Nervous System

Question 1

heartbeat

Answer 1

• initiated by the sino-atrial node
• regulated by the accelerator nerve (sympathetic) and the vagus nerve (parasympathetic)
• then picked up by the AV node

Question 2

SA (sino-atrial) node

Answer 2

-located in the wall of the right atrium
-travels through the atria
-responsible for the heart beat (“pacemaker”)
not functionally dependent on nervous system

Question 3

AV (atrioventricular) node

Answer 3

• signals the bundle of His (AV bundle) which transport contractions through ventricles
• does not have contractile ability

Question 4

contraction of ventricles

Answer 4

• filling of ventricles with blood from the atria

- delay between contraction of atria

Question 5

systolic pressure

Answer 5

• pressure of the ventricular contraction

- higher than diastolic pressure

Question 6

diastolic pressure

Answer 6

• pressure between contractions

- lower than systolic pressure

Question 7

knee-jerk (patellar) reflex arc

Answer 7

• monosynaptic reflex arc
• does not require the function of an interneuron in the spinal cord
• sensory neuron synapses directly with the motor neuron

Question 8

neurotransmitter

Answer 8

• stored in membrane-bound vesicles in the nerve terminal
• chemical messenger released as action potential reaches the end of axons
• after crossing synaptic cleft, causes the depolarization of the adjacent cell membrane; neurotransmitter is released into synapse
• can diffuse across synapse and depolarize post-synaptic membrane causing a consequent firing of an action potential

Question 9

removal of neurotransmitters

Answer 9

• uptake carrier protein may take it back through the nerve terminal where it can be degraded (by enzymes in the synapse) or reused
• may simply diffuse out of the synapse

Question 10

acetylcholine

Answer 10

• neurotransmitter used in the parasympathetic nervous system
• inactivated by acetylcholinesterase in the synapse

Question 11

hypothalamus

Answer 11

thirst, emotion, sex drive, hunger, blood pressure, temperature, sleep, water balance

Question 12

cerebellum

Answer 12

muscle coordination and tone, maintain posture

Question 13

cerebral cortex

Answer 13

vision, hearing, smell, memory, voluntary movement

Question 14

medulla oblongata

Answer 14

blood CO2 levels and pH, breathing, heart rate, coughing, sneezing, swallowing, reflex activity

Question 15

reticular activation system

Answer 15

sensory processing

Question 16

myelin

Answer 16

• fatty compound that surrounds the axons
• compared to insulation on a wire
• speeds conduction along the nerve cell
• produced by Schwann cells