidermis is made up of stratified(multiple) squamous(flattened) epithelial tissue and lacks blood vessels
-the outermost layer of the skin
-outermost layer is dead while innermost layer of epidermis is living
Epidermis is further layered into
(from innermost to outer most)
1)Statrum Basale(basal layer)
- forming a basal layer of living and dead cells which can replace cells in granular and cornified layers
2)Stratum Granulosum(Granular Layer)
-cells contain melanin pigment contsins a substance melancoytes, which give colour and prevent UV radiation
3)Stratum Corneum(Cornified layer)
-dead cells of keratin used for protection and prevention of growth of microbes on the surface of the skin
56
in depth describe the dermis
the dermis is made up of dense collective tissues with tough collagen and elastic fibres. (these act as support for dermis layer)
Contains
1) Sensory fibres
- detect changed in temperature, responsible for pain touch and pressure
2) Nerve Fibres
-conduct impulses
3) Blood vessels
-used to give nutrients to the cells in the epidermis muscles
- can constric for heat gain(vasoconstriction), dilate for heat loss,(vasodilation)
4) Sebaceous gland
-releases an oil secretion called sebrum
5) Hair follicles
-found in nearly all regions of the skin
-contsins hair(a deposit of keratin)
-hair erector muscles are founr nesr the side of the hair follicle.
-sensorr nerve found in thre base of hair follicles to help detect pain and touch:
-can contract to help trap air keeping hear in colder climates
-hair erector muscles can flatten in hot areas to help with heat loss
6) sweat glands
-a ball of cuboidal cells
-surrounded by blood capilliaries to help in the formation of sweat(made up of water and sofium chloride salt)
57
An example of a modified sweat gland?
Found in the ear canal can excrete wax
or secrete milk in women
58
3) In depth describe the hypodermis
Made up of loose connective tissues( protein) and insulating adipose tissue(adipose cells thst contsin fact) which allows it to act as an insulating layer
acts as a covering for softer organs
m
59
Types of sensory receptors found in the skin
1) Merkel Cells which sense light
2) meissbeer corpuscles responsible for the transmitting the sensation of fine discrimitsble touch and vibrations
3) ruffins corpuscles sense skin stretching, movement and finger position
4) pacinan corpuscle
5) heat receptors
6 cold receptors
60
what is thermoregulation?
the abulity of an organism to keep its body temperature within certain boundaries
1) core temperature of deep tissues in the human body is 36.5-37.5'C
2) Skin trmpersture in contrast rises snd falls with the temperature of the surroundings
61
describe Hypothalamus in the role of thermoregulation
has teo centred which regulate body temperature,
1) Heat loss centre
2) heat gain centre
62
explain what happens when temperature outside is low/cold
stimulus
-blood and skin temperature falls
receptor
-temperature receptors detect changes and send impulses to the brain
-hypothalamus detects and sends impulses to relevant body parts such as
1) blood vessels construct so less blood to the surface of the skin to keep warmth
2) sweat gland stops producing sweat
3) skeletal muscles contract so no more ATP
4) hair erector muscles contract to trap air(causes hair to stand up)
63
explain the homeostasis of temperature when outside temperature is high
stimulus
-blood and skin temp rises
receptors
-thermoreceptors detect changes and send impulses to the brain
-hypothalamus stimulates and sends more implses to relevant body parts such as
1) blood vessels dilate to mroe easily transfer wamrth out
2) sweat glands are more active
3) hair erector muscles relax so less air is trap
4) skeletal muscles relax so no shivering
64
describe hyperthermia and hypothermia
hypthermia
-means when the body temperature is above average
-chsracterised by shivering, confusion, stuttered speech, low energy and body cells begining to die
cure: drink alot of water
hypothermia
-means when the body temperature is below average
-shivering
-a person could die
cure: bring the person to a warm environment
eitherway both are incredibly harmful
65
describe ectotherms
ectotherms
-organisms which control their body temperature through external means
-depend on environmental heat sources
have behavioural adaptations to help this such as
-seeking shade, movement of wings to absorb light and warmth, a low metabolic rate so less food is required to survive, huddling together
disadvantage
-when it is cold ecotherms become sluggish, therefore are unable to escape from predators easily
66
endotherms
endotherms
-are organisms that produce heat through internal means
-keeps warm through negstive feedback loop
disadvantage
-can get overheated or over cooled
67
function of excretory system
removes liquid and gsseous waste from the bodu
68
how is different foods stored?
