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ANIMAL COORDINATION, CONTROL & HOMEOSTASIS
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Adrenaline – produced by adrenal glands to prepare body for fight/flight
Heart: adrenaline binds to specific receptor cells in heart, causes it to contract: more frequently: increases heart rate
with more force: increases blood pressure
Liver: adrenaline binds to receptors in liver – causes conversion of glycogen→glucose: increases blood sugar levels – source of energy for rapid contractions
Blood vessels:
To muscles/brain: widen – increased blood flow – cells receive more oxygen/glucose – increased respiration – work faster
To other organs: narrow – increases blood pressure
Lungs: Airways widen – more oxygen intake – increases respiration rate
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Menstrual Cycle
Stage 1: Day 1-4
Uterus lining breaks down
Stage 2: Day 4-14
Uterus lining repairs – until thick spongy layer full of blood vessels, is ready for fertilised egg to implant there
Stage 3: Day 14
Ovulation: egg develops & released from ovary
Stage 4: Day 14-28
Lining maintained
No fertilised egg landed on uterus wall: spongy lining starts to break down – cycle restarts
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Hormonal contraception
Mixed pill / contraceptive patch: Oestrogen & Progesterone
Oestrogen levels constantly high: FSH inhibited – no eggs mature
Lining stops developing
mucus in cervix thickens so no sperm can reach egg
Progesterone only pill has less side effects
IUD / contraceptive implant / contraceptive injection: releases continuous amount of progesterone
Prevents ovaries releasing egg
Mucus in cervix thickens so sperm can’t reach egg
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ART – assisted reproductive technology
IVF
FSH + LH given to woman to stimulate egg production
Egg collected from female body and fertilised with man’s sperm in lab – grown into embryos
Embryos transferred to women’s uterus
Excess embryos deep frozen for later use – liquid nitrogen
Clomifene therapy
Drug: blocks negative feedback of oestrogen on pituitary, causing more FSH/LH to be released – stimulates egg maturation/ovulation as infertile women
don’t ovulate (regularly / at all)
By knowing when ovulation is, couple can have intercourse during time period to improve chance of pregnancy
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Homeostasis
Thermoregulation – body temperature
Internal body temperature must stay at 37˚C: for enzymes to work at optimum temperature – lower: slows down & higher: may denature
Thermoregulatory centre in hypothalamus in brain – negative feedback responses to keep body at right temperature
Brain (blood-temperature receptors) & impulses from receptors in skin (dermis/epidermis (nerve endings)) – provide information of external temperature
Osmoregulation – water content
Kidneys control how much water reabsorbed & how much lost in urine
Removal of urea from blood – produced in liver from breakdown of excess amino acids
Adjust ion/water levels of blood
Ultrafiltration & selective reabsorption
High glucose / low water concentration: Water will osmote out of cell – chemical reactions won’t happen properly, cell will shrink
Low glucose / high water concentration: Water will osmote into cell – it will burst (no cell wall)
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Thermoregulation
Hot
Vasodilation: blood vessels supplying capillaries near skin dilate: more blood flows to surface of skin – transfers more energy to surroundings – increases
heat loss
Sweat glands produce sweat – passes to skin’s surface through pores in epidermis: uses thermal energy for evaporation – cools down skin

Erector muscles: relax – hairs lay flat
Cold
Vasoconstriction: blood vessels supplying capillaries near skin constrict: less blood flows to surface of skin – transfers less energy to surroundings – less
heat loss
Shivering: contraction/relaxation of muscles: increases rate of respiration – transfers more energy to warm body
Erector muscles contract: hairs stand on end – traps insulating air layer on skin surface
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Glucagon – Gone
Blood glucose concentration fall: exercise – respiration to release
energy, used up faster
Low blood glucose concentration
Pancreas releases glucagon – promotes:
conversion of glycogen→glucose: released from
liver/muscles stores

Controlling blood sugar: Sugar comes from glucose in food & liver
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Type 2 diabetes – insulin resistant
Target organs don’t respond / lose sensitivity to insulin
Pancreas doesn’t produce enough insulin – blood sugar level rises

How controlled
Inject insulin before meals: removes glucose from blood quickly
once food digested
Injected into subcutaneous (fatty) tissue: diffuses into blood slower
Diet:
Low-glucose diet: not as much insulin needed
High-glucose diet: more insulin needed – eat less simple
carbohydrates: complex take longer to absorb
Regular exercise: muscles take in glucose in respiration – not as
much insulin needed

How controlled
Medicines:
Reduce amount of glucose liver/muscles release into blood
Increase cell sensitivity in target organs that respond to insulin
Diet & Regular exercise

How monitored
Blood glucose test by finger prick

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