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Human Physiology > Exam 2 LO > Flashcards

Exam 2 LO Flashcards

1
Q

Synapse between a somatic motor neuron and skeletal muscle fiber

A

Neuromuscular junction

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2
Q

What is located in the motor end plate

A

ACh receptors, Junctional folds

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3
Q

Steps for neuromuscular transmission of skeletal muscle beginning with somatic neuron generating action potential

A
  1. Somatic neuron generates action potential from VG Na/K channels to presynaptic axon terminal
  2. Depolarization opens VG Ca2+ channel and Ca2+ enters channel
  3. ACh released
  4. ACh binds to AcH ligand gated receptor on motor end plate
  5. Binding allows Na+ influx
  6. Membrane depolarizes, creating an EPP (graded potential) that initiates the action potential
  7. Opening of VG Na+ channels allows AP to travel through muscle fiber (EPP spreads like Local current flow)
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4
Q

3 ways neurotransmitter (ACh) is removed from synaptic cleft after nerve signaling

A

Reuptake of ACh
Enzyme degradation by AChE
Diffusion

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5
Q

Excitation Contraction Coupling process (think of picture Dr wu drew of the t tubule)

A
  1. AP propagates fast along sarcolemma into t tubules, depolarizing the cell
  2. AP in t tubules stimulates the DHPR from Ca2+ release
  3. DHPR is linked to RyR, Ca2+ binds to RyR in SR and RyR opens releasing Ca2+
  4. Ca2+ exits SR, flowing down concentration gradient into sarcoplasm
  5. Ca binds to troponin on actin, changing the shape, and moving tropomyosin away from the myosin binding sites on actin
  6. Myosin head hydrolysis ATP
  7. Myosin head binds to actin and phosphate is released forming a crossbridge
  8. Myosin head executes a power stroke
  9. Crossbridge remains attached to actin until a new ATP binds to myosin
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6
Q

What happens in a power stroke

A

Myosin head pivots, pulling thin filament past thick filament toward the center of the sacromere—releasing ADP

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7
Q

Allows AP to move quickly from cell to cytosol

A

T tubules

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8
Q

Stores calcium

A

SR

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9
Q

Thin filament, calcium sensor triggers muscle contraction

A

Troponin

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10
Q

Blocks myosin binding sites on thin filament during relaxation, moves out of the way during muscle contraction

A

Tropomyosin

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11
Q

In the presence of calcium in the contraction cycle…

A

Myosin and actin bind and form a crossbridge

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12
Q

Sliding of the thin filaments and Z discs coming closer together results in what sacromere length

A

Shortened length

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13
Q

What is the role of SERCA

A

Pumps calcium from sarcoplasm into the SR after contraction

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14
Q

What leads to stop in muscle contraction and muscle relaxes

A

SERCA

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15
Q

SERCA pumps calcium back into SR going

A

Against gradient

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16
Q

3 roles of ATP in skeletal muscle contraction and relaxation

A
  1. ATP hydrolysis by SERCA provides energy for active transport of calcium into SR (muscle relaxation)
  2. ATP provides energy for crossbridge
  3. New atp binding to myosin allows for detachment
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17
Q

Energy sources for muscle contraction

A

Creatine Kinase, glycolysis, oxidative phosphorylation

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18
Q

Creatine kinase, glycolysis, and oxidative phosphorylation
- type of reaction

A

Creatine kinase= 1 step rxn
Glycolysis and phosphorylation= multi step

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19
Q

What must occur first before oxidative phosphorylation

A

Glycolysis to make 2 pyruvic acid from glucose

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20
Q

Transfers phosphate to ADP to regenerate ATP

A

Creatine kinase

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21
Q

Storehouse of high energy phosphate at rest

A

Creatine kinase

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22
Q

How long does creatine kinase last? What does it power? How fast is atp production?

A

Provides atp during first few seconds of contraction, atp production rapid but limited, powers very short periods of muscle activity

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23
Q

Glycolysis is what kind of process (think metabolism)

A

Anaerobic, converts 1 glucose to 2 ATP

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24
Q

Occurs in high intensity exercise

A

Glycolysis

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25
Q

Glycolysis powers what type of activity?

