Chapter 7 Nervous system reverse Flashcards Preview

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Flashcards in Chapter 7 Nervous system reverse Deck (91):
1


Sensory input

integration

motor output

Nervous System

2


monitor changes occuring inside and outside the body

gather information


Sensory input

3


process and interpret sensory input

decide if action is needed


Integration

4


respond to integrated stimuli

activate muscles or glands

voluntary and involuntary


motor output

5


Central Nervous system

Peripheral Nervous System


Organization of Nervous System

6


brain and spinal cord


Central Nervous System

7


nerves outside the brain and spinal cord

cranial and spinal nerves


peripheral nervous system

8


sensory (afferent) division

Motor (efferent) division


Nerve functional classification

9


nerve fibers that carry information to the CNS
and the central canal


Sensory nerves

10


nerve fibers taht carry impulses away from the CNS

1  Somatic nervous system:  voluntary, skeletal muscle

2: Autonomic nervous system: involuntary, smooth and cardiac muscle and glands


motor nerves

11


consists of neurons and neuroglia


Nervous tissue
 structure

12


structural and functional unit of the nervous system and conduct nerve impulses


neurons

13


supports cells that provide physical support, insulation and nutrients to neurons


neuroglia

14


astrocytes

microlia

ependymal cells

oligodendrocytes

satellite cells

schwann cells


Support cells

15


abundant star chaped cells

form barrier between capillaries and neurons

control chemical environment of brain


Astrocytes

16


phagocytose bacterial cells anc cellular debris in the CNS

Remove debris


microglia

17


line cavities of the brain and spinal cord

circulate cerebrospinal fluid


ependymal cells

18


wrap around nerve fibers (axons) in the CNS

poroduce myelin sheaths


oligodendrocytes

19


protect neuron bodies in ganglia of the peripheral nervous system

 


satellite cells

20


form myelin sheath around axons in the PNS


schwann cells

21


Nerve cells

specialized to transimt nerve impulses


Neurons

22


cell body

Dendrites

Axon


Neuron regions

23


nucleus

large nucleolus

nissl substance

specialized rough ER

Neurofibrils maintain shape


Cell body

24

short highly branched cytoplasmic extensions

conduct signals toward the cell body


Dendrites

25


1 per neuron

arises from the axon hillock

may have many branches (collaterals)

trigger zone region that initiates action potential (impulse)

conduct impulse away from cell body to axon termials

terminals contain vessels with neurotransmitters

 

 


axon

26


separated by gap from next neuron

1 synaptic cleft: fluid filled gap between adjacent neurons

2 synapse: junction between nerves


axon terminals

27


schwan cells surrounds region of several axons but does not form myelin sheath


unmylenated axon

28


in PNS schwann cells wrap around peripheral axons in jelly roll fashion

layers of cell membrane create myelin sheath, whitish fatty material

neurilmma: portion of schwann cell that contains most of the cytoplasm and nucleus (outer surface)

in CNS aligodendrocytes form the myelin sheath (no neurolemma)

Nodes of ranvier: gaps in myelin sheath


myelinated axon

29


most are located in CNS

1  gray matter: cell bodies and unmyelinated fibers

2 Nucleus: cluster of cell bodies within the white matter of CNS

 


Locatoin of neuronal cell bodies

30


collectoin of cell bodies outside the CNS or in the PNS


Ganglion

31


Sensory (afferent)

Motor (efferent)

