Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BMSC 207 > Midterm #2 > Flashcards

Midterm #2 Flashcards

1
Q

What two components of the body are considered the “anatomy of the CNS?”

A

Brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Brain and spinal cord are separated into ___ matter and ____ matter

A

gray, white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Gray matter consists of _______ somas, _____, and ____

A

unmyelinated, dendrites, axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

White matter consists mainly of _______ axons

A

myelinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The spinal cord contains major pathways for information flowing back and forth between the ____ and the ____, _____ and ____ of the body

A

brain, skin, joints, muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The spinal cord is divided into ____ main regions: ?

A

4: cervical, thoracic, lumbar, sacral, AND coccygeal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many segments does the cervical region contain?

A

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How many segments does the thoracic region contain?

A

12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many segments does the lumbar region contain?

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How many segments does the sacral region contain?

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many segments does the coccygeal region contain?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Each segments gives rise to a ____ ___ of spinal nerves, and each nerve splits into ____

A

bilateral pair, roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The _____ root carries sensory (afferent) information to the CNS

A

dorsal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The _____ root carries motor (efferent) information to muscles and glands

A

ventral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Gray matter also consists of sensory and motor ____

A

nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

_____ are clusters of cell bodies in the CNS

A

Nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

_____ are clusters of cell bodies in the PNS

A

Ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

White matter in the spinal cord consists of tracts of axons carrying information to and from the ____

A

brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are ascending tracts?

A

Dorsal and external lateral, and carry sensory information to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are descending tracts?

A

Ventral and interior lateral, and carry commands to motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The spinal cord can act as the ______ ____ to initiate a response to a stimulus without receiving input from the _____

A

integrating center, brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The fact that the spinal cord can act as an integrating center without the brain is particularly important in ?

A

body movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 6 major divisions of the brain?

A
  1. Cerebrum
  2. Cerebellum
  3. Diencephalon
  4. Midbrain
  5. Pons
  6. Medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What major divisions of the brain are part of the brainstem?

A

Midbrain, pons, medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 4 major regions of the brainstem?

A

Midbrain, pons, medulla, reticular formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The brainstem contains 11/12 ___ nerves

A

cranial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the purpose of the cranial nerves?

A

To carry sensory and motor information for the head and neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The brainstem is involved in 6 basic processes in the body, what are they?

A
  1. Sleep and arousal
  2. Muscle tone
  3. Stretch reflexes
  4. Coordination of breathing
  5. Blood pressure regulation
  6. Modulation of pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

In the medulla, the white matter contains all ascending _____ tracts and descending ______ tracts

A

somatosensory, corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Nuclei in the medulla control many involuntary functioning including the ? and the ?

A

cardiovascular center, medullary respiratory center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The medulla also contains the ____ center, the _____ center, and is responsible for _____, _____, and _____

A

vomiting, deglutition, coughing, sneezing, hiccuping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The Pons contains ____ and ____, and relays information between the ____ and _____, and assists the medulla in the ?

A

nuclei, tracts, cerebellum, cerebrum, coordination of breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The midbrain is also know as the ?

A

mesencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The midbrain is the junction between the lower ___ and ____

A

brainstem, diencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The primary function of the midbrain is controlling ?, it also relays _____ and _____ reflexes and contains the ?

A

eye movement, auditory, visual, substantia nigra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

The reticular formation extends throughout the ____

A

brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The Ret. Formation is important in 3 main functions: ?

A
  1. Consciousness
  2. Arousal
  3. Attention and Alterness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The ret. formation also projets and filters sensory information to the ____

A

cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

The RAS is inactivated during sleep, and damage can induce a ____

A

coma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The ____ is the second largest brain structure, and contains 2 cerebellar hemispheres

A

cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The cerebellum processes sensory information related to ____, and coordinates the ?

