CNS

Question 1

central nervous system

Answer 1

Brain + spinal cord

Question 2

peripheral nervous system

Answer 2

Nerve fibers that carry info between CNS and othe rparts of body

Question 3

afferent vs efferent

Answer 3

afferent = sensory
- (you are being “affected”)

efferent = doing
- (you are putting in the “effort”)

Question 4

somatic nervous system

Answer 4

efferent division of PNS:
(General Somatic Efferent (GSE) )
- innervates skeletal muscle

Question 5

autonomic nervous system (ANS)

Answer 5

efferent division of PNS:
(General Visceral Efferent (GVE) )

• innervates smooth and cardiac muscles exocrine glands

Question 6

sympathetic nervous system

Answer 6

subdivision of ANS
- dominates in emergency / stressful situations
- prepares body for strenuous physical activity

Question 7

parasympathetic nervous system

Answer 7

subdivision of ANS
- dominates in quiet, relaxed situations
- promotes body maintenance activities (i.e digestion and emptying urinary bladder)

Question 8

Properties of spinal cord crey matter

Answer 8

Contains (3) horns

1. Dorsal horn
   (cell bodies of interneruons on which afferent neurons terminate)
2. Lateral horn
   (cell bodies of autonomic efferent nerve fibres)
3. Ventral horn
   (cell bodies of somatic efferent neurons)

Question 9

folds of the cerebrum (2)

Answer 9

1. surface folds = gyri

(2 important gyrus)
- Precentral gyrus (primary motor cortex)
- postcentral gyrus (primary somatosensory cortex)

2. grooves == sulci
   (folds between each segment of the brain)
   (large sulci == fissures, occurs when you age and lose brain cells)

Question 10

Frontal Lobe Functions (3)

Answer 10

1. Motor control (premotor cortex)
2. Problem solving (prefrontal area)
3. Speech production (broca’s area)

Question 11

Temporal Lobe Functions (3)

Answer 11

1. Auditory processing (hearing)
2. Language comprehension (Wernicke’s area)
3. Memory / information retrieval

Question 12

Brainstem function (1)

Answer 12

1. involuntary responses

brain dead == non-functioning brainstem

Question 13

Cerebellum Function (1)

Answer 13

1. balance and coordination

Question 14

Occipital Lobe Function (2)

Answer 14

1. Sight (visual cortex)
2. Visual reception and interpretation

Question 15

Parietal Lobe (2)

Answer 15

1. Touch perception (somatosensory cortex)
2. Body orientation and sensory discrimination

Question 16

Brainstem parts (3)

Answer 16

1. Midbrain
2. Pons
3. Medulla oblongata

Question 17

Sensory and Motor homunculus

Answer 17

Homunculus:
Represents the point-for-point correspondance of a body area to a specific part of the brain

Increased (exaggerated) size of body parts == more of the somatosensory cortex is used for that specific body part

Question 18

Dr. Wilder Penfield’s experiment

Answer 18

live surgical experiments

• Dr. Wilder would send electrical impulses to specific parts of the brain and observe which body parts were related to it

Question 19

White vs grey matter

Answer 19

white:
portion of CNS composed of myelinated nerve fibers
- receives and sends signals

grey:
portion of CNS composed of densely packaged neuronal cell bodies and dendrites

Question 20

Types of Fibers (3)

Answer 20

1. Association fibers
   (closely associated - same hemisphere)
2. Commissural fibers
   (commute - different hemisphere)

• originate from cell bodies in cortext of one hemisphere
• cross midline
• synapse w/ neurons in the other hemisphere

3. Projection Fibers
   - project to and from cortex

Question 21

Why does the portion of white matter decrease as you go down the spinal cord?

Answer 21

Purpose: stagger the transduction of nerve signals
- the further up the spine, the more nerve fibers are attached, thus more white matter is needed for signal transduction

Question 22

What modalities do the sympathetic and parasympathetic nervous system carry?

Answer 22

Visceral Motor Efferent pathway

Question 23

Thalamus

Answer 23

brain region that serves as a synaptic integrating center for preliminary processing of all sensory input on its way to the cerebral cortex

(i.e, the control center of nerve signals into and out of the brain)

Question 24

Cortex

Answer 24

outermost layer of brain

Question 25

Describe the sensory pathway for "discriminative touch, vibration, proprioception"

Answer 25

1. sensory signal reaches spinal ganglion 2. moves along to the spinal cord 3. travels up the Posterior Column Medial Lemniscus Pathway (PCML) 4. synapses in the medulla 5. crosses the midline while in the medulla 6. goes up the pons and midbrain 7. synapeses in the thalamus 8. reaches the cortex

Question 26

Describe the sensory pathway for "pain & temperature"

Answer 26

1. sensory signal reaches spinal ganglion 2. synapses in the spinal cord 3. crosses the midline while in the spinal cord 4. travels up the spinothalamic tract 5. crosses the medulla, pons, and midbrain 6. synapses in the thalamus 7. reaches the cortex

Question 27

Describe the motor pathway for muscles

Answer 27

1. upper motor neuron in cortex sends electrical signal 2. signal travels through midbrain and pons along the cortiocospinal tract 3. signal crosses the midline at the medulla 4. signals travel from the medulla to the spinal cord (still on the corticospinal tract) 5. signal synapses at the spinal cord and reaches the lower motor neuron 6. lower motor neuron sends signals to appropriate muscles

Question 28

Somatic Nerve plexuses list (5) and explain function

Answer 28

1. Cervical plexus 2. Brachial plexus 3.Intercostal nerves (located between ribs) 4. lumbar plexus 5. scaral plexus What is it? - group of nerve fibers originating at different spinal nerves coming together to innervate the same specific body parts (come together as one nerve) Function: - allows signals to criss-cross and form interconnected motor units - ensures that damaging one nerve fiber will not result in total loss of function (just a weaker response)