Nervous System - Somatic and Autonomic Nervous Systems

Question 1

sensory nervous system

Answer 1

provides info to the CNS about what’s happening in the external environment
- PNS to CNS

Question 2

components of sensory nervous system

Answer 2

1. sense organ
2. receptors (specific stimulus for specific receptors)
3. pathways to CNS
4. parts of brain involved in sensory perception

Question 3

special senses

Answer 3

• taste, smell, hearing, sight, EQ

- receptors are localized in a particular area

Question 4

general senses

Answer 4

• pain, tactile, pressure, temperature, and proprioception (position, orientation)
• receptors widely distributed in body
• divided into somatic senses and visceral senses

Question 5

somatic senses

Answer 5

associated with skin and body in general

Question 6

visceral senses

Answer 6

associated with internal organs

Question 7

types of sensory receptors

Answer 7

• exteroreceptors (outside environment)

- interoreceptors (inside environment)

Question 8

sensory receptors (4)

Answer 8

1. mechanoreceptors
2. thermoreceptors
3. chemoreceptors
4. nociceptors

Question 9

mechanoreceptors

Answer 9

detect changes in pressure or movement

Question 10

thermoreceptors

Answer 10

detect changes in temperature

Question 11

chemoreceptors

Answer 11

detect changes in chemical concentration of substances

Question 12

nociceptors

Answer 12

• detect tissue damage (eg pain)

- only sense receptors that do not adapt!

Question 13

nocere

Answer 13

“harm”

Question 14

cutaneous mechanoreceptors (5)

Answer 14

1. pacinian corpuscles
2. meissner’s corpuscles
3. merkel’s discs
4. ruffini’s corpuscle
5. free nerve endings

Question 15

pacinian corpuscles

Answer 15

respond to higher frequency vibration and deep heavy pressure

Question 16

meissner’s corpuscles

Answer 16

respond to lower frequency vibrations and light pressure

Question 17

merkel’s discs

Answer 17

respond to steady touch - pressure

Question 18

ruffini’s corpuscle

Answer 18

respond to push or pull on skin

Question 19

free nerve endings

Answer 19

respond to temperature and pain

Question 20

sensory modality principles (4)

Answer 20

1. labeled line theory
2. frequency coding
3. population coding
4. adaption

Question 21

labeled line theory

Answer 21

• stimulus recognized by the place the sensory cells excited in the CNS
• tells brain where a stimulus is/ what kind it is

Question 22

sensory modality = stimulus modality

Answer 22

sensory modality is an identifiable class of sensation

Question 23

frequency coding

Answer 23

intense stimuli produce a higher frequency of action potentials

Question 24

population coding

Answer 24

more intense stimuli increase the number of cells that participate

Question 25

adaption

Answer 25

decrease in sensation that occurs upon continued stimulation

Question 26

sensory perception

Answer 26

- occurs only after impulses are interpreted by the brain

Question 27

steps in sensory perception

Answer 27

1. stimulus acting on a receptor 2. action potential generated, 3. impulse conducted to CNS 4. impulse translated into info in CNS, 5. info interpreted in CNS 6. stimulus is PERCEIVED!

Question 28

ascending sensory pathway

Answer 28

1. dorsal column pathways - touch + proprioception 2. spinothalamic tract - temperature + pain

Question 29

primary somatosensory cortex: somatotropin representation of of body on cortex

Answer 29

- projections of sensory neurons form a "neural map" of the body - adjacent areas of the cortex receiving sensory input from adjacent areas of the body - "point-for-point correspondence of an area of the body to a specific point in the CNS (somatosensory cortex)"

Question 30

descending motor pathways (pyramidal tracts)

Answer 30

1. coritcobulbar tract 2. ventral corticospinal tract 3. lateral corticospinal tract

Question 31

corticobulbar tract

Answer 31

supplies motor commands to cranial nerve motor nuclei of the head and neck (face and tongue)

Question 32

ventral corticospinal tract

Answer 32

innervates lower motor neurones of the axial and proximal muscles

Question 33

lateral corticospinal tract

Answer 33

supplies inputs to lower motor neurons controlling the muscles of the distal extremities

Question 34

neuronal processing of motor programs

Answer 34

- motor activity begins in sensory areas together with premotor areas - motor control is hierarchical and serial

Question 35

extrapyramidal system - basal ganglia and cerebellum

Answer 35

- both play important roles in coordination of movement

Question 36

vestibular apparatus

Answer 36

- sense of balance originates in sensory hairs cels here - utricles and saccules contain hair cells that respond to static gravity - ampulla of the three semicircular canals detect acceleration - afferent info from here is carried over the cranial nerve and projects to the vestibular nuclei in the medulla (down to spinal cord to maintain posture)

Question 37

general ascending sensory pathways

Answer 37

1. stimulus 2. sensory organ with receptors 3. 1st, 2nd, 3rd, 4th order neurons ascend to brain (somatosensory cortex) 4. pyramidal tracts then extrapyramidal tracts 5. alpha motor neuron 6. muscles

Question 38

divisions of the autonomic nervous system

Answer 38

1. sympathetic (fight or flight) 2. parasympathetic (rest and digest) 3. enteric nervous system (restricted to gastrointestinal system) - most organs receive both sympathetic and parasympathetic efferents that usually have opposite effects

Question 39

functions served by autonomic nervous system

Answer 39

1. homeostatic | 2. adaptive

Question 40

control of ANS

Answer 40

- internal functions | - involuntary reflexes

Question 41

internal functions controlled by ANS

Answer 41

cardiovascular system, digestive, respiratory tract, kidney, etc

Question 42

involuntary reflexes controlled by ANS

Answer 42

constriction of pupil, vasodilation of skin and sweating with high body temperature, etc

Question 43

somatic vs autonomic efferents

Answer 43

somatic motor system - single-neuron efferent pathway autonomic nervous system - two-neuron efferent pathway (preganglionic neuron and postganglionic neuron)

Question 44

sympathetic NS efferents

Answer 44

1. sympathetic preganglionic fibers - short - orientate from thoraco-lumbar segments 2. autonomic ganglia - para-vertebral ganglia (sympathetic chains) - pre-vertebral ganglia (unpaired, in abdomen) 3. sympathetic postganglionic fibers - long - originate in autonomic ganglia

Question 45

parasympathetic NS efferents

Answer 45

1. parasympathetic preganglionic fibers - long - originate in the cranial-sacral segments 2. autonomic ganglia - located near or within visceral organs 3. parasympathetic postganglionic fibers - short

Question 46

neurotransmitters used by PSNS vs SNS

Answer 46

- SNS/PSNS: preganglionic synapse uses acetylcholine (nicotinic receptors) - SNS: postganglionic synapse uses norepinephrine (alpha and beta receptors) - PSNS: postganglionic synapse uses acetylcholine (muscarinic receptors)

Question 47

postganglionic neurons: adrenergic receptors

Answer 47

metabotropic receptors: - excitatory alpha 1 - inhibitory alpha 2 - excitatory beta 1 - inhibitory beta 2

Question 48

postganglionic neurons: muscarinic receptors

Answer 48

metabotropic receptors: - excitatory M1, M3, M5 - inhibitory M2, M4

Question 49

cortico means

Answer 49

cortex

Question 50

vagus nerve X

Answer 50

major parasympathetic nerve