Respnding to Change Flashcards
Describe how body temperature is reduced when you’re too hot
You sweat in order to let off heat
Your blood dilates to allow blood to flow near to the surface to release heat (vasodilation)
Erector muscles relax
What is homeostasis
Homeostasis is maintaining a stable internal environment
Describe how body temperature is increased when you’re too cold
Erector muscles contract to make hairs stand up which will trap a layer of air to stay warm
Very little sweat
Blood vessels will constrict (vasoconstriction) so that no blood is flowing near the surface
What are hormones
Hormones are chemical messengers
how do hormones travel around the body
In the blood
What name is given to the chemicals found at synapses
Neurotransmitters
List the four main difference between nerves and hormones
Nerves give a very fast message. Hormones give a slow message
Nerves act for a very short time. Hormones act for a long time
Nerves act on a specific area. Hormones are more general
Nerves are an electrical message, hormones are a chemical message
List the five sense organs and the receptors that each one contains
Eyes (light receptors) Ears (sound receptors) Nose (smell receptors) Tongue (taste receptors) Skin (touch pressure)
What does CNS stand for
Central nervous system
What does the CNS consist of
Brain and spinal cord
What does the CNS do
The CNS creates a response, decides what to do about the stimulus
It sends information to an effector (muscle or gland) along a motor neurone
What is the purpose of a reflex
Automatic response to certain stimuli
Reduce the chance of being injured
Describe the pathway of a reflex arc
A stimulus is detected by receptors
Impulses are sent along sensory neurones to the CNS
The CNS pass on the message to a relay neurone
Relay neurones relay the impulses to a motor neurone
They travel along the motor neurone to the effector
The muscle contracts
What happens when blood glucose is too high
When glucose levels are too high the pancreas will release insulin into the blood
Then some glucose is removed for the blood by the liver which turns it into glycogen
Describe what happens when blood glucose is too low
When it’s too low the pancreas will secrete glucagon into the blood
The glucagon goes to the liver and makes the liver turn the glycogen into glucose
The glucose is added into the liver
Glucagon stops being secreted