A

Powers short periods of muscle activity

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26
Q

Oxidative phosphorylation requires what

A

O2

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27
Q

Oxidative phosphorylation converts what to what

A

1 glucose to 36 atp (and fatty acids and amino acids)

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28
Q

Oxidative phosphorylation occurs in the

A

Mitochondria

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29
Q

Oxidative phosphorylation, after glycolysis, gives what fuel

A

Fatty acids

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30
Q

Oxidative phosphorylation powers what exercise

A

Powers extended periods of muscle activity

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31
Q

Muscle fiber types are classified by their

A

Max velocity or shortening and pathways for ATP formation

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32
Q

Postural muscles and endurance activities use what muscle fiber

A

Slow oxidative

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33
Q

Slow oxidative muscle fibers:
- Diameter size
- Less or more tension development
- type of metabolism
- fast or slow myosin ATPase
- resistance to fatigue

A

Small diameter
Slow tension development
Aerobic metabolism, uses oxidative phosphorylation
Slow myosin ATPase
Resistant to fatigue

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34
Q

Fast oxidative muscle fiber:
- diameter
- tension development
- type of metabolism
- fast or slow myosin ATPase
- resistance to fatigue

A

Large diameter
Faster tension development than slow oxidative muscles
Anaerobic and aerobic (oxidative phosphorylation and glycolysis)
Fast myosin ATPase
Somewhat resistant to fatigue

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35
Q

Sprinting involves what type of muscle fiber

A

Fast oxidative

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36
Q

Fast glycolytic muscle fibers:
- tension development
- diameter
- fast or slow myosin ATPase
- type of metabolism
- fuels what?
- myoglobin amount
- resistance to fatigue

A

Most tension, fastest development
Large diameter
Fast myosin ATPase
Small myoglobin amounts, less capillaries
Prone to fatigue

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37
Q

What type of muscle fiber controls explosive movements such as weight lifting or fast, forceful movements

A

Fast glycolytic

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38
Q

Factors that do NOT contribute to muscle fatigue

A

absence of ATP or lactic acid

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39
Q

Factors that do contribute to muscle fatigue

A

High extracellular K concentration, buildup of ADP that inhibits crossbridge, and disruption of calcium regulation (malfunctioning calcium channels on the SR)

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40
Q

Tension is maintained in what muscle fiber

A

Slow oxidative

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41
Q

Able to maintain initial tension than decreases to fatigue

A

Fast oxidative muscle fiber

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42
Q

Most likely to fatigue rapidly

A

Fast glycolytic muscle fiber

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43
Q

A motor neuron and the population of muscle fibers it innervates

A

Motor unit

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44
Q

When a large amount of tension needs to be generated…

A

More motor neurons are recruited

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45
Q

What factors determine the tension developed in a whole muscle

A

Motor unit size and recruitment

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46
Q

Affects the amount of tension the muscle can generate

A

Motor unit size

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47
Q

Muscles that control precise movements, such as the hands have what size motor units

A

Small (less muscle fibers)

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48
Q

When a muscle needs to generate more force during a contraction, more motor units are activated

A

Motor unit recruitment

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49
Q

How does motor unit recruitment work

A

Smaller and weaker motor units are recruited first and then larger/stronger motor units added as needed

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50
Q

Duration of a muscle fiber action potential vs. muscle contraction

A

Muscle fiber Action potential lasts a few seconds (shorter), contraction (twitch) lasts longer because of latent, contraction, and relaxation phase

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51
Q

Why is contraction longer than action potential

A

Shortness of an AP allows frequency to increase, continuing to release calcium until tetanus

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52
Q

Brief contraction of a group of muscle fibers by a single action potential

A

Twitch

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53
Q

1 stimulus equals how many twitches

A

1

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54
Q

Muscle contraction where action potentials continue to fire because calcium continues to be released

A

Tetanic contraction

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55
Q

Once calcium is present, it binds to troponin and pulls all the tropomyosin away. What is the relationship between this and tetanus

A

All the myosin binding sites are exposed, max contraction reached

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56
Q

Is a twitch or tetanic contraction smaller, why?