A

movement, execution of movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The cerebellum sends feedback signals to ____ areas of the cerebral cortex via its connections to the ___ and ___

A

motor, thalamus, pons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

The cerebellum is the main area of regulating ____ and ____

A

posture, balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The diencephalon lies between the _____ and _____

A

brainstem, cerebrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

The diencephalon contains two primary structures, the _____ and the _____

A

thalamus, hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The diencephalon also contains two endocrine structures, the ____ ____ and _____

A

pineal gland, pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The thalamus is considered the ____ center

A

relay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

The thalamus receives sensory information from the ____ tract, ___, ____ ___ and relays it to the relevant sensory areas in the ____

A

optic, ears, spinal cord, cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The thalamus also relays information from the cerebellum to ____ areas in the cortex

A

motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the main function of the pineal gland?

A

Cyclically release melatonin involved in sleep/wake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

The hypothalamus is considered the center for _____

A

homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

The _____ influences autonomic and endocrine function

A

hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the 4 main functions of the hypothalamus?

A
  1. Helps maintain blood glucose concentrations
  2. Maintains body temperature
  3. Controls body osmolarity
  4. Controls food intake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Pituitary is the ____ of the hypothalamus

A

output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Posterior pituitary is _____ tissue

A

neural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Anterior pituitary is _____ tissue

A

endocrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is neurohypophysis?

A

The posterior pituitary gland, stores and releases oxytocin and vasopressin produced in the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the two main organs/glands that are influenced by oxytocin?

A

mammary glands and the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the main organ that is influenced by vasopressin?

A

kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the hypothalamic–hypophysial portal system?

A

The conduit that connects the brain to the anterior pituitary. Controls growth, metabolism, and reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

The ____ is the largest and most distinctive part of the brain

A

cerebrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Gray matter in the cerebrum includes the ____ _____, ____ ____, and the _____ ____

A

cerebral cortex, basal ganglia, limbic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

White matter in the cerebrum includes _____?

A

tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Cerebrum is the area of _____ processing

A

higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

The cerebrum is divided into __ hemispheres, further divided into __ lobes, and is connected by the _____ ______

A

2, 4, corpus callosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

The basal ganglia is __ nuclei collectively termed

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the 3 nuclei in the basal ganglia?

A

Globus pallidus, putamen, caudate nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are the major roles of the basal ganglia?

A

Regulating the initiation and termination of movement. Receives input from cerebral cortex and provides output to motor portions of the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the role of the limbic system?

A

Plays a primary role in a range of emotions, including pain, pleasure, docility, affection, and anger. Also learning and memory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What are the 3 major components of the limbic system?

A

Cingulate gyrus, amygdala, hippocampus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

The _____ ____ is the outermost layer of the cerebrum and is the integrating center for the CNS

A

Cerebral cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

The cerebral cortex is divided into 3 specializations: ?

A
  1. Sensory areas (sensory input into perception)
  2. Motor areas ( skeletal muscle movement)
  3. Association areas (integrate info from sensory and motor and helps direct voluntary behaviors and deal with complex integrative functions)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Describe the Frontal lobe

A

Skeletal muscle movement
Primary motor cortex
Motor association area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Describe the Parietal lobe

A

Primary somatic sensory cortex
Sensory association area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Describe the Occipital lobe

A

Vision
Visual association area
Visual cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Describe the Temporal lobe

A

Hearing
Auditory cortex
Auditory association area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Which cortex is responsible for taste?

A

Gustatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Which cortex is responsible for smell?

A

Olfactory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

True or False: the cortex can undergo plasticity?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

The distribution of functional areas in the two hemispheres is considered ?

A

not symmetrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Sensory systems provide us with information about the environment both ____ and _____ our body

A

inside, outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What are examples of special senses versus somatic senses?

A

Special: vision, taste, smell, hearing, equilibrium
Somatic: touch, pain, itch, temperature, proprioception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is the general property of a sensory system?

A

A sensory neuron with a transducer (receptor), that converts a physical stimulus into an intracellular signal, usually through the opening or closing of gated channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Describe Simple Receptors

A

Neurons with free nerve endings. They may have myelinated or unmyelinated axons. Pain, itch, and temperature are under this category

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Describe Complex Neural Receptors

A

Nerve endings are enclosed in connective tissue capsules. Touch and proprioception are under this category

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Describe Special Sense Receptors

A

Cells that release neurotransmitter onto sensory neurons. Special senses except olfactory are under this category

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is considered as under the category of Chemoreceptors?

