B7

what is the endocrine system

system made of endocrine glands that release chemical substances known as hormones into the blood stream

difference between nuerones and hormones

nuerone’s have faster action. Hormones are longer lasting. Hormones act more generally .

list all endocrine glands

pituitary gland, thyroid glands, adrenal gland , pancreas, ovaries, testes

adrenal gland hormones and function

produces adrenaline which stimulates the flight or fight response when in a dangerous situation

pituitary gland function

known as master gland. releases hormones to regulate body conditions and acts on other glands

thyroid gland hormone and function

thyroxine which regulates metabolism

pancreas hormone and function

insulin to regulate blood glucose levels

testes hormones and function

testosterone which controls puberty and sperm production

ovaries hormones and function

produces oestrogen and progesterone which are involved in menstrual cycle

negative feedback

homeostatic mechanism to maintains body conditions and return the body to normal after a change

negative feedback cycle when thyroxine levels are low

hypothalamus detects change and releases more TRH. This stimulates release of more TSH from the pituitary which stimulates more thyroxine to be produced by the thyroid

negative feedback cycle for when thyroxine levels are high

hypothalamus detects change and releases less TRH which inhibits TSH production from pituitary gland which inhibits thyroxine production from thyroid.

adrenaline

released from adrenal gland , prepares body for fight or flight in scary or stressful situations.

how does adrenaline affect the body

• pupils dilate to let more light enter retina

• glycogen reserves break down increasing blood glucose concentration for increased respiration in muscle cells

• increased heart rate and breathing rate so glucose and oxygen can be delivered to cells and co2 can be taken away more quickly

• blood flow diverts from non-essential parts such as the digestive system

comparison of thyroxine and adrenaline against time

thyroxine increases and decreases as an example of negative feedback whilst adrenaline increases to a peak and then decreases

homeostasis

controlling a constant internal environment

examples of homeostasis

osmoregulation , thermoregulation , blood glucose regulation

importance of homeostasis

ensure the reactions in body cells can function at optimum

label the skin cell

1. sweat pores

2. erector muscles

3. capillaries

4. sweat gland

5. arteriole

6. muscles

7. hair

8. temperature receptors / nerve endings

9. epidermis

10. dermis

11. sensory nuerone

12. fat

body response to an increase in temperature

sweating, vasodilation, erector muscles relax / pilorelaxation

body response to a decrease in temperature

vasoconstriction , shivering, erector muscles contract / piloerection

how does the thermoregulatory centre detect temperature change

it has receptors that are sensitive to the blood temperature in the brain. It also receives impulses from receptors in the skin that provide information about external temperature

where is the thermoregulatory centre

hypothalamus

how does sweating decrease body temperature

when sweat evaporates off the skin , heat energy its lost to the environment

how does shivering increase body temperature

it requires more energy from respiration which releases heat energy. the rapid contraction of muscles can also heat the body due to the friction

how does pilorelaxation / piloerection affect body temperature

when the erector muscles contract, the hairs stand trapping an Insulating layer of air which warms you. When the erector muscles relax, no insulating air is trapped

how does vasodilation / vasoconstriction affect body temperature

when the blood vessels dilate , they are closer to skin surface so heat is lost by radiation. When they constrict , less energy is lost by radiation

what does the body do to regulate blood glucose levels when its too high

the pancreas releases insulin which stimulates the liver and muscle cells to store excess glucose from the blood stream and store it as glycogen

what does the body do to regulate glucose levels when they are too low

the pancreas releases glucagon which stimulates the liver to break down glycogen into glucose and release it into the blood

what is type 1 diabetes and how is it treated

the pancreas produces little or no insulin . It is treated with insulin therapy

what is type 2 diabetes and how is it treated

cells no longer respond to insulin. It is treated with a low sugar diet and exercise

what is a risk factor for type 2 diabetes

obesity

why is osmoregulation important

as the cytoplasm of all cells and the blood plasma is largely composed of water , osmoregulation is important to prevent harmful changes to cells as a result of osmosis like cell shrinking or bursting.

