Brainscape's Knowledge GenomeTM

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


See full index

BIOL 131 - Spinal Cord, Spinal Nerves, and Spinal Reflexes > Nervous System > Flashcards

Nervous System Flashcards

1
Q

What are the (3) main functions of the nervous system?

A

1) Sensory input - sensory receptors monitor changes inside and outside the body

2) Integration - the processing and interpretation of the sensory input

3) Motor output - causing a response by activating effector organs (muscles and glands)

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

What are the two main cell types that make up the nervous system?

A
  1. Neuron (nerve cells) - excitable
  2. Neuroglia (supporting cells) - surround and wrap around neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The Nervous System works through _________ signals?

A

Electrical

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

What is the nervous system?

A

The fast-acting master control and communication system of the body

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

What are the components/process of neural pathways?

A
  1. Receptors: stimulate the sensory neuron to send an electrical signal to the spinal cord (sensory input)
  2. The Signal: is received by an interneuron, which conveys the signal to the cell body of a motor neuron in the spinal cord (integration)
  3. The Motor Neuron: sends the signal to a muscle gland (motor output)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Organization of the nervous system?

A
  1. Central Nervous system - brain and spinal cord
  2. Peripheral Nervous system - spinal and cranial nerves outside the CNS. Divided into
    a) sensory division (afferent) - conveys impulses to the CNS
    b) motor division (efferent) - conveys impulses from the CNS

b) efferent (motor) division: carries instructions out from CNS to effector organs and is divided into:

i) somatic nervous system
- instructions to skeletal muscles
ii) autonomic nervous system
- instructions to visceral effectors (peripheral smooth muscle, cardiac muscle and glands)

ii) autonomic nervous system is divided into
a) sympathetic division - responsible for fight or flight
b) parasympathetic division - responsible for sleep and digest (conserving energy)

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

Where does the spinal cord start and end?

A

Extends from the medulla to the first or second lumbar vertebrae (L1/L2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does information travel to and from the brain?

A

The spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many pairs of spinal nerves are there?

A

31 pairs; exits from the intervertebral foramen that service both the somatic and autonomic nervous system

8 cervical (C1-C8)
12 thoracic (T1-T12)
5 lumbar (L1-L5)
5 sacral (S1-S5)
1 coccygeal (Co1)

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

What is the dura mater?

A

The dura mater is the outermost layer of the meninges, the protective membranes that surround the brain and spinal cord.

it is not attached to the bones of the vertebra, thus an epidural space exists consisting of fat and blood vessels

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

What is an epidural space?

A

The epidural space is a gap between the dura mater (the outermost layer of the meninges) and the inner surface of the vertebral column (bones of the spine) in the spinal cord region. It contains fat and blood vessels, and it plays a key role in medical procedures involving spinal anesthesia or injections.

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

Where is the spinal cord anchored?

A

The coccyx by a fibrous extension of the pia mater called the filum terminale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the cauda equina?

A

Lumbar and sacral spinal nerves; a collection of nerves that exists inferior to the cord, and exits via the lumbar and sacral intervertebral foramen forming the cauda equina (horse tail)

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

What is the conus medullaris?

A

Inferior portion of the spinal cord

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

Spinal cord emerges from brain and descends to _____?

A

L1-L2

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

Cervical enlargement supplies nerves to?

A

Shoulder and upper limb

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

Lumbar enlargement supplies nerves to?

A

Lower limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the cervical and lumbar enlargements?

A

Cervical Enlargement:

Location: Found in the cervical region of the spinal cord, approximately from C4 to T1.

Function: This enlargement is associated with the nerve fibers that innervate the upper limbs (arms and hands). The cervical enlargement gives rise to the brachial plexus, a network of nerves that controls the muscles and sensory functions of the arms.
Significance: The enlargement reflects the greater demand for motor and sensory control of the upper limbs, which require a high level of coordination and fine motor skills.

Lumbar Enlargement:

Location: Located in the lumbar region of the spinal cord, typically from L1 to S3.

Function: This enlargement is associated with the nerve fibers that innervate the lower limbs (legs and feet). It gives rise to the lumbosacral plexus, which controls the muscles and sensory functions of the legs.
Significance: Similar to the cervical enlargement, the lumbar enlargement reflects the need for more motor and sensory neurons to control the larger muscles and more complex movements of the lower limbs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What age does that spinal cord stop growing?

A

Grows until around 4 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are spinal nerves numbered?