excess protein goes to the liver and is converted into amino acid
carbohydrates are stored as glycogen in the liver
fat is stored in the adipose tissue of rhe skin
69
what is the ornithine cycle?
the cycle in whcih ammonia is converted into urea to be excreted as waste products
NH2 becomes
-NH+4 ion
-NH3 -> CO2 -> Urea -> uric acid(waste containing nitrogen)
70
how do different waste products form?
1) carbon dioxide forms from respirstion, moves into the vlood and exhaled by the lungs
2) ammonia is from the cells breakdown of old proteins, removed through water in urination
excreted into the blood from the cells and carried to the liver where it is converted to urea, which is less toxic and carried into the kidneys
71
what is the role of the kidney in osmoregulation
responsible for cleaning the blood of waste
72
describe the regulation of water levels in a hot day and cold day
in a hot day sweat is released so blood becomes hypertonic, kidney reabsorbs more water so amount of urine is less concentrated, blood becomes isotonic
cold day sweat is nto given out, blood is hypotonic, kidney absorbs less water/no absorbtion so amoutn of urine is more dilate, blood becokes isotonic
isotonic means balanced
73
The two ways to measure health
BMI and Waist Hip ratio
74
explain the BMI table and tell BMI formula
BMI | Conclusion
<20 | underweight
20/25| normal
25-30| Overweight
>30| obese
weight/(height)^2
75
why BMI might not be a reliable indicator
atheletes are physically fit but may have a high BMI due to alot of muscld maaa and not due to fat mass
76
How to measure waist hip ratio
find midpoint betweenn the lower margin of the last palpable rib and the top of the lilac crest
the widest portion of the buttocks with the top parrallel to the floor
77
what forms does Excretory System excrete waste? and how does digestion system give out waste?
excretory (excretion)
1) sweat 2) urine 3) air rich of CO2 and H2O vapour
digestion system (egestion)
-faeces
78
describe the kidney
-kidney helps to maintain homeostasis by filtering the blood
-bean like, reddish brown
-found beneath the ribcage
-externally protected by a fatty layer
-made up of two layers, cortex and medulla
-contains filtering units cslled nephrons and renal artery+ renal vein
79
different parts of the excretory system
1) renal pelvis
2) renal artery (responsible for bringing impure oxygenated blood because it contains urea(
3) renal vein (carries pure deoxygenated blood because it contains low amounts of urea)
4) renal capsule
5) ureters(tube that carry urine from the pelvis of the kidney)
6( urinary bladder(temporarily stores urine till it is released from the body)
7) urethra(tuvs thst carries urine from the urinary blood)
8) sphinceter(outsr end of the urethra id controlled by circular muscled callled spin enter muscle)
80
what happens when one lidney is removed/failed?
other ine becomes bigger to compensate and maintain the workload
81
what does kidney also excrete?
-uric acid produced from the breakdown of DNA to RNA
-creatinine is a waste producd of muscle atom
82
describe the medulla and corrext of the kidney
medulla has few conical projections called renal pyramids projecting into the calycers
cortex extends in between the medulla phramids as renal columns called columns of bertini
83
basic functions kidney has to maintain homeostasis
1)remove wate from blood
2) help to maintain electrolyte, pH and fluid balances
3) release key hormones
84
What are nephrons?
Nephrons are the filtering units in the kidney, which clean blood and produce urine.