A

Twitch because less calcium is in the sarcoplasm and ATPase can catch up to calcium being released by 1 stimulus

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57
Q

Isometric vs isotonic muscle contractions

A

Isometric: tension generated but muscle length doesn’t change while contracting
Isotonic= tension stays the same but muscle length changes

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58
Q

Trying to lift an object too heavy is what contraction

A

Isometric

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59
Q

A bicep curl is what kind of contraction

A

Isotonic

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60
Q

How long is the latent period in isometric contractions? Isotonic?

A

Isometric= short, less calcium released and can’t generate enough tension

Isotonic= longer, able to develop enough tension

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61
Q

Occurs to maintain posture and support objects in a fixed position

A

Isometric contraction

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62
Q

Tension develops in the muscle, but it doesn’t reach the force needed to move the load

A

Isometric contraction

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63
Q

Used for moving objects and body movements

A

Isotonic contraction

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64
Q

Tension generated during contraction is great enough to exceed the load of an object, shortening the muscle

A

Isotonic contraction

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65
Q

More calcium releases results in a

A

Higher frequency

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66
Q

More Myosin binding sites exposed=

A

More contractions

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67
Q

The stretch reflex involves

The tendon reflex involves

The knee jerk reflex involves

The withdrawal reflex involves

A

Muscle spindles

Golgi tendon organs

Muscle spindles

Nociceptors

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68
Q

Somatic nervous system system:
- pathway
- effectors
- neurotransmitters
- receptor type on effector organ
- action of neurotransmitter on effector
-voluntary or involuntary control

A
  • one neuron pathway
  • skeletal muscle
  • ach
  • cholinergic
  • always excitatory (contraction of skeletal muscle)
  • voluntary control
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69
Q

Autonomic nervous system system:
- pathway
- effectors
- neurotransmitters
- receptor type on effector organ
- action of neurotransmitter on effector
-voluntary or involuntary control

A
  • two neuron pathway
  • smooth, cardiac, glands
  • ach or norepi
    -cholinergic or adrenergic
  • excitatory or inhibitory
  • involuntary
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70
Q

Describe the two neuron pathway for the autonomic nervous system

A
  1. Preganglionic neuron that extends from CNS to an autonomic ganglion
  2. Post ganglionic neuron extends from autonomic ganglion to effector

OR
preganglionic neuron may extend from CNS to synapse with chromaffin cells of medulla

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71
Q

Responds to overstretching of muscle, controlling muscle length

A

Muscle spindles

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72
Q

Sensory input directly synapses to motor neuron or effector

A

Monosynaptic reflex arc

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73
Q

Sensory input enters the spinal cord in the same side motor output exits

A

Ipsilateral reflex

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74
Q

Interneurons connects sensory and motor neurons

A

Polysynaptic reflex arc

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75
Q

Respond to excessive muscle tension, causes relaxation, protects tendon and muscle from damage

A

Golgi tendon organs

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76
Q

What happens in a knee/patellar jerk reflex

A
  1. Tap on tendon stimulates muscle spindle to stretch
  2. AP travels
  3. In integrating center, sensory neuron synapses in spinal cord activating motor neuron

OR

Interneurons inhibits motor neuron, relaxing hamstring allowing extension of leg through reciprocal innervation

  1. Motor neuron excited and leads to effector of quadriceps contracting, leg swinging forward
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77
Q

Explain the withdrawal reflex by a nociceptor

A
  1. Pain stepping on sharp object stimulates nociceptor
  2. Sensory neuron excited & in integrating center activates many Spinal cord segments
  3. Multiple motor neurons excited and either ascend to pain and postural adjustment pathways or withdrawal reflex pulls foot away from stimulus by contracting leg muscles
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78
Q

What level of motor control of brain regions coordinates movements based on intention and sensory feedback

A

Middle level

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79
Q

Made up of several masses of gray matter found in cerebral hemispheres

A

Basal nuclei

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80
Q

Controls inititation of movement, suppression of unwanted movements, regulate muscle tone, and regulate non motor processes such as attention, memory, plannings and emotional behavior

