Homeostasis and Response Flashcards
What is homeostasis and why is it important?
Homeostasis is maintaining a stable internal environment. This is important because your cells need the right conditions to function properly and for enzyme action.
What is the Central Nervous System (CNS)?
In vertebrates this consists of the brain and spinal cord only
In mammals the CNS is connected to the body by sensory neurones and motor neurones.
What is the sensory neurones?
The neurones that carry information as electrical impulses from the receptors to the CNS.
What are motor neurones?
The neurones that carry electrical impulses from the CNS to effectors.
What are effectors?
All your muscles and glands which respond to nervous impulses.
What is a stimulus?
A change in the environment.
What are receptors?
Receptors are the cells that detect stimuli.
What is a synapse?
The connection between two neurones.
What happens at a synapse?
The nerve signal is transferred by chemicals which diffuse across the gap. These chemicals set off a new electrical signal in the next neurone.
What are hormones?
Hormones are chemical molecules released directly into the blood. They are carried in the blood to other parts of the body.
What are hormones produced in and secreted by?
Glands called the endocrine glands. These glands make up the endocrine system.
What does the pituitary gland do?
It produces many hormones that regulate body conditions. Called the master gland.
What do the ovaries do?
Produce oestrogen which is involved in the menstrual cycle.
What do the testes do?
Produces testosterone which controls puberty and sperm production.
What is the thryoid?
Produces thyroxine which is involved in regulating things like the rate of metabolism, heart rate and temperature.
What does the adrenal gland do?
Produces adrenaline which issued to prepare the body for a fight or flight response.
What does the pancreas do?
Produces insulin which is used to regulate the blood glucose level.
What happens when the blood glucose level is too high?
Insulin is added which makes the liver turn glucose into glycogen. Insulin is secreted by pancreas.
What happens when the blood glucose level is too low?
Glucagon is added which makes the liver turn glycogen into glucose. The glucagon is secreted by the pancreas.
What is Type 1 diabetes?
When the pancreas produces little or no insulin. This means that a persons blood glucose level can rise to a level that can kill them. People with Type 1 diabetes need insulin therapy which usually involves several injections of insulin throughout the day.
What is Type 2 diabetes?
This is when the body’s cells don’t respond to the insulin that is being made. This can cause the blood sugar level to rise to a dangerous level.
