Slides in this set
Control and Co-ordination
Control of the body's functions and responses involves hormones and the
Hormones are chemical messengers, secreted by glands, that
are transported in the blood to activate target organs/cells.
Different glands secrete different hormones:
Pituitary gland LH, FSH
Adrenal gland Adrenaline…read more
Reflex actions are rapid and automatic responses to certain stimuli, they do not
involve the brain.
This reduces the chances of injury, there is no thinking time so the
response is very fast.
The route taken by information in a reflex is reflex arc.
This bypasses the conscious areas of the brain (usually through spinal
STIMULUS RECEPTOR SENSORY NEURONE
RELAY NEURONE MOTOR NEURONE EFFECTOR…read more
The Menstrual Cycle-
The menstrual cycle is usually around 28 days long, with ovulation at day 14.
Stage 1: Bleeding starts. Uterus lining breaks down for about 4 days (at the same
time, a new egg begins to mature in the ovary).
Stage 2: Lining of uterus builds up again (from day 4-14) into thick layer ready to
receive a fertilised egg.
Stage 3: Mature egg is released from ovary: ovulation.
Stage 4: Lining is maintained for about 14 days, until day 28. If no fertilisation by day
28 the lining starts to break down.…read more
The menstrual cycle is controlled by hormones.
FSH- produce in the pituitary gland
- causes egg to mature in one of the ovaries
- stimulates ovaries to produce oestrogen
LH- stimulates ovulation
- produced in pituitary gland
Oestrogen- causes lining of uterus to thicken and grow
- stimulates production of LH & inhibits production of FSH
- produced in ovaries
The contraceptive pill-
Contains oestrogen which (when taken every day to keep levels high) inhibits the
production of FSH so no eggs can mature, and thus prevents pregnancy.
FSH can be taken by women who do not produce enough, (so cannot get pregnant as
eggs cannot mature) to stimulate ovaries to produce oestrogen, which stimulates
production of LH, so ovulation can occur.…read more
Homeostasis is keeping a constant internal environment.
Humans need to maintain a constant internal environment by balancing inputs with outputs.
· Water content need to keep a balance with the water you drink & produce in
respiration with water lost in urine, sweat and breathing.
· Body temperature get rid of excess body heat when hot, but retain heat when
environment is cold.
· Ion content
· Blood sugar levels…read more
A Balanced Diet-
A healthy diet contains the right balance of different foods you need in the correct
· Carbohydrates for energy
· Proteins for growth and repair of cells
· Fats as a store of energy and for insulation
· Vitamins and minerals in small amounts for good health
A person is malnourished if their diet is not balanced. If a person does not have the right
amounts of different foods, such as vitamins and minerals, they may suffer a deficiency
Energy and nutrient needs vary in different people.
Age children and teenagers need more protein for growth.
old people need more calcium to protect against degenerative bone diseases such
ajdjdj as osteoporosis.
Gender females need more iron to replace that lost in menstrual blood
Physical activity active people need more protein for muscle developments and more
carbohydrates for energy.…read more