A

Basal nuclei

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81
Q

Monitors intention for movement and actual movement

A

Cerebellum

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82
Q

Compares command signals with sensory information and sends corrective feedback

A

Cerebellum,

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83
Q

What brain regions are in the middle level of motor control

A

Basal nuclei and cerebellum and brainstem

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84
Q

Upper motor neurons from cerebral cortex make up the

A

Higher centers of control in motor cortex

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85
Q

Involves the sensory, motor, and association cortex, and brainstem

A

Higher centers in motor control

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86
Q

Helps control posture and balance, regulation of muscle tone, assists with movements of body in response to unexpected stimuli, controls precise and voluntary movements of upper limbs

A

Brainstem

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87
Q

Voluntary control of muscles of the limbs and trunk though the corticospinal pathway

A

Primary motor cortex

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88
Q

What tract crosses at the midline if the body at the medulla, responsible for precise and agile movements of hands and feet

A

Lateral tract

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89
Q

What tract crosses at the midline at spinal cord, responsible for trunk and upper limbs

A

Ventral tract

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90
Q

Right cerebral cortex controls muscles on the…

A

Left side of body

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91
Q

Smooth vs skeletal muscle relaxation

A

Smooth muscle relaxation: decrease calcium in sarcoplasm, dephosphorylation or myosin phosphate

Skeletal: new atp mist bind to myosin on actin for crossbridge to detach

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92
Q

Smooth muscle vs skeletal muscle activation

A

Smooth muscles have slower contraction speed and contraction is triggered by calcium changes to the thick filament vs the thin filament in skeletal muscle

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93
Q

Smooth muscles have troponin—true or false

A

False, calcium binds to calmodulin instead to activate cross bridge

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94
Q

Why do smooth muscles contract slower than skeletal muscle?

A
  1. No calcium burst, slower diffusion rate
  2. Rate of action potential, can be uncoupled
  3. Slower crossbridge formation (no troponin)
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95
Q

Role of calmodulin in smooth muscle

A

Calcium binds to calmodulin, which binds to MLCK, transfers phosphate and phosphorylated myosin binds actin (forms crossbridge)

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96
Q

There is no need to trigger an action potential in __ muscle because…

A

Smooth, doesn’t rely on membrane changes from AP

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97
Q

Calcium sources that contribute to smooth muscle activation (contraction)

A

Extracellular calcium (main source)= enters down gradient by VG calcium channels

SR= release calcium by g coupled receptor

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98
Q

Ligand gated channels, stretch activated sodium and calcium channels are located in

A

Extracellular concentration for calcium

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99
Q

Dip into z discs, action potentials travels through this….contains the DHPR

A

T tubules

100
Q

RyR releases calcium into cell when

A

Triggered by calcium binding

101
Q

SR contains what

A

RYR and SERCA

102
Q

Explain the contractile unit in cardiac muscle

A

Calcium binds to troponin, shortens sacromere
Unbinds and relaxes sacromere

103
Q

Force generation of cardiac muscle is directly proportional to

A

Number of active cross bridge (determined by calcium concentration bound to troponin)

104
Q

Shorter sacromere results in

A

Contraction

105
Q

Connect myocytes

A

Intercalated discs

106
Q

Intercalated discs contain

A

Desmosomes and gap junctions

107
Q

Function of a desomosome? Gap junction?

A

Desmosome transmits force

GJ transfers electrical current in the form of calcium, allows for communication and transfer of materials between cells

108
Q

Why do gap junctions in cardiac muscle work as a pump?

A

AP quickly spreads to all fibers, contracting together as a single unit

109
Q

In cardiac cells, this provides Energy to contract and relax, higher in number and larger compared to skeletal muscle

A

Mitochondria

110
Q

Proteins in the cardiac muscle responsible for excitation contraction coupling

A

DHPR and RyR

111
Q

DHPR is a

A

voltage gated calcium channel

112
Q

RyR is a

A

SR Ca release channel

113
Q

What protein responsible for calcium induced calcium release

A

DHPR

114
Q

What is the difference between skeletal and cardiac muscle cells? Speed of contraction? Role of DHPR?

A

Skeletal: fast to contract and relax
-short refractory periods to allow tetanus
- DHPR is just a voltage sensor
-mechanically coupled to AP (allowing calcium release from SR)

Cardiac: a little slower, prevents tetanus
- DHPR is a VG ca channel
- calcium mostly comes from SR, not as much ECF

115
Q

How does the length of the refractory period prevent tetany in cardiac cells?

