Intro to nervous system

Question 1

What are the two anatomical divisions of the nervous system and what do they include?

Answer 1

• Central nervous system (CNS)
  
  • Brain
  • Spinal cord
• Peripheral nervous system (PNS)
  
  • Nerves

Question 2

What are the three main functions of the nervous system?

Answer 2

1. Receive stimuli from external and internal environment
2. Analyse and integrate these messages
3. Co-ordinate a response via innervation of organs and tissues

Question 3

Primary communicative cell type of nervous tissue?

Answer 3

neuron

Question 4

Label these parts of a neuron.

Answer 4

Question 5

What is the difference between grey matter and white matter in the nervous system?

Answer 5

Grey matter includes areas of nerve cell bodies (nuclei of neurons), while white matter invovles regions of neuron axons only.

Question 6

What are the three main divisions of the brain and their primary functions?

Answer 6

1. Cerebrum: interpretation of vision, sound; decision making, initiation of movement; memory
2. Cerebellum: co-ordination of movement
3. Brainstem: monitoring of visceral functions

Question 7

Where is the spinal cord found?

Answer 7

vertebral canal (vertebral foramen)

Question 8

What are the inputs and outputs of peripheral nerves?

Answer 8

Input: sensory information
Output: motor information

Question 9

Label these stages of a neuron action potential.

Answer 9

Question 10

What happens at the synapse of a neuron?

Answer 10

Neurotransmitter vesicles move to cell membrane and chemicals are released at the synapse. This causes an action potential to start in the postsynaptic neuron.

Question 11

Name the two functional divisions of neurons and their functions.

Answer 11

Incoming (afferent) neurons

• Pain, temperature, position, stretch
• From somatic tissues ie skin, muscle sensations and visceral tissues- bladder, gut sensations
• Also special senses- vision, hearing etc

Outgoing (efferent) neurons

• Somatic- to skeletal muscles for movement
• Autonomic- to viscera for smooth muscle and glandular function

Question 12

In the skin, what are some of the pressure, pain, and temperature detecting receptors called?

Answer 12

• Pacinian corpuscles & Meissner’s corpuscles are receptors that detect pressure in skin
• Free nerve endings detect temperature and pain in skin

Question 13

What are the five “special senses”?

Answer 13

• Hearing (audition) - ear canal channels sound to inner ear receptors (cochlea)
• Vision - retina of eye has photoreceptors for light
• Balance (vestibular) - inner ear receptors for head position
• Taste (gustatory) - tongue taste ‘bud’ chemoreceptors
• Smell (olfactory) - chemoreceptors in caudal nasal mucosa

Question 14

Cranial nerves enter and exit directly from the _____ aspect of the brainstem. They are mainly involved in
_____ _______ and sensorymotor (somatic and visceral) innervation of face, head and neck. There are _____ pairs of cranial nerves.

Answer 14

Cranial nerves enter and exit directly from the ventral aspect of the brainstem. They are mainly involved in
special senses and sensorymotor (somatic and visceral) innervation of face, head and neck. There are 12 pairs of cranial nerves.

Question 15

What are the two functional divisions of efferent neurons?

Answer 15

Somatic efferent ‘motor neurons’

• To skeletal muscle

Autonomic efferent neurons

• To cardiorespiratory, gastrointestinal, urogenital

Question 16

What is the name of the nerve-muscle interface?

Answer 16

neuromuscular junction

Question 17

What are spinal cord reflexes? Example?

Answer 17

Reflexes occur without brain involvement

• Sensory receptor – detects pinprick
• Sensory neurons relay to spinal cord
• Synapses through to motor neuron
• Motor neurons to muscle- move hand/paw away

Sensory information may be passed to brain for conscious perception, but movement due to reflex arc

Question 18

What are the two functional divisions of the autonomic nervous system? What do they do?

Answer 18

Sympathetic nervous system

• ‘Fight or flight’ response
• Increases heart rate, dilates airways, increases blood pressure, increases blood flow to skeletal muscle, adrenalin release from adrenal gland medulla, dilates pupil of eye

Parasympathetic nervous system

• ‘Rest and digest’ response
• Increases gut smooth muscle and glandular function, increases blood flow to gut, lowers heart rate and blood pressure