Nervous System

Question 1

what is the nervous system

Answer 1

-communication and control system of the body
-monitors conditions then directed actions and responses
-uses neurotransmitters to carry messages

Question 2

neurotransmitters

Answer 2

-chemical messengers to carry messages (acetylcholine)
-produced by neurons and travel short distances across synapses
-rapid but short response

Question 3

2 divisions of the nervous system

Answer 3

-central nervous system
-peripheral nervous system

Question 4

central nervous system (CNS)

Answer 4

-brain and spinal cord
-concious mind
-control centers for digestive, respiratory, and other body functions

Question 5

Peripheral Nervous System (PNS)

Answer 5

-nerves that link the CNS to the rest of the body

Question 6

where do nerves originate from?

Answer 6

directly from the brain (cranial nerves) or from spinal cord (spinal nerves)

Question 7

spinal cord

Answer 7

-extends from brain within the spinal canal

Question 8

how is the spinal canal formed?

Answer 8

by the arches of vertebrae

Question 9

brain

Answer 9

-within skill
-4 parts

Question 10

what are the 4 divisions of the brain

Answer 10

-cerebrum
-cerebellum
-diencephalon
-brainstem

Question 11

cerebrum

Answer 11

learning, intelligence, memory

Question 12

cerebellum

Answer 12

coordinated movement, balance

Question 13

diencephalon

Answer 13

location of hypothalamus and pituitary

Question 14

brainstem

Answer 14

functions related to heart, breathing, subconscious functions

Question 15

sensory nerve fibers

Answer 15

carry information towards the spinal cord and brain

Question 16

motor nerve fibers

Answer 16

carry information outward from the brain to tell the body what to do

Question 17

neuron

Answer 17

-nerve cell
-smallest functional unit of nervous system
-high requirement for oxygen

Question 18

glial cells

Answer 18

-support and protect neurons
-NOT involved in electrical impulse transmission through nervous system

Question 19

neuron structures

Answer 19

-dendrites
-axon
-schwann cell
-myelin sheath
-node of ranvier
-telotendron
-synaptic knob

Question 20

dendrites

Answer 20

-receive stimuli or impulses from other neurons and conduct stimulation
-may be modified into sensory receptors

Question 21

axon

Answer 21

-long cellular extension that conducts nerve impulses away from the cell body toward another neuron or an effector cell
-bundled together = a nerve
-examples: muscle or gland cell

Question 22

Schwann Cell

Answer 22

-type of glial cell associated with axons of peripheral nerves
-its cell membrane forms the myelin sheath

Question 23

Node of Ranvier

Answer 23

-gaps in the myelin sheath covering between adjacent Schwann cells
-helps increase the speed of impulse conduction

Question 24

Telodendron

Answer 24

-branched end of an axon
-each branch ends at a synaptic knob

Question 25

Synaptic Knob

Answer 25

-area at the end of an axon that releases neurotransmitter

Question 26

8 steps to muscle contraction process

Answer 26

-nerve impulse travels down axon of motor neuron
-realize of acetylcholine from synaptic vesicles
-acetylcholine diffuses across synaptic cleft and binds to receptors on sarcolemma (start of contraction process)
-impulse tacked along sarcolemma and into T-tubules to sarcoplasmic reticulum
-Calcihm ions are released from sarcoplasmic reticulum and diffuse into myofibrils powered by ATP
-actin and myosin filaments interact in ratchet type motion to shorten muscle fibers during contraction
-Calcium ions are pumped back into sarcoplasmic reticulum (ATP) and stops contraction process
-elasticity of muscle fiber restores it to its original length, relaxing fiber