Unit 10

Question 1

2 functions of the spinal cord

Answer 1

1. Essential structural and functional link between brain and torso and limbs. Inputs and outputs. Information goes up and down the spinal cord
2. Spinal reflexes. Iniate fastest reaction to stimulus. Ex you touch something hot you immediately take your hand off.
   (carries input and output)

Question 2

Cranial Meninges

Answer 2

Dura mater
Arachnoid mater
Pia mater

Question 3

Dura Mater

Answer 3

thick, fibrous heavy layer than forms a tough sac that encloses cord. 2 spaces associated, subdural space (internal) and epidural space (external)

Question 4

Arachnoid mater

Answer 4

up against dura mater. Partially exposed of delicate web. Immediately deep is the subarachnoid space.

Question 5

Pia Mater

Answer 5

pressed up against the cord supplies nutrients to cord. External, mesh like made up of elastic and collagen fibres

Question 6

Epidural space

Answer 6

runs outside the dura mater

Question 7

Subdural space

Answer 7

Between the dura and arachnoid

Question 8

Subarachnoid space

Answer 8

Between cord and arachnoid mater, where CSF circulates

Question 9

Gray matter

Answer 9

is formed from neuronal cell bodies and dendrites (no myelin). Functional process center. Resembles an H or a butterfly.

Question 10

Anterior Gray horn

Answer 10

part of the spinal gray matter which is situated ventral to the central canal. It is motor in function and is the place where motor information exits from the central nervous system through efferent neurons to reach out to the effector organs, including muscles and glands.

Question 11

Lateral gray horn

Answer 11

the central component of the sympathetic division of the autonomic nervous system.

Question 12

posterior gray horns

Answer 12

part of the spinal gray matter which is situated dorsal to the central canal. It is sensory in function and is the place where information from the body surface and underlying tissues first reaches the central nervous system.

Question 13

White matter

Answer 13

formed of aggregations of myelinated axons from many neurons (The lipid part of myelin imparts the white appearance) (fatty substance) (info transmits) (delivering)

Question 14

Sensory pathways

Answer 14

Nerve signals ascend to the brain in sensory pathways

Question 15

Primary nerve

Answer 15

First neutron in the chain, Extends from sensory receptors to CNS where it synapses with a secondary neuron

Question 16

Secondary Neuron

Answer 16

an interferon. It extends from the primary neutron to either tertiary or cerebellum

Question 17

Teritary

Answer 17

Also interneuron. It extends from the secondary neutron to the cerebellum. Pathways that lead to the cerebellum of non have tertiary neurons

Question 18

posterior funinculus-medial lemniscal pathway

Answer 18

transmits information about discriminative touch and proprioception (uses 3 chain)

Question 19

anterolateral pathway

Answer 19

detects crude touch, pressure, pain, and temp. 3 chain.

Question 20

Spinothalamic tract

Answer 20

a sensory tract that carries nociceptive, temperature, crude touch, and pressure from our skin to the somatosensory area of the thalamus.

Question 21

Spinocerebellar Pathway

Answer 21

Only uses 2 chains to transmit. The sensory input provides information to the brain (maintain balance and posture)

Question 22

Motor Pathways

Answer 22

Start in brain and works its way down. Begins in the primary motor areas of the brain

Question 23

Upper Motor Neurons

Answer 23

connects to the appropriate level in spinal cord. Info tells muscle to start to move.

Question 24

Lower motor Neurons

Answer 24

descend to innervate skeletal muscle. The entire function of the CNS is manifested through the lower motor neuron.

Question 25

Endoneurium

Answer 25

surrounds axon

Question 26

Fascicles

Answer 26

bundles of axon

Question 27

Perineurium

Answer 27

surrounds fascicles

Question 28

nerves

Answer 28

bundles of fascicles

Question 29

Epineurium

Answer 29

surround nerve

Question 30

Reflex arc

Answer 30

a neural pathway composed of neurons that control rapid, subcutaneous, preprogrammed responses to a stimulus.

Question 31

Spinal reflexes

Answer 31

a fast, involuntary response to a stimulus. In a spinal reflex the integration takes place in the spinal cord, not the brain

Question 32

Spinal reflexes involve

Answer 32

stimulus, rapid, preprogrammed, involuntary

Question 33

monosynaptic

Answer 33

has only a sensory and a motor neurone and lacks an interneuron. There is direct communication between sensory and motor neurons

Question 34

Polysynaptic

Answer 34

has one or more inter neurons positioned between the sensory and the motor neurons. These reflex arcs are more complicated and not as rapid. Interneurons facilitate sensory-motor communication.

Question 35

Stretch reflex

Answer 35

causes contraction of a skeletal muscle -Monosynaptic reflex arc. Initated by a muscle spindle.

Question 36

Steps in stretch reflex

Answer 36

1. muscle spindle detects stretch
2. muscle stretch stimulates sensory nerve signals to travel to the CNS
3. sensory nerve directly stimulates a motor neuron
4. motor neurons transmit nerve signals to extramural muscle fibres resulting in contraction of the muscles
5. Interneurons synapse with a motor neuron antagonist muscle inhibiting muscle contraction

Question 37

tendon reflex

Answer 37

(Golgi tendon reflex) Is initiated by Golgi tendon organ proprioceptor
1. muscle contraction increases tension to tendons by Golgi tendon organ
2. nerve signals are propagated along sensory neurones to the CNS
3. sensory neurones stimulate interneurons within the spinal cord
4. Interneruson inhibit a motor neuron to muscle
4b. interneurons stimulate a motor neurons to antagonist muscle
5. muscle relaxes and there is a relief of tension on tendon
5b. Muscle contracts

Question 38

Withdrawl reflex

Answer 38

often occurs when contracting a body part from a painful stimulus.

Question 39

Crossed-Extensor reflex

Answer 39

occurs in conjunction with the withdrawal reflex. Usually the lower limbs.

Question 40

how many pairs of spinal nerves

Answer 40

31

Question 41

what are all the spinal nerves

Answer 41

8 cervical, c1-c8
12 thoracic, T1-T12
5 lumbar, L1-L5
5 Sacral, S1-S5
1 coccygeal

Question 42

Anterior root

Answer 42

contains motor neurons that extend to effectors. Relay nerve signals from the spinal cord and control effectors. Does not contain ganglion.

Question 43

posterior root

Answer 43

houses sensory neurons that extend from sensory receptors relay receptors to the spinal cord. Positioned along the length of the axon. They are located external to spinal cord and form the posterior root ganglion