A

According to where they exit the vertebral column

C1-C7: exit superior (above) to vertebrae they are named from
C8: exists inferior (below) to 7th cervical vertebra

rest of spinal nerves exit inferior to vertebrae they are named for

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is dermatome?

A

Specific region of skin monitored by a single pair of spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is myotome?

A

Specific region of muscles monitored by a single pair of spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the clinical significance of myotome and dermatome?

A

Location of loss of sensation or motor control can help locate area of damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the functions of the spinal cord/components?

A
  1. Dorsal root: serves as a channel for sensory info that travels into and up spinal cord (located on the dorsal side, thick)
  2. Gray matter: serves as a center for coordinating certain reflexes
  3. Ventral root: serves as a channel for motor info that travels out of the spinal cord (located on the ventral side)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Entrance and exit of spinal nerves:

A

Entrance of Spinal Nerves:

Spinal nerves enter the spinal cord through the dorsal root.
The dorsal root carries sensory (afferent) information from the body to the spinal cord. The sensory fibers come from the dorsal root ganglion (DRG), where the cell bodies of the sensory neurons are located.

These sensory neurons transmit information such as touch, temperature, pain, and proprioception from the peripheral tissues (skin, muscles, etc.) to the spinal cord.

Exit of Spinal Nerves:

Spinal nerves exit the spinal cord through the ventral root.
The ventral root carries motor (efferent) information from the spinal cord to the muscles and glands of the body.
The motor fibers in the ventral root are responsible for voluntary muscle movement and autonomic functions (e.g., regulation of internal organs).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 3 gray horns?

A
  1. Posterior/dorsal horn of gray matter
  2. Lateral horn of gray matter
  3. Anterior/ventral horn of gray matter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are meninges?

A

the three protective layers of connective tissue that surround the brain and spinal cord, providing cushioning, protection, and structural support to the central nervous system (CNS).

  1. pia mater (innermost)
  2. arachnoid mater (spider web looking)
  3. dura mater (outermost)
28
Q

How is the spinal cord protected?

A
  1. Bone of vertebrae: protects against bumps, shocks, and blows to the back
  2. within vertebral canal: 3 layers of spinal meninges (a series of specialized membranes provide stability, and shock absorption)
    a) pia mater
    b) arachnoid mater
    c) dura mater
29
Q

What is the dura mater?

A

“Tough mother”

  • dense collagen fibers
  • fuses with periosteum of occipital bone around foramen magnum, then continuous with cranial dura mater which surrounds the brain
  • outermost layer of meninges
30
Q

What is the epidural space?

A

Between dura mater and bone
- contains areolar tissue, blood vessels, and adipose tissue

31
Q

What is the arachnoid mater? (3 parts)

A

a) arachnoid trabeculae: loose covering; collagen and elastic fibers, cob-web like extensions connect it to pia mater
b) arachnoid membrane: simple squamous epithelia next to dura mater
c) subarachnoid space: deep to the arachnoid mater, filled with cerebrospinal fluid; shock absorber, diffuse gas, nutrients, chemical messenger and water = lumbar puncture

32
Q

What is lumbar puncture

A

A lumbar puncture (also known as a spinal tap) - in subarachnoid space
- is a medical procedure in which a needle is inserted into the lower back (the lumbar region) to collect a sample of cerebrospinal fluid (CSF) or to administer medications, such as anesthesia or chemotherapy.

The CSF analysis can provide crucial information about the health of the CNS. It is analyzed for:
- White blood cell count (elevated in infections like meningitis)
- Protein levels (high in certain diseases)
- Glucose levels (low in bacterial infections)
- Presence of microorganisms like bacteria or viruses

33
Q

What is the pia mater?

A

“gentle mother”

  • clings to surface of spinal cord and contains blood vessels
  • innermost meninge
  • meshwork of elastic and collagen fibers
34
Q

What are denticulate ligaments?

A

Anchors spinal cord in place

35
Q

What are gray commissures?

A

Contains axons that cross from one side of the cord to the other

36
Q

What are the gray matter regions?

A
  1. Anterior gray horn: the anterior horn contains cell bodies of somatic motor neurons, whose axons leave the cord through the ventral root to innervate skeletal muscles
  2. Lateral gray horn: the lateral horn contains cell bodies of autonomic motor neurons whose axons also leave the cord through the ventral root
  3. Posterior gray horn: the posterior gray horn contains cell bodies of interneurons that receive information from incoming sensory neurons from the dorsal root
37
Q

What is the dorsal root ganglion?

