UNIT 4: LO5 (Control Systems) Flashcards
What is a stimuli?
A change in the environment.
What are receptors?
Organs which detect the stimuli.
What is the central nervous system (CNS) made up of?
- The brain
- The spinal cord (butterfly shape)
- Nerves
What does the CNS work together to give and how?
Voluntary and involuntary actions by sending electrical impulses to the brain.
What is the voluntary system made up of?
Peripheral nerves
What are the two types of peripheral nerves and their functions?
Sensory neurons:
- travel into spinal cord from body’s receptors
- involved with the eyes, ears, taste buds, skin, nose
Motor neurons:
- travel out of spinal cord to body’s effectors
- involved with the muscles (contract/movement) and glands (hormones)
What is a response?
An action taken to counteract the effect of the stimulus.
What is an effector?
A muscle movement or gland which will release a hormone to generate a response.
What is the autonomic nervous system and what are the nerves it controls?
Made up of nerves that control the body’s organs (involuntary control) and controls the sympathetic and parasympathetic nerves.
What are the roles of the sympathetic nerves?
- Speeds up organs e.g. heart rate increases
- Prepares body for survival
What are the roles of the parasympathetic nerves?
- Slows organs down e.g. decrease heart rate
- Keeps body in an efficient resting state
What is the structure of a neuron made up of?
Nucleus, cytoplasm, dendrites, axon, myelin sheath, nerve endings, nodes.
What is the role of the myelin sheath?
It is wrapped around axon for insulation and increases speed that impulse moves along axon.
What are the roles of the axon?
- Connects neurons to different parts of the body
- Carries electrical nerve impulses
What is the roles of the dendrites?
Receive incoming impulses from other neurons
What is the role of the nerve endings?
They connect to muscles and glands.
What is the role of the sensory neurons?
Carry information as electrical impulses from the receptor in the sense organs to the CNS.
What is the role of the relay neurons?
Carry electrical impulses from sensory neurones to motor neurones (found in the CNS).
What is the role of the motor neurons?
Carry electrical impulses from the CNS to the effectors .
What are reflex arcs?
Don’t involve the brain, they happen without us thinking (involuntary responses)
What is the order of the reflex arc?
Stimulus, receptor, sensory neuron, CNS, motor neuron, effector, response.
What is the endocrine system?
It is composed of glands which secrete hormones directly into the blood - hormones carried to target organ where it produces an effect but less targeted than nervous system and slower but long-lasting. Once hormone used is destroyed by liver.
What is the pituitary gland and its roles?
- Key part in endocrine system
- ‘Master gland’ because controls all other glands by allowing them to release other hormones
Where is the thyroid gland and what is the role of thyroxine?
At the front of the neck
Role:
- controls metabolism
Where is the adrenal gland and what are the roles of adrenalin?
On top of the kidneys
Roles:
- allows more glucose and oxygen to muscles (aerobic respiration can take place)
- triggers body’s ‘flight or fight’ response
What does the pancreas produce and what are the roles?
Insulin which decreases blood sugar levels and glucagon which increases blood sugar levels.
What is the cerebral hemisphere?
Folded with deep crevices that increase the size of the brain but allow it to fit inside of the cranium (skull).
What do the meninges do?
Protects the outside of the brain (triple layer of tough membranes).