label 1-4 and explain

1. kidney = organs that filter the blood

2. ureter - tube connecting kidney to bladder

3. bladder- organ that stores urine

4. urethra - tube that connects bladder to the exterior - where urine is released

urinary system steps

liver produces urea which enters kidney via renal artery. it is filtered and the clean blood leaves via renal vein. the remaining waste products are sent to bladder via ureter and excreted via urethra

label kidney structure 1-7

1. adrenal gland

2. cortex -outermost region

3. medulla - intersection of the kidney

4. nephrons

5. renal artery

6. renal vein

7. ureter

label the nephron structure

1. Proximal convoluted tubule

2. distal convoluted tubule

3. glomerulus

4. bowman’s capsule

5. collecting duct

6. loop of henle

3 processes in the nephron

ultrafiltration , selective reabsorption, excretion

ultrafiltration steps

high pressure blood is forced from the capillaries of the glomerulus into the bowman’s capsule past a partially permeable membrane . large molecules like proteins and red blood cells are forced out

where does selective reabsorption happen

in the PCT , DCT, Loop of Henle and part of the collecting duct

reabsorption of glucose in selective reabsorption in the kidney

only occurs at the PCT , takes place by active transport. The nephron has many mitochondria to provide enough energy for the active transport

reabsorption of water and salts in selective reabsorption

in the loop of henle , DCT and collecting duct. Water is reabsorbed into the blood by osmosis and any salts by diffusion

excretion steps

whatever isn’t reabsorbed continues out the nephron via the collecting duct and then passes through the ureter into the bladder

what does ADH do

makes the kidney tubules in collecting duct more permeable

what is the response in the body when there is water loss

brain detects less water content in the blood and instructs the pituitary gland to release ADH into the blood . ADH makes the collecting ducts more permeable so more water is reabsorbed .

what is the body’s response if there’s water gain

the brain detects more water content in the blood and instructs the pituitary gland to release less ADH. The collecting ducts are now less permeable so less water is reabsorbed

how does water content affect pee colour

more water = more dilute pee = clear colour.
less water = more concentrated pee = yellow colour due to more urea

how does the dialysis machine work

patients blood is pumped into machine. It flows in a tube with a partially permeable membrane. The waste products like urea and excess ions diffuse into the dialysis fluid from blood and glucose and water could diffuse back into blood. The blood is now filtered from harmful waste

what is specific about the dialysis fluid

it has to have the same concentration of salts and glucose as the blood plasma

what is added to blood in dialysis machine to stop clotting

anti-coagulant

what is a benefit of dialysis treatment

can filter your blood and keeps you alive until a transplant. It is also readily available

what is a negative of dialysis treatment

time consuming and expensive. Restrictive diet

positive of kidney transplant

long term solution for kidney failure. Less restrictive diet

negative of kidney transplant

risk of rejection . Have to take immunosuppressant drugs for life

where does deamination occur and what is it?

In the Liver. It is when excess amino acids are broken down. carbon is broken down into glycogen and nitrogen into ammonia. ammonia breaks down to urea

what happens to the urea produced by the liver

it dissolves in the blood and is taken to the kidney to be excreted.

FSH function

causes a follicle ( an egg ) to mature

oestrogen

causes the lining of the uterus to thicken and grow

Luteninsing hormone function

stimulates the release of an egg

progesterone purpose

maintains the lining of the uterus

where is FSH and LH released

pituitary gland

where is progesterone released

corpus luteum

FSH and Oestrogen relationship

FSH stimulates oestrogen production. Oestrogen inhibits FSH production

LH and progesterone relationship

LH stimulates progesterone production. Progesterone inhibits LH production

describe stages of menstrual cycle

• menstruation

• lining starts to thicken

• ovulation

• lining is maintained ( luteal phase )

