Chapter 11 Nervouse System Flashcards Preview

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Flashcards in Chapter 11 Nervouse System Deck (96)
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1
Q

functions of nervous system

A
  1. Sensory input
  2. integration
  3. motor input
2
Q

Sensory input

A

gathers sensory info form outside and inside the body

3
Q

integration

A

responsible for processing & interprets sensory input and decides how to respond

4
Q

motor input

A

causes a response called motor output, by activating muscle & glands

5
Q

Central Nervous System

A
  • CNS

- includes the brain & the spinal chord-control center, interprets sensory input & dictates motor response

6
Q

Peripheral nervous System

A
  • PNS

- cranial and spinal nerves, communicating between CNS and the rest of the body

7
Q

2 subdivisions of PNS

A

a. sensory (afferent) fibers

b. motor (efferent) fibers

8
Q

Sensory afferent division

A

arrival, info coming in, somatic and visceral sensory nerve fibers (axons) take info from receptors to CNS

  1. somatic afferent fibers
  2. Visceral afferent fibers
9
Q

somatic afferent fibers

A

take signals from your skin, skeletal, muscles and joints

10
Q

visceral afferent fibers

A

conducts signals from your organs

11
Q

Motor efferent division

A

(going away) include motor nerve fibers , they take information away from effectors

  1. somatic nervous system
  2. Autonomic nervous system(sympathetic, parasynpathetic)
12
Q

Somatic nervous system

A

take impulses from CNS to skeletal muscles

-voluntary

13
Q

Autonomic nervous system-CH 14

A

includes visceral or involuntary - CNS to smooth cardiac muscles & glands, sending signals from CNS to involuntary

14
Q

Sympathetic division

A

fight or flight

  • involuntary
  • speed things up
15
Q

Parasympathetic division

A
  • resting & digesting

- maintaining day to day activities

16
Q

nervous system

A

master controlling and communicating system of the body.

17
Q

Graded potential

A

Short-lived, localized change in membrane potential; often occurring from the dendrites to the cell body. Membranes here have lots of leaky channels , so signals don’t get far

18
Q

Hyperpolarization

A

Some K+channels remain open, while Na+ channels reset; inside of the cell is temporarily more negative than usual

19
Q

chemical synapses

A
  • much more common, release and receive chemical neurotransmitters
    1) AP arrives at axon terminal, open volt gated channels Ca2+
    2) Ca2+ release, releases neurotransmitter crosses synaptic cleft
    3) Binding of nrtmters to the postsynaptic membrane opens ion channels, result GP
    4) Nrtmters effects are terminated by reuptake via astrocytes, degradation by enzymes, or diffusion away from the synapse
20
Q

action potential

A

Long distance signals generated by nerve or muscle cells; brief reversal of membrane potential pf about 100mV (from -70 to +30 mV)

  • these signals do not decrease with distance.
  • travel whole length of axon
21
Q

3 functions of nervous system

A

1) sensory input- gathers sensory info from outside & inside body
2 )integration- responsible for processing & interprets, sensory input and decides how to respond
3) motor output- causes a response called MO, by activating muscles and glands

22
Q

divisions of nervous system

A

CNS & PNS

  1. CNS
  2. PNS
    a. sensory(afferent) division -(somatic & visceral afferent fibers)
    b. motor (efferent) division -(somatic & autonomic–sympathetic & parasympthetic–nervous system)
23
Q

neuroglia

A

much more common than neurons, support neurons by producing chemicals to help neurons find connections, promoting neuron health and growth, and speeding up action potential conduction
-found in CNS & PNS

24
Q

6 Types of Neuroglia

A

1) CNS- Astrocytes- starshaped , abundant, help with synapse formation, participate in information processing in the brain
2) CNS- Microglia- small ovoid thorny process, monitor health of nearby neurons, turn into macrophages
3) CNS- Ependymal cells- squamous to columnar shaped, cilia, they split the CSF(Cerebrospinal fluid) from the cavities around the cells
4) CNS- Oligodendrocytes- branching, form myelin sheaths
5) PNS- Satellites cells- like Astrocytes
6) PNS- Schwann cells-srround neuron cell bodies-form myelin sheaths- they can help with regeneration of damaged nerves

25
Q

structural classification -sensory (afferent)

A

taking signals from skin or internal organs to CNS

-cell bodies are outside the CNS

26
Q

structural classification- motor (efferent)

A

-transmit signals from CNS to effectors(muscle/glands)- multi-polar- cell bodies are inside the CNS

27
Q

structural classification- interneurons (association neurons)

A

between sensory & motor neurons, most in CNS, most multi-polar

28
Q

resting membrane potential

A

difference in voltage across the cellular membrane (40-90mV)
-inside of the cell is negatively charged, usually polarized

29
Q

leakage channels

A

always open

30
Q

chemical(ligand)-gated channels

A

this opens when the appropriate chemical binds

31
Q

voltage-gated channels

A

open or close in response to changes in membrane potential

32
Q

mechanically gated channels

A

open in response to physical deformation

ex. touch and pressure receptors

33
Q

What 2 things can produce a change in membrane potential?

