Nerves Hormones And Drugs Flashcards
Name your neurones and their purposes?
Sensory neurone- the nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the central nervous system.
Relay neurone- the nerve cells that carry signals from the sensory neurone to the motor neurone.
What are your five different sense organs and their receptors?
Eyes-light receptors Ears- sound receptors Nose-smell receptors Tongue-taste receptor Skin-sensitive to touch,pressure, pain and temperature change
How do synapses connect neurones?
The connection between two neurones is called a synapse. Nerve signals are transferred by chemicals which diffuse across the gap. These chemicals then set off new electrical signals in the next neurone.
Explain how the reflex arc goes through the nervous system?
The neurones in a reflex arc go through the spinal cord or am unconscious part of the brain. When the stimulus is detected by the receptor, electrical
Impulses are sent along the sensory neurone to the central nervous system. When these impulses reach a synapse between the sensory neurone and the relay neurone, it triggers chemicals to be released which cause new impulses to be sent along the relay neurone.
These impulses then reach a synapse between the relay neurone and the motor neurone and the same thing happens. The chemicals cause impulses to be sent along the motor neurone. These impulses are sent from the motor neurone to the effector which in this case is a muscle. This would cause the muscle to contract this pulling your body part away from the danger. You don’t have to think about the response in a reflex arc which makes it quicker.
Explain how the central nervous system works?
The Cns is where all the information from the sense organs is sent , and where all the reflexes and actions are coordinated. Neurones(nerve cells) transmit the information( electrical impulses) very quickly to and from the Cns. Instructions from the Cns are sent to the effectors who respond accordingly.
What is a hormone?
Hormones are chemical messengers which travel in the blood to activate target cells.
How are hormones carried and what do they do?
Hormones are chemicals released directly into the blood. They are carried in blood plasmas to other parts of the body but only affect particulate cells that are target cells in particular places. Hormones control things in organs and cells that need constant adjustment.
How are hormones produced?
Hormones are produced and secreted in various glands and travel at the speed of blood.
What is the pituitary gland?
This produces many important hormones such as FSH and LH which are involved in the menstrual cycle.
What are ovaries?
Ovaries produce oestrogen which is involved in the menstrual cycle.
Explain the stages and days of the menstrual cycle?
Stage 1: day 1- the bleeding starts and the breaking down of the lining of the uterus happens for about four days
Stage 2: day 4-14- the uterus lining builds up again into a thick sponges layer full of blood vessels ready to receive a fertilised egg.
Stage3 :day 14- the egg is released from the ovary
Stage 4: day 28- the wall is maintained. If by day 28 a fertilised egg has not landed on the wall of the uterus the thick sponges layer starts to break down and the cycle starts again.
What is the menstrual cycle?
The monthly release of an egg from a women’s ovaries and the build up and breakdown of the protective lining of the uterus( womb)
Explain FSH?
FSH is the follicle stimulating hormone that is produced by the pituitary gland. It causes the egg to mature in one of the ovaries. It stimulates the ovaries in producing oestrogen.
OESTROGEN is produced in the ovaries. It causes the produce of LH in the pituitary gland. It inhibits the further release of FSH.
LH is the luteneising hormone. It’s stimulate the release of the egg in the middle of the menstrual cycle.
