Week 4 - Central Nervous System

Question 1

Fill in the blanks:

The structural cell units of the nervous system that transmit electrical signals are…..

Answer 1

Neurons

Question 2

Fill in the blanks:

The nervous system of the body is made up of two sections. These are the …… and the …

Answer 2

• central nervous system (CNS)
• peripheral nervous sytem (PNS)

Question 3

Fill in the blanks:

The central nervous system is composed of the ……. and the ……

Answer 3

• brain
• spinal cord

Question 4

Fill in the blanks:

The peripheral nervous system is composed of the …… and the …..

Answer 4

• Cranial nerve
• Spinal nerve

Question 5

Fill in the blanks:

The peripheral nervous system is also divided into two divisions. These are the … and the ….

Answer 5

• sensory
• motor

Question 6

Fill in the blanks:

The motor division of the peripheral nervous system is divided into the …. and the …

Answer 6

• somatic
• autonomic

Question 7

Fill in the blanks:

The protective and supporting cells of the nervous system are called

Answer 7

neuroglia

Question 8

State why brain cancer originate from the neuroglia and meninges not the neurons

Answer 8

• neuroglia undergo mitosis
• neutrons are amitotic (no centrioles)

Question 9

Identify the structural feature of the neuron on the previous page that indicates that this neutron belongs to the peripheral nervous system

Answer 9

Schwann cells

Question 10

Describe the role of the myelin sheath

Answer 10

white fatty around axon of some neurone insulates axon to speed up nerve impulse (signal) transmission

Question 11

Describe the events associated with an action potential

Answer 11

Electrical event, once initiated spreads along neuron toward axon terminal, due to the influx of Na

Question 12

name the chemical substance that is in the synaptic vesicles of the axon terminal

Answer 12

neurotransmitter

Question 13

Name 3 neurotransmitters

Answer 13

1 = Acetylcholine
2 = Adrenalin (epinephrine), nor adrenalin (nor epinephrine)
3 = serotonin, dopamine

Question 14

Spinal reflex arcs. A neurological examination of a patient evaluates the sensory, motor and cognitive functions of the nervous system. Somatic reflexes provide valuable information about the location of damage to the spinal nerves or spinal cord. They can involve two or three neurons

Name the 5 essential components of a somatic reflex arc

Answer 14

1: Receptor
2: Sensory neuron
3: integration centre (neurosoma of motor or interneuron)
4: motor neuron
5: effector

Question 15

The knee jerk response assess the L2-L4 level of the spinal cord

name the muscle that contracts

Answer 15

Quadriceps

Question 16

Name the mixed nerve that carries Thi sensory (afferent) and motor (efferent) information toward and away form the spinal cord

Answer 16

Femoral

Question 17

Name the 3 areas of the brain stem

Answer 17

• midbrain
• pons
• medulla oblongata

Question 18

Explain why trauma to the base of the brain is often more dangerous than to the front

Answer 18

Medulla Oblongata= respiratory, cardiac, vasomotor etc centres (nuclei)
Reticular activating system (RAS) extends length of brain stem (consciousness)

Question 19

List the structures through which the cerebrospinal fluid (CSF) circulates

Answer 19

Ventricles of brain, subarachnoid space, central canal of spinal cord
Reabsorbed into veins via arachnoid graduations

Question 20

List the functions of the CSF

Answer 20

• Buoyancy for brain (less brain weight)
• Protects
• oxygen, glucose, proteins, electrolysed , waste etc

Question 21

neurons

Answer 21

nerve cell that transmit information as electrical signals

Question 22

Neuroglia

Answer 22

protective and supportive cells of nervous system

Question 23

Ependymal cell

Answer 23

ciliated support cell that lines the inside of cavities of the brain and spinal cord: helps produce CSF

Question 24

Astrocyte

Answer 24

most abundant support cell: covers brain surface, helps form blood brain barrier

Question 25

Ganglia

Answer 25

cluster of neurosoma within the PNS

Question 26

Nuclei

Answer 26

cluster of neurosoma (grey matter) within the CNS

Question 27

Microglia

Answer 27

Support cell that engages in phagocytosis of pathogens and cell debris

Question 28

Schwann Cells

Answer 28

Support cell that forms the myelin sheath around neurons in the PNS

Question 29

Oligo-dendrocyte

Answer 29

octopus-shaped support cell that forms the myelin sheath around neurons in the CNS

Question 30

state the most obvious effect from damage to the temporal lobe

Answer 30

- hearing, speech, language, memory disturbances

Question 31

5. Blood supply. The brain has a high demand for ATP and thus oxygen (O2) and glucose. A ten- second disruption to the blood flow is enough to make someone go unconscious, a four-minute disruption is enough to cause irreversible brain damage. Name the two pairs of arteries that supply blood to the brain (Figure 13.21).

Answer 31

1) Internal Carotid 2) Vertebral

Question 32

6. The above anterior and posterior blood vessels are connected by small communicating arterial branches (anastomosis). Name this circle of blood vessels in the brain.

Answer 32

cerebral arterial circle (circle of Willis)

Question 33

7. Sleep is a temporary state of unconsciousness (in contrast to coma) from which one can be awakened. Across one night, humans progress through five cycles of sleep, each cycle being composed of lightest (stage 1) to deepest (stage 4) and rapid eye movement (REM) sleep. However, stage four is only attained in the first cycles of the first hours. a) one; six b) two; three c) three; four d) four; eight

Answer 33

b) two; three

Question 34

8. Excess consumption of is(are) associated with a lower quality of sleep e.g., fragmented sleep, less deep sleep and less REM sleep. Also, beyond 30 years of age the amount of deep sleep reduces. a) ultra processed ‘foods’ b) alcohol, some medications c) caffeine d) all the above

Answer 34

d) all the above

Question 35

9. Boredom is a cue to the body that it needs to move. Regular exercise is associated with deeper sleep, better cognition and off setting of dementia. Interestingly, exercise results in the enlargement of the (sea horse-shaped), one of only two places in the nervous system that can perform mitosis. This structure is associated with memory as part of the limbic system of the . a) medulla oblongata; brain stem b) hippocampus; brain c) corpus callosum; spinal cord d) amygdala; enteric nervous system

Answer 35

b) hippocampus; brain