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MCAT BIOLOGY FLASHCARDS > MCAT BIO CH. 8 PART 1 > Flashcards

MCAT BIO CH. 8 PART 1 Flashcards

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1
Q

What is action potential?

A

Localized area of depolarization of the plasma membrane that travels along an axon

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2
Q

What is synaptic transmission?

A

Signal exiting the end of an axon at a synapse, transformed into a chemical signal with the release of neurotransmitter into the synaptic cleft

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3
Q

What is the soma?

A

Central cell body of the neuron

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4
Q

What does the soma contain?

A

The nucleus and biosynthetic activity takes place

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5
Q

What is the structure axons and dendrites?

A

Slender projections from the neuron; only one axon and multiple dendrites

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6
Q

What are bipolar neurons? What about multipolar neurons?

A
  1. Neurons with only one axon 2. Multipolar
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7
Q

What are synaptic knobs?

A

A button-like swelling on an axon where it has a synapse (connection) with another neuron

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8
Q

What is the synaptic cleft?

A

Small gap that chemical messengers travel across after being released from synaptic knob

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9
Q

What is the difference between a neuron and a nerve?

A

Neuron is a single cell; nerve is a large bundle of many different axons from different neurons

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10
Q

What are the two primary membrane proteins are required to establish the resting membrane potential?

A
  1. Na+/K+ ATPase

2. Leak K channels

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11
Q

How does the Na+/K+ ATPase work in regards to its ion pumping?

A

Pumps three Na out, two K in with hydrolysis of 1 ATP molecule

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12
Q

What type of transport s Na+/K+ ATPase?

A

Primary active transport

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13
Q

Are there only K+ leak channels?

A

No; very few sodium leak channels

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14
Q

Because the cells are negative on the inside and positive on the outside, they are described as _____?

A

Polarized

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15
Q

Action potential, based on the cell being always polarized, is a….?

A

Disturbance to the membrane potential, a wave of depolarization of the plasma membrane traveling along an axon

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16
Q

After depolarization, what returns the membrane potential normal?

A

Repolarization

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17
Q

Why is action potential considered electrochemical?

A

Because its no just movement of electrical impulse (electrons) but also ions

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18
Q

What are key proteins in the propagation of action potentials?

A

Voltage-gated sodium channels

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19
Q

What happens in response to a change in the membrane potential?

A

Ion channels open to allow sodium to flow down their gradient into the cell and depolarization

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20
Q

When are the voltage-gated sodium channels opened based on depolarization?

A

At threshold potential, approx -50 mV

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21
Q

When do the ion sodium channels become inactive? (To what voltage?) based on depolarization?

A

-35 mV

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22
Q

How does the neighboring neurons also go through depolarization?

A

Some sodium ions flow down the interior of the axon and depolarize the next section of the membrane

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23
Q

What happens in the beginning of repolarization?

A
  1. Na channel inactive

2. K+ channels open but more slowly and for longer

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24
Q

Does the K+ channels cause the mV to return to - 70mV?

A

No, it overshoots and reaches - 90 mV before the channels close

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25
Q

What is the axons wrapped in?

A

Insulating sheath called myelin

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26
Q

What are myelin sheaths created by?

A

Schwann cells

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27
Q

What is Schwann cell?

A

Type of glial cell; wrap layers of specialized membrane around axons

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28
Q

Where are Schwann cells found? What about the central nervous system?

A

Peripheral nervous system; myelination accomplished by oligodendrocytes

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29
Q

How does myelin affect the ions in the axons?

A

No ions can enter or exit the neuron, allowing it to travel and depolarize

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30
Q

What are gaps known in the myelin sheath termed?

A

Nodes of Ranvier

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31
Q

If there are no membrane depo. and no voltage-gated Na+ channels in regions wrapped in myelin, then where are they located?

A

Nodes of Ranvier

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32
Q

What is saltatory conduction?

