Lecture 1 - Organization of the Nervous System

Question 1

What is the CNS and PNS and what are their properties in terms of regeneration?

Answer 1

The CNS is the brain and spinal cord including the neurons and neuroglia located there
The PNS is the neurons and neural tissue elsewhere
-PNS can regenerate CNS cannot regenerate since they are stuck in G0 of the cell cycle

Question 2

What are the two divisions of the PNS and the corresponding subdivisions of those two divisions?

Answer 2

PNS - somatic (voluntary) and autonomic (involuntary)
-the somatic system: afferent sensory neurons; efferent motor neurons
-the autonomic system: parasympathetic (rest and digest) and sympathetic (fight or flight) branches

Question 3

What are the neuroanatomical directions for the brain?

Answer 3

-rostral = close to nose
-caudal = back of brain
-dorsal = top side of brain
-ventral - under belly of brain
-anterior = rostral
-posterior = caudal
-superior = dorsal
-inferior = ventral

Question 4

What are the neuroanatomical directions for the spinal cord?

Answer 4

rostral = top of spinal cord close to brain or the cervical spinal cord
caudal = bottom of spinal cord close to butt or the sacral spinal cord
ventral - spinal cord close to belly
dorsal - spinal cord close to back
anterior = ventral spinal cord
posterior = dorsal spinal cord
superior = rostral spinal cord
inferior = dorsal spinal cord

Question 5

What are the overlaps of the neuroanatomical directions for the spinal cord and brain?

Answer 5

superior = dorsal brain = rostral spinal cord
inferior = ventral brain = caudal spinal cord
anterior = rostral brain = ventral spinal cord
posterior = caudal brain = dorsal spinal cord

Question 6

What are the planes for the brain?

Answer 6

-sagittal plane is vertical - can be mid or parasagittal
-horizontal plane is parallel to the floor
-frontal plane or coronal plane is like a headband

Question 7

What are flexures?

Answer 7

bends only present in utero in development

Question 8

Which flexure persist in bi pedal organisms even after birth and what does it cause?

Answer 8

Cervical flexure; causes a 90 degree bend between the brain and the spinal cord
-in other organisms all the flexures disappear in quadrupedal organisms which make them horizontal organisms since they no longer have the bend

Question 9

What is the cephalic flexure and does it persist?

Answer 9

cephalic flexure - slight bend between the brain stem and the spinal cord
-yes it is present in both bipedal and quadrapedal organisms

Question 10

What is a shallow valley in the brain?

Answer 10

sulcus

Question 11

What is a small hill in the brain?

Answer 11

gyrus

Question 12

What is a deep valley in the brain?

Answer 12

fissure

Question 13

What is the frontal lobe and what is it involved in?

Answer 13

-frontal lobe is rostral in the brain
-involved in executive function and decisions and planning and decision making, cognitive inhibition, motor function, aspects of personality, long terms learning (overall: movement and executive function)

Question 14

What is the parietal lobe and what is it involved in?

Answer 14

-parietal lobe - caudal to the frontal lobe
-involved in somatosensation, detecting innocuous touch and pain, spatial orientation
-when people have a stroke on the right side of the brain they neglect the left side of the body (tends to be contralateral)

Question 15

What is the temporal lobe and what is it involved in?

Answer 15

-the temporal lobe is on the dorsal rostral side of the brain below the frontal lobes
-it is involved in language and memory and speaking; tend to be on the right side of the temporal lobe

Question 16

What is the occipital lobe and what is it involved in?

Answer 16

-the occipital lobe is caudal and ventral in the brain below the parietal lobe
-it is involved in sight such as visual processing and early perception and relaying those perceptions to other lobes (i.e. object, word, and face recognition)

Question 17

What is the central sulcus?

Answer 17

separates the frontal and parietal lobes

Question 18

What is the lateral sulcus or sylvian fissure?

Answer 18

separates the frontal and parietal lobes from the temporal lobe

Question 19

What is the insula and what is it involved in?

Answer 19

-under the sylvian fissure or lateral sulcus and it is below the frontal and temporal lobes
-involved in speech production and processing pain and disgust

Question 20

What is the diencephalon and what two structures does it relate to?

Answer 20

the diencephalon is related to the thalamus and hypothalamus
-the thalamus in the diencephalon functions as a relay center which receives sensory information and relays it to other motor cortical and subcortical regions

Question 21

What is the brainstem, what are the three parts of the brainstem and where is it located relative to the diencephalon?

Answer 21

-the oldest part of the brain where autonomic and essential motor functions are localized to its structures
-midbrain, pons, and medulla oblongata
-it is caudal and ventral to the diencephalon

Question 22

What does the midbrain do and what is another name for it?

Answer 22

-important for motion detection and other visual processing including sound localization as well
-mesencephalon

Question 23

What is the pons, what structure is it related to, and what is another name for it?

Answer 23

-important to note that between the pons and cerebellum is the fourth ventricle
-related to the bulb
-it and the cerebellum form the mentencephalon

Question 24

What is the medulla oblongata and what is another name for it?

Answer 24

-controls the respiratory system and the heart rate via the autonomic nervous system
-myencephalon

Question 25

What exits the brainstem?

Answer 25

cranial nerves

Question 26

What is the corpus callousum and what does it have alot of due to its axonal projections?

