Nervous System- Pt 2

Question 1

What are the structural types of neruons?

Answer 1

multipolar, Bipolar and unipolar

Question 2

What is a multipolar neuron?

Answer 2

contains one axon and multiple dendrites. Most interneurons in the brain and spinal cord are multipolar and also most motor neurons to the skeletal muscles.

Question 3

What is a bipolar neuron?

Answer 3

contains one axon and one dendrite. Eye, ear and nose, where they take impulses from the receptor cells to other neurons

Question 4

What is a unipolar neuron?

Answer 4

contains just one extension (axon). The cell body is to one side of the axon. Most sensory neurons that carry messages to the spinal cord are unipolar.

Question 5

Nerve Impulses

Answer 5

• need to be passed from one neuron to another

- must cross the synapse.

Question 6

What is a synapse?

Answer 6

the junction between 2 adjacent neurons.

Question 7

Divisions of the nervous system

Answer 7

1. CNS
2. PNS
3. a Afferent: which is split into somatic and visceral
4. b Efferent: which is split into somatic and Autonomic (sympathetic and parasympathetic)

Question 8

Reflexes

Answer 8

rapid, automatic response to a stimulus (change in internal or external environment)

Question 9

All reflexes…

Answer 9

1. have a stimulus
2. are involuntary
3. are rapid
4. are stereotyped (occur same way each time)

Question 10

Spinal Reflexes

Answer 10

carried out by spinal cord, with NO brain involvement required

Question 11

All spinal reflexes consist of?

Answer 11

1. a receptor (neuron or specialised receptor cell at the end of a neuron)
2. a sensory neuron (dorsal root)
3. at least one synapse
4. a motor neuron (ventral root)
5. an effector (muscles or glands)

Question 12

Receptors

Answer 12

receptors detect changes in the bodies internal/external environment.
some are simple nerve endings
others are receptor cells grouped together to form sense organs (eye)

Question 13

What are the types of receptors?

Answer 13

1. thermoreceptors- respond to heat and cold
2. osmoreceptors- sensitive to osmotic pressure (substances dissolved in water)
3. chemoreceptors- stimulated by particular chemicals (O2, CO2, hydrogen ions, PH level)
4. Touch receptors- sensitive to touch (surface of skin)
5. pain receptors/ nocireceotors- stimulated by damages to tissue (bumps, cuts, burns) mainly found in skin and mucous membranes. they warn us that damage to tissue is occuring.

Question 14

Protective Reflexes

Answer 14

present from birth
some complex motor patterns are learned and are clled acquired reflexes. (learned through repetition)
muscle adjustments while bike riding, jamming on brakes, catching a ball.