chapter 27 nervous system

Question 1

what are the effectors of the nervous system

Answer 1

any part of the body that produces the response (example: a muscle contracting to move the arm, a muscle squeezing saliva from the salivary gland, and a gland releasing a hormone into the blood.)

Question 2

what are the four parts of a neuron – what is the function of each part

Answer 2

–»cell body –contains the nucleus of other organelles involved in growth and metabolism

–»dendrites—cytoplasmic extensions of the cell body that are thin, brushy, and usually short— they function to receive incoming signals

–»axon—also a cytoplasmic extension of the cell body, but generally unbranched (except at the end) and much longer than dendrites — function to conduct impulses away from the cell body

–»terminal braches— of the axon — with tiny swollen tips called synaptic knobs between neurons neurotransmitter chemicals that relay the impulse across the synapse between neurons

Question 3

what type of neuron makes up the central nervous system

Answer 3

sensory neuron

Question 4

what is the most abundant type of neuron in the human body

Answer 4

interneurons

Question 5

where do the neurons of the somatic nervous system lead

Answer 5

consists of motor neurons that lead from CNS to skeletal muscles

Question 6

where do the neurons of the autonomic nervous system lead

Answer 6

consists of motor neurons that lead from CNS to cardiac muscle, smooth muscles and glands

Question 7

what are the main functions of the medulla, cerebellum, cerebrum, and hypothalamus

Answer 7

–»medulla— communication link between spinal cord and brain—exerts control over heart rate, breathing, blood vessel diameter

–»cerebellum —- controls balance and skeletal muscle coordination

–»hypothalamus — controls many involuntary aspects of behavior –e.g. appetite, thirst, body temperature, sexual responses and emotions like anger, fear, and pleasure— also secretes hormones, thus integrates nervous and endocrine systems

–»cerebrum— largest and most complex part of the brain , 80% of total brain volume—processes much of the sensory input to the brain and initiates many motor responses – also is the center for many of the more complex functions of the brain, including learning, memory, abstract thinking and personality