Cells and Tissues of the Nervous System

Question 1

What are the division of the nervous system?

Answer 1

Question 2

What direction do motor and sensory nerves run?

Answer 2

motor - form CNS to periphery

sensory - from periphery to CNS

Question 3

What cells make up the nervous system?

Answer 3

Neurons

Glial cells

Question 4

What are neurons?

Answer 4

structural and functional units of the nervous sytem

excitable cells

impulses are carried as action potentials

Question 5

What are glial cells?

Answer 5

non-excitable cells

supporitng cells

much smaller than neurons but higher in numbers

Question 6

How many dendrites and axons do neurons have?

Answer 6

multiple dendrites

one axon

Question 7

How does an impulse travel through a typical neuron?

Answer 7

in only one direction from cell body to synaptic terminal

Question 8

What are the 2 main types of neuron? and what are they for?

Answer 8

Question 9

What is a sensory neuron called?

Answer 9

pseudounipolar

Question 10

What is a motor neuron called?

Answer 10

multipolar

Question 11

What are the features of a neuron?

Answer 11

Nucleus - loose chromatin, prominent nucleolus

Cell organelles - Mitochondria, rER( Nissl bodies), diffuse Golgi apparatus

High metabolic rate

Cytoplasm in the cell body is perikaryon, and in the axon is axoplasm

Long living and amitotic - dont regenerate when damaged

Question 12

What is the process of an impulse and the events along a neuron?

Answer 12

Question 13

What is the function of the myelin sheath?

Answer 13

Increase conduction speed in axons by ‘saltatory conduction (jumping from one node of Ranvier to the next node)

Question 14

Depending on presence or absence of myelin sheath, neurons may be….

Answer 14

myelinated or non-myelinated

Question 15

What is the myelin sheath formed by?

Answer 15

Schwann cells in PNS

Oligodendrocytes in CNS

Question 16

The clinical importance of the myelin sheath is that it can related to Multiple Sclerosis (MS), how does it?

Answer 16

Patchy loss/scarring of myelin sheath (demyelination) - nerve conduction across affected axons abnormal

Cause unknown (? Viral, ?autoimmune)

Question 17

How owuld demyelination show on an MRI?

Answer 17

whitish plaques of demyelination

Question 18

What is the prognosis of MS

Answer 18

varies

Question 19

What makes up white and grey matter in the spinal cord?

Answer 19

White matter: myelinated axons

Grey matter: neuronal cell bodies

Question 20

What is a tract?

Answer 20

Things carried to and form the brain and carried in tracts

Different modalities clustered together for various speeds

All these different receptors (touch, pain, vibrations, temperature, pressure) are connected to different sensory neurons and their axons pass through spinal cord on the way to the brain and cluster in different bundles

Question 21

What are nuclei?

Answer 21

a nucleus (plural form: nuclei) is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem

Collections of grey mater in the brain are called nuclei and are just collection of neuronal cell bodies

Question 22

What is 1?

Answer 22

sensory so a pseudounipolar

Question 23

What is 2?

Answer 23

dorsal root ganglion

Question 24

what is 3?

Answer 24

tract and white matter

Question 25

What is 4 called?

Answer 25

nucleus

Question 26

Do glial cells carry action potentials?

Answer 26

no they are non-excitable

Question 27

How many types of glial cells are there and where are they located?

Answer 27

4 in CNS and 2 in PNS

Question 28

a

Answer 28

satellite cell

Question 29

b

Answer 29

schwann cell

Question 30

c

Answer 30

astrocytes

Question 31

d

Answer 31

oligodendrocytes

Question 32

e

Answer 32

microglia

Question 33

f

Answer 33

ependymal cell

Question 34

What is the function of satellite cells?

Answer 34

surrounds neuronal cell bodies

Question 35

What is the function of schwann cells?

Answer 35

myelination

Question 36

What is the funciton of astrocytes?

Answer 36

have endfeet - surround synapses and capillaries - help in the blood brain barrier help in K+ buffering

Question 37

What is the function of oligodendrocytes?

Answer 37

myelination

Question 38

What is the function of microglia?

Answer 38

phagocytosis scar tissue formation

Question 39

What is the function of ependymal cells?

Answer 39

line ventricles

Question 40

What is the bloodbrain barrier?

Answer 40

Is a protective mechanism that helps maintain a stable environment for the brain and prevents harmful amino acids & ions present in the bloodstream and blood cells from entering the brain Barrier created between capillaries and brain tissue and prevents a lot of stuff leaking out of the capillaries

Question 41

What 3 things make up the blood brain barrier?

Answer 41

Question 42

A?

Answer 42

cerebrum

Question 43

B?

Answer 43

cerebellum

Question 44

C?

Answer 44

Diencephalon

Question 45

D?

Answer 45

Brainstem

Question 46

What is the function of the cerebrum?

Answer 46

seat of consciousness ^{e.g. interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement}

Question 47

What is the function of the cerebellum?

Answer 47

balance and coordination

Question 48

What makes up the diencephalon

Answer 48

Thalamus Hypothalamus

Question 49

What makes up the brain stem?

Answer 49

the midbrain, the pons and medulla (oblongata)

Question 50

What is the function of the brain stem?

Answer 50

Vital centres eg: cardiorespiratory, Pathway for fibre tracts ^{The brain stem controls the flow of messages between the brain and the rest of the body,controls basic body functions such as breathing, swallowing, heart rate, blood pressure, consciousness, and whether one is awake or sleepy}

Question 51

What is A?

Answer 51

midbrain

Question 52

What is B?

Answer 52

PONS

Question 53

What is C?

Answer 53

Medulla

Question 54

What are ventricles?

Answer 54

cavities in the brain filled with CSF

Question 55

What are the first 2 ventricles called?

Answer 55

The **lateral ventricles** are C-shaped cavities which lie in the cerebral hemispheres

Question 56

What is the 3rd ventricle?

Answer 56

The **interventricular foramen** connects the lateral ventricles with the **3rd ventricle** - the cavity within the diencephalon

Question 57

What part of the ventrical system lies in the midbrain?

Answer 57

The **cerebral aqueduct** lies in the midbrain

Question 58

What is the 4th ventricle?

Answer 58

The diamond-shaped **4th ventricle** lies in the hindbrain

Question 59

Overall what is all of the ventricular system made up of?

Answer 59

The ventricular system is composed of: 2 lateral ventricles the third ventricle the cerebral aqueduct the fourth ventricle

Question 60

What is A?

Answer 60

lateral ventricles

Question 61

What is B?

Answer 61

interventricular foramen

Question 62

What is C?

Answer 62

third ventricle

Question 63

What is D?

Answer 63

cerebral aqueduct

Question 64

What is E?

Answer 64

Fouth ventricle

Question 65

study this picture of the ventricular system

Answer 65

Question 66

What part of the ventricular system do you have in the cerebrum?

Answer 66

Within cerebral hemispheres (x2) = lateral ventricle (x2)

Question 67

What part of the ventricular system do you have in the diencephalon?

Answer 67

3rd ventricle

Question 68

What part of the ventricular system do you have in the midbrain?

Answer 68

cerebral aqueduct

Question 69

What part of the ventricular system do you have between the Pons + medulla (infront) and cerebellum (at back)?

Answer 69

4th ventricle

Question 70

What are the meninges?

Answer 70

3 coverings of the CNS

Question 71

What is A?

Answer 71

dura mater

Question 72

What is B?

Answer 72

arachnoid mater

Question 73

What is C?

Answer 73

pia mater

Question 74

What is the dura mater?

Answer 74

outer layer The dura mater is tough, fibrous and has dural folds

Question 75

What is the arachnoid mater?

Answer 75

spider web like middle layer dont normally see in wet specimens

Question 76

What is the pia mater?

Answer 76

The pia mater is vascularised and dips into the folds of the brain The inner layer

Question 77

What is the subdural space?

Answer 77

Between the dura and arachnoid mater The subdural space is a potential space which is traversed by blood vessels penetrating into the CNS

Question 78

What is present in the subarachnoid space?

Answer 78

The subarachnoid space contains cerebrospinal fluid

Question 79

What is cerebrospinal fluid (CSF)?

Answer 79

fluid in teh cavity of the brain (i.e. the ventricles) and central canal of the spinal cord it is to some extent responsible for maintenance of intracranial pressure also present surrounding the brain and the spinal cord in between the layers of the meninges which are coverings of the brain (between pi and arachnoid mater)

Question 80

Where is CSF present?

Answer 80

Inside ventricles Between pia & arachnoid mater

Question 81

Where is CSF formed?

Answer 81

By choroid plexus in each ventricle

Question 82

Where is CSF absorbed?

Answer 82

By Arachnoid villi (small protrusion of the arachnoid mater) into saggital sinus (venous channel in brain)

Question 83

What is the prcoess of CSF?

Answer 83

CSF secreted by choroid plexus, enters subarachnoid space, absorbed by arachnoid villa

Question 84

What does the blood brain barrier maintain?

Answer 84

Blood Brain Barrier maintains homeostasis in brain parenchyma