Lecture 1 - General Overview

Question 1

What are the two neuroanatomical divisions?

Answer 1

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Question 2

Where is the CNS located?

Answer 2

Along central axis of the body

Question 3

What comprises the CNS?

Answer 3

Brain & Spinal Cord

Question 4

What are the two types of neural tissue in the CNS known as?

Answer 4

Grey matter & White matter

Question 5

In the CNS, grey matter can refer to:

Answer 5

Neuron cell bodies, nuclei

Question 6

In the CNS, white matter can refer to:

Answer 6

Myelinated axons, tracts, fasciculus, commissures

Question 7

What structures are found in the brain portion of the CNS?

Answer 7

Cerebrum, cerebellum, brainstem

Question 8

Where does the spinal cord end? What is the structure inferior to its ending called?

Answer 8

At approx. the lumbar vertebrae of the vertebral column; cauda equina

Question 9

Everything that is NOT the CNS is the?

Answer 9

The PNS!

Question 10

What two groups of nerves are found in the PNS? How many pairs of each are there?

Answer 10

31 pairs of spinal nerves
12 pairs of cranial nerves

Question 11

Spinal nerves enter & exit where?

Answer 11

The spinal cord

Question 12

MOST cranial nerves enter and exit where? Which cranial nerves are the exception?

Answer 12

Brainstem; olfactory & optic

Question 13

PNS Efferent nerves send ________ to the periphery for _____ and ______

Answer 13

motor innervation; muscle control & gland secretion

Question 14

PNS Afferent nerves bring _____ to the ______

Answer 14

Sensory info; CNS

Question 15

What two types of neural tissue are found in the PNS?

Answer 15

Ganglia and nerves

Question 16

Ganglia are groups of what?

Answer 16

Cell bodies

Question 17

Nerves are bundles of what?

Answer 17

Axons

Question 18

How do neurons in the CNS vs PNS respond to injury?

Answer 18

CNS - very limited regeneration; restricts recovery from brain injuries
PNS - neurons here can regenerate! (e.g. cutting your finger off, it can be stuck back on). Spinal nerves & cranial nerves can regenerate

Question 19

A neuron in the CNS may degenerate back of a lack of _______ (___) or lack of ________ (____)

Answer 19

Sender (presynaptic), receiver (postsynaptic)

Question 20

Axon sprouts are guided back together after severage through tubes made by ______ cells

Answer 20

Schwann

Question 21

What divisions are found within the motor system of the somatic nervous system?

Answer 21

pyramidal & extrapyramidal

Question 22

The pyramidal system is concerned with _____, where the extrapyramidal system is concerned with ______

Answer 22

Voluntary motor movement, subconscious motor control

Question 23

Where are the origins of the pyramidal and extrapyramidal systems?

Answer 23

Pyramidal - cerebral cortex
Extrapyramidal - primarily brainstem

Question 24

What two tracts are located in the pyramidal system? What are their responsibilities and where do they synapse?

Answer 24

Corticospinal tract - movement of limbs/trunk, synapses in SC & on lower motor neurons
Corticobulbar tract - movement of face, head & neck, synapses with cranial nerves

Question 25

Damage to the lateral corticospinal tract results in what? These effects occur to muscles _____ to the level of injury

Answer 25

- ipsilateral paralysis (inability to move) - paresis (decreased motor strength) - hypertonia (increased tone) ... Caudal to the level of injury

Question 26

What are the main responsibilities of the extrapyramidal system?

Answer 26

Control of: - involuntary movements for tone/balance - reflexes - movements that have become automatic Facilitates: - voluntary movements Inhibition of: - involuntary movements

Question 27

What are the responsibilities of the sensory system within the somatic nervous system?

Answer 27

Collecting afferent signals from: - skin, joints, and skeletal muscles - the senses of: taste, smell, hearing, balance Relays info about: - limb position - touch - pressure at the body surface

Question 28

The autonomic nervous system is responsible for only involuntary/voluntary control

Answer 28

Involuntary

Question 29

What's the difference between the sympathetic and parasympathetic system?

Answer 29

Sympathetic - increases heart reate, slows digestion (fright, flight, or fight) Parasympathetic - restoring and maintaining homeostasis (rest-and-digest)

Question 30

Where are the cell bodies for the sympathetic and parasympathetic systems?

Answer 30

Symp - thoracic and lumbar regions of SC (legs and lungs!) Parasymp - brainstem & sacral regions of spinal cord (dream & stream!)

Question 31

What are the 5 major divisions of the brain (from top to bottom)

Answer 31

Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon

Question 32

What structures comprise each of the 5 divisions of the brain

Answer 32

Telencephalon - cerebral hemispheres, basal ganglia, parts of limbic system Diencephalon - thalamus, hypothalamus, subthalamus Mesencephalon - midbrain Metencephalon - pons, cerebellum Myelencephalon - medulla oblongata

Question 33

What is the soma of a neuron?

Answer 33

The central body, what contains the nucleus

Question 34

What are dendrites

Answer 34

Tree like structures that project from the soma, 'input structures'

Question 35

What is an axon

Answer 35

A transmission channel Typically one per cell

Question 36

What is a myelinated axon? What disease causes the breakdown of myelin?

Answer 36

Provides insulation and faster speed of transmission Multiple sclerosis - breakdown of myelin

Question 37

Where do we find unmyelinated axons?

Answer 37

Very short axons do not always need myelin to be fast e.g. Touch, heat, pain; hot surface touch reflex

Question 38

How long are axons?

Answer 38

Axons can be short; <100 microns (micron is 1/1000 of a millimeter) to longer than a meter (e.g. sciatic nerve)

Question 39

What are terminal buttons?

Answer 39

Output zones for the axon

Question 40

What are projection neurons?

Answer 40

Long axons - can be efferent or afferent

Question 41

What are interneurons?

Answer 41

Function locally More than 99% of all neurons in the body Connect sensory with motor neurons Interconnect neurons in the brain

Question 42

Upper motor neurons have their cell body and synapse entirely in the _______

Answer 42

CNS

Question 43

Lower motor neurons have their cell body in the ______ and synapse on the _____, making it part of the _

Answer 43

CNS, muscle, PNS

Question 44

The action potential travels along what?

Answer 44

The axon

Question 45

At the _________: neurotransmitters are released into the _______ cleft

Answer 45

Presynaptic terminal, synaptic

Question 46

Neurotransmitters bind to the receptors in the __________ membrane. This is known as a __________ potential, and can be __________ or ________

Answer 46

Post-synaptic, postsynaptic, excitatory or inhibitory

Question 47

One neuron may make contact with up to how many synapses?

Answer 47

10,000!

Question 48

The most abundant cell type in the brain are?

Answer 48

Glial cells

Question 49

Glial cells are also known as?

Answer 49

Support cells

Question 50

What types of glial cells are found in the CNS? What are their functions?

Answer 50

Astrocytes (nutrients and oxygen, recycling neurotransmitters, blood brain barrier, long-term memory and formation of synapses) Oligodendrocytes (myelin sheet around axons) Microglia (immune defense system in the brain)

Question 51

What type of glial cell is found in the PNS? What is its function?

Answer 51

Schwann cells, responsible for the myelin of peripheral nerves