There are approximately millions of nephrons in a kidney
Nephrons contain two parts
1) Malphigian Body(Renal Capsule)
2) Renal Tube
85
describe the parts in the malpighian body
1) Glomerulus
-a tuff of capilliaries formed by an afferent arteriole
-blood from glomerulus is carried away by and an efferret arterioles
2) Bowman's capsule
-a double walled up like structure which encloses the glomerulus
86
describe the renal tube
renal tube
-containd PCT(proximal convoluted tubule), henle's loop and distal convoluted tubule(PCT)
-henle's loop is hairpin shaped, havi mg descending and ascending limbs
-DCTs of many nephrons open into a collecting duct
-loop of henle dips into medulla
-peritubular cappilaries found all around PCT and DCT
-vasa recta is found around rhe Henle's loop
87
Describe the process of Urine formation in simple terms
1) Ultra Filteration of water, electrolysis, amino acids, glucose, urea and small molecules
2) reabsorption
88
Describe Ultrafilteration in detail
Ultra Filteration
-is the filteration of small molecules such as electrolytes amino acids glucose etc
-small molecules diffuse out of the blood creating filterate
-through the glomerulus into the bowman's capsule
-pressure is built in the capillaries which has tiny pores where smaller molecules filter out. the filterate is called glomerular filtrate
89
Describe reabsorption in detail
-from the renal tube to the capillaries
-takes place from PCT, Henle's loop, DCT to collecting duct
1) PCT absorbd H2O, ions, orgsnic nutrients which is used to msintain isotonic/osmotic concentration
2) Henle's loop made of descending and ascending loop, descending loop water is reabsorbed(hypertonic) and in ascending sodium ions and Cl ions are reabsorbed(hypotonic)
3) DCT reabsorptiond occurs due to ADH, water and ions are then reabsorbed
-peritubular capilliaried surround the DCT
4) collecting duct reabsobs H2O and ions due to ADH
90
role of ADH HORMONE anti durietic hormone
controls the ability to reabsorb in DCT and collecting duct
91
name factors that affect kidney function
1) ADH, prevents excess water loss from kidneys
2) Alcohol inhibits the secretion of ADH to more urine volume
3) aldosterone prevente excess loss of sodium and water from kidnet
4) Caffine incresses the rate of salt and warer loss from kidneys
5) increased blood pressure increases retrnof water loss from kidneys
6) higher temperature causes less ADH produced so less urine volume
92
Describe the negative feedback mechanism for urine formation
Osmoreceptors detect water content in the blood
osmoreceptors stimate posterior pituitary to release ADH. so permability of distilled tissue and collecting duct increases, so less water is given out
(then explain structure oc nephron, formation of urine and negative feedback mechanism for thr full 6 marks in these sorts of qs)
93
What happens if kidney dails
Wastr build up in blood stream, unable to regulate water and ion levels
94
several ways to cure kidney failrure
1. medication
2. kidney transplant
3. dialysis
mild kidney disease can be treated with medication
95
explain dialysis
dialysis is a treatment to remove waste and substances in excess from the blood,
used for patients with damaged/failed kidneys without access to transplant
(ref page157 for dialysis diagram)
96
how does dialysis work?
through the process of diffusion excess substances leave as urea,
dialysate fluid contains glucose amino acids and water
blood is always removed in an artery and brought into a vein, vein carries deoxy blood and artery is where vlood is flowing in high pressure
97
advantages and disadvantages to dialysis
pros
1) no shortsge of supply
2) eliminates need for immunosupport drugs
cons
1) restriction of diet
2) regular hospitsl vidists
3) expensive
4) general unwell feeling
5) could cause blood clots
98
what is haemodislysis
prritonal dialysis is a form of dialysis in which the patient csn avoid regular visits from the hospital
- a device is fitted to the patients body which would have sensors thet would detect the changes in concentration of blood and purify the blood
99
What is kidney transplant
a surgical procedure in which the kidney is rremoved and replaced with a heslthier kidney
patient nust be kept in isolation and given immunosuppressant drugs
100
pros and cons of kidney transplant
pros
1) avoid frequent visits to hospitsl
2) more effective
disadvantsges
1) organ can be rejected
2) too much immunnedupptreddsnt drugs the immune system can be oke weakened