Answer 26

-great extent of white matter
-is a white matter bridge which communicates between the two hemispheres

Question 27

What other two structures also help communicate between the two hemispheres of the brain?

Answer 27

-anterior and posterior commissure

Question 28

Where is the cerebellum located in the brain?

Answer 28

caudal and ventral

Question 29

What is gray matter and what is an example of it in the CNS and PNS respectively?

Answer 29

-gray matter is the accumulation of cell bodies
-in the CNS that is the cell bodies of neurons which exist in a terms called nuclei or nucleus if singular cell cluster
-in the PNS the cell bodies of neurons are called ganglia or ganglion if singular
-in the CNS and PNS nuclei and ganglia are used to define a set of cells which work together

Question 30

What is white matter and why is it white?

Answer 30

-the axons of the cell bodies which project out
-it is white due to the high lipid content of the axons since they are myelinated

Question 31

What is the arrangement of white and gray matter in the spinal cord and what “shape” does it seem to form?

Answer 31

-the white matter surrounds the central gray matter creating a butterfly esque shape

Question 32

What is the meninges?

Answer 32

-three layers which protect the brain and spinal cord

Question 33

What are the three layers of the meninges?

Answer 33

-dura mater
-arachnoid layer
-pia mater

Question 34

What is the dura mater?

Answer 34

-outer meningeal layer which translates to tough mother and provides protection between the brain and the skull and the spinal cord and the vertebral column

Question 35

What is the arachnoid layer and what does it contain?

Answer 35

-the middle meningeal layer
-it is named for its resemblance to spiderwebs since it contains collagen and connective tissue and sinuses; very dense connective tissue

Question 36

What are sinuses?

Answer 36

-empty cavities in the brain

Question 37

What is the Pia mater?

Answer 37

-the innermost meningeal layer
-translated to soft mother and contains blood vessels; very attached to the cortical surface and has great vasculature due to blood vessels making it difficult to separate from the brain

Question 38

What is the condition when the three meningeal layers are inflammed?

Answer 38

meningitis

Question 39

What is a ventricle and how many total are there in the brain?

Answer 39

-a deliberate hole or cavity in the brain filled with CSF
-the four ventricles plus the central hole through which the spinal cord passes

Question 40

What is CSF?

Answer 40

-cerebrospinal fluid and it is a filtrate of blood filled with ions and molecules needed for the brain

Question 41

What structure are the lateral ventricles associated with?

Answer 41

the forebrain

Question 42

What cluster of cells is found near the lateral ventricles and what do they do?

Answer 42

arachnoid clusters; produce CSF

Question 43

How does CSF travel?

Answer 43

through the ventricles and then to the spinal cord where it is recycled
1.CSF is produced by the arachnoid clusters surrounding the lateral ventricles
2. CSF flows to the third ventricle below the hypothalamus
3. CSF travels down to the central canal which reaches the spinal cord

Question 44

What happens if a tumor is present in the ventricle?

Answer 44

the ventricles can misshapen causing pressure on the surrounding brain tissue

Question 45

What is the term for abnormally large ventricles and what can it cause?

Answer 45

-hydrocephalus, causes pressure on other tissues

Question 46

What are the four cranial nerve associated with the eye?

Answer 46

optic nerve CN II (sensory)
oculomotor nerve CN III (motor)
trochlear nerve CN IV (motor)
abducens nerve CN VI (motor)

Question 47

What are the three cranial nerves associated with the tongue?

Answer 47

-facial nerve CN VII (both sensory and motor)
-glossopharyngeal nerve CN IX (both sensory and motor)
-hypoglossal nerve CN XII (motor)

Question 48

What does the optic nerve CN II do?

Answer 48

-sensory neuron which convey info from the retina about visual stimuli

Question 49

What does the oculomotor nerve CN III do?

Answer 49

-motor nerve which controls four out of the six intraocular muscles that allow for light movement and the pupillary light reflex

Question 50

What does the trochlear nerve CN IV do?

Answer 50

-somatic motor neuron which controls one of the six ocular muscles

Question 51

Whats does the abducens nerve CN VI do?

Answer 51

-somatic motor neurons which controls one of the six ocular muscles

Question 52

What does the facial nerve CN VII do?

Answer 52

-both sensory and motor and it controls sensation in the face and is not regulated by the trigeminal nerve; controls the anterior two thirds of the tongue to convey feeling and gustatory info

Question 53

What does the glossopharyngeal nerve CN IX?

Answer 53

-both sensory and motor controls the gustatory info from the posterior one third of the tongue and the muscles for swallowing

Question 54

What does the hypoglossal nerve CN XII do?

Answer 54

-motor nerve which controls the muscles for speech

Question 55

What are the four regions of the spinal cord going rostral to caudal?

Answer 55

-cervical - neck and upper back
-thoracic - torso or trunk region
-lumbar - hips and legs
-sacral - lower back

Question 56

What is the dorsal horn of the spinal cord?

Answer 56

-where sensory cell bodies or gray matter is

Question 57

What is the ventral horn of the spinal cord?

Answer 57

-where motor cell bodies or gray matter is

Question 58

What happens to the cranium and brain in size with evolution?

Answer 58

-it shrinks and has more sulci or gyri

Question 59

What is indicative of greater complexity in the brain?

Answer 59

-more sulci and gyri
-size is not indicative