A

A collection of cell bodies for the incoming sensory neurons. Incoming axons enter through the dorsal root and synapse on interneurons in the posterior horn

38
Q

How is the white matter divided?

A

Each side divided into 3 columns (funiculi)

  1. Posterior column: contains ascending tracts (afferent division, sensory information)
  2. Lateral column: contains both ascending and descending tracts
  3. Anterior column: contains both ascending and descending tractions

2 and 3 are mixed

39
Q

What is found within each white column?

A

Tracts
= bundle of axons of similar diameter, degree of myelination, carry same sort of information in same direction
- columns of information ascending or descending

40
Q

What is the posterior white column responsible for?

A
  1. Posterior column: contains ascending tracts (afferent division, sensory information)

contains ascending tracts providing sensations from the trunk and limbs
- leg, hip, trunk, arm

41
Q

What is the process of pain response?

A
  1. sensory receptor: responds to a stimulus producing a generator or receptor potential (ex. stepping on a sharp tack)
  2. sensory neuron: axon conducts impulses from receptor to integrating center (goes up dorsal root)
  3. integrating center: one or more regions within the CNS that relay impulses from sensory to motor neurons
  4. motor neuron: axon conducts impulses from integrating center to effector (goes down ventral root)
  5. effector: muscle or gland that response to motor nerve impulses
42
Q

What are the three layers of connective tissue on spinal nerves?

A
  1. endoneurium: around each axon
  2. perineurium: around each fascicle
  3. epineurium: around entire nerve
43
Q

The PNS:

A
  • nerves consist of myelinated and unmyelinated axons that send information to and from the CNS
  • each axon within a nerve is wrapped in a layer of loose connective tissue called a endoneurium
  • axons are grouped together into bundles called fascicles, which are wrapped in the perineurium
  • finally, groups of fascicles are wrapped in a tough fibrous sheath called the epineurium
  • most nerve tracts are mixed, containing both efferent and afferent axons
  • nerves also contain blood vessels that supply the axons
44
Q

Spinal nerves:

A

Ventral and dorsal root merge to form a spinal nerve, the nerve branches to form the dorsal ramus and ventral ramus

  • this brief merger allows for somatic afferent and efferent axons to mingle, creating mixed nerves
  • the ventral rami form 4 extensively branches complexes called plexuses, which are convergences of ventral rami that allow fibers from different nerves to sort and supply a particular efferent region
  • 2 of these plexuses are produced from the cervical region (cervical and brachial plexuses), 1 from the lumbar and 1 from the sacral
  • the thoracic region does not produce a plexus; its ventral rami travel between the ribs and innervate the intercostal muscles, the abdominal wall and skin
45
Q

What are the 4 nerve plexuses?

A
  1. Cervical plexus
  2. Brachial plexus
  3. Lumbar plexus
  4. Sacral plexus
46
Q

What are plexuses?

A

Spinal nerves branch and some intertwine to form complex networks

a nerve emerging from a plexus contains fibers (axons) from several spinal nerves

47
Q

What does the brachial plexus innervate?

A

Muscles and skin of pectoral girdle and upper limb

48
Q

What does the cervical plexus innervate?

A

Muscles of neck and diaphragm, skin of neck and superior part of chest

49
Q

What does the Lumbar and Sacral plexuses innervate?

A

Skin and muscles of pelvic girdle and lower limb

50
Q

What is the function of interneurons?

A

Form complex networks to process and interpret sensory information, make decisions, and control motor neurons

51
Q

What are the principles of functional organization?

A

Neuronal pools
- functional groups of interconnected neurons

5 types of neural circuits
= stimulate or depress activity of sensory or motor neurons

52
Q

What are the 5 types of neural circuits?

A
  1. divergence
  2. convergence
  3. serial processing
  4. parallel processing
  5. reverberation
53
Q

What is divergence?

A

Spreads stimulation to multiple neurons or pools

e.g. visual info distributed to different areas of the brain, consciousness, interpretation areas, and cerebellum

   0   0       0        I 000   000     v
54
Q

What is convergence?

A

Provides input to a single neuron or pool from multiple neurons

e.g. breath control is under conscious and subconscious control

0 0 0 0
I (thats an arrow pointing downward)
0 v

55
Q

What is serial processing?

A

Neurons or pools work sequentially

0

0 I
v
0

0

56
Q

What is parallel processing?

