Animal coordination, control and homeostasis 🐾 Flashcards
Where are hormones produced
In the endocrine gland
Describe the endocrine glands communicate with organs around the body
The endocrine glands release chemicals called hormones into the blood which carries them around the body to the target organs
What hormone does the adrenal gland release
Adrenaline
What hormone does the thyroid gland produce
Thyroxine
Which hormones does the pituitary gland produce
ACTH
FSH
LH
growth hormone
What do we mean by metabolism
All the chemical reactions that occur in the body
State the three conditions are required to measure resting metabolic rate
Warm room
gap in time since eating
no movement
How does thyroxine (produced in the thyroid gland) affect the metabolic rate as an example of negative feedback
Causes heart cells to contract more strongly and rapidly
Increases the rate at which proteins and carbohydrates are broken down inside cells
Recall the steps in how thyroxine controls the metabolic rate
low levels of thyroxine stimulates production of TRH in hypothalamus
this causes release of TSH from the pituitary gland
TSH acts on the thyroid to produce thyroxine
when thyroxine levels are normal thyroxine inhibits the release of TRH and the production of TSH
Define the term negative feedback
A control mechanism that reacts to a change in conditions, such as temperature, by trying to bring the condition back to a normal level
Explain how adrenaline (produced in the adrenal glands) prepares the body for ‘fight or flight’
increases heart rate
increases blood pressure
increases blood flow to the muscles
raises blood sugar levels (muscles have energy to contract)
How does the body cause an increased heart rate and blood pressure (ADRENALINE)
Heart muscle cells contract
more rapidly (heart rate)
and more strongly (blood pressure)
How does the body create an increased blood flow to muscles (ADRENALINE)
Diameter of blood vessels LEADING TO MUSCLES widens
and Diameter of blood vessels LEADING TO OTHER ORGANS narrows eg. Digestive system
How does the body increase blood sugar concentration (ADRENALINE)
Stimulates liver cells to change glycogen to glucose and release it into the blood
Explain how an increase in adrenaline prepares the body for a sudden burst of activity
Insures the muscles have a good supply of oxygen and glucose for aerobic respiration which enables contraction of muscles for fight/flight response
What is ovulation
When an egg is released from an ovary
What is fertilisation
When a sperm cell fuses with an egg
What is menstruation
When the unfertilised egg and part of the uterus lining a shed from the body
What time period in menstruation is fertilisation most likely to occur
days 14-25
What is the function of the menstrual cycle
To allow a woman to be fertile
When does ovulation occur
Day 14
What are the 4 key hormones involved in regulating the menstrual cycle
Oestrogen
Progesterone
LH
FSH
Which gland releases FSH and LH
Pituitary gland
What’s are oestrogen and progesterone released by
Ovaries
What is the function of the FSH hormone
Causes the maturation of an egg follicle before ovulation
What is the function of the LH hormone
Stimulates the release of the egg
What is the function of the oestrogen hormone
Repairing/thickening the uterus lining 
What is the function of the progesterone hormone
Maintains the uterus lining
Recall the steps of a sperms journey
Sperm duct ——> penis ——> vagina ——> cervix ——->uterus ——-> oviduct
What is the difference between conception and contraception
Conception = getting pregnant
Contraception = prevention of fertilisation
Define IVF (in vitro fertilisation)
Fertilisation in the laboratory outside the mothers body
What happens in IVF (common 6 mark question)
Before IVF the woman is given hormones to encourage her ovaries to release eggs.
The eggs are harvested and a sperm sample is provided.
The sperm is used to fertilise the eggs in a Petri dish.
The fertilised eggs are left to develop into embryos.
When they are at the 8 cell stage, viable embryos are implanted into the woman’s uterus (mother / surrogate)
This can result in multiple pregnancies
Spare embryos can be frozen for future events, donated to other couples or sometimes they are destroyed (this is decided by the biological parents)

What organs are involved in regulating blood glucose
Brain
Pancreas
Liver
Explain the steps made to regulate blood glucose if it is HIGH
Brain detects high level of blood glucose
Pancreas is stimulated to produce insulin
Insulin allows glucose to enter the cells of the body (out of the blood)
Also stimulates the liver to turn glucose into glycogen where it can be stored
Blood glucose level decreases so pancreas stops producing more insulin
Explain the steps made to regulate blood sugar when it is LOW
Brain detects low level of blood glucose
Pancreas is stimulated to produce glucagon
Glucagon stimulates the liver to convert glycogen back to glucose and release this back into the bloodstream
Blood glucose level returns to normal causing pancreas to stop producing glucagon
What is diabetes associated with
Not being able to control blood glucose levels
Describe type 1 diabetes
Pancreas cells cannot produce insulin because they have been destroyed by the immune system.
