Nervous System Neurons, CNS, and PNS

Question 1

Functions of the nervous system: (3)

Answer 1

Sensory input
Integration
Motor output

Question 2

2x Divisions of the Nervous system, and their related physiology.

Answer 2

Central Nervous System (CNS): Brain and Spinal Cord.

Peripheral Nervous System (PNS): communicating line between the CNs and rest of the body. Cranial nerves, Spinal nerves, Peripheral nerves.

Question 3

Principle parts of brain

Answer 3

Cerebral Hemispheres/Cerebrum.
Diencephalon
Brain stem
Cerebellum

Question 4

Functions of the brain x2

Answer 4

Interpret sensory impulses.

Control muscular movement (motor functions).

Question 5

Structure, location, and function of the basal ganglia

Answer 5

Areas of Grey matter found deep in the floor of the lateral ventricles ( underneath of the brain) control gross muscle movements and regulate muscle tone.

Question 6

What is the central nervous system composed of (2), and what type of neurons does it contain?

Answer 6

Composed of the brain and spinal cord, contains relay neurons.

Question 7

What is the peripheral nervous system composed of (3)? And what type of neurons does it contain?

Answer 7

Contains sensory and motor neurons. Composed of cranial, spinal, and peripheral nerves.

Question 8

What are the two divisions of the peripheral nervous system?

Answer 8

sensory and motor.

Question 9

What are the two divisions of the motor impulse?

Answer 9

Somatic (voluntary) and autonomic (involuntary)

Question 10

What are the two divisions of the autonomic motor impulse?

Answer 10

Sympathetic (fight or flight) and parasympathetic (resting and digesting)

Question 11

What cells make up the nervous system and what are the three parts of this cell?

Answer 11

Neurons make up the nervous system.
Three parts of the neuron:
Central cell body (soma/perikaryon) that contains the nucleus.
Dendrite (the branches around the soma - receives stimuli).
Axon (the tail - don’t call it a tail in the exams) sends information away.

Question 12

Functions of the soma, dendrites, and axon.

Answer 12

The soma sustains the life of the cell, contains the nucleus. Dendrites: Thick, cytoplasmic extensions that conduct impulses from outside of the cell to the soma. Axon: A thick, cytoplasmic extension that conducts impulses away from the soma.

Question 13

What is myelin and what makes it? What is the function of myelin?

Answer 13

A fatty substance made out of Schwann cells that wraps itself around the axon of the neuron. The gaps between them are named the Nodes of Ranvier. Impulses cannot be conducted through the Schwann cells, so the impulses jump from Node of Ranvier to Node of Ranvier to reach the axon terminal. This speeds up the transmission of impulses

Question 14

What are the three classifications of neurons and their function?

Answer 14

Sensory/Afferent: Transmits impulses from sensory receptors to the CNS. Cell bodies located in sensory ganglia (group of soma) outside the CNS.
Motor/Efferent: Carries impulses away from the CNS and to effector organs (muscles and glands).
Association: Lie within the CNS between the sensory and motor neurons. 99% of neurons are association neurons.

Question 15

What are the five types of sensory receptors?

Answer 15

Mechanoreceptors: Pressure, touch, stretch.
Thermoreceptors: Heat.
Photoreceptors: Light.
Chemoreceptors: Taste, Smell, O2, and CO2 levels.
Nociceptors: Pain.

Question 16

What is a synapse and what are the two types of synapses?

Answer 16

Synapses are the gap between the axon terminal of one neuron and the dendrites of another neuron.
Electrical synapses are found in the heart (sinoatrial node), allowing synchronised contractions in the smooth muscle.
Chemical Synapses where chemical neurotransmitters transfer the action potential from one neuron to the next.

Question 17

What is a reflex arc?

Answer 17

A reflex arc is a neural pathway consisting of 5 steps that causes a reflex. Reflexes can be somatic (skeletal muscle), or autonomic (involuntary muscle and glands).

Question 18

what are the five steps of a reflex arc?

Answer 18

Receptor: site of stimulus.
Sensory neuron: afferent impulses to CNS.
Integration in CNS: may be one synapse only.
Motor neuron: efferent impulses to the effector.
Effector: Muscle or gland.