Interneurons


Functional classification of neurons

32


most unipolar some bipolar

cell bodies in ganglia

carry impulses from sensory receptors to the CNS

receptor-specialized dendritic ending

cutaneous sensr organs

proprioceptors-dectect stretch or tension


sensoru neuron function

33


multipolar neurons

cell body within the CNS

carry implulses from teh CNS to viscera, muscles and glands


motor neuron function

34


found in pathways within the CNS

multipolar

some cell bodies in nuclei of CNS

connect neurons


interneurons function

35


multipolar:  many extensions from the cell body

bipolar:  one axon and one dendrite

unipolar: short single process leaving the cell body


Structural classification of Neurons

36


irritability: ability to respond to stimuli

conductivity: ability to transmit an impluse


functional properties of neurons

37


potential difference across cell membrane

plasma membrane is polarized at rest

fewer + ions are inside the cell than outside

resting potential caries with cell type-40 to -90 mV


Cell membrane potential

38


distributino of ions across plasma membrane

1  Na+ high outside cell, low inside

2 K+ low outside cell, high inside

negatively charged molecules: DNA, RNA, proteins

membrane permeable to Na+ and K+

Na+/K+ pump (2 Na+ out, 2 K+ in)


Membrane potential cause

39


depolarization

repolarization


Membrane potential changes

40


membrane potential bnecomes less negative

Na+ channels open

K+ channels close

Na+ enters cell


membrane depolarization

41


membrane potential returns to resting membrane potential (RMP)

K+ channel opens

Na+ channel closes

K+ leaves cell


Membrane repolarization

42


rapid sequence of depolarization and repolarization

 


Nerve impulses

Action potentials

43


membrane potential at which an action potential is genterated

stimuli from other neurons sum to bring membrane to threshold


Nerve impulse threshhold potential

44


if the action potential starts it is propagated over the entire axon

if not enough it begins ar trigger zone and ends at axon terminals


nerve impulse propagation

45


action potentials occur only at nodes of ranvier

saltatory conduction: AP appears to jump from node to node

Fast 120m/sec


Nerve impulse

myelinated axons

46


action potential travels along the entire plasma membrane

slow .5 m/sec


Nerve impulse

unmyelinated axon

47


neurons not in direct contact

separated by small gap : synaptic cleft


Synapse

48


axon terminal of presynaptic neuron

synaptic vesicles filled with neurotransmitter

synaptic cleft

receptors on postsynaptic membrane


synapse structure

49


impulses not directly able to cross to another nerve

action potential causes vesicle to move to membrane

neurotransmitter is released from axon terminal

neurotransmitter diffuses across synaptic cleft

neurotransmitter binds to protein receptors on dendrite of next neuron, post synaptic neuron

to stop a signal the neurotransmitter is broken down


synapse signal transmission

50


rapid predictable and involuntary response to stimuli

simplest neural pathway (reflex arc)


Relexes

51


Sensory receptor-sensory neuron-interneuron-motor-neuron-effector


reflex pathway

52


somatic reflexes: effectors are skeletal muscles

autonomic reflexes:

                             smooth muscle regulation

heart and BP regulation

regulation of glands

digestive system regulation


Reflex types and regulation

53


3 lbs

contains about 100 billion multipolare neurons

4 major sections

cerebrum, diencephalon, brain stem, cerebellum


Brain anatomy

54


2 cerebral hemispheres

paird left and right superior part of brain

connected internally by corpus callosum

includes more than half of brain mass

surface is made of ridges (gyri) and grooves (sulci)


Cerebrum

55


fissures divide the cerebrum into lobes

frontal lobe

parietal lobe

occipital lobe

temporal lobe


Lobes of cerebrum

56


primary motor area:

voluntary control of skeletal muscle

sends impulses to skeletal muscles

Borca's area:

motor speech

involved in our ability to speak

problem solving and language comprehension


Frontal lobe

57


somatic sensory area

receives and interprets impulses from the bodies sensory receptors

speech and language region


parietal lobe

58


visoin center


Occipital lobe

59


olifaction (smell

Hearing


Temporal lobe

60


gray matter:  outer layer in cerebral cortex composed mostly of neuron cell bodies

white matter:  fiber tracts deep to the gray matter

tract: bundle of fibers (axons) within the CNS

Basal nuclei: regions of gray matter burried within the white matter


Cerebrum layers

61


sits on top of the brain stem

enclosed by cerebral hemispheres

main parts:  Thalamus and Hypothalamus


Diencephalon

62


surrounds third ventricle

relay staton for sensory impulses

transfers impulses to the correct part of cortex for localization and interpretation


