Organization of the Nervous System

Question 1

Describe dendrites

Answer 1

-collect electric signals
-have ion channels

Question 2

What is a cell body

Answer 2

-integrates incoming signals and generates outgoing signal to an axon

Question 3

What is the purpose of the axon

Answer 3

-passes electrical signals to dendrites of another cell

Question 4

What is the CNS

Answer 4

-brain and spinal cord
-integrates, processess and coordinates sensory data and motor commands

-where higher functions lie
->intelligence
->memory
->learning
->emotions

Question 5

What is the PNS

Answer 5

-carries sensory information from receptors to the CNS
->afferent

-carries motor commands from the CNS to the periphary

Question 6

Describe the brain in terms of the CNS? What are the three major parts

Answer 6

-cerebrum, brainstem, cerebullum(little brain)

Question 7

How is the PNS divided into nerves

Answer 7

-31 pairs of spinal nerves
-12 pairs of cranial nerves

Question 8

What is the term for a collection of axons for CNS vs PNS

Answer 8

-CNS is a tract
-PNS are nerves

Question 9

How is the CNS protected

Answer 9

-it is protected by:

-bone encases the brain

-meninges
->dura(thickest meninges) and wraps the brain
->arachnoid matter is in the middle(you can see blood vessels through it)
->pia matter is closest to the cerebral cortex

-cerebral spinal fluid in between arachnoid and pia matter
->CSF runs all around the brain

Question 10

Is there space between dura, skull and arachonoid matter

Answer 10

-no

Question 11

Describe the arachnoid matter

Answer 11

-sealed in epithelial tissue
-if you are touching blood vessels, you know you are touching the arachnoid matter

Question 12

What are gyri or gyrus

Answer 12

-the lumps on the brain

Question 13

What are valleys in between gyri

Answer 13

-sulcus or sulci

Question 14

What happens as you grow up from being a new born to an adult

Answer 14

-increased folds
->increased surface area as a result
->more cortical tissue added as a result

Question 15

What is a major sulci in the brain

Answer 15

-the central sulcus
->divides the brain into its lobes
->a border

-divides the precentral gyrus(primary motor cortex) and the post central gyrus(primary somatosensory cortex)

Question 16

What is a fissure

Answer 16

-a bigger sulcus
->an example is the lateral(sylviian) fissure
->also helps you find the lobes of the brain

Question 17

Where is the precentral gyrus

Answer 17

-it is in the frontal lobe

Question 18

Where is the postcentral gyrus

Answer 18

-it is in the parietal lobe

Question 19

What are features of the frontal lobe

Answer 19

-thinking, planning, personality
-motor planning
->frontal lobe is the motor coordinating part of the brain

Question 20

What are the features of the parietal lobe

Answer 20

-it deals with sensation, association, perception
->parietal lobe interprets sensations

Question 21

What are the features of the occipital lobe

Answer 21

-it is for vision

Question 22

What are the features of the temporal lobe

Answer 22

-auditory cortex, learning and memory

Question 23

What does more innervation for a tissue mean for cortical space

Answer 23

-more innervation-increased cortical space

Question 24

What is the grey matter

Answer 24

-cortex

Question 25

What is the white matter

Answer 25

-medulla

Question 26

Where do cortical neuronal cell bodies reside in

Answer 26

-they reside in the cortex(gray matter) ->they are not mylienated

Question 27

Where do axons of cell bodies extend into?

Answer 27

-they extend into the medulla ->they are mylienated in most cases

Question 28

What is a short association fiber

Answer 28

-it goes from one gyrus to another

Question 29

What are long association fibers

Answer 29

-staying in the same side of the hemisphere ->they can go from one lobe of the brain to another -an example would be limbic system

Question 30

What is a commissural fibers

Answer 30

-axons that crosses into another side of the brain hemisphere -communication between the different sides of the brain

Question 31

What are projection fibers

Answer 31

-go down from brain to spinal cord or brain stem

Question 32

Is spinal cord encased in bone

Answer 32

-yes

Question 33

Describe the grey matter of the spinal cord

Answer 33

-central canal for the CSF -Dorsal horn ->receives sensory information from the periphary nervous system -ventral horn ->motor commands to motor neurons