A

Myelin sheath spending movement of action potential by forcing it to jump from node to node

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33
Q

What glial cells?

A

Specialized, non-neuronal cells that typically provide structural and metabolic support to neurons

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34
Q

Glial cells generate action potentials T/F

A

False: they only maintain a resting membrane potential

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35
Q

What are the five types of glial cells you should maybe remember?

A
  1. Schwann cells
  2. Oligodendrocytes
  3. Astrocytes
  4. Microglia
  5. Ependymal cells
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36
Q

Where are astrocytes located and what is their purpose?

A

CNS; Guide neuronal development and regulate synaptic communication (with neurotransmitters)

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37
Q

Where are microglia located and what is their purpose?

A

CNS; remove dead cells and debris

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38
Q

Where are ependymal cells located and what is their purpose?

A

CNS; produce and circulate cerebrospinal fluid

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39
Q

What is equilibrium potential?

A

No net movement of ions across the membrane

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40
Q

How are equilibrium potential measured (based on what it moves (hint)) ?

A

Equilibrium potential is specific for particular ion

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41
Q

How do the equilibrium potential of Na and K differ?

A

Na is + 50 mV while K+ is - 90 mV

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42
Q

What is the name of the equation that can predict the equilibrium potential for a specific ion?

A

Nersnt equation

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43
Q

What does Eion represent in the equilibrium potential equation?

A

The equilibrium potential for the ion

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44
Q

What does R represent in the equilibrium potential equation?

A

Is the universal gas constant

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45
Q

What does T represent in the equilibrium potential equation?

A

Temperature in Kelvin

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46
Q

What does z represent in the equilibrium potential equation?

A

valence of the ion

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47
Q

What does F represent in the equilibrium potential equation?

A

Faraday’s constant

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48
Q

What does [X] represent in the equilibrium potential equation?

A

concentration of the ion on each side of the plasma membrane

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49
Q

What does the valence of the electron help determine based on the Nersnt equation? What about the concentrations of the ion?

A

Chemical gradient; electrical gradient

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50
Q

What is the Nersnt equation?

A

Eion = RT/zF In ( [X]outside /[X]inside)

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51
Q

Since the resting membrane potential is close to the equilibrium potential of K+ (-90 mV), what does that indicate?

A

There are a large number of K+ leak channels in the membrane

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52
Q

If the cell is almost completely permeable to potassium, which is there a slightly positive mV compared to the equilibrium potential of K+ ?

A

Because there are a few Na+ leak channels allowing Na+ in

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53
Q

What is the refractory period?

A

Neuron unresponsive to membrane depolarization and unable to transmit another action potential for a shot period of time

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54
Q

What are the two phases of the refractory period?

A
  1. Absolute refractory period

2. Relative refractory period

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55
Q

What is the absolute refractory period?

A

Neuron will not fire another action potential no matter how strong a membrane depo. is induced

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56
Q

Why can’t the neuron not fire another action potential during absolute refractory period?

A

Sodium channels have been INACTIVATED (not closed)

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57
Q

What is the relative refractory period?

A

Neuron can be induced but depo. required is greater than normal because the membrane is hyperpolarized

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58
Q

When do electrical synapses occur?

A

When the cytoplasm of two cells are joined by gap junctions

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59
Q

When do chemical synapses occur?

A

End of axons meet their target cells; action potential converted into chemical signal

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60
Q

What happens when the action potential goes through the axon, where does it end up? (based on synaptic transmission)

A

Synaptic knob

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61
Q

What does the depolarization in the synaptic knob from the action potential causes? (based on synaptic transmission)

A

Depolarization of the presynaptic membrane opens voltage-gated calcium channels

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62
Q

What does the opening of voltage-gated calcium channels cause? (based on synaptic transmission)

A

Calcium influx into the presynaptic cell; exocytosis of neurotransmitter stored in secretory vesicles

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63
Q

What happens after the exocytosis of the neurotransmitters that were stored in secretory vesicles? (based on synaptic transmission)

A

Diffuse across the synaptic cleft

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64
Q

What is the synaptic cleft?