A

Plateau phase Allows for complete contraction and relaxation of cardiac muscle
-crossbridge effects amplitude not frequency

116
Q

An SA nodal cell has what kind of Rmp

A

Unstable

117
Q

Where are funny channels located

A

Sa nodal cells

118
Q

What is the role of a funny channel

A

Causes unstable RMP because it’s permeable to sodium and potassium at the same time

119
Q

In the depolarizing phase of an sa nodal cell what channels open

A

Calcium

120
Q

What channels open at a plateau phase of a cardiac myocyte

A

Calcium

121
Q

Flow of depolarization

A

SA Node
Internodal pathways
AV Node
Bundle of His
Intervenricular septum (left and right bundles split into bundle branches)
Purkinje fibers in ventricles

122
Q

What’s the difference between AV Nodal cells and Purkinje fibers

A

AV nodal cells have slower electrical activity and less gap junctions and nodal cells

Purkinje fibers have fast electrical activity and more nodal cells and gap junctions

123
Q

2 electrodes detecting potential differences because depolarization or repolarization is in progress

A

Deflection

124
Q

Lead can’t detect change in electrical activity in…

A

An isoelectric event

125
Q

Electrical activity is __ to a lead

A

Perpendicular

126
Q

What equals an interval

A

Segment plus deflection

127
Q

An upward deflection is a __

A downward deflection is a __

A

Depolarization
Repolarization

128
Q

Draw an ecg reading and explain what events happen at the different sections

A

P wave= atrial systole, atrial depolarization
PRQ segment= atria fully contracted, av nodal delay
QRS segment= ventricular systole, ventricular
depolarization and atrial repolarization (can’t see)
ST complex= ventricles fully contracted, ventricles fully depolarizaed
T wave= early diastole of ventricles, repolarization of ventricles
TP segment= full diastole, fully repolarized ventricles

129
Q

What makes up a positive deflection (ventricular diastole)

A

Repolarization x opposite

130
Q

In to out, endocardium to epicardium is what kind of electrical activity

A

Depolarization

131
Q

Epicardium to endocardium, out to in is what electrical activity (and what wave)

A

Repolarization, t wave

132
Q

What lead is most parallel to overall direction of depolarization and electrical activity (MVA)

A

Lead 2

133
Q

What sets the basic heart rate

A

SA node and nodal cells

134
Q

What would happen if all the nerves to the sa node was severed?

A

Heart would still beat

135
Q

Normal cardiac output is what? Formula?

A

CO= SV x HR

5 L/min

136
Q

How to find stroke volume

A

EDV- ESV

137
Q

amount of blood ejected out of the heart in 1 minute

A

Cardiac output

138
Q

Amount of blood ejected per bear

A

Stroke volume

139
Q

Ensure one way flow of blood

A

Valve

140
Q

What are the kinds of valves

A

Atrioventricular valves and pulmonary/aortic valves

141
Q

Types of AV valves

A

Tricuspid= right av valve
Mitral or bicuspid= left av valve

142
Q

What is the important thing to remember about opening and closing of valves

A

All 4 valves can be closed at the same time but never open at the same time; set of valves open at a time

143
Q

What is ventricular diastole

A

Filling of blood; aortic and pulmonary valves closed & av valves open

144
Q

What is ventricular systole

A

Ejecting of blood in ventricles
Av valves close, pulmonary and aortic valve open

145
Q

Lub vs. dub sounds

A

S1= lub, after qrs complx
S2= dub, after t wave

146
Q

Aortic valves close in what sound

A

Lub

147
Q

Aortic and pulmonary valves close in what sound

A

Dub

148
Q

Contractility is regulated by…

Heart rate is regulated by…

A

Contractility= sympathetic nervous system

Heart rate= sympathetic and parasympathetic ns

149
Q

Parasympathetic nervous system
- releases what
- rate of depolarization (heart rate)
- innervates what?

A

AcH
Slows heart rate, slows rate of depolarization
Innervates nodes only: calcium permeability of nodal cells decrease

150
Q

sympathetic nervous system
- releases what
- rate of depolarization (heart rate)
- innervates what?