menstruation

loss of lining from the uterus, occurs at the start of the cycle if no fertilisation has occurred

ovulation

egg matures and is released from ovary to the uterus down the oviduct

name 2 chemical contraceptives

IUD , contraceptive pill / implant / injection

how do contraceptive pills , implants or injections work

they release progesterone or a mixture of progesterone and oestrogen to prevent egg maturation and egg release

how does the IUD work

releases hormones that thicken lining making it difficult for sperm to travel to egg. The copper also acts as a spermicide

barrier methods of contraception

condom , diaphragm - rubber cap over cervix entrance

surgical contraception

• cutting sperm ducts

• tying off oviducts

clomifene therapy

women who don’t ovulate or don’t ovulate regularly are given clomifene. this releases more FSH and LH

In-Vitro fertilisation- IVF

• women given FSH and LH to stimulate maturation of several eggs

• eggs are collected from the mother ovaries and fertilised by sperm from father in lab

• fertilised eggs develop into embryos and are inserted in the uterus

why is thermoregulation important

most of cellular processes use enzymes. too high of a temp means they denature, too low of a temp means they are not working as efficiently .

how do blood vessels dilate/constrict

muscles in walls of arterioles relax/ constrict

what happens to blood glucose regulation in a person w type 1 diabetes

no insulin released after blood glucose rises to dangerous levels. need insulin therapy

how does controlling your diet help with type 2 diabetes

by having a diet with less sugar means that blood glucose doesn’t rise too quickly so that insulin can cope

why is dialysis fluid constantly pumped inside

maintain the concentration gradient

what happens to blood glucose regulation in a person w type 2 diabetes

pancreas produces insulin. liver receptors do not respond and do not convert glucose to glycogen

what happens to blood glucose during exercise

decreases as it is used in respiration

what happens to ADH levels when someone is sleeping

increase, body becomes dehydrated during sleep

what happens to adh levels when exercising

increase as water is lost by sweating

how does caffeine and alcohol effect adh and pituitary gland

they act on pituitary gland and inhibit adh . kidneys reabsorb less water and there is more urine

when should a woman avoid sexual intercourse if she doesn’t want to be pregnant

when ovulation happens. 13-15 days as that Is when they are the most fertile

does ovulation always happen on the 14th day

no , factors like stress and illness contribute to varying times

hyperthyroidism

overactive thyroid gland

hypothyroidism

underactive thyroid gland

why would an underactive thyroid cause someone to feel tired and have increased body mass and feel cold

not enough thyroxine is produces so a reduced basal metabolic rate so less heat generated and less calories used from food.

when is IVF used over clomifene therapy

unhealthy sperm , blocked oviducts

why would hyperthyroidism cause people to lose weight, have increased energy and feel warmer

more thyroxine and higher metabolic rate. more heat generated from respiration and more calories used from food meaning less fat stored.

symptoms of hyperthyroidism

weight loss, increased BMR and protein synthesis, feel warmer, increased energy

symptoms of hypothyroidism

weight gain, decreased BMR and protein synthesis, feel colder, more tired, nerve and heart problems

how can progesterone reduce fertility

stimulate production of thick mucus preventing sperm from reaching egg.

how can adrenaline restore heart function

cause blood vessels to other organs to constrict increasing blood pressure and restores blood flow to coronary arteries

what does high levels of oestrogen stimulate

release of LH

FSH levels in the stages of menstrual cycle

1. high at start then decreasing

2. increasing

3. peaks before ovulation

4. low

LH levels in menstrual cycle

1. low

2. low but slightly increasing

3. peaks sharply

4. low

oestrogen levels in menstrual cycle

1. low

2. increasing and peaks before ovulation

3. very high

4. high then decreasing if no pregnancy

progesterone levels in menstrual cycle

1. low

2. low

3. low

4. high, peaks then decreases if no pregnancy