Chapter 14 Flashcards

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1
Q

The nervous system and endocrine system work together how?

A
  • they work together to perform the vital function of communication for the body
  • communication provides the means to control and integrate the many difference functions performed by organs, tissues, and cells.
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2
Q

The nervous system is made up of what

A
  • the brain
  • the spinal cord
  • the nerves (most intriguing body system)
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3
Q

The nervous system is organized to detect what

A

(Stimuli) in the internal and external environment, evaluate that information and respond by initiating changes in muscles or glands

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4
Q

Central nervous system

A

Brain
Spinal cord

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5
Q

Peripheral nervous system

A

Cranial nerves
Spinal nerves

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6
Q

Afferent and efferent division

A
  • both the CNA and PNS nerves that form incoming information pathways and outgoing information pathways
    Afferent: consists of all of the incoming sensory information
  • “Carry towards the CNS” Information -> CNS
    Efferent: consists of all oof the outgoing sensory information
  • “carry away from the CNS” CNS -> body
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7
Q

Peripheral nervous system

A
  • somatic nervous system
    • carry information to the somatic effectors
      - “Skeletal muscles”
  • autonomic nervous system
    - carry information to the autonomic or visceral effectors
    “Smooth muscle
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8
Q

Autonomic nervous system

A
  • carry information to the autonomic or visceral effectors
  • smooth muscles, cardiac muscles, glands, adipose tissue and other voluntary tissues
  • sympathetic division
    - “fight or flight”
  • parasympathetic division
    - “resting and digesting”
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9
Q

The two main types of cells that compose the nervous system

A

Neurons: excitable cells that conduct the impulses that make possible all nervous system
- “wiring of the nervous system”
Glia: do not usually conduct information but support the function of neurons
- supporting cells

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10
Q

Types of neuroglia

A

Astrocytes: provide metabolic (feeding) and structural (BBB) to neurons
Microglia: phagocytic cells that help remove bacteria and debris
Ependymal cells: form thin sheets that line fluid-filled cavities in the brain and spinal cord
Oligodendrocytes: produce the fatty myelin sheath around nerve fibers in the CNS
Schwann cells: produce myelin sheath around nerve fibers in the PNS

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11
Q

The three parts of a neuron

A

Cell body (soma): main part of the cell, has the nucleus and most of the cytoplasm and organelles
Dendrites: small, slender extensions of the cell body, which receive incoming information
Axon: long, slender extension, specialized to conduct electrical impulses away from the cell body

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12
Q

Physiology of a neuron

A
  • neurons generate and transmit action potentials
  • an action potential is basically an electrical impulse
  • action potentials are the primary means of communication throughout the nervous system
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13
Q

Membrane potential - all living cells, maintain a a difference in the concentration of ions across their membranes

A
  • a difference in electrical charge across a cell’s plasma membrane
  • outside the PM has a slight excess of cations
  • inside the PM has a slight excess of anions
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14
Q

Functions of Na+/K+ pump

A
  • maintains cell volume
  • establishes and maintains resting potential by ongoing active transport of three Na+ out of the cell and two K+ into the cell
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15
Q

Resting potential

A

Resting potential: measurable difference in voltage across the cell membrane in a resting cell
-> -70 mV
-> interior of cell is negative relative to the exterior

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16
Q

Graded potential

A
  • transient local changes in the resting potential
  • may depolarize or hyperpolarize the membrane
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17
Q

Summation

A
  • graded potentials ca add up in space or time
  • this additive effect may reach a “trigger point” or threshold, which initiates an action potential
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18
Q

An action potential is a sudden reversal of membrane voltage
Depolarization
Repolarization
Reestablishment of the resting potential

A
  • initiated when graded potentials reach a certain threshold (triggering point)
    Depolarization: voltage-sensitive Na+ channels open, Na+ moves into the axon (this reverses the voltage across the membrane, interior becomes +)
    Repolarization: Na+ channels close, K+ channels open, K+ moves out of the axon (this restores the initial polarity, becomes temporarily hyperpolarized)
    Reestablishment of the resting potential: K+ channels close, the normal activity of the sodium-potassium pump restores resting potential
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19
Q

Steps of the mechanism of action potential

A

1) when adequate stimulus is applied to the neuron, stimulus - gates Na+ channels open
- causing rapid Na+ diffuse into the cell
2) Threshold potential: the minimum magnitude a voltage fluctuation in the condition zone must have to trigger the opening of a voltage-gated ions channels
- -55mV = threshold
- More, rapid Na+ diffuse into the cell
3) as more Na+ rushes into the cell, the membrane moves rapidly toward 0mV
- continuing, is a positive directly until it reaches + 30mV
4) Na+ gates close automatically (Na+ channels open for the same amount of time and magnitude each action potential
- All-or-none response
5) K+ voltage gated ions channels open (these gates are stimulate at the same time as the Na+ but are slow
- K+ rapidly diffuses out of the cell, returning the cell to RMP
6) Hyperpolarization occurs while the K+ gates close
- at which point the sodium-potassium pump returns the cell to its RMP

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20
Q

All-or-none action potential

A
  • individual neuron threshold sets extent of stimulus needed
  • if threshold is achieved, it triggers an action potential
  • once triggered, an cation potential is always the same in speed and voltage
21
Q

Self-propagating

A
  • continues to propagate itself in the next region of the axion
  • moves like a wave down the axon, with constant speed and amplitude
22
Q

The number of action potential/unit time encodes the strength of the stimulus

A
  • stronger stimuli generate more action potentials/unit time
    Speed of action potential
  • always the same for a particular neuron
  • can be different in different neurons
    • in larger diameter axons, action potentials travel at greater speed
23
Q

