YR11 Core Question: Cells Flashcards
What is homeostasis?
The regulation of your internal environment to maintain optimum conditions
What is a receptor?
Specialised cell that can detect an environmental change
What is a stimuli?
A change in the internal or external environment. E.g. light
What is an effector?
Muscle or gland
What is the main human coordination centre?
Brain
What is a neurone?
Specialised cell that carries electrical impulses
What is an impulse?
Electrical signal passing from one neurone to another
What is a nerve?
A bundle of neurones
What is the central nervous system (CNS)?
Brain and spinal cord
What do sensory neurones do?
Carry impulses from receptors to the CNS
What do motor neurones do?
Carry impulses from the CNS to muscles or glands
What is a reflex?
An automatic response
What is the reflex arc?
Sensory neurone -> Relay neurone -> Motor neurone
What does a relay neurone do?
Carry an impulse directly from sensory to motor neurone
What is a synapse?
Junction between neurones
How does a nervous impulse cross a synapse?
The impulse causes chemicals to diffuse across the gap
What is the endocrine system?
A network of glands that secrete hormones
What is a hormone?
Chemical messenger
What does the hormone insulin regulate?
Blood glucose levels
What is glucagon?
Hormone that increases blood glucose levels
What is diabetes?
A disease of blood glucose regulation
How is Type I diabetes treated?
Insulin injections
How is Type II diabetes usually treated?
Low-carbohydrate diet and exercise
What is negative feedback?
An opposite response
What does the hormone thyroxine regulate?
Metabolic rate and growth
How does the hormone adrenaline affect the body?
Increased heart rate, breathing, blood glucose and blood flow to muscles