A

Norepi released on beta 1 receptor
Speeds up rate of depolarization and heart rate
Innervates myocardium and nodes

151
Q

What events occur at the cardiac cycle

A
  1. Electrical
  2. Mechanical
  3. Pressure changes
  4. Valve/ volume event
152
Q

Example of electrical cardiac event

A

QRS ventricular depolarization

153
Q

Example of mechanical event in cardiac cycle

A

Ventricular systole or diastole

154
Q

Example of pressure changes in cardiac cycle

A

Increase in Left ventricular pressure when left av valve closes

155
Q

Valve and volume event in cardiac cycle

A

Aortic valve opens, blood travels through aorta to body; blood leaves the ventricle (systole)

Example of volume event is stroke volume

156
Q

What is ejection fraction

A

SV/EDV x 100

157
Q

3 factors that regulate stroke volume

A

Preload, Contractility, afterload

158
Q

Order of events beginning with atrial kick…

A

Atrial kick
Isovolumetric contraction
Ejection
Isovolumetric relaxation
Passive filling

159
Q

Order of events that occur at the P wave:
- electrical event
- mechanical event
- pressure gradient (artery, atria, ventricle)
- valve event
- volume event

A
  • atrial depolarization
  • atrial contraction
  • atria> ventricles and artery> ventricles
  • av valves are open, semilunar valves are closed
  • atrial kick
160
Q

Order of events that occur at the QRS complex:
- electrical event
- mechanical event
- pressure gradient (artery, atria, ventricle)
- valve event
- volume event

A

Ventricular depolarization
Ventricles contract
PVentricles> Patria, Partery > PVentricles
Av valves closed, s1 sound
Isometric contraction

161
Q

Order of events that occur at the ST segment:
- electrical event
- mechanical event
- pressure gradient (artery, atria, ventricle)
- valve event
- volume event

A

Ventricles fully depolarized
Ventricles continue to contract
P ventricles> p atria, PVentricles> p artery
AV valves closed, SL valves open
Ejection

162
Q

Order of events that occur at the T wave:
- electrical event
- mechanical event
- pressure gradient (artery, atria, ventricle)
- valve event
- volume event

A
  • ventricular repolarization
  • ventricles start relaxing
  • PVentricles> patria, partery> PVentricles
  • SL valves closed, s2 heart sound
  • Isovolumetric relaxation
163
Q

Order of events that occur at the Isoelectric between T and P waves:
- electrical event
- mechanical event
- pressure gradient (artery, atria, ventricle)
- valve event
- volume event

A

Ventricles fully repolarized
Ventricles fully relaxed
P atria> p ventricle and partery> p ventricle
AV valves open, SL valves closed
Passive filling

164
Q

What effect does an increase in venous return have on the heart

A

Stretches the heart muscle and larger stroke volume

165
Q

What does the frank starling law say

A

More you fill the heart, the more forceful the ejection, increase EDV, increase SV

166
Q

EDV is determined by the

A

Venous return, proportional to cardiac output

167
Q

Degree of stretch of the heart by the blood in the ventricles, amount of blood before ejection (EDV)

A

Preload

168
Q

What were to have if a cardiac muscle could overstretch

A

Decrease number of cross-bridges and decrease force

169
Q

What is the length tension relationship?

A

The more EDV, the more SV unless EDV goes past 300 mL them SV decreases

170
Q

What influences venous return

A

Sympathetic innervation with norepi, skeletal muscle and respiratory pump

171
Q

The more calcium inside the SR, the higher

A

Number of crossbridges

172
Q

Contractility is affected by

A

Inotropes

173
Q

What is the effect of a positive inotrope

A

Increase Contractility, increase calcium concentration, increase stroke volume

174
Q

What effect does a negative inotrope have

A

Decrease contractility, decrease stroke volume

175
Q

The sympathetic nervous system has a __ inotropic effect; what is it?