A

1) changes in ion concentration on either side

2) changes in membrane permeability

34
Q

what two factors do the speed of nerve signal conduction depend on?

A

1) axon diameter

2) degree of myelination

35
Q

continuous conduction

A

this occurs on unmyelinated axons and its slow

36
Q

saltatory(jumping) conduction

A

this is in myelinated axons, the signal jumos from one node of Ranvier to the next very fast, prevents very little signal to be lost

37
Q

Excitatory synapses and EPSPs

A

Binding at these synapses opens chemically gated channels, lets NA+ in and K+ out; net flow of Na+ in- depolarization (inside more positive)

38
Q

Inhibitory synapses and IPSPs

A

This opens chemically gated channels lets K+ out or Cl- in. More polarized, more negative, less likely to create an action potential

39
Q

spatial summation of postsynaptic neuron

A

-if you have enough pre-synaptic neurons stimulating the post synaptic neuron

40
Q

temporal summation of postsynpatic neuron

A

summation of one or more of pre-synaptic neurons transporting EPSP on rapid succession , summation over time.

41
Q

synaptic potentiation

A

repeated or continuous use of synapse enhances the excitability of the post synaptic neuron

42
Q

presynaptic inhibition

A

occurs when a release of an excitatory neurotransmitter by one neuron is inhibited by activity of another

43
Q

Acetylcholine Ach

A

-nrtmter-stimulates skeletal muscles, also used by subneurons

44
Q

Biogenic Amines

A
  • nrtmter- dopamine, norepinephrine, epinephrine, serotonin and histamine
  • these play a role in emotions and regulate the biological clock
45
Q

Amino Acids

A
  • nrtmters- GABA(drinking alcohol), glycine, aspartate and glutamate
  • usually act as inhibitory
46
Q

Peptides

A

Substance P-mediates pain signals; as well as endorphins which reduce pain perception

47
Q

Purines

A

ATP is a nrtmter in both CNS and PNS; produces fast excitatory response at certain receptors. Adenosine also acts outside of cells as an inhibitor, caffeine blocks adenosine receptors

48
Q

nitric oxide and carbon monoxide

A

nrtmters that pass quickly into cells binding to intracellular receptors

  • NO involved in formation of new memories, sends signals to increase synaptic strength, excessive can lead to brain damage
  • CO performs similar function in mempry, but different pathway
49
Q

excitatory nrtmters

A

excitatory causes depolarization and by depolarization- makes cell membrane more positive, makes it closer to initiating AP

50
Q

inhibitory neurotransmitters

A

causes hyperpolarization

ex. Ach is excitatory at neuromuscular junctions but inhibitory at cardiac muscle.

51
Q

direct neurotransmitter

A

nrtmter bind to and open ion channels directly, cause rapid responses in postsynaptic

52
Q

indirect neurotransmitter

A

-“second messenger”-slower but causes longer lasting responses , neurotransmitter works through 2nd messenger

53
Q

divergent neuronal circuit

A
  • one signal triggers response signal on to increasing numbers of others(neurons)
    ex. signals from the brain to thousands of muscle fibers.
54
Q

converging neuronal circuit

A

you have input from several signals going into one area

ex. when different sensory stimuli, sight, sound, smell have same effect

55
Q

reverberating/oscillating neuronal circuit

A

creates a chain of neurons, signal going through a chain over and over (continuous)
ex. sleep wake cycle

56
Q

parallel after-discharging

A

incoming signal segregated into many pathways, and info delivered by each pathway is dealt with simulltaneously by different parts of neural activity
-signal from many neurons to one, but occurs one at a time in short bursts(as opposed to coverging)

57
Q

serial processing

A

the whole system works in a predictable all or nothing manner with one neuron stimulating the next and so on
-reflexes- rapid automatic responses to stimuli, they go to the spinal chord and back out bypassing the brain

58
Q

parallel processing

A

integrating input from many pathways and information dealt with by different neuronal circuits

59
Q

dorsal horn (posterior horn)

A

-gray matter-has sensory function and all are interneurons

60
Q

ventral horn ( anterior horn)

A

-gray matter- somatic motor

61
Q

what kind of info does dorsal and ventral roots carry?