Therefore blood glucose level increases & can be found in the urine
They must inject themselves with insulin before eating to convert glucose to glycogen
Describe type 2 diabetes
Caused by either :
insulin releasing cells not producing enough insulin OR target organs not responding properly to the hormone
For some change in diet/more exercise may help but others will require medicine
BMI =
Mass divided by height^2
What is the test for diabetes involving urine samples
Benedicks solution added to urine solution
heat in hot water bath for five minutes
Colour change from blue to brick red = diabetic
Colour change from blue to yellow/ green = mildly diabetic
No colour change = non diabetic

What is homeostasis
Controlling conditions in the body
What is the responses does the body have when temperatures are TOO COLD
SHIVERING
HAIRS STAND UP
VASOCONSTRICTION
SUBCUTANEOUS FAT
What responses does the body have when temperatures are TOO HOT 
SWEATING
VASODILATION 
Why does SHIVERING help the body to keep warm
Releases heat from respiration
Why does SUBCUTANEOUS FAT keep us warm
Insulates
Why does HAIRS STANDING ON END keep us warm
Traps an insulatory layer of air around the body
How does VASOCONSTRICTION keep us warm
Blood vessels get thinner reducing blood flow near to the skin surface
How does SWEATING keep us cool
Evaporation of the sweat on the skin surface takes heat away from the blood causing it to cool
How does VASODILATION keep us cool
Blood vessels get wider increasing blood flow near to the skin surface
What is the function of the urinary system
To remove excess amounts of substances from the blood including water, mineral salts and waste products such as urea
What is Osmoregulation
The control of water and salt levels in the body
What is urea
If you eat too much protein it is broken down into amino acids
These amino acids are broken down by the liver and make urea.
Urea is poisonous so must be removed
What are the 2 processes that occur in the nephron
Filtration
Selective reabsorption
Does the renal artery carry blood to the heart or away from the heart
AWAY from the heart
Renal vein carries it BACK
What is the process of filtration in the nephron
Blood flows through the glomerulus and Bowman’s capsule (network of capillaries)
Allows small molecules such as water, urea and glucose through
large molecules such as proteins stay in the blood
Where does most of the water reabsorption occur
The Loop of Henle and the collecting duct
What useful substances are selectively reabsorbed (kidneys)
Glucose and some mineral ions
What happens at the end of the nephron (kidneys)
Remaining fluid (excess water, urea and other substances) flow into the ureter where it is stored in the bladder up until you urinate through the urethra
What are the adaptations of the nephron
Large surface area of contact between the nephron and the capillaries
Cell membrane of first convoluted tubule has MICROVILLI (increase sa:volume ratio)
Cells that have PROTEIN PUMPS in their cell membranes contain many MITOCHONDRIA
What is the role of ADH
Increases the permeability of the cell membranes in the collecting duct of the nephron so more water is reabsorbed from urine by osmosis
What happens when the brain detects a low level of water in the blood
Stimulates pituitary gland to produce more ADH
ADH increases the permeability of the collecting duct
More water is reabsorbed from the tubule to the blood
Small volume of concentrated urine is produced
How can alcohol and caffeine affect the production of urine
They are both DIURETICS meaning they make you URINATE MORE
Name 2 treatments for kidney failure
Kidney dialysis and organ donation
Describe the pathway of blood through the kidney
Enters through renal artery —— glomerulus —— capillaries surrounding 1st convulated tubule —— loop of henle —- out through renal vein
What do high levels of oestrogen stimulate ?
Release of LH
What does low levels of progesterone stimulate?
Release of FSH
What effect does increasing progesterone levels have on the body ?
Inhibits release of FSH and LH
What effect does clomifene have on the body
Increases FSH and LH levels in the blood (increases fertility)
What are the differences between hormonal and barrier contraceptive methods
Hormonal contraceptives are MORE EFFECTIVE however they do NOT PROTECT AGAINST STI’S whereas barrier methods do
What problems can IVF overcome
Blocked oviducts
If a man produces very few healthy sperm
