II: 10.1 - Nervous control in humans Flashcards
Define
central nervous system (CNS)
The processing center for the nervous system, consisting of the brain and spinal cord. It receives information from and sends information to the peripheral nervous system.
The brain processes and interprets sensory information sent from the spinal cord. Both the brain and spinal cord are protected by three layers of connective tissue called the meninges.
Define
peripheral nervous system (PNS)
The nerves and neurones which connect the body to the central nervous system, and thus allow the CNS to control the body.
What type of neurone is this?
Complete the labels.
Motor neurone
carries impulses from CNS to the effector (muscles/gland)
- A: cell body
- B: dendrite (receives information from another cell’s axon)
- C: cell membrane
- D: nucleus
- E: cytoplasm
- F: myelin sheath (improves speed of nerve impulse by insulating the axon)
- G: axon (nerve fibre, sends information)
- H: terminal nerve endings (connects with effector)
What type of neurone is this?
Complete the labels.
Sensory neurone
carries impulses from sense receptors to CNS
- A: dendrite (receives information from sensory receptors)
- B: axon (nerve fibre, sends information)
- C: myelin sheath (improves speed of nerve impulse by insulating the axon)
- D: cytoplasm
- E: nucleus
- F: cell membrane
- G: cell body
- H: terminal nerve ending (connects to another neurone)
What type of neurone is this?
Complete the labels.
Connector/relay neurone / interneurone
passes information between two neurones (between a motor and sensory neurone)
- A: dendrite (receives information from another neurone)
- B: cell body
- C: cell membrane
- D: nucleus
- E: cytoplasm
- F: myelin sheath (improves speed of nerve impulse by insulating the axon)
- G: axon (nerve fibre, sends information)
- H: terminal nerve ending (transmits information to another neurone)
What is a synapse?
The juction between the axon of one neurone and the dendrite of another.
Ina chemical synapse, information is transmitted by neurotransmitters diffusing across the synaptic gap.
Distinguish between voluntary and involuntary actions
Voluntary: controlled by the person’s will, e.g. moving your arm
Involuntary: out of the person’s control, e.g. pupil reflex, peristalsis
What is a reflex arc?
The nerve pathway reponsible for a reflex action, an involuntary, quick action to respond to a stimulus, in order to protect the body from danger (e.g. quickly removing your hand from a hot metal surface).
Describe how a reflex arc works
