Brainscape's Knowledge GenomeTM

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


See full index

A&P - Study Sets > Chapter 13 > Flashcards

Chapter 13 Flashcards

1
Q

The PNS consists of all neural structures outside…

A

Brain and spinal cord (CNS)

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

PNS is divided into two categories…

A

Sensory (afferent) division and Motor (efferent) division

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

Motor (efferent) division is divided into two categories…

A

Somatic nervous system and autonomic nervous system (ANS)

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

Autonomic nervous system (ANS) is divided into two categories…

A

Sympathetic and parasympathetic division

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

Sensory receptors:

A
  • specialized to respond to changes in environment (stimuli)
  • activation results in graded potentials that trigger nerve impulses
  • awareness of stimulus (sensation) and interpretation of meaning of stimulus (perception) occur in brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Three ways to classify receptors:

A
  • types of stimulus
  • body location
  • structural complexity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mechanoreceptors

A

respond to touch, pressure, vibration, and stretch

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

Thermoreceptors

A

sensitive to changes in temperature

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

Photoreceptors

A

respond to light energy (ex: retina)

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

Chemoreceptors

A

respond to chemicals (ex: smell, taste, changes in blood chemistry)

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

Nociceptors

A

sensitive to pain-causing stimuli (ex: extreme heat/cold, pressure, inflammatory chemicals)

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

Exteroceptors

A
  • respond to stimuli arising outside body

- receptors in skin for touch, pressure, pain and temperature

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

Interoceptors (viscerorecptors)

A
  • respond to stimuli arising in internal viscera and blood vessels
  • sensitive to chemical changes, tissue stretch, and temperature changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Proprioceptors

A
  • respond to stretch in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles
  • inform brain of ones movements

(these are how we know where our body is in space)

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

Majority of sensory receptors belong to one of the two categories:

A

Simple receptors of general senses

  • modified dendritic endings of sensory neurons
  • are found throughout body and monitor most types of general sensory information

Receptors for special senses

  • vision, hearing, equilibrium, smell, and taste
  • all are housed in complex sense organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Survival depends upon…

A

Sensation: the awareness of changes in the internal and external environment

Perception: the conscious interpretation of those stimuli

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

Somatosensory system:

A

part of sensory system serving body wall and limbs

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

Somatosensory system receives inputs from:

A
  • exteroceptors
  • proprioceptors
  • interoceptors

input is relayed toward head, but processed along the way

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

Three levels of neural integration in sensory systems

A
  1. ) receptor level: sensory reception and transmission to CNS (muscle spindles and kinesthetic receptors)
  2. ) circuit level: processing in ascending pathways (on the way ‘up’ the spinal cord and through the brainstem, midbrain, and cerebellum)
  3. ) perceptual level: processing in cortical sensory centers (particularly the somatosensory)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Processing at the receptor level: Generating a Signal

A

for sensation to occur, the stimulus must excite a receptor, and the action potential must reach CNS

  • stimulus energy must match receptor specificity
  • stimulus must be applied within Receptive Field
  • Transduction must occur, energy of stimulus is converted into graded potential called Generator Potential or Receptor Potential
  • graded potentials must reach threshold… Action Potential
  • strength of stimulus is encoded by Action Potential frequency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Three types of Neurons:

A
  • multipolar
  • bipolar
  • unipolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Multipolar

A

many processes extend from the cell body. all are dendrites except for a single axon.

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

Bipolar

A

two processes extend from the cell body. one is a fused dendrite, the other is an axon.

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

Unipolar

A

one process extends from the cell body and forms central and peripheral processes, which together comprise an axon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Multipolar, bipolar, and unipolar have different “trigger zones”

A

These zones are essentially the regions of the neuron where generator/receptor potentials summate to determine if an action potential will be fired by that neuron.

26
Q

Adaptation:

A

change in sensitivity in presence of constant stimulus
- receptor membranes become less responsive
receptor potentials decline in frequency or stop

Phasic receptors: (fast-adapting) send signals at beginning or end of stimulus, report changes in environment (ex: receptors for pressure, touch, smell)

Tonic receptors: adapt slowly or not at all (ex: nociceptors and most prorioceptors)

27
Q

How many neurons does it take to “sense” something?