A

Positive; norepi binds to b1 receptor—> atp is converted into cAMP—> cAMP activates kinase a which causes faster calcium cycling and more crossbridges

176
Q

What has the biggest influence on resistance

A

Radius

177
Q

What is vasodilation

A

Increase in radius, decrease in resistance and increase blood flow

178
Q

What is vasconstriction

A

Decrease radius, decrease blood flow, increase resistance

179
Q

Relationship between length and resistance

A

If length increases, resistance of vessels increases

180
Q

Relationship between resistance and viscosity

A

Increase viscosity, increase resistance

181
Q

Relationship between resistance and radius

A

Radius inversely proportional to resistance: increase in radius then decrease in resistance

182
Q

If there’s no pressure change in Ohms law, then

A

No pressure gradient or blood flow

183
Q

Relationship between blood flow and change in pressure

A

If change in pressure increases then blood flow increases

184
Q

Relationship between blood flow and resistance

A

If resistance increases, blood flow decreases

185
Q

Blood is directly proportional to __ and inversely proportional to

A

Pressure gradient( arterial resistance) and vascular resistance

186
Q

Thin wall, slow blood flow, no smooth muscle

A

Capillaries

187
Q

Greatest control of radius of vessel, has most smooth muscle, high resistance, innervates by SNS

A

Arteries or arterioles

188
Q

Greatest radius, thin smooth muscle, less pressure

A

Veins or venules

189
Q

2/3 of blood is stored where

A

Venous system

190
Q

What does mean arterial pressure reflect

A

Systemic BP

191
Q

How to calculate mean arterial pressure…

A

DP+ (PP/3)

PP= SP-DP

192
Q

Estimate of pressure from aorta to vena cava

A

MAP

193
Q

The aorta is

A

Compliant and elastic

194
Q

Ability to stretch because of pressure change

A

Compliant

195
Q

How does compliance work with the aorta and blood flow…

A

As stroke volume/blood enter the aorta it expands

196
Q

__ more compliant then __

A

Veins, arteries

197
Q

Compliance has what kind of blood flow vs. elastance

A

Stretch= pulsatile
Elastance= smooth

198
Q

What is the concept of elastance

A

Ability of a vessel to return to its original shape after stretching

199
Q

Elastance effect on arteries

A

Keeps blood flowing during diastole pressure

200
Q

Greatest change in pressure is at the

A

Arteriole

201
Q

Compare and contrast laminar vs turbulent flow

A

Laminar is smooth, no sound

Turbulent= blood bounces off vessel walls, loud, noisy (korotkoff sounds)

202
Q

When is blood flow silent (laminar) and when is it turbulent (loud)

A

Pressure above 120 mmHg= cuff stops arterial flow and no sound heard

Pressure between 80-120 mmHg= Korotkoff sounds made by pulsatile blood through artery (systole)

Pressure below 80 mmHg=blood flow is silent (diastole)

203
Q

Properties of arterioles in blood distribution
- innervated by?
-greatest control of?

A

Highly innervated by smooth muscle (sympathetics) and greatest control of radius from high resistance

204
Q

Allow for control of distribution of cardiac output

A

Arterioles

205
Q

Both blood pressure and blood flow in the arteries is what kind of blood flow?

A

Pulsatile

206
Q

Pulsatile blood flow, increases during __ and decreases during __

A

Ventricular systole, diastole

207
Q

Ejection of blood by ventricles into arteries is

A

Not continous

208
Q

The most common indirect method of measuring systemic arterial blood pressure is referred to as an

A

Auscultatory

209
Q

Characteristics of the continuous capillaries

A

No holes/clefts, only molecules can diffuse for gas exchange

210
Q

characteristics of the discontinuous capillaries

A

not in full contact, large proteins/molecules go through (liver)

211
Q

characteristics of fenestrated capillaries

A

small holes in endothelium, small molecules can pass through like ions (for filtration)

212
Q

What controls blood flow in capillaries, rings of smooth muscle

A

precapillary sphincters

213
Q

precapillary sphincters found on what end

A

arterial end

214
Q

Precapillary sphincters close capillaries in response to

A

local (intrinstic factors)

215
Q

When sphincters relax…

A

blood flows in

216
Q

Vasodilation instrinsic factors for precapillary sphincters are

A

increased CO2 and decreased O2

217
Q

Vasocontriction instrinsic factors for precapillary sphincters are

A

endothelin and metabolites

218
Q

Blood flow is the __ in capillaries because

A

slowest, has the highest total cross sectional area

219
Q

Capillaries vs arterioles with blood pressure

A

Capillaries have the lowest blood pressure and velocity

220
Q

Starling’s forces describe…

A

bulk flow (capillary exchange/transport)

221
Q

From the interstitial space to capillary =
From the capillary to the interstitial space=

A

absorption, filtration

222
Q

Bulk flow from filtration across a capillary depends on a balance of ….