A

Blood chemoreceptors, taste, and smell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What is considered as under the category of Mechanoreceptors?

A

Touch, proprioceptors, auditory (hair cells), and balance (cupula)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is considered as under the category of Photoreceptors?

A

Vision (rods and cones)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is considered as under the category of Thermoreceptors?

A

Thermal receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Physical stimuli are transduced into_____ _____ (graded potentials)

A

receptor potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Mechanically gated channels converts mechanical stimulus into ______ signals

A

electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What are receptive fields?

A

Sensory neurons are activated by stimuli that fall within a specific physical area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

______ creates larger receptive fields, whereas small receptive fields are found in more _____ areas

A

Convergence, sensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Somatosensory neurons bring information to the ___

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Visceral sensory information is integrated in the _____ and _____ ____

A

brainstem, spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Almost all special and somatic sensory information is routed through the ___

A

thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Special senses have dedicated _______ regions, somatic senses are integrated in the _____ ______ cortex

A

cortical, primary somatosensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

CNS distinguishes 4 properties of a stimulus: ?

A
  1. Modality
  2. Location
  3. Intensity
  4. Duration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What is sound localization?

A

Depends on the timing in which sound reaches the auditory cortex from each ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

The location of the stimulus is coded according to ?

A

Which receptive fields are being activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Most sensory stimuli for specific regions of the body are projected to ?

A

Particular areas of the somatosensory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Lateral inhibition can _____ accuracy of localization

A

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Because action potential amplitude is constant, ____ cannot be determined by amplitude

A

intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Intensity is determined by ?

A

The number of receptors being activated (population coding) and the frequency of action potentials coming from receptors (frequency coding)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Duration of stimulus is determined by ?

A

How long action potentials are being activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Order these following statements into the following order in terms of intensity and duration of stimulus:
1. Receptor potential is integrated at the trigger zone
2. Frequency of action potential is proportional to stimulus intensity. Duration of a series of action potentials is proportional to stimulus duration
3. Neurotransmitter release varies with the patters of action potentials arriving at the axon terminal
4. Receptor potential strength and duration vary with the stimulus

A

4, 1, 2, 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Duration also depends on _____ ______

A

receptor adaptation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What are Tonic receptors?

A

Slowly adapting receptors that respond for the duration of a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

What are Phasic receptors?

A

Rapidly adapt to a constant stimulus and turn off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Each receptor is most sensitive to a particular type of _____

A

stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

A stimulus above threshold initiates AP’s in a sensory neuron that projects to the ___

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Stimulus intensity and duration are coded in the ?

A

pattern of AP’s reaching the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Stimulus location and modality are coded according to ?

A

which receptors are activated or by the timing of receptor activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Each sensory pathway projects to a specific region of the _____ _____ dedicated to a particular receptive field. The brain can then tell the ____ of each incoming signal

A

cerebral cortex, origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

The autonomic nervous system of the ______ control of _____ muscle, _____ muscle, many _____, and some _____ tissue

A

involuntary, smooth, cardiac, glands, adipose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

The autonomic system is subdivided into 2 categories: ?

A

Sympathetic and parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Which subdivision of the autonomic system is responsible for rest-and-digest, and which is responsible for fight-or-flight

A

Parasympathetic: rest-and-digest
Sympathetic: fight-or-flight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

______ reflexes are important for homeostasis

A

Autonomic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

The autonomic nervous system works closely with the ____ system and ______ system to maintain homeostasis

A

endocrine, behavioral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

The _______, ____, and ______ initiate autonomic, endocrine, and behavioral responses

A

hypothalamus, pons, medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

_______ control is a hallmark of the autonomic division

A

Antagonistic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Autonomic pathways consist of __ neurons that synapse in an autonomic ganglion

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

______ is common in autonomic pathways, __ preganglionic will synapse with __-__ postganglionic neuron

A

Divergence, 1, 8-9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Self contained neurons within ganglia can act as mini-______ ____

A

integrating centers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

Sympathetic and parasympathetic branches originate in ____ regions

A

different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

Pathways differ by _____ __ ______ in the CNS and the ______ __ _____

A

point of origin, location of ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

In the Sympathetic system, ganglia are mainly found in __ ganglion chains running alongside the ______ column

A

2, vertebral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

In the Sympathetic system, preganglionic neurons originate in what region(s)?

