[EXAM 2] CNS

Question 1

What cells make up nervous tissue?

Answer 1

Neurons and Glia

Question 2

What are neurons?

Answer 2

the functional unit of the nervous system

Question 3

What are glia cells?

Answer 3

non-conducting support cells in contact with neurons

Question 4

What systems make up the nervous system?

Answer 4

Central nervous system

Peripheral system

Question 5

What is composed in the CNS?

Answer 5

Brain and spinal cord

Question 6

What divisions make up the the peripheral nervous system?

Answer 6

Sensory Division–> Visceral Sensory Division/ Somatic sensory division

Motor Division–> Visceral Motor Division–> Sympathetic Division & Parasympathetic division & Enteric Division
–> Somatic Motor Division

Question 7

What makes up a neuron?

Answer 7

Cell Body (soma, perikaryon)
Nissl bodies
Dendrites
Axon Hillock 
Axon
Myelin Sheath

Question 8

What is a multipolar neuron?

Answer 8

many dendrites ,one axon

• from CNS to periphery (signal such as muscle to contract)
• integrative-neuron to neuron in CNS, ganglia, or special sense organs

Question 9

What is a bipolar neuron?

Answer 9

one dendrite, one axon
-special sense organs- often the cells that translate something physical or mechanical into electrical impulse to be sent to the brain

Question 10

What is a unipolar (pseudounipolar) neuron?

Answer 10

no dendrites, one axon

-Sensory- often found in ganglia ,carries signal from periphery to CNS

Question 11

What is a anaxonic neuron?

Answer 11

many dendrites, no axon

Question 12

What are motor neurons?

Answer 12

function: conduct impulses from CNS or ganglia to effector cells (muscles or glands)
Somatic efferent neurons: send voluntary impulses to skeletal muscle
Visceral efferent neurons- send involuntary impulses to smooth muscle Purkinje fibers and glands

Question 13

What are interneurons?

Answer 13

form a network between sensory and motor neurons

Question 14

What are sensory neurons?

Answer 14

Function: conduct impulses from the receptors or sense organs to the CNS

Somatic afferent fibers- convey sensations of pain, temperature, touch and pressure from the body surface, as well as pain and proprioception from organs within the body

Visceral afferent fibers- transmit pain impulses and other sensations from internal organs, mucous membranes, glands and blood vessels

Question 15

What cells are myelinated?

Answer 15

Oligodendrocytes-CNS

Schwann Cell- PNS

Question 16

What part of the nerve fiber do signals use to “skip” along the nerve fiber?

Answer 16

Node of Ranvier

Question 17

Are Schwann cells myelinated?

Answer 17

Yes and they have extended cytoplasm

Question 18

What are the two main demyelinated diseases talked about in lecture 1?

Answer 18

Multiple Sclerosis (Oligodendrocytes are having their myelin attacked by immune system)
Guillain-Barre syndrome (Schwann cells are having their myelin attacked by immune system)

Question 19

What is the order from smallest to largest of peripheral nervous tissue/connective tissue covering?

Answer 19

axon+myelin —> nerve fiber —> endonerium –> nerve fascicle –>perineurium–> epinerium –> nerve

Question 20

Describe the difference between a chemical synapse and electrical synapse

Answer 20

differ morphologically and by mechanism

Chemical synapse

• Vesicles contain neurotransmitters stored in the axon terminal
• released when electrical impulse reaches the axon terminal
• bind to receptors on effector cell
• has a neural junction

Electrical synapse
-use gap junction channel and coupling potentials

Question 21

What is a nucleus?

Answer 21

a group of neuron cell bodies in the CNS

Question 22

What is a tract?

Answer 22

a group of nerve fibers traveling in parallel

Question 23

What is a nerve fiber?

Answer 23

axon, or axon +myelin sheath

Question 24

What is gray matter?

Answer 24

Area of gray matter where neuron cell bodies are located

Question 25

What is white matter?

Answer 25

area of the CNS with no neuron cell bodies

Question 26

What is the Soma or perikaryon?

Answer 26

neuron cell body (conducting)

Question 27

What are glial cells?

Answer 27

support cells, nonconducting

Question 28

What does a myelin stain show?

Answer 28

myelinated axons

Question 29

What does a silver stain show?

Answer 29

shows nerve fibers and cell bodies

Question 30

What is the Golgi method?

Answer 30

shows the cell body, axons and dendrites in their entirety

Question 31

What do Nissl stains show?

Answer 31

shows Nissl substance (show ribosomes and rough ER) | -axon hillocks appear best in Nissl or toluidine blue

Question 32

What are the four main anatomical sections of the CNS?

