Homeostasis P2 Flashcards
Reflex action order
Stimulus, receptor, sensory neurone, relay neurones, motor neurone, effector and response
What is a reflex arc ?
The nerve pathway followed by a reflex response action
What is a synapse
Tiny gaps at the junction between two nerve cells which nerve signals must cross
How does the electrical impulse travel through a synapse
Electric impulse travels along the first axon. This triggers the nerve ending of a neurone to release chemical messengers called neurotransmitters. These chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the second neurone. The receptor molecules on the second neurone bind only to the specificneurotransmitters released from the first neurone which stimulates the second neurone to transmit the electrical impulse
Hormone
A chemical substance produced by a gland and carried in the bloodstream, which alters the activity of a specific target organs e.g. the release of the hormone adrenaline
What happens after a hormone has been used
It is destroyed by the liver
What type of signal is the nervous system ? What time of signal is the hormonal system?
Electrical (chemical at synapses). Chemical
What is the transmission of response for the nervous system? The hormonal system?
By nerve cells. By the bloodstream
What are the effectors in the nervous system ? The hormonal system?
Muscles or glands. Target cells in particular tissues
What is the type of response in the nervous system? The hormonal system ?
Muscle contraction or secretion. Chemical change
Speed of response for the nervous system. The hormonal system?
Very rapid. Slower
What is the duration of the nervous system? The hormonal system?
Short (until nerve impulses). Long (until hormone is broken down)
Where is the pituitary gland and what is it known as?
“The master gland” in the brain
What does the master gland secrete and what can these do?
It secretes several hormones into the blood. That’s can also act on other glands to stimulate the release of different types of hormones and Bring about effects
What hormone does the thyroid gland produce and where is the gland situated
Thyroxine and neck
What hormone does the pancreas produce
Insulin
What hormone does the Testes produce
testosterone
What hormone does the adrenal gland produce
Adrenaline
What hormone does the ovaries produce
Produces oestrogen
ADH (anti-diuretic hormone) does what and what does this lead to ?
Controlling the water control of the blood. This increases reabsorption of water by collecting ducts
Adrenaline and its role and effect
Preparation for “fight or flight” which increases breathing and heart rate, flow of blood To muscles, conversion of glycogen to glucose
Insulin role and effect
Controlling blood glucose levels which increases the conversion of glucose into glycogen for storage