A

Neurons or pools process information simultaneously

e.g. pain in the foot produces many results simultaneously: shifting of weight, moving arms, feeling pain, shouting ouch

0

0 0 0

0 0 0

57
Q

What is reverberation?

A

A positive feedback mechanism, cont. to function until synaptic fatigue or inhibitory stimuli

e.g. maintain conscious and normal breathing

0 <
0 -> ^
0

58
Q

Explain the steps of reflex arc

A
  1. Arrival of stimulus and activation of receptor
  2. Activation of a sensory neuron
    - travels up dorsal root
    - sensation relayed to the brain by collateral
  3. Information processing in CNS
    - information travels down ventral root
  4. Activation of a motor neuron
  5. Response by effector (ex. bicep muscle in retracting arm from tack)
59
Q

How can reflexes by classfied?

A
  1. by development
    a) innate reflexes: genetically or developmentally determine; withdrawal, startle, eye-tracking,
    chewing, sucking
    b) acquired reflexes: learned; typing, driving, athletic movements
  2. by response
    c) somatic reflexes: control skeletal muscle contraction, include superficial and stretch reflexes;
    jaw jerk, breath hold, abdominal
    d) visceral autonomic reflexes: controls actions of smooth and cardiac muscles, glands
  3. by complexity of circuit
    e) monosynaptic: one synapse, very fast
    f) polysynaptic; multiple synapses two to several hundred
  4. by processing site
    g) spinal reflexes: processing in the spinal cord
    h) cranial reflexes: processing in the brain; blind, gag, vestibulo-ocular
60
Q

How do reflex responses occur?

A

Automatically occur, and do not require input from higher centers

descending axons from the brain can interact with interneurons in spinal cord and either strengthen/enhance a reflex = facilitation
(enhancing can be exhibited by using the jendrassik maneuver)
or inhibit/lessen a reflex

61
Q

What is the patellar reflex?

A

Spinal reflex, stretch reflex
- monosynaptic
- ipsilateral: The reflex occurs on the same side of the body (i.e., the leg that is tapped).

(also known as the knee reflex, knee jerk, or quadriceps reflex)
- to elicit the typical response, strike the patellartendon, which is just below the knee cap
- when testing for this reflex, a phenomenon called clonus can sometimes occur.
(clonus: a succession of jerk-like contractions that follow the normal reponse and persist for ashort time)
- this reflex functions through the second, third and fourth lumbar spinal nerves (L2,L3, L4)

62
Q

What is a stretch reflex

A

The stretch reflex is a monosynaptic reflex that helps maintain muscle tone and posture by responding to muscle stretch. One of the most commonly tested stretch reflexes is the patellar reflex (also known as the knee-jerk reflex).

Stretch Reflex:
Definition: A stretch reflex occurs when a muscle is stretched, causing a contraction in the same muscle to resist the stretch and maintain posture and stability.
Type: It is monosynaptic, meaning it involves only one synapse between the sensory neuron and the motor neuron, without involvement of an interneuron.

63
Q

What is a myotatic reflex?

A

Stretch reflex with reciprocal innervation

  1. stretching stimulates sensory receptors (muscle spindle=receptor that monitors length of a muscle)
  2. Sensory neuron is excited
  3. Within integrating center (spinal cord), sensory neurons activates motor neuron
    - motor neuron to antagonist muscles is inhibited
  4. motor neuron is excited
  5. effector (same muscle) contracts and relieves the stretching
    - antagonist muscle relaxes, being inhibited because agonist received contraction signal
64
Q

What is reciprocal innervation

A

Reciprocal innervation is a neural mechanism that ensures smooth and coordinated movement by controlling opposing muscle groups. It refers to the process where the activation of one muscle is accompanied by the inhibition of its opposing muscle, which helps to facilitate movement and maintain balance.

65
Q

What is golgi tendon reflex with reciprocal innervation?

A
  1. increased tension stimulates sensory receptors (tendon organ)
  2. sensory neuron excited
  3. within integrating center (spinal cord) sensory neuron activates inhibitory interneuron
  4. motor neuron inhibited
    - motor neuron to antagonist muscles is excited, causes muscles to relax when muscle tension is too grade, protecting tendon from tearing
  5. effector (muscle attached to the same tendon) relaxes and relieves excess tension
66
Q

What is bilateral involvement?

A

Both sides of the spinal cord are involved in the reflex

67
Q

reflexes**

A

BIOL 131 - Spinal Cord, Spinal Nerves, and Spinal Reflexes (1 decks)

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