Question 34

What surrounds the grey matter of the spinal cord

Answer 34

-mylienated axons

Question 35

Where in the brain do cranial nerves come off

Answer 35

-brain stem

Question 36

Where do spinal nerves come off

Answer 36

-they come off the vertebrae

Question 37

How many cervical vertebrae and neurons

Answer 37

-7 cervical vertebrae and 8 cervical neurons

Question 38

How many thoracic vertebrae and nerves

Answer 38

-12

Question 39

How many lumbar, sacral and coccygeal vertebrae and nerves

Answer 39

-Lumbar(5) -Sacral(5) -Coccygeal(1)

Question 40

What is the plexus

Answer 40

-bunch of spinal nerves that intermix with each other

Question 41

Where do bunch of spinal nerves that don't intermix

Answer 41

-segmental ->T2-T12

Question 42

Where are the cell bodies of sensory neurons found

Answer 42

-in the dorsal root ganglion of the PNS

Question 43

Does the spinal cord have dorsal sensory and ventral motor

Answer 43

-yes

Question 44

Are the motor roots in the CNS or PNS

Answer 44

-CNS -the sensory roots are in the opposite, or the PNS

Question 45

What is the dorsal ramus and the ventral ramus

Answer 45

-the dorsal innervates the back of the body, while the ventral innervates the front of the body -they both have motor, sensory and autonomic nerves

Question 46

What is the dermatome

Answer 46

-band of skin with its own sensory innervation

Question 47

Describe the 5 landmark dermatomes

Answer 47

-T2=sternal angle -T4=nipple -T7=xiphoid -T10=umbilicus -L1=suprapubic -the dermatomes in between those landmarks can be filled in

Question 48

What does the somatic nerves innervate

Answer 48

-skin, muscle, bone of body wall -parietal membranes(pleura, pericardium, peritoneum)

Question 49

Why is the T7 spinal nerve important

Answer 49

-because that is where the dorsal primary and ventral primary ramus seperates -dorsal primary goes to pravertebral muscles -the ventral primary ramus goes to skeletal muscle such as intercostal muscles or abdominal muscles

Question 50

Where does the sensory afferent travels

Answer 50

-it travels via visceral afferent fibres -there are other ones specific for pain sensation

Question 51

Where in the spinal cord is the sympathetic nervous system housed

Answer 51

-thoracolumbar outflow

Question 52

Where is the parasympathetic nervous system housed

Answer 52

-craniosacral outflow

Question 53

Does the sympathetic nervous system go to the skin at all levels?

Answer 53

-yes -sweat glands, skin, shivers

Question 54

Does skin have pharasympathetic

Answer 54

-no

Question 55

Are the sympathetic and parasympathetic nervous system two cell body systems

Answer 55

-yes ->both have preganglionic and postganglionic cell bodies -para has a longer preganglionic axon, while it is the opposite for the sympathetic

Question 56

Is visceral afferents associated with sympathetic

Answer 56

-yes ->primarily for pain ->ischemia or inflammation

Question 57

Why is there sympathetic innervation at every level of skin

Answer 57

-because sympathetic is just at thoracolumbar ->to reach everything else, all part of the skin ned to be innervated

Question 58

What are the sympethatic nerves that go to the heart directly

Answer 58

-cardiac nerves

Question 59

What are the 3 different paths for sympathetic

Answer 59

-skin -heart -digestion

Question 60

Is direct pain always somatic

Answer 60

-yes -it is sharp, well focused and easily localized -carried by spinal nerves

Question 61

What is referred pain

Answer 61

-pain that arises from an injured or inflamed structure in the body -you get injury in one place but feel the pain elsewhere -feeling of tingling in your fingers after hitting your funny bone

Question 62

How is referred pain classified

Answer 62

-somatic or visceral -visceral is always referred to dermatome ->no visceral map in the brain

Question 63

Describe visceral referred pain

Answer 63

-the pain arises from the visceral organ but goes to the dermatome ->so that's because it is carried by visceral afferent fibres, which respond to stretch, ischemia and chemoreception

Question 64

How does the pain of visceral referred pain feel

Answer 64

-it is vague, dull and ill focused