SB7 Flashcards
What are hormones
Chemical messengers
What are the endocrine glands
Organs that that release hormones into the blood
Pituitary gland, thyroid gland, pancreas, adrenal glands, testes, ovaries
What does the pituitary gland do
It releases ACTH, FSH, LH and the growth hormone
What does the pancreas do
Contains cells that create insulin and others that produce glucagon
What do the ovaries do
Produce oestrogen and progesterone
What do the testes do
Release testosterone
What do the adrenal glands do
Releases adrenalin
What does the thyroid gland do
Produces thyroxine
What is a target organ
An organ that is affected by a certain hormone
What is metabolic rate
The amount of energy stored by an organism in a given time period that is then transferred
What is resting metabolic rate
The metabolic rate when the body is at rest
What does thyroxine do
It causes heart cells to contract more rapidly and strongly
It also increases the breaking down rate of carbohydrates and proteins
What is negative feedback
A control mechanism that reacts to a change in condition by trying to change the condition back
What does adrenalin do
During frightening or exciting, adrenalin causes liver cells to turn glycogen into glucose, causes blood vessels leading to muscles to widen and blood vessels leading to other organs
What happens in the first 1-5 days in the menstrual cycle
- Start of menstruation
- Uterus lining breaks down and egg is lost
What happens in the 6-12 days in the menstrual cycle
The uterus lining begins to thicken again after menstruation
What happens in the 13-15 days in the menstrual cycle
An ovary releases an egg around day 14
What happens in the 16-22 days in the menstrual cycle
Uterus lining continues to thicken
fertilisation can lead to pregnancy
What happens in the 23-28 days in the menstrual cycle
Egg cell travels along the oviduct to uterus
The cycle starts again
What are some symptoms of periods and why are they caused
Mood swings, abdominal pain, breast tenderness, tiredness
They are caused by the changes in hormone concentration
What is ovulation
The release of an egg from an ovary
What does a hormone pill/implant do
Releases hormones to prevent ovulation by thickening mucus at the cervix, making it difficult for sperm
What does FSH do
It causes an egg to mature in the ovary
What does LH do
It causes the egg to be released from the ovary
What happens after the egg is released
The ovary releases progesterone and this stops the pituitary gland from releasing FSH and LH (to prevent any more eggs being released or matured)
Progesterone also keeps uterus lining thick
Where is LH and FSH released from
The pituitary gland
What is ART
It stands for assisted reproductive technology and uses hormones and other techniques to increase the chance of pregnancy
What is clomifene therapy
Clomifene is a drug that helps increase the concentration of FSH and LH in the blood
What is IVF
It stands for in vitro fertilisation
1) An egg is matured by hormones
2) An cell released by follicles is taken from ovary
3) Sperm is taken from men
4) Egg and sperm cell fuse
5) One or two healthy embryo are placed in uterus to grow
What happens as blood glucose concentration rises
It stimulates cells in the pancreas to release insulin, the insulin causes cells in the liver and other organs to turn glucose into glycogen and the blood glucose concentration falls
What happens if the blood glucose concentration falls too low
The pancreas detects this and releases glucagon to the liver and other organs, the liver turns glycogen into glucose and releases it into the blood
What causes type 1 diabetes
Pancreatic cells that have been destroyed by the body’s immune system and now cannot produce insulin
What is type 2 diabetes caused by
Insulin releasing cells not producing enough insulin or target organs not responding properly
How can you get rid of type 2 diabetes
Being physically active
Having a healthy diet
Be given medicine
What is a fever
Having a body temperature of over 38°C
What is hypothermia
Having a body temperature of less than 36°C
Why are fevers and hypothermia dangerous
They affect how enzymes work
What is thermoregulation
The control of body temperature, keeps the temperature of most organs close to 37°C
What is the hypothalamus
A small part of the brain that monitors body temperature
What can a cold temperature do to the body
It can cause shivering (when muscles start to contract and relax rapidly)
Erector muscles in the skin dermis contract and cause the body hairs to stand upright
Reduced blood flow new the skin to reduce rate of energy transfer to air
What can a hot temperature do to the body
Sweat
Increased blood flow around the skin surface
Hair lies flat as erector muscle is relaxed
How does shivering heat you up
Energy from cell respiration for shivering warms you up
What is vasoconstriction
The narrowing of blood vessels near the surface of the skin
What is vasodilation
The widening of blood vessels that increases blood flow to the skin surface
What are nephrons
Microscopic tubes in the kidneys that make urine
What does the Bowman’s capsule do
Adapted to let very small molecules through, water, urea and glucose (not protein)
Larger molecules stay in the flood
This is called filtration
What is osmoregulation
The control of water balance in the body
How can water be lost
When we breathe out we lost water
When we sweat
When we urinate
What happens if cells take in too much water
The shape of the cell can change
What do the renal veins do
They carry blood with wastes removed back to the body
What do the renal arteries do
They carry blood with waste from the body to the kidneys
What do the kidneys do
They remove wasteful substances from the blood and make urine
What does the bladder do
It stores urine
What does the muscle above the urethra and the urethra do
The muscle keeps the exit from the bladder closed until a person decides to urinate and the urethra allows urine to flow through
What is kidney failure
When both kidneys stop working completely
How can you get rid of kidney failure
Kidney dialysis
Kidney transplant
What is dialysis
Dialysis is the process a person goes through to keep the concentration of substances in the blood at safe levels
What happens in dialysis
- Blood carrying wastes passes through a machine
- Blood passes through a semi-permeable membrane (allows urea, ions and water to pass through but not blood and proteins)
- On the other side is the dialysis fluid which contains a normal amount of water and ions
Why does dialysis fluid not contain any urea but does contain some glucose molecules
So that urea can fully diffuse out of the blood as it’s a waste produce but glucose molecules are needed in the blood so not all of them diffuse into the dialysis fluid
What are advantages and disadvantages of kidney transplant
It maybe too much for weak patients Kidneys can be rejected It can take a long time to find a suitable kidney Expensive Patient can lead a normal life
What are advantages and disadvantages of dialysis
Expensive in the long run
Requires a controlled diet
Requires frequent treatment
What happens to the filtration fluid in the first convoluted tubule of the nephron
Selective reabsorption happens back into the bloodstream, glucose and mineral ions are pumped back into the blood by active transport
What happens in the collecting duct and the loop of Henle
Water us reabsorbed into the bloodstream by osmosis
What happens at the end of the nephron
Remaining fluid flows into the ureter, excess water, urea and other substances are now called urine
How is the nephron adapted for reabsorption
Large surface area between nephron and capillaries
Cell membrane have microvilli that increase surface area
Protein pumps in cell membranes that contain many mitochondria
What does ADH do
Changes the permeability of the collecting duct in the nephron
Why is ADH released
When the pituitary gland detects too little water in the blood
What happens when ADH is present
Collecting duct is highly permeable to water and water us absorbed by osmosis
Why is ADH released
When there is a low water concentration in the blood
What does the liver break down
Excess amino acids in the blood and produces ammonia (deamination)
What does the kidney do to ammonia
As it is very toxic, it converts ammonia into urea