A

Small space between cells

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65
Q

After the diffusion of neurotransmitter across the s. cleft, what does it do? (based on synaptic transmission)

A

Binds to receptor proteins in the postsynaptic membrane

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66
Q

What are included in the receptors proteins in the postsynaptic membrane? (based on synaptic transmission)

A

Ligand-gated ion channels

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67
Q

What does the opening of the ligand-gated ion channels cause? (based on synaptic transmission)

A

Changes the membrane polarization

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68
Q

What happens to the neurotransmitter that had bonded to the receptor protein? (based on synaptic transmission)

A

Degraded or removed; terminates signal

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69
Q

What is an example of a chemical synapse commonly used?

A

Neuromuscular junction between neurons and skeletal muscle

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70
Q

What neurotransmitter is released from the neuromuscular junction?

A

Acetylcholine (AChE)

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71
Q

What happens in the neuromuscular junction when an action potential reaches such a synapse, based on neuromuscular junction?

A

Acetylcholine is released into the synaptic cleft

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72
Q

Where does the acetylcholine go when it is released into the synaptic cleft, based on neuromuscular junction?

A

Binds to the acetylcholine receptor on the surface of the postsynaptic cell membrane

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73
Q

What happens when the acetylcholine receptor is binded to by ACh, based on neuromuscular junction?

A

The receptor opens its associated sodium channel, allowing sodium to flow down a gradient into the cell

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74
Q

Allowing sodium to flow down a gradient into the postsynaptic cell, does what (based on neuromuscular junction)?

A

Depolarizes the postsynaptic cell membrane

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75
Q

What happens to the acetylcholine that had bonded to the receptor (based on neuromuscular junction)?

A

Degraded by the enzyme acetylcholinesterase (AChE)

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76
Q

What is an excitatory neurotransmitter?

A

Depolarizes the postsynaptic membrane

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77
Q

What is an inhibitory neurotransmitter?

A

Induce hyper polarization of the postsynaptic membrane

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78
Q

It is not the neurotransmitter that determines the effect on the postsynaptic cell, it is the ________?

A

Receptor

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79
Q

What is summation?

A

The decision of a postsynaptic neuron to whether fire an action potential is determined by both excitatory and inhibitory effects of the synapses

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80
Q

What is temporal summation?

A

Pre-synaptic neuron fires action potentials so rapidly that the EPSPs and IPSPs pile up on top of another

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81
Q

What does EPSPs stand for?

A

Excitatory postsynaptic potentials

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82
Q

Whatdoes IPSPs stand for?

A

Inhibitory postsynaptic potentials

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83
Q

What is spatial summation?

A

The EPSPs and IPSPs from all the synapses on the postsynaptic membrane are summed at a given moment in time

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84
Q

What is the sensory function of a nerve? What is it carried by?

A

Receiving information; PNS

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85
Q

What Is the integrative function of a nerve? What is it carried by?

A

Processing the information; CNS

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86
Q

What is the motor function of a nerve? What is it carried by?

A

Acting on it; PNS

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87
Q

What are two types of effectors?

A

Muscles and glands

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88
Q

What do motor neurons do?

A

Carry information from the nervous system toward organs which can act upon that information

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89
Q

What are efferent neurons? Where do they go?

A

Carry information away from the central nervous system and intervene effectors; carry to effectors

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90
Q

What are sensory neurons?

A

Carry information towards the central nervous systems

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91
Q

What are afferent neurons?

A

Sensory neurons that carry information towards the central nervous systems

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92
Q

How do reflexes occur?

A

Sensory neuron transmits an action potential to synapse with a motor neuron in the spinal cord, causing an action to occur

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93
Q

What is an example of a reflex?

A

Muscle stretch reflex

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94
Q

What happens during the muscle stretch reflex?