A

Most sensory pathways involve 3 neurons

28
Q

Processing at the Circuit Level (ascending pathways)

A
  • first-order sensory neurons
  • second-order sensory neurons
  • third-order sensory neurons
29
Q

First-order sensory neurons

A

conduct impulses from receptor level to spinal reflexes or second-order neurons in CNS (cell body in DRG, synapse in spinal cord)

30
Q

Second-order sensory neurons

A

transmit impulses to third-order sensory neurons (spinal cord to thalamus)

31
Q

Third-order sensory neurons

A

conduct impulses from thalamus to the somatosensory cortex (perceptual level)

32
Q

Processing at the Perceptual Level

A

interpretation of sensory input depends on specific location of target neurons in sensory cortex

33
Q

Aspects of sensory perception:

A

perceptual detection: ability to detect a stimulus (requires summation of impulses from multiple receptors)

magnitude estimation: intensity coded in frequency of impulses

spatial discrimination: identifying site or pattern of stimulus (studied by two-point discrimination test)

34
Q

Perception of Pain

A
  • warns of actual or impending tissue damage so protective action can be taken
  • stimuli include extreme pressure and temperature, or chemicals (histamine, K+, ATP, acids, bradykinin)
  • some pain impulses are blocked by inhibitory endogenous opioids (ex: endorphins and enkephalins)
35
Q

Perception of Pain: Pain tolerance…

A
  • all begin to perceive pain at the same stimulus intensity
  • pain tolerance varies
  • “sensitive to pain” means low pain tolerance, not low pain threshold
  • genes help determine pain tolerance as well as response to pain medications
36
Q

Perception of Pain: Visceral and referred pain…

A
  • Visceral pain results from stimulation of visceral organ receptors (felt as aching, gnawing, burning / activated by tissue stretching, ischemia, chemicals, muscle spasms)
  • Referred pain: pain from one body region perceived as coming from different region (visceral and somatic pain fibers travel along same nerves, so brain assumes stimulus comes from common somatic region / ex: left arm pain during heart attack)
37
Q

Nerve:

A
  • cordlike organ of PNS
  • bundle of myelinated / unmyelinated peripheral axons enclosed by connective tissue
  • TWO TYPES of NERVES: spinal or cranial, depending on where they originate
38
Q

Endoneurium vs. Perineurium

A
  • Endoneurium wraps around individual axons / forms outer covering of the nerve
  • Perineurium wraps around bundles of axons called fascicles
39
Q

Most nerves are mixtures of …

A

afferent and efferent fibers and somatic (motor) and autonomic (visceral) fibers

40
Q

Nerves are classified according to…

A

the direction they transmit impulses

41
Q

Mixed nerves:

A

contain both sensory and motor fibers (impulses travel to and from CNS)

42
Q

Sensory (afferent) nerves:

A

impulses only TOWARD CNS

43
Q

Motor (efferent) nerves:

A

impulses only AWAY from the CNS

44
Q

Pure sensory (afferent) or pure motor (efferent) nerves are…

A

RARE, most nerves are mixed

45
Q

Types of fibers in mixed nerves:

A
  • Somatic afferent (muscle to brain)
  • Somatic efferent (brain to muscle)
  • Visceral afferent (organs to brain)
  • Visceral efferent (brain to organs)
46
Q

Ganglia:

A

contain neuron cell bodies associated with nerves in PNS

  • ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons (dorsal root ganglia, sensory/somatic)
  • ganglia associated with efferent nerve fibers contain autonomic motor neurons (autonomic ganglia, motor/visceral)
47
Q

How many pairs of spinal nerves are there?

A

31 pairs

  • 8 pairs of cervical nerves
  • 12 pairs of thoracic nerves
  • 5 pairs of lumbar nerves
  • 5 pairs of sacral nerves
  • 1 pair of tiny coccygeal nerves
  • all are mixed nerves named for point of issue from spinal cord
  • supply all body parts except head and part of neck
48
Q

Major nerves of Cervical…

A

Phrenic

49
Q

Major nerves of Brachial…

A

Axillary, musculocutaneous, median, radial, ulnar

50
Q

Major nerves of Lumbar…

A

Femoral, obturator

51
Q

Major nerves of Sacral…

A

Sciatic (composed of tibial and common fibular)

52
Q

Peripheral Motor Endings (Reflex Activity)

A
  • Inborn (intrinsic) reflex: rapid, involuntary, predictable motor response to stimulus
  • ex: maintain posture, control visceral activities
  • Learned (acquired) reflexes result from practice or repetition
  • ex: driving skills
53
Q

Five basic components of all reflex area:

A
  1. ) receptor
  2. ) sensory neuron
  3. ) integration center
  4. ) motor neuron
  5. ) effector
54
Q

1.) receptor

A

site of stimulus action

55
Q

2.) sensory neuron

A

transmits afferent impulses to CNS

56
Q

3.) integration center

A

either monosynaptic or polysynaptic region within CNS

57
Q

4.) motor neuron

A

conducts efferent impulses from integration center to effector organ

58
Q

5.) effector

A

muscle fiber or gland cell that responds to efferent impulses by contracting or secreting

59
Q

Reflexes are classified functionally as:

A
  • Somatic Reflexes: activate skeletal muscle

- Autonomic (visceral) reflexes: activate visceral effectors (smooth or cardiac muscle or glands)

60
Q

Ex: of a stretch reflex

A

The patellar (knee-jerk) reflex

  • A stretch reflex helps keep muscles at the appropriate length, in this case the quadriceps to prevent knee buckling upon standing

A&P - Study Sets (3 decks)

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