B1 Topic 2 - Responding To Change Flashcards
What is osmoregulation?
Water content, keeping a balance between the water you gain and the water you lose
What is thermoregulation?
Body temperature, getting rid of body heat when you’re hot but keep heat when you’re cold.
What does the hypothalamus do?
It is a part of your brain that keeps your body temperature around 37 degrees C
It contains receptors that can sense the bloody temperature in the brain
It gets messages from receptors in the skin about your temperature
What happens when you’re too hot?
When the water in sweat evaporates it transfers heat from your skin into the environment
The hair erector muscles cause hairs to lie flat
Blood vessels close to the surface of the skin widen. This lets more bloody flow near the surface do it can lose more heat
What happens when you’re too cold?
Not much sweat is produced
The hair erector muscles cause the hairs to stand on end. They trap a layer of air next to the skin which helps keep you warm
Blood vessels near the surface of the skin narrow. This means less blood flows near the surface so less heat is lost to the environment
Neurones send what around the body?
Electrical impulses
Name the parts of the neurone and explain their purpose
DENDRONS - these branches allow the end of the neurone to connect with lots of other neurones
AXON - the electrical impulse travels along it
MYELIN SHEATH- this is an electrical insulator- it stops the nerve impulse getting lost and it also speeds it up
What is a synapse?
A synapse is where two neurones are joined together and it’s a gap between the nerves.
1) electrical impulses are passed across the gap by chemicals called neurotransmitters
2) the neurotransmitters set off a new electrical impulse in the next neurone
What are effectors, motor neurones, relay neurones and sensory neurones?
EFFECTORS - muscles contract and glands secrete hormones
MOTOR NEURONES - the nerve cells that carry electrical impulses from the CNS to the effectors
RELAY NEURONES - the nerve cells in the CNS that carry electrical impulses from sensory neurones to motor neurones
SENSORY NEURONES - the nerve cells that carry electrical impulses from receptors to the CNS
How does the CNS coordinate a response?
- a stimulus is detected by receptors
- the information is sent along the sensory neurones to the CNS
- the CNS is made up of the brain and the spinal chord
- the CNS sends information along a motor neurone to an effector (muscle or gland)
- the effector then responds
What is the reflex pathway
Stimulus Receptors Sensory neurone Relay neurone in CNS Motor neurone Effector Response
What are hormones?
They are chemicals produced in various glands (called endocrine glands)
Hormones are carried in the blood around the body
But only particular organs respond to the hormone - these are called target organs
What is type 1 diabetes and what is it caused by?
It is caused by a lack of insulin. This means the persons bloody level cannot get too high
It can be controlled by not eating too much sugary food or injecting insulin into the blood, usually at meal time.
It is usually injected into subcutaneous tissue
What is type 2 diabetes?
A person may become resistant to insulin
This means their blood sugar can get too high
Type 2 diabetes can be controlled by eating a healthy diet, getting regular exercise and losing weight
Over weight people have a higher risk of developing this.
What classes if you’re over weight?
It they have a body mass index (BMI) of over 30. This is calculated from a persons body weight and height.
Body mass/(height)2
