Hormones and Homeostasis Flashcards
What is a hormone?
proteins that are used in the Endocrine system and released into the blood stream by glands and target specific cells in the body
What name is given to an organ that produces hormones?
endocrine glands
Adrenaline
Source: Adrenal gland
Target: Heart and lungs
Effects/function: increases heart and breathing rate for fight, fright or flight
Progesterone
Source: Ovaries
Target: Uterus
Effects/function: Maintains uterus lining and controls the development of secondary female characteristics and inhibits FSH production
Oestrogen
Source: Ovaries
Target: Uterus
Effects/function: Stimulates uterus lining to develop and the development of secondary female characteristics
AHD (anti-diuretic hormone)
Source: Pituitary gland
Target: Kidney
Effects/function: Reduces the amount of water lost in urine
Insulin
Source: Pancreas
Target: Liver
Effects/function: Causes liver and muscles to take up glucose and convert it to glycogen for storage
Testosterone
Source: Testes
Target: Testes
Effects/function: Stimulates development of male secondary sexual characteristics
FSH
Source: Pituitary gland
Target: Ovaries
Effects/function: Stimulates an egg to mature in the ovary
LH
Source: Pituitary gland
Target: Ovaries
Effects/function: Stimulates the release of an egg from the ovary (ovulation)
What is homeostasis?
the maintenance of a constant internal environment
Which part of the brain monitors body temperature and controls response?
hypothalamus
What are the main ways the body controls the temperature?
- sweating
- shivering
- controlling heat loss by controlling the amount of blood which flows near the surface of the skin
How does hairs stand on end help warm up the body?
The hairs trap a layer of air which,
provides insulation for conduction of heat.
Less heat loss
How does less sweat released help warm up the body?
Less sweat is released therefore less heat lost via evaporation.
Less heat loss
How does vasoconstriction help warm up the body?
Arterioles supplying the capillaries near the surface of the skin constrict. Less blood will
flow through capillaries near the surface of the skin, therefore less heat will be lost by radiation.
Less heat loss
How does hair lies flat help cool down the body?
Hairs lie flat and therefore an insulating layer of air is not formed.
More heat loss
How does more sweat released help cool down the body?
the sweat evaporates, heat energy is
taken away from the skin as evaporation of water requires energy
More heat loss
How does vasodilation help cool down the body?
Arterioles supplying the capillaries near the surface of the skin dilate. More blood will flow through capillaries near the surface of the skin, therefore more heat will be lost by radiation.
More heat loss
Where does osmoregulation occur in the body?
collecting duct in the nephron (in the kidney)
What part of the brain detects the water concentration of the blood?
hypothalamus
What part of the brain releases ADH?
pituitary gland
What effect does ADH have on the collecting duct?
ADH diffuses out of the blood and binds with receptors on the surface of the collecting duct cells.
If ADH binds this triggers the wall of the collecting duct to become more permeable to water.
Therefore more water is reabsorbed into the
blood.
Less urine is produced; it is more concentrated and darker coloured.
If there is a high concentration of ADH in the blood, what will happen to urine production?
urine concentration is increased and darker in colour