A

Sensory neuron detects stretching of a muscle, using sensory neuron to contract i

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95
Q

What is a monosynaptic reflex arc?

A

A reflex involving only two neurons and one synapse

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96
Q

What is an inhibitory interneuron?

A

A short neuron that forms an inhibitory synapse with a motor neuron

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97
Q

The interneuron is the simple example of the ____ role of the nervous system?

A

Integrative

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98
Q

What is reciprocal inhibition?

A

Concurrent relaxation and contraction, basically one and the other

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99
Q

If a reflex occurs without the involvement of the brain, how are we aware of the action?

A
  1. Sensory neuron also branches to form a synapse with a neuron leaning to the brain
  2. Other sensory information is received after the action is taken
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100
Q

What is included in the CNS?

A

Brain and spinal cord

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101
Q

What is included in the PNS?

A

All nerves and sensory structures outside of the brain and spinal cord

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102
Q

What are the two categories of the PNS?

A
  1. Somatic

2. Autonomic

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103
Q

What is the somatic division of the PNS?

A

Conscious sensation and deliberate, voluntary movement skeletal muscle is the somatic division

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104
Q

What is the autonomic division of the PNS?

A

Concerned with digestion, metabolism, circulation, perspiration and other involuntary processes

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105
Q

Where are the two categories of the autonomic division?

A
  1. Sympathetic

2. Parasympathetic

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106
Q

What is the sympathetic system?

A

Fight or flight

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107
Q

What is the parasympathetic system?

A

Rest and digest

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108
Q

What system does the adrenal medulla use and what hormone is released?

A

Sympathetic system; epinephrine (adrenaline)

109
Q

What are the differences between the CNS and PNS, based on what are included?

A

CNS: brain and spinal cord
PNS: axons, dendrites, and cell bodies

110
Q

What is white matter?

A

Myelinated axons

111
Q

What is the white matter in the brain? Spinal cord? PNS?

A

Tract, tract or column, nerve

112
Q

What is grey matter?

A

Unmyelinated axons

113
Q

What is grey matter in the brain? In the spinal cord? In the PNS?

A

Nucleus and cortex, horn and ganglion (p. 289)

114
Q

What are the three subdivisions of the brain?

A
  1. Hindbrain
  2. Forebrain
  3. Midbrain
115
Q

What is the cerebrospinal fluid (CSF)?

A

A clear liquid that serves various functions

116
Q

What does the hindbrain include?

A

Medulla, pon and cerebellum

117
Q

Where is the medulla located?

A

Below the pons and connects brain to the spinal cord

118
Q

What is the function of the medulla?

A

Relaying information between other areas of the brain and regulates vital autonomic functions

119
Q

Where is the pons located?

A

Below the midbrain and above the medulla; connection b/n brain stem and cerebellum

120
Q

What is the function of the pons?

A

Controls some autonomic functions and coordinates movement; plays a role in balance and antigravity posture

121
Q

Where is the cerebellum located?

A

Behind the pons and below the cerebral hemisphere

122
Q

What is coordinated in the cerebellum?

A

Integrating center where complex movement are coordinated

123
Q

What is the function of the cerebellum?

A

Execution of movements

124
Q

What is the purpose of the midbrain?

A

Relay for visual and auditory information and contains much more of the reticular activating system (RAS)

125
Q

What is the reticular activating system responsible for?

A

Arousal and wakefulness

126
Q

What is the brainstem?

A

Medulla, pons, and midbrain

127
Q

What is important about the brainstem?

A

Contains important processing centers and relays information to or from the cerebellum doc cerebrum

128
Q

What does the forebrain include?

A

Diencephalon and telencephalon

129
Q

What are the divisions of the diencephalon?

A

Thalamus and hypothalamus

130
Q

Where is the thalamus located?

A

Near the middle of the bran

131
Q

What is the purpose of the thalamus?

A

Relays and processing centers for sensory information

132
Q

What is the purpose of the hypothalamus?

A

Controlling emotions and autonomic function, hormone production and release

133
Q

What is different with the telencephalon compared to the diendcelphalon?

A

Consists of two separate cerebral hemispheres

134
Q

What is the corpus callous?

A

Thick bundle of axons connecting the cerebral hemispheres

135
Q

What is the largest region of the human brain?

A

Cerebrum

136
Q

What is the cerebral cortex?

A

Outer layer of gray matter

137
Q

What part of the brain contains cerebral cortex?

A

Hemispheres of the cerebrum

138
Q

What is the cerebral hemisphere responsible for?

A

Conscious thought processing and intellectual functions

139
Q

What are the four categories of the cerebral hemispheres?

A
  1. Frontal lobe
  2. Parietal lobe
  3. Temporal lobe
  4. Occipital lobes
140
Q

Function of the frontal lobe?

A

Initiate voluntary movement; involved in reasoning and problem solving

141
Q

Function of the parietal lobes?

A

Involved in general sensations and gustation

142
Q

Function of temporal lobe?

A

Auditory and olfactory sensation; short-term memory, language, emotion

143
Q

Function of the occipital lobe?

A

Visual sensaiton

144
Q

What is the function of the basal nuclei of the brain (basal ganglia)?

A

Voluntary motor control and learning related to habits

145
Q

How do the basal ganglia and cerebellum work together?

A
  1. Basal nuclei: Inhibitory

2. Cerebellum: Excitatory

146
Q

What is the function of the limbic system of the brain?

A

Emotion and memory

147
Q

What is a homunculus?

A

Motor and sensory regions of the cortex are organized such that a particular small area of cortex controls a particular body part

148
Q

The neurons entering and exiting the CNS are carried by what?

A

12 cranial nerves and 13 spinal nerves

149
Q

What is the function of cranial nerves?

A

Convery sensory and motor information to and from the brainstem

150
Q

What is the function of the spinal nerves?

A

Convey sensory and motor information to and from the spinal cord

151
Q

What is an important example of the cranial nerve?

A

The vagus nerve

152
Q

What structures does the vagus nerve effect?

A

The heart and GI

153
Q

What is the function of the vagus nerve?

A

Decrease the heart rate and increase GI activity

154
Q

What is the vagus nerve apart of based on systems?

A

The parasympathetic division of the autonomic nervous system

155
Q

What is the physical structure of the vagus nerve?

A

Bundle of axons that end ing anglia not he surface of the heart, stomach and visceral organs

156
Q

Where do the axons in the vagus nerve come from?

A

Preganglionic and come from cell bodies located in the CNS

157
Q

What do the somatic motor neurons supply?

A

Skelete muscle cells

158
Q

What neurotransmitter do somatic motor neurons use?

A

ACh

159
Q

Where are the somatic motor neurons cell bodies located?

A

In the bran stem or the ventral portion of the spinal cord

160
Q

What do all somatic sensory neurons have?

A

A long dendrite

161
Q

Where does the long dendrite of the somatic sensory neuron extend from and towards?

A

Extends from sensory receptor towards the soma

162
Q

Where is the soma located, based on somatic sensory neurons?

A

Outside the CNS in a dorsal root ganglion

163
Q

What is the dorsal root ganglion?

A

Bunch of somatic and autonomic sensory neuron cell bodies located dorsal to the spinal cord

164
Q

What are meninges?

A

Protective sheath of the brain and cord

165
Q

Are the dorsal root ganglion located in meninges? Then what are they not included with?

A

No; CNS

166
Q

What are the dorsal root ganglion protected by?

A

The vertebral column

167
Q

In all somatic sensory neuron, the axon is located where?

A

Either synapses in the cord or stretches all the way up to the brain stem before its first synapse

168
Q

The efferents of the sympathetic and parasympathetic systems consists of two neurons, what are they?

A

Preganglionic and postganglionic neuron

169
Q

How is the preganglionic cell body, based on autonomic PNS anatomy?

A

Its cell body int he brainstem or spinal cord

170
Q

What does the preganglionic cell body send, autonomic PNS anatomy?

A

An axon to an autonomic ganglion

171
Q

Once the preganglionic cell body sends the axon to an autonomic ganglion, what does hat axon do, based on autonomic PNS anatomy?

A

Axon synapses with postganglionic neuron

172
Q

The postganglionic neuron sends an axon to an _____? Based on autonomic PNS anatomy?

A

Effector (smooth muscle or gland)

173
Q

All autonomic preganglionic neuron release __ as her neurotransmitter?

A

Acetylcholine

174
Q

All parasympathetic postganglionic neurons release _____?

A

Acetylcholine

175
Q

All sympathetic postganglionic neurons release _____?

A

Norepinephrine

176
Q

Which part of the autonomic PNS anatomy have the cell bodies in the thoracic (chest) or lumbar (lower back) regions of the spinal cord?

A

All sympathetic preganglionic efferent neurons

177
Q

What is the parasympathetic system known as and why?

A

Craniosacral system; all preganglionic neurons have cell bodies in the brainstem or lower portion of spinal cord

178
Q

The sympathetic postganglionic cell sends a long axon to____? The parasympathetic postganglionc cell sends a long axon to _____?

A

The effector; a small ganglion which is close to the effector

179
Q

Why is the adrenal gland named that way?

A

Ad-above and renal - kidney

180
Q

Where are the adrenal glands located?

A

One above each kidney

181
Q

What is the medulla? What about the cortex?

A

Inner portion of the adrenal; outer portion of the adrenal

182
Q

What does the cortex secrete that is very important, based on the adrenal gland?

A
  1. Glucocorticoids (cortisol)
  2. Mineralcorticoids (Aldosterone)
  3. Sex hormones
183
Q

What nervous system is the adrenal medulla apart of?

A

Sympathetic nervous system

184
Q

What is the adrenal gland stimulated to release?

A

Epinephrine (or adrenaline)

185
Q

What is an important effect of epinephrine?

A

Stimulation of the heart

186
Q

Where do sensory receptors send the information for processing?

A

Central nervous system

187
Q

What is sensation? What is perception?

A

The act of receiving information; the act of organizing, assimilating and interpreting

188
Q

How does the brain know the difference between stimulation of visual receptors and olfactory receptors?

A

Brain distinguishes sensory stimuli based on which sensory neurons are signaling

189
Q

What are exteroceptors?

A

Sensory receptors that detect stimuli from the outside world

190
Q

What are interoceptors?

A

Sensory receptors that respond to internal stimuli

191
Q

What do mechanoreceptors respond to?

A

Respond to mechanical disturbances

192
Q

What are two important examples of a mechanoreceptor?

A
  1. Pacinian corpuscles

2. Auditory hair cell

193
Q

What are pacinian corpuscles?

A

Pressure sensors located deep in the skin

194
Q

What is the physical structure of Pacinian corpuscles?

A

Concentric layers of specialized membrane

195
Q

What happens when the Pacinian corpuscles membranes are distorted by firm pressure on the skin?

A

The nerve ending becomes depolarized and the signal travels up the dendrite

196
Q

Where is the auditory hair cell is found? How does it get stimulated?

A

In the cochlea of the inner ear; vibrations caused by sound waves

197
Q

Where are vestibular hair cells located?

A

Within special organs called semicircular canals also found in the inner ear

198
Q

What is the role of the vestibular hair cell?

A

Detect acceleration and position relative to gravity

199
Q

What do chemoreceptors respond to?

A

Respond to particular chemicals

200
Q

What are two types of chemoreceptors?

A
  1. Olfactory receptors

2. Gustatory receptors

201
Q

What do olfactory receptors detect?

