Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology 190 > The Spinal Cord > Flashcards

The Spinal Cord Flashcards

1
Q

What is the spinal cord (SC)?

A

= bundles of nervous tissue and supporting cells
> extends from the medulla oblongata to the superior border of the lumbar 2 vertebra

  • integration center = provides quick, reflexive responses to stimuli
  • sc is the pathway for sensory input to the brain and motor output away from the brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define conus medullaris

A

= the lower end of the sc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define filum terminale

A

=secures the sc to the coccyx (is a pia mater extension)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the sc look like?

A

it is oval shaped slightly, and flattened posteriorly- anteriorly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What protects the sc? (4)

A
  • vertebral colum
  • spinal meninges
  • CSF
  • fat/connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Vertebral column provides?

A

the back bone, skeletal support/protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Spinal meninges provide? What are the three membranes?

A
  1. dura mater (superficial)
  2. arachnoid layer
  3. pia mater (deepest)
  • is connective tissue surrounding the core
  • are continuations of the cranial meninges encircling the brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CSF provides? Where does it lay?

A

lies between the inner and middle meninges (arachnoid and pia)

  • reduces friction
  • absorbs shock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Fat/ connective tissue layer provides?

A

insulation, cushion.

lies in the epidural space (on top of dura) between the dura and vertebral canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define spinal nerves

A

= the paths of communication between sc and body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many spinal nerves do we have?

A

31 pairs > one pair from each vertebra set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 5 sections these nerves are divided into?

A 
cervical (8)
thoracic (12)
lumbar (5)
sacral (5)
coccygeal (1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does each nerve contain?

A

a sensory neuron that supplies part of the body

|&raquo_space; dermatomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define dermatome

A

area of skin on body that supplies enery input to a given spinal segment in the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where do spinal nerves connect?

A

to the sc via ROOTs and ROOTLETS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the posterior root ganglion?

A

= dorsal root ganglion

contains the cell bodies of sensory neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the anterior root ganglion? and rootlets?

A

= ventral root ganglion

contains axons of motor neurons > conduct nerve impulses from the CNS to the effectors

18
Q

each root also ha rootlets. what are rootlets?

A

even smaller bundles of axons

19
Q

What are the steps of processing sensory input? (8)

A
  1. sensory receptors detect and input e.g. pain
  2. sensory neurons convey info > impulses to 3 places
  3. info goes to WM of sc and extends to brain
  4. info > posterior gray horn/ synapses with interneuron
  5. synapse with somatic motor neuron > sc reflex
  6. synapse with motor neurones from anterior gray horn
  7. somatic motor neurons convey output along neurons > thru anterior gray horn/root > enters sc > extends to skeletal muscles
  8. autonomic motor neurons extend to cardiac muscle, smooth muscle and glands
20
Q

What are the two grooves diving the white matter of the sc?

A
  1. posterior median sulcus

2. anterior median fissure

21
Q

Describe the shape of the gray matter in the sc

A

like a butterfly/ ‘letter h’

22
Q

What is the cross bar?

A

the gray commissure

23
Q

What is the central canal?

A

is full of CSF (continuous of the 4th ventricle), extends the length of the sc (right down the middle)

24
Q

What are the characteristics of gray matter?

A
  • contains dendrites and cell bodies
  • contains nuclei
    » motor nuclei provides output via motor neuron
    » sensory nuclei receives inout via sensory neuron
  • is unmyleinated
    -splits into horns
    > posterior (sensory)
    > anterior (motor)
    > lateral
25
Q

What are the characteristics of white matter?

A 
is bundles of white, myleinated axons
- splits into horns
> anterior white
> posterior white
> lateral white
 >>> each contain specific bundles of axons which can span long stances of sc and are called 'tracts'
26
Q

What are the two functions of the SC?