A

hydrostatic and protein/osmotic pressure gradients

223
Q

Hydrostatic and protein/osmotic pressure gradients favor….

A

Hydrostatic: filtration
Protein/osmotic= absorption (increase in protein in blood attracts water)
-Greater pressure inside the capillary than interstitial fluid

224
Q

Roles of lymphatic vessels in the maintenance of interstitial fluid

A

Drains excess interstitial fluid from tissue spaces and returns it to the blood to maintain normal blood volume
- Filters pathogens

225
Q

What happens if lymphatic system cannot keep up with drainage…

A

Edema: filtration is greater than absorption, inadequate drainage (fluid accumulates in interstitial space), capillaries more permeable

226
Q

What side has a lower BP, venous or arterial

A

venous

227
Q

How to mobilize venous return (increase preload…

A
  1. Musculoskeletal and respiratory pump
  2. Venous pressure gradient= need pressure change to move blood
  3. Venous valves= 1 way valve
  4. Sympathetics innervates veins through venoconstriction
228
Q

Descrube the musuloskeletal and respiratory pump

A

M: when contraction occurs, muscle pinches off capillaries and force VR
R: when you inhale, diaphragm contracts and squeezes vena cava, pushing deoxy blood back to heart

229
Q

Preload=

A

EDV

230
Q

SV=

A

EDV-ESV

231
Q

What are baroreceptors?

A

Stretch receptors, monitor BP in the walls of carotid arteries and aorta

232
Q

What factors regulate blood flow

A

intrinsic

233
Q

What intrinsic factors dictate vasoconstriction and dilation

A

Vasoconstriction= decrease Co2, increase endothelin, decrease O2 in lungs
Vasodilation= increase CO2, increase NO and metabolites, decrease O2 (systemic circulation)

234
Q

What are factors regulate blood pressure

A

neural, hormones

235
Q

extrinsic vasodilation factors? vasoconstriction?

A

Vasodilation= neural (NE binds to B2 adrenergic receptors) and hormonal (NO)
Vasoconstriction= neural (NE binds alpha 1 adrenergic receptor) and hormonal (Angiotension ii)

236
Q

How do baroreceptors wok?

A

Respond to BP changes (stretch)–> sends AP

237
Q

Baroreceptor is what kind of reflex

A

negative

238
Q

Describe the parts of the baroreceptor reflex arc:

A

Stimulus= decrease BP change
Receptor= baroreceptor
Afferent: sensory neuron
Integrating center= cardiovascular center in medulla
Efferent/motor neuron= ANS (PNS–SA nodes/AV nodes and SNS–Nodes, myocardium, blood vessels)
Response: increase in BP

239
Q

What effectors are dually innervated of the baroreceptor reflex

A

AV/SA nodes

240
Q

Blood flow relationship to pressure and resistance

A

Blood flow proportional to pressure, but inversely proportional to resistance

241
Q

Hydrostatic pressure is

A

blood pressure (fluid) + gravity

242
Q

Effects distribution of blood in CV system

A

Hydrostatic pressure

243
Q

In a standing person explain above and below the heart hydrostatic pressure

A

Above heart= low hydrostatic pressure, lowest at the head
Below heart= high hydrostatic pressure, greatest at the feet
BLOOD pulled toward the feet

244
Q

Blood distribution and hydrostatic pressure are even throughout the body when?

A

Supine

245
Q

Explain Orthostatic hypotension

A

getting dizzy or passing out when getting up too quick; blood pulled toward feet by gravity; barcoreceptors can’t respond quick enough to change in hydrostatic pressure (comprimising VR, decrease in VR=decrease in CO)

246
Q

Neural vs hormonal reflexes

A

Neural is faster, reacts to change in position
Hormone has longer term effects

Human Physiology (14 decks)

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