Thalamus

63


located under the thalamus

important autonomic nervous system center

helps regulate body temp

controls water balance

regulates metablolism

important part of the limbic system (emotions)

pituitary gland attached


Hypothalamus

64


attaches to spinal cord

3 parts

Midbrain

Pons

medulla oblongata


Brain stem

65


mostly composed of tracts of nerve fibers

reflex center for vision and hearing


midbrain

66


mostly composed of fiber tracts

modifies activity of respiratory centers in the medulla


pons

67


lowest part of brain stem

merges into spinal cord

includes important fiber tracts

contains important control centers

heart rate control, BP regulatoin, respiratory centers sets rate and depth of breathing, swallowing and vomiting


medulla oblongata

68


cooridinates skeletal muscle activity

helps maintain posture, balance and equilibrium


Cerebellum

69


scalp and skin

skull and vertebral column

meninges

cerebrospinal fluid

blood brain barrier


CNS protection

70


3 connective tissue membranes covering brain and spinal cord

dura mater

arachnoid mater

pis mater


meninges

71


double layered external covering

periosteum: attached to inner surface of skull

Meningeal layer: out covering of brain

folds inward in several areas


dura mater

72


middle layer

web like


arachnoid mater

73


clings to surface of brain and spinal cord

contains superficial blood vessels


Pia mater

74


space between acrachnoid and pia mater

filled with cerebrospinal fluid


subarachnoid space

75


space bewtreen meninges surrounding spinal cord and bonds of vertebral canal

filled with adipose and loos connective tissue


Epidural space

76


similar to blood plasma composition

formed by the choroid plexus, reabsorbed by arachnoid villi

watery cushion to protect brain

ciculated in subarachnoid space, ventricles and central canal of spinal cord


cerebrospinal fluid

77


4 interconnected cavities with in the brain filled with CSF

CSF flows through


Ventricles

78


CSF accumulates and exerts pressure on the brain if not allowed to drain

newborns


Hyrocephalus

79


includes the least permeable capillaries of the body

excludes many potentially harmful substances

useless against:

fats and fat soluable molecules

respiratory gases (CO2 and O2)

alcohol

Nicotine

Anesthesia


Blood brain barrier

80


slender column of nerve fibers (tracts) and neurons

center for spinal reflexes


Spinal Cord

81


extends from the foramen magnum of skull to the first or second lumbar vertebra

31 pairs of spinal nerves arise from spinal cord

Cauda equina

anterior median fissure

posterior median sulcus


Spinal cord surface anatomy

82

gray matter is mostly cell bodies

Dorsal (posterior) horns

Anterior (ventral) horns

Gray commissure surround the central canal

central canal is filled with CSF


Spinal cord internal anatomy

83


White mater-fiber tracts

ascending tracts carry sensory information to brain

descending tracts conduct motor impulses from brain to motor neurons

pathways between brain and spinal cord


Spinal cord exterior

84


leave at each level of vertebra

dorsal roots: sensory fibers

sensory neurons found in dorsal root ganglia

ventral roots: motor fibers

motor neurons are found in the anterior horn

spinal nerve forms where posterior and anterior roots merge


Spinal nerves

85


Nerves and ganglia outside the CNS

cranial nerve arises from brain

spinal nerves arise from spinal cord


Peripheral Nervous System

PNS

86


bundle of neuron fibers


nerve

87


neuron fibers bundled by connective tissue

endoneurium surrounds each fiber

groups are bound into fascicles by perineurium

fascicles are bound together by epineurium


nerve structure

88


portion of PNS that function automatically

2 neurons in series from CNS to effector

regulates activites of cardiac, smooth muscle and glands

 


Autonomic Nervous System

89


Sympathetic nervous system

Parasympathetic nervous system


autonomic nervouse subdivisions

90


extraordinary situations-fight or flight

exercise, excitement, emergency and embarrassment


Sympathetic Nervous System

91


housekeeping activites (rest and repose)

digestoin, defacation and diereses


Parasympathetic Nervous System