Exam IV

Question 1

overall functions of the nervous system

Answer 1

• main control and regulatory system
• has three overlapping functions of sensory input, neural integration and motor output
• communicates electrically with action potentials
• communicates with neurotransmitters
• sends messages quickly from the CNS, the brain and spinal cord, to the periphery of the body and back again

Question 2

sensory receptors

Answer 2

specialized structures that detect changes–sensory input (temperature, pressure, touch, stc.)

ex. the eyes, Merkel/tactile cells, ears, temperature and pain receptors (nociceptors)

Question 3

afferent pathway

Answer 3

nerve pathway through which sensory input is transmitted to CNS; formed by axons of sensory neurons

Question 4

control center

Answer 4

interneurons (CNS) that analyze the sensory input and make a decision to respond to the change; interneurons

Question 5

efferent pathway

Answer 5

nerve pathway through which motor output is sent away from CNS; carried by axons of motor neurons

Question 6

effectors

Answer 6

carry out the decision (motor output)

ex. skeletal muscles contract; smooth muscle relaxes blood vessels; glands produce sweat

Question 7

somatic

Answer 7

this division of the nervous system mainly controls skeletal muscles of the body; it is voluntary

Question 8

autonomic

Answer 8

this division of the nervous system is also called the visceral motor division; it carries signals to the internal organs (viscera) like glands, cardiac muscles, and smooth muscles; it is involuntary

Question 9

CNS

Answer 9

brain (enclosed and protected by the cranium) and spinal cord (enclosed and protected by the vertebral column)

have somas of interneurons

Question 10

PNS

Answer 10

nerves (spinal and cranial nerves) and ganglia (like dorsal root ganglion); has sensory (afferent_ and motor (efferent division); somatic and visceral (autonomic) division

have axons of sensory and motor neurons

Question 11

unipolar

Answer 11

this neuron has one extension coming off the soma that divides into a dendrite and an axon; seen in sensory neurons of dorsal root ganglion

Question 12

bipolar

Answer 12

has one dendrite and one axon; rare; found in sensory organs (smell and vision)

Question 13

multipolar

Answer 13

has multiple dendrites and one axon; most common neuron; found mostly in CNS

Question 14

dendrites

Answer 14

are receiving (receptive) regions of neurons; usually short and branching; local potentials are usually created on dendrites and then travel to axon hillock; a neuron usually has multiple dendrites

Question 15

soma

Answer 15

this part of the neuron contains the nucleus and other organelles and integrates information