2.3 control and communication Flashcards
Where is the cerebrum located on the brain?
on the top
Where is the medulla located on the brain?
in the middle / sticking out of the middle
Where is the cerebellum located on the brain?
at the back
What is the role of the cerebrum?
it enables conscious thought and memory
What is the role of the cerebellum?
it controls co-ordination and balance
What is the role of the medulla?
it controls heart rate and breathing rate
What is the CNS made up of?
the brain and the spinal cord
What is the function of the CNS?
Processing information from the senses and bring about appropriate responses. it allows communication between the cells of a multicellular organism.
What is the stimulus?
it is a change in conditions that is detected by receptors
what is the role of a sensory neurone?
passing information to the CNS in the form of electrical signals.
What is the role of the motor neurone?
enabling a response to occur
State the differences in responses brought about by the CNS.
some may be fast, like those from a muscle, and some may be slow, such as those from a gland.
What are reflex reactions?
fast automatic responses which require no input from the brain
Give 3 examples of reflex reactions
- coughing or sneezing
- choking
- blinking
Why do we need reflex reactions?
They protect the body from harm as they are fast and produce fast reactions.
Describe a reflex arc
The passage of an impulse from a sensory neurone, across an inter neurone to a motor neurone.
How do electrical impulse move?
Along the neurone.
What is a synapse?
a gap between neurones that allows chemicals to transfer from one neurone to another. it allows messages to be transferred to another neurone.
What are hormones?
chemical messengers
What do endocrine glands do?
release hormones into the blood stream where they travel to target tissues
describe the structure of target tissues.
they have cells with special receptors for the hormone on their surface
Why do hormones only affect their target tissue?
because only cells with the corresponding receptor will be affected by a specific hormone.
What detects a change in blood glucose levels?
pancreas
how can glucose be stored if glucose levels are too high?
as glycogen in the liver
What happens when blood glucose levels increase?
the pancreas releases more insulin which travels to the liver where it activates enzymes in the liver cells to convert glucose to glycogen.
What happens when blood glucose levels decrease?
the pancreas releases more glucagon which travels to the liver where it activates enzymes in the liver cells to convert glycogen into glucose.
Describe type 1 diabetes
a disease caused by lack of insulin causing high blood glucose levels, treated by injecting insulin
Describe type 2 diabetes
a disease caused by lack of response to insulin causing high blood glucose levels, treated by a good diet and exercise.
Why is it important to control blood glucose levels?
if they are high they can cause damage to blood vessels and affect the functioning of the eyes and kidneys in particular.
What can uncontrolled blood glucose levels cause problems with?
osmosis in cells