A

Thoracic and lumbar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

In the Sympathetic system, there are ____ preganglionic, and ____ post ganglionic neurons

A

short, long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

In the Parasympathetic system, preganglionic neurons originate in the _____ and exit via _____ ___ or from the ____ ____ of the spinal cord

A

brainstem, cranial nerves, sacral region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

In the Parasympathetic system, the ganglia are mainly located on or near their ____ ____

A

target organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

In the Parasympathetic system, there are ____ preganglionic, and ____ post ganglionic neurons

A

long, short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

In the Parasympathetic system, the cranial nerve __ (____) contains 75% of all parasympathetic neurons

A

X, vagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

The sympathetic pathways use ______ and _____

A

acetylcholine, norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

The parasympathetic pathways use ____

A

acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

Nicotinic is ____, but Adrenergic and Muscarinic are _______, while some sympathetic neurons are _____ (ACh)

A

ionotropic, metabotropic, cholinergic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

True or False: all autonomic neurons are adrenergic and cholinergic?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

The adrenal medulla secretes _______

A

catecholamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

The adrenal medulla is a specialized _______ structure associated with the ______ nervous system

A

neuroendocrine, sympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

The adrenal medulla is often described as a modified sympathetic ganglion, and contains _______ cells which are modified postganglionic neurons

A

chromaffin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

Receptors are not clustered under _____, neurotransmitter diffuses to _______

A

varicosities, receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Autonomic neurotransmitters are synthesized in the _____

A

axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

The primary neurotransmitters, acetylcholine and norepinephrine can be synthesized in the ______

A

varicosities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

Neurotransmitter release is _____ to other types of neurons

A

similar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

Order these statements properly according to norepinephrine release:
1. NE is removed from the synapse
2. Action potential arrives at the varicosity
3. NE is metabolized by monoamine oxidase
4. Receptor activation ceases when NE diffuses away from the synapse
5. Ca2+ entry triggers exocytosis of synaptic vesicles
6. NE can be taken back into synaptic vesicles for re-release
7. NE binds to adrenergic receptor on target
8. Depolarization opens voltage-gated Ca2+ channels

A

2, 8, 5, 7, 4, 1, 6, 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

What is ACh synthesized from?

A

Choline and acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

Order these statements properly according to ACh synthesis:
1. In the synaptic cleft, ACh is rapidly broken down by the enzyme acetylcholinesterase
2. Recycled choline is used to make more ACh
3. Acetylcholine (ACh) is made from choline and acetyl CoA
4. Choline is transported back into the axon terminal by the cotransport with Na+

A

3, 1, 4, 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

Sympathetic adrenergic receptors are all __-_____ ____ receptors (metabotropic receptors)

A

g-protein coupled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

There are two main categories of sympathetic adrenergic receptors: ?

A

Alpha, the most common
Beta, with multiple subtypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

Parasympathetic cholinergic (ACh) receptors in target tissues are __-_____ coupled receptors: ______ receptors

A

g-protein, muscarinic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

There are __ subtypes of muscarinic receptors

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

Where is M1 receptor found in, and the effect of the second messenger?

A

Found in: stomach, salivary glands
Effect of second messenger: activates phospholipase C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

Where is M2 receptor found in, and the effect of the second messenger?

A

Found in: heart
Effect of second messenger: decreases cAMP, inhibits voltage gated calcium channels, activates K+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

Where is M3 receptor found in, and the effect of the second messenger?

A

Found in: smooth muscle of some organs, airways, glands
Effect of second messenger: activates phospholipase C

156
Q

What is the primary function of all muscle is to ?