Saltitory glands

A
  • the propagation of action potentials along myelinated axons from one node of Ranvier to the next
    - increasing the velocity of action potentials
    - “jumping from node to node”
24
Q

Synapse

A
  • the place where signals are transmitted from one neuron to another
25
Q

The two main types of synapses

A
  • electrical: occurs when two cells are joined end-to-end by gap junctions
    - occur between cardiac muscle cells and between some smooth muscle cells
    Chemical: utilize neurotransmitters to send signals from presynaptic cells to the postsynaptic cells
26
Q

The three structure that make up a chemical synapse

A
  • synaptic knob
  • synaptic cleft
  • plasma membrane of a postsynaptic neuron
27
Q

Action potentials travel where

A
  • action potentials travel along the length of a neuron and stops at its axon terminals
  • Action potentials can not cross synaptic clefts
28
Q

Neurotransmitter are needed for what

A

Neurotransmitters are needed in order to bring a response by the post synaptic neuron
- excitatory neurotransmitter: causes depolarization
- inhibitory neurotransmitter: causes repolarization

29
Q

CNS protection

A

Bone: protective membranes
Meninges: protective membranes (dura mater, arachnoid, pia mater)
Cerebrospinal fluid: bathes the brain, spinal cord (shock absorber; produced within the ventricles of the brain)
Blood-brain barrier: prevents entry of certain white matter (outer portion of the spinal cord; consists of myelinated ascending (sensory and descending (motor) nerve tracts

30
Q

The CNA is composed of what two types of nervous tissue?

A

White matter: consist of myelinated exceeding (sensory) and descending (motor) nerve tracts
Gray matter: contains cell bodies, densities and short, unmyelinated axons

31
Q

Brain

A

command center of the body

32
Q

Cerebrum

A

The cerebrum is the largest portion of the brain in mammals
- it is the last center to receive sensory input
- responsible for: language, decision making, conscious thought

33
Q

Functions of the cerebral cortex

A

Memory storage, Abstract thought, conscious awareness, conscious control of skeletal muscle

34
Q

The four lobes of the cerebral cortex

A

Occipital lobe - processes visual information
Temporal lobe - interprets auditory information, comprehends spoken/written language
Parietal lobe: receives and interprets sensory information from the skin
Frontal lobe: initiates motor activity, responsible for speech, conscious thought

35
Q

Cerebrum

A
  • cerebrum deals with higher brain function
    - structure
    Right and left hemispheres; connected by corpus callosum
    Nerve tracts in the corpus callosum allow two hemispheres to share information
    - Cerebral cortex: gray matter, the outer layer of the cerebrum
36
Q

Beneath the cerebral cortex lies what
- the three main tracts

A

Beneath the cortex lies the large interior of the cerebrum (composed mostly of white matter)
- Projection: extensions of ascending (sensory) tracts and descending (motor) tracts
- association: extend rom one convolution to another in the same hemisphere (most numerous)
- commissural: extend from a point in one hemisphere to a point in another

37
Q

Gray matter

A
  • there are few islands of gray matter deep inside the white matter of each hemisphere
  • Basal Nuclei: Caudate nucleus, lentiform nucleus, amygdaloid nucleus
    - the basal nuclei may play a critical role in thinking and learning
38
Q

Limbic system

A

“Emotional Brain”
- function in some way to make us experience many kinds of emotions (anger, fear, joy, sadness, surprise, disgust)

39
Q

Brain stem

A

Medulla oblongata: part of the brain that attaches to the spinal cord; interaction of cardiac, Vasomotor, respiratory, digestive and other reflexes
Midbrain: cranial nerve reflexes (eye movements, pupillary reflexes, ear reflexes)
Pons: autonomic reflexes

40
Q

Diencephalon

A

Thalamus: crude sensations, mechanism responsible for emotions, arousal, complex reflex movements
Hypothalamus: integration/coordination of many autonomic reflexes, hormonal functions
- arousal, appetite, thermoregulation
Pineal gland: Produces melatonin; “biological clock”

41
Q

Memory involving storing and retrieving information

A

Short-term: working memory; information from previous few hours; stored in the limbic system
Long-term: information from previous days to years; permanent changes in neurons and development of additional synapses in the cerebral cortex

42
Q

Overview of the peripheral nervous system

A
  • 31 pairs of spinal nerves are connected to the spinal cord
    • numbers according to the level of the vertebral column
      -> 8 cervical nerve pairs (with only 7 cervical vertebrae)
      -> 12 thoracic nerve pairs
      -> 5 lumbar nerve pairs
      -> 5 sacral nerve pairs
      -> 1 coccygeal nerve pair
43
Q

Nerves

A

Bundles of peripheral nerve fibers held together by several layers of connective tissues that together form a multilayered sheath

44
Q

The three types of nerves

A
  • epineurium: fibrous coat that cover fascicles and forms a complete nerve
  • Perineurium: Fibrous connective tissue holding fascicles together
  • Endoneurium: Fibrous coat around each individual fascicles
45
Q

Nerves: white and grey matter

A

White: bundles of myelinated fibers
Grey: cell bodies and unmyelinated fibers

46
Q

Projection are where?
Association are where?
Commissural are where?

A

Projection - top and bottom
Association - forward and backward
Commissural - left and right

47
Q

The brain stem is most commonly associated with what

A

The brain stem is most commonly associated with reflexes

48
Q

The hypothalamus connects what

A

The hypothalamus connects the nervous and endocrine systems