A
  1. nerve impulse propagation: WM contains ascending and descending tracts&raquo_space; are the highways for nerve impulse propagation
  2. integration of information: sc is an integration centre for some reflexes
27
Q

What are two sensory tracts of the sc?

A
  1. posterior column

2. spinothalamic tract

28
Q

Posterior column receives information on…

A
  • touch
  • light pressure
  • vibration
  • proprioception
29
Q

Spinothalamic tract receives information on…

A
  • pain
  • warmth
  • crude touch
  • coolness
  • itching
  • tickling
  • deep pressure
30
Q

The ascending tracts are of ___ information

A

SENSORY

  • keep CNS informed of changes in internal environment
  • are integrated in sc and brain by interneurons
31
Q

the descending tracts are of ___ information

A

MOTOR

  • convey nerve impulses in from the cerebral cortex and brain stem
  • cause voluntary and automatic movements
  • where output to muscles travels
32
Q

Define reflex. Can they be learned? Or are they innate?

A

= fast, involuntary sequence of events
can be learned and innate
- when integration occurs in sc: spinal reflex e.g. knee jerk
- when integration occurs in brain stem: cranial reflex e.g. eye tracking

33
Q

reflex arc

A

pathway followed by a nerve impulse, that produces a reflex

34
Q

What are 4 examples of somatic spinal reflexes?

A
  1. stretch reflex
  2. tendon reflex
  3. flexor (withdrawal) reflex
  4. crossed-extensor reflex
35
Q

Stretch reflex

  • what does it cause/control
  • how can it occur
A

causes contraction of the muscle that has been stretched
can occur by ‘tapping tendons’
controls muscle length by contraction

36
Q

Stretch reflex

  • stimulus
  • receptor
  • integration
  • nerve impulse
  • effect
A

S: muscle stretch or lengthen
R: muscle spindles&raquo_space; generate impulse
I: sensory neuron > motor neuron in anterior gray horn (excitatory synapse)
N: leaves the sc via the anterior root
E: muscle contraction of the SAME muscle stimulated (ACH released > AP > contraction; antagonist relaxed)

37
Q

Tendon reflex

  • what does it control
  • how can it occur
A

controls muscle tension by causing muscle relaxation before the force becomes SO GREAT that the tendons could be torn

38
Q

Tendon reflex

  • stimulus
  • receptor
  • integration
  • nerve impulse
  • effect
A

S: increase in tendon tension
R: golgi tendon organs
I: sensory neuron > activates an inhibitory motor neuron (motor neuron synapse)
N: inhibitory neuron inhibits (hyper.) the neuron THEREBY decreasing impulses generated
E: muscle relaxation > relieves tension ( antagonist muscle contracts)

39
Q

Flexor (withdrawal) reflex

  • what causes it
  • what does it cause
A

occurs with stepping on a tack (for example)
stimulates pain neurons…
is involved in the intersegmental reflex arc

40
Q

Flexor (withdrawal) reflex

  • stimulus
  • receptor
  • integration
  • nerve impulse
  • effect
A

S: pain
R: pain sensitive neuron receptors
I: sensory neurons > activate interneurons > that extend to several sc segments
N: interneurons > activate motor neurons > generate nerve impulse
E: contraction of flexors in the IPSILATERAL thigh

41
Q

Crossed- extensor reflex

  • what causes it
  • what does it cause
A

e.g. stepping on a tack&raquo_space; causing you to lose BALANCE

synchronized flexion of stimulated leg and extension of contralateral leg

42
Q

Crossed-extensor reflex

  • stimulus
  • receptor
  • integration
  • nerve impulse
  • effect
A

S: pain
R: pain sensitive neuron receptors
I: sensory neuron > activates several interneurons (synapse with motor neuron…
- on the OPPOSITE side
- and in several segments of the sc)
N: interneurons activate motor neurons > generate nerve impulse
E: contraction of extensors in thigh of UNstimulated leg switching the weight to the opposite leg

Physiology 190 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions