General structure of the nervous system Flashcards Preview

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Flashcards in General structure of the nervous system Deck (65):
1

What is the PNS made up of?

Nerves and ganglia

2

What is the brainstem composed of?

Midbrain, pons and medulla

3

Where is the white matter located in the cortex?

Inner

4

What is white matter composed of in the cortex?

Myelinated axons and glia

5

Where is the grey matter located in the cortex?

Outer

6

What is the grey matter composed of in the cortex?

Neuron cell bodies and glia

7

What cell type is found in both they grey and white matter of the cortex?

Glial cells

8

What technique can be used to visualise only white matter tracts in the brain?

Diffusion weighted MRI

9

What can diffusion weighted MRI be utilised for?

Viewing white matter tracts in the brain

10

Where does the kink/change in direction of the brain occur?

Between midbrain and diencephalon

11

What is the consequence of the kink/change in direction of the brain?

Twist in brain axis
Dorsal shifts from being 'upwards' to 'backwards'

12

What separates the two cerebral hemispheres?

Longitudinal fissure

13

What does the longitudinal fissure separate?

Left and right cerebral hemispheres

14

What are the ridges in the cerebrum called?

Gyri

15

What are gyri?

Ridges in the cerebrum

16

What are the grooves in the cerebrum called?

Sulci

17

What are sulci?

Grooves in the cerebrum

18

What is the surface of the cerebrum?

Cerebral cortex

19

What is the functional significance of the four lobes of the cortex?

Very limited functional significance
They are arbitrary boundaries

20

Why are Brodmann areas significant?

Functional mapping of the brain, with defined boundaries that are functionally significant

21

What are Brodmann areas based on?

Cellular differences

22

How are the left and right cerebral hemispheres joined?

Corpus callosum

23

Describe the structure of the cortex?

1 cm thick
Outer grey matter, inner white matter
Layered structure (6 layers)

24

What types of neurons are found in the cortex?

Pyramidal neurons and interneurons

25

What are the major roles of the cerebellum?

Motor control
Comparing what you want to do with what you are doing
Refines execution of motor program

26

Where are most of the brain's neurons located?

Cerebellum (half of all neurons)

27

Where are basal ganglia found in the brain?

Diencephalon
Deep within brain, beneath white matter

28

What are the roles of basal ganglia?

Motor control
Selects and initiates voluntary movements

29

What is the consequence of damage to the basal ganglia?

Parkinson's Disease
Huntington's Disease

30

Within which brain structure is the thalamus found?

Diencephalon

31

What is the major role of the thalamus?

Major sensory relay to cortex

32

Describe the structure of the thalamus?

Pair of nuclei
Distributed bilaterally

33

Describe the three ways in which thalamic nuclei project?

1. Relays sensory info to cortex
2. Relays non-sensory info from cortex and basal ganglia to specific areas of cortex
3. Projects globally to cortex

34

What are the major roles of the hypothalamus?

Regulates homeostasis
Controls pituitary

35

Where is the pituitary gland located relative to the hypothalamus?

Located beneath it

36

What are the major functions of the brainstem?

Facial muscle control
Control of sensation from face and head
Cardiorespiratory control
Sleep/wake cycle

37

Which brain structure does the spinal cord connect to?

Medulla

38

Describe the arrangement of grey and white matter in the spinal cord?

Grey matter inner
White matter outer

39

What are the three major regions in the grey matter of the spinal cord?

Dorsal horn
Intermediate zone
Ventral horn

40

What information do the dorsal and ventral horns deal with?

Dorsal horns deal with incoming sensory information
Ventral horns deal with outgoing motor information

41

What are the divisions of the spinal cord?

Cervical
Thoracic
Lumbar
Sacral

42

How does the spinal cord change along its length?

Changes shape, but maintains overall 'H' shape
Enlarged at lower cervical and lumbar regions

43

Where does the spinal cord terminate?

L1/L2

44

What do the spinal segments correspond with?

Each vertebra has a corresponding spinal segment

45

What do spinal segments give rise to?

Pair of spinal nerves

46

What are spinal nerves formed from?

Dorsal and ventral roots

47

What is the DRG?

Dorsal root ganglia
Contains sensory nerve cell bodies

48

Where are DRG found?

Hidden between vertebrae

49

What is the character of most peripheral nerves?

Mixed (both sensory and motor)

50

What is a dermatome?

Region of the body innervated by a bilateral pair of dorsal root ganglia

51

What are ventricles?

Hollow sections of brain that contain CSF

52

List the ventricles found in the human brain?

2 x lateral ventricles
1 third ventricle
1 fourth ventricle
Cerebral aqueduct

53

Where is CSF formed?

Formed by vascular choroid plexus in ventricles

54

Describe the flow of CSF?

Formed in ventricles > flows out at fourth ventricle > bathes brain

55

What is the function of CSF?

Bathes brain and acts as shock absorber

56

List the meninges of the brain?

Dura mater
Arachnoid mater
Pia mater

57

Describe the morphology of the three layers of meninges?

Dura - thick
Arachnoid - fibrous
Pia - thin

58

Where does the CSF lie as it bathes the brain?

Sub-arachnoid space

59

What does the sub-arachnoid space contain?

CSF

60

How is CSF resorbed?

Resorbed by major veins in sub-arachnoid space

61

What is the falx?

Extension of meninges that divides cerebral hemispheres

62

What is the tentorium?

Extension of meninges that separates cerebellum and occipital lobe

63

What is the function of the blood brain barrier?

Limits free access of material in the blood to the brain
So, protects ECF of brain

64

What is the blood brain barrier formed by?

Endothelial cells of capillaries with very tight junctions

65

What type of transport is required for substances to access the brain?

Active transport