A

Detect airborne chemicals and allow us to smell things

202
Q

What do gustatory receptors detect?

A

Taste buds

203
Q

What are nocireceptors?

A

Pain receptors

204
Q

What do nocireceptors respond to?

A

Stimulated by tissue injury

205
Q

What does the nocireceptor consist of?

A

Generally consisting of a free nerve ending that detects chemical signs of tissue damage

206
Q

What are the types of nocireceptors?

A
  1. Somatic

2. Autonomic

207
Q

What do autonomic pain receptors lack?

A

Do not provide the conscious mind with clear pain information

208
Q

What is referred pain?

A

Illusion of pain on the skin, when their nerves cross paths with somatic afferents from the skin

209
Q

What do electromagnetic receptors respond to?

A

Stimulated by electromagnetic waves

210
Q

What is an example of the electromagnetic receptors?

A

Rod and cone cells of the retina of the eye

211
Q

What is an example of a photoreceptors in humans?

A

Rod and cone cells of the retina of the eye

212
Q

What are the four properties of sensory receptors that must be communicated to the CNS?

A
  1. Modality
  2. Location
  3. Intensity
  4. Duration
213
Q

What is stimulus modality?

A

The type of stimulus

214
Q

How does the CNS determine the stimulus modality?

A

Type of receptor is firing

215
Q

What is stimulus location?

A

The receptive field of the sensory receptor sending the signal

216
Q

How is the stimulus intensity processed?

A

By the frequency of action potentials

217
Q

What is the dynamic range based on stimulus intensity?

A

Range of intensities that can be detected by sensory receptors

218
Q

How can the dynamic range of sensory receptors be expanded?

A

By range fractionation; multiple groups receptors with limited ranges to detect a wider range overall

219
Q

What is stimulus duration?

A

Important for communicating changes stimulus and adapt immediately if a stimulus continues at the same level

220
Q

What is adaptation based on sensory stimuli?

A

Decrease in firing frequency when the intensity of a stimulus remains constant

221
Q

Why receptors do not adapt regardless of the constant stimuli?

A

Nocireceptors

222
Q

What is proprioceptors? What is it also known as?

A

Refers to awareness of self; your kinesthetic sense

223
Q

What are examples of a proprioceptor?

A
  1. Muscle spindle; also a mechanoreceptor
  2. Golgi tendon organs
  3. Joint capsule receptors
224
Q

What is a muscle spindle mechanoreceptor?

A

Sensory organ specialized to detect muscle stretch

225
Q

What is the purpose of the Golgi tendon organs?

A

Monitor tension in the tendons

226
Q

What is the purpose of the joint capsule receptors?

A

Detect pressure, tension and movement in the joints

227
Q

What does the prioreceptive component of the musculoskeletal system do?

A

The component of the somatic sensory system allows us to know the positions of our body parts

228
Q

What are the five flavors taste buds can distinguish?

A
  1. Sweet 2. Salty 3. Bitter 4. Sour 5. Unami
229
Q

What is the composition a taste bud?

A

Center is a taste pore, with taste hairs that detect food chemicals

230
Q

Where is the information of taste transmitted?

A

Transmitted by cranial nerviest an area of the brain’s temporal lobe

231
Q

Where are the olfactory receptors found?

A

Roof of he nasopharynx

232
Q

How do the olfactory receptors detect chemicals?

A

Detect airborne chemicals that dissolve in the mucus covering the nasal membrane

233
Q

What do the nerves do once olfactory receptors have been stimulated?

A

Olfactory nerves project directly to the olfactory bulbs of the brain

234
Q

Where are the olfactory bulbs located?

A

The temporal lobe of the brain near the limbic system, an area important for memory and emotion

235
Q

What are pheromones?

A

Chemical signals that cause a social response in members of the same species

236
Q

What compromises the outer ear?

A

The auricle (pinna) and the external auditory canal

237
Q

How is the middle ear divided from the outer ear?