A

a. dorsal root-sensory

b. ventral root- motor info

62
Q

gyri

A
  • singular-gyrus

- ridgges

63
Q

sulci

A
  • singular- sulcus

- grooves - they separate the gyri

64
Q

fissures

A

-deep grooves - these separate regions of the brain

65
Q

5 lobes of each cerebral hemisphere

A
  1. frontal
  2. temporal
  3. parietal
  4. occipital
  5. insula
66
Q

gray matter

A

contains mostly nerve cell bodies, dendrites, neuroglia , blood vessels and unmyelinated

67
Q

white matter

A

regions of the brain and spinal chord containing dense collections of myelinated fibers(insulation for nerve cells), they’re white becuase they are fatty and function as insulation for axons

68
Q

nucleus (nuclei)

A

-cluster of cell bodies in the CNS

69
Q

ganglion

A
  • ganglia

- in PNS , cluster of cell bodies

70
Q

tract

A
  • axons in CNS

- bundles of axons

71
Q

nerve

A
  • axons in the PNS

- bundles of axons

72
Q

primary motor cortex

A
  • in cerebrum- located in precentral gyrus of frontal lobe

- voluntary skeletal muscle control-motor homunculus

73
Q

Broca’s area

A
  • left hemisphere of frontal lobe

- motor speech area- directs lips, tongue, mouth for speech

74
Q

primary somatosensory cortex

A
  • postcentral gyrus of parietal lobe
  • receives sensory input from the body
  • sensory homunculus
75
Q

prefrontal cortex

A
  • anterior association area

- involved with things like intellect, complex learning and personality

76
Q

posterior association area

A
  • includes parts of Temporal, Parietal, and occipital

- known as Wernicke’s area or the “sensory speech area” because it enables you to understand written and spoken language

77
Q

basal nuclei

A
  • AKA basal ganglia
  • function: start, stop and monitor intensity of movements ordered by the cortex and coordinate several movements occuring at once ( swinging your arms as you walk)
78
Q

thalamus

A
  • inner room- gateway to cerebral cortex
  • function: relay station for info coming into the cortex
  • relay afferent (arriving) impulses from all senses to the sensory cortex for interpetration
  • all other inputs ascending to the cerebral cortex go through thalamic nuclei
  • involved in memory
79
Q

hypothalamus

A

-below thalamus
- connects pituatary gland by the infundibulum
-function: as the main visceral control center of the body, it helps to maintain homeostasis
7 functions:
1) autonomic control center
2) center of emotional response
3) body temp regulation
4) regulate food intake
5) regulate water balance, thirst
6) regulate sleep/wake cycle
7) control endocrine system functioning

80
Q

epithalamus

A
  • most dorsal portion of diencephalon
  • pineal gland: endocrine gland that secretes melatonin which controls sleep/wake cycles; involved in mood and jet-lag
  • choroid plexus- forms the CSF
81
Q

superior and inferior colliculi

A

-are nuclei that are visual and auditory reflex centers that make us do things such as turn our head toward a loud noise

82
Q

substantia nigra

A
  • associated with (part of ) basal nuclei of cerebrum
  • looks dark because of melatonin
  • is a precursor for the nrtmter dopamine
83
Q

pons

A
  • middle area pons= bridge
  • composed of conduction tracts
  • some muclei help medulla regulate normal rythym of breathing
84
Q

medulla oblongata

A
  • most inferior AKA “primitive brain”
  • continuous with spinal cord
  • decussatioin of pyraminds:crossing over of fibers so right motor cortex controls left side of body
  • visceral motor nuclei found here:
    1. cardiac center
    2. vasomotor center
    3. respiratory center
    4. vomiting, hiccupping, swallowing, coughing, sneezing
85
Q

functions of cerebellum

A
  • receives input from : motor areas , sensory input from proprioceptors in skeletal muscle, tendons and joints, allows you to know your body position and how you’re moving
  • cognitive function: sends information to the brain stem nuclei, word association and puzzle solving
  • symptoms resulting from damage to cerebellum : loose muscle tone-become clumsy
86
Q

function of limbic system

A

-function: emotional brain

87
Q

function of reticular formation

A
  • function:
  • contains the Reticular Activating System (RAS)
  • governs arousal & awareness of the brain as a whole
  • filters out 99% of all sensory input
88
Q

what are the 3 meninges

A
  1. Dura mater- outermost-tough mother
  2. Arachnoid mater- thin middle layer-means spider
  3. Pia mater-innermost means gentle mother
89
Q

why is blood brain barrier important?

A
  • living protective barrier between blood and CNS that maintain a stable environment for the brain
  • no other body tissue is dependent on a constant internal environment as the brain
  • if brain is exposed to such chemical variations(in the blood) the neurons would fire uncontrollably
90
Q

Huntington’s disease

A

is a hereditary disease with degeneration of basal nuclei (coordinated movements)

  • symptoms: chorea(wild, jerky movements, cannot control)
  • occurs in middle age
  • due to defective mitochondria so lactic acid builds up
91
Q

Parkinson’s disease

A
  • symptoms: are rigidity , shuffling gate, inability to communicate
  • this disease is caused by degeneration of the neurons in the substantia nigra, preventing them from releasing dopamine
92
Q

meningitis

A

inflammation of the meninges- cause pressure on the brain

93
Q

encephalitis

A

inflammation of the brain itself

94
Q

hydrocephalus

A
  • “water in the brain”
95
Q

stroke

A
  • cerebrovascular accident (CVA)
  • AKA stroke
  • 3rd leading cause of death
96
Q

Alzheimer’s disease

A

progressive degenerative disease of the brain