Answer 32

Meninges- connective tissue cover of the brain and spinal cord Brain- anatomy of the brain + main cranial nerves Spinal cord- main nerves that transmit sensory to the brain and motor to the periphery Blood supply- main vessels that feed the brain and spinal cord

Question 33

Describe the layers of the meninges?

Answer 33

Dura mater- tough, outer layer; dense irregular connective tissue Arachnoid matter- transparent, middle layer; thin, delicate CT lined with simple squamous epithelium - subarachnoid space- filled with CSF Pia mater- delicate, inner layer; the thin layer of CT lined with simple squamous epithelium

Question 34

What are the regions of the spinal cord?

Answer 34

cervical thoracic lumbar sacral

Question 35

What are the enlargements of the spinal cord?

Answer 35

Cervical-nerves feed upper limb | Lumbosacral-nerves that feed lower limbs

Question 36

What is the medullary cone?

Answer 36

cone shape terminal portion of the spinal cord found between the L1 and L2 serves to stabilize the spinal cord by connecting the conus to the coccyx via the coccygeal ligament

Question 37

What is the Cauda equine?

Answer 37

bundle of nerves at the lower end of the spine

Question 38

What is the function of the spinal cord?

Answer 38

Conduction - sensory information ascends - motor commands descend Neural integration - processing of information from diverse sources Locomotion -central pattern generators coordinate simple repetitive movements Reflexes -involuntary stereotyped responses to stimuli

Question 39

What is the spinal tract?

Answer 39

``` in the spinal cord Ascending -carries sensory information to the brain Descending -carries motor information from the brain. Contralateral -crosses the midline Ipsilateral -does not cross the midline ```

Question 40

What are the regions of the brain?

Answer 40

``` Cerebrum -Cerebral cortex -Basal ganglia -limbic system Brain Stem -midbrain - pons -medulla Diencephalon - Thalamus -Hypothalamus Cerebellum ```

Question 41

What components make up the cerebrum?

Answer 41

cerebral cortex basal ganglia limbic system

Question 42

What makes up the brain stem?

Answer 42

midbrain pons medulla

Question 43

What makes up the diencephalon?

Answer 43

Thalamus | Hypothalamus

Question 44

What are the major landmarks for the cerebrum?

Answer 44

- Two cerebal hemispheres - Gyri-folds - Sulci- grooves - longitudinal cerebral fissure-big sulcus between hemispheres

Question 45

What is the cerebellum responsible for?

Answer 45

balance and control fine motor movement muscle tone coordination maintenance of normal posture

Question 46

What are the layers of the cortex in the cerebellum?

Answer 46

Molecular layer Purkinje layer Granular layer

Question 47

What lobes make up the cerebrum?

Answer 47

``` Frontal Pariental Occipital Temporal Insula ```

Question 48

What are functions of the cerebrum?

Answer 48

``` control voluntary motor activity receive and store sensory information sensory processing learning and memory language and communication integration and coordination of other nerve activity ```

Question 49

What are the layers of the cerebral cortex?

Answer 49

- plexiform layer - external granular layer - may contain pyramidal cells - medium pyramidal cell layer - internal granular layer - large pyramidal layer - polymorphic layer

Question 50

What makes up the Diencephalon?

Answer 50

Thalamus -relay and integration -relay nuclei: motor and sensory information - association nuclei: connect to the limbic system (awareness, emotion, memory) Midline nuclei: stress, fear, reward Hypothalamus-connects the nervous and endocrine system - connects to the limbic system, brainstem, regulates emotions, autonomic control, thermoregulation Epithalamus -dorsal region of the diencephalon containing mainly the pineal gland

Question 51

What makes up the brainstem?

Answer 51

Midbrain - cranial nerves III & IV function: motor control, pain, visual attention, and auditory attention Pons: cranial nerves V-VII, some of VIII function: facial sensation and expression, control of chewing, respiration, and sleep Medulla oblongata: cranial nerves IX, X, XI, and some of VIII function-respiration, heart rate, blood pressure, etc.

Question 52

Where cerebral spinal fluid held?

Answer 52

``` Lateral ventricles - Interventricular foramen -choroid plexus Third Ventricle - cerebral aqueduct -choroid plexus Fourth Ventricle -choroid plexus Central Canal ```

Question 53

Where is CSF made?

Answer 53

Choroid plexus

Question 54

What glial cells make up the CNS?

Answer 54

Astrocytes- Structure: large cells with processes that form networks Function: provide physical and metabolic support Oligodendrocytes Structure: small cells Function: synthesize and maintain myelin Microglia Structure: small cells with small dark elongated nuclei Function: phagocytic Ependymal cells Structure: columnar cells Function: move fluid, synthesize CSF in brain ventricles

Question 55

What are the blood-brain barrier components and its function?

Answer 55

endothelial cells basal lamina end foot processes of astrocytes function: protect CNS by restricting the passage of molecules