A

The tympanic membrane (eardrum)

238
Q

What does the middle ear consists of?

A
  1. Ossicles
  2. Malleus (hammer)
  3. Incus (anvil)
  4. Stapes (Stirrup)
239
Q

What divides the middle and inner ear?

A

Th oval window which is under stapes

240
Q

What are the structures of the inner ear?

A
  1. Semicicurlar canals
  2. Utricle
  3. Saccule
241
Q

What part of the inner ear is important for balance?

A
  1. Semicicurlar canals
  2. Utricle
  3. Saccule
242
Q

What is the round window?

A

A membrane covered hole in the cochlea near the oval window

243
Q

What is the purpose of the round window?

A

Releases excess pressure

244
Q

What is the Eustachian tube based on the air and what else it is known as?

A

Passageway from the back of the throat to the middle ear; auditory tube

245
Q

What happens when the eardrums vibrate, what does it pass to?

A

Malleus receives vibrations and passed it to the incus and then the stapes then the oval window

246
Q

What happens when vibration reaches the oval window?

A

Creates pressure waves in the perilymph and endolymph

247
Q

What are the perilymph and endolymph?

A

Fluids in the cochlea

248
Q

How are the sounds conveyed through the ear?

A

From air to bone and through liquid before being sensed

249
Q

What does the pressure waves in the endolymph cause?

A

Vibration of the basilar membrane

250
Q

What is the basilar membrane?

A

A thin membrane extending throughout the oiled length of the cochlea

251
Q

What is the basilar membrane covered with?

A

Auditory receptor cells also known as hair cells

252
Q

What do auditory receptor cells or hair cells have?

A

Cilia

253
Q

What do the hair cells on the basilar membrane contact?

A

The tectorial membrane

254
Q

What happens when the basilar membrane moves?

A

The hairs are dragged across the tectorial membrane and they bend

255
Q

What happens when the hair (cilia) from the basilar membrane bend based on the basilar membrane moving?

A

Opens ion channels and neurotransmitters are released

256
Q

What is the organ of Corti?

A

The basilar membrane, hair cells and tectorial membrane

257
Q

When neurotransmitters are released based on the work of the basilar membrane, what does it stimulate and what does it lead to?

A

Dendrites from bipolar auditory afferent neurons are stimulated and sound vibrations are converted to nerve impulses

258
Q

The outer ear and middle ear convey sound to the….? The organ of Corti in the ______ is the the primary site at which _______?

A

cochlea, cochlea, auditory stimuli are detected

259
Q

How is pitch (frequency) distinguished?

A

By the regions of the basilar membrane vibrate which stimulates different auditory neurons

260
Q

How does the size and structure of the basilar membrane differ in different regions?

A

Narrow, thick and sturdy near the oval window and gradually becomes wider, thin and floppy near the apex of the cochlea

261
Q

Lower frequency / Longer wavelength sounds stimulate hair cells at the _______?

A

Apex of the cochlear duct, farthest away from the oval window

262
Q

Higher frequency / Shorter wavelength sounds stimulate hair cells at the ________?

A

Base of the cochlea, near the oval window

263
Q

How is the loudness of sounds distinguished?

A

By the amplitude of vibration

264
Q

What is the purpose of the auditory cortex based on sound?

A

That is where sound is processed, located in the temporal lobe of the brain

265
Q

What is the vestibular complex made up of?

A

Three semicircular canals, the utricle, the saccule and the ampullae

266
Q

What do the vestibular complex have in each component?

A

Tubes filled with endolymph, cotton hair cells that detect motion

267
Q

What is the function of the vestibular complex?

A

Rotational acceleration of the head

268
Q

What are present in the vestibular complex based on neurons?

A

Innervated by afferent neurons which send balance information

269
Q

What does the vestibular complex monitor?

A

Static equilibrium and linear acceleration, which contribute to sense of balance

MCAT BIOLOGY FLASHCARDS (23 decks)

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