A

Generate force and/or movement in response to a physiological stimulus

157
Q

In all muscle types, the generation of force depends on the ?

A

conversion of chemical energy (ATP)

158
Q

Skeletal muscles are primarily ____ by somatic motor neurons

A

voluntary

159
Q

Skeletal muscles are _____ and ______

A

striated, multinucleated

160
Q

Cardiac muscles are primarily ____ by spontaneous ___ activity

A

involuntary, electrical

161
Q

______ muscle can be altered by autonomic NS, or hormones

A

Cardiac

162
Q

Cardiac muscles are _____ and ______

A

striated, uninucleated

163
Q

Smooth muscle is primarily ____ by autonomic control, spontaneous, hormones, paracrines, or autocrines

A

involuntary

164
Q

Smooth muscle provides mechanical control of ?

A

Digestive tract, urinary tract, reproductive tract, blood vessels, airways

165
Q

Skeletal muscle is usually attached to ____ by ____

A

bones, tendons

166
Q

What is the origin of skeletal muscle?

A

Closest to the trunk or to more stationary bone

167
Q

What is the insertion of skeletal muscle?

A

More distal or more mobile attachment

168
Q

What are the antagonistic muscle groups in skeletal muscle?

A

Flexor-extensor pairs

169
Q

What is a flexor?

A

Brings bones together

170
Q

What is an extensor?

A

Moves bones away

171
Q

Skeletal muscle takes up about __% of the total body weight and __-__% of daily energy expenditure

A

40, 15-60

172
Q

What is the muscle terminology equivalent of a “muscle cell?”

A

Muscle fiber

173
Q

What is the muscle terminology equivalent of a “cell membrane?”

A

sarcolemma

174
Q

What is the muscle terminology equivalent of a “cytoplasm?”

A

sarcoplasm

175
Q

What is the muscle terminology equivalent of a “modified endoplasmic reticulum?”

A

sarcoplasmic reticulum

176
Q

What is a muscle fasicle?

A

bundle of fibers

177
Q

Single muscle fibers often extend the ____ length of a muscle

A

entire

178
Q

Striations correspond to ordered arrays of ?

A

thick and thin filaments within the myofibrils

179
Q

What is F-Actin?

A

Backbone of thin filaments, double stranded alpha helical polymer of G-actin molecules. Contains binding site for thick filaments (myosin)

180
Q

What is tropomyosin?

A

2 identical alpha helices that coil around each other and sit in the two grooves formed by actin strands, regulates the binding of myosin to actin

181
Q

_____ ____ is a heterotrimer

A

Troponin complex

182
Q

The troponin complex consists of:
[1] troponin __ (TnT): binds to a single molecule of tropomyosin
[2] troponin __ (TnC): Ca2+ binding site
[3] troponin __ (TnI): under resting conditions is bound to actin inhibiting contraction

A

T, C, I

183
Q

The troponin complex is situated every __ actin molecules

A

7

184
Q

Thick filaments consist of a _____ of myosin molecules

A

bundle

185
Q

Each heavy chain contains __ light chains

A

2

186
Q

Thick filaments consists of __ intertwined heavy chains

A

2

187
Q

Myosin head contains a region for binding ____ as well as a site for binding and hydrolyzing ___

A

actin, ATP

188
Q

Regulatory light chain regulates ?

A

ATPase activity of myosin

189
Q

Essential light chain stabilizes the ?

A

myosin head

190
Q

What is Titin?

A

A very large protein extending from M line to Z line, appears to be involved in stabilization of thick filaments and the elastic recoil behavior of muscle

191
Q

What is Nebulin?

A

A large protein that interacts with the thin filaments, believed to regulate the length of thin filaments and contribute to the structural integrity of myofibrils

192
Q

What is the Z disk?

A

Zigzag protein structure that is the attachment site for the thin filaments

193
Q

What are I bands?

A

Lightest band of sarcomere, region occupied only by thin filaments

194
Q

What are A bands?

A

Darkest band of sarcomere, encompasses entire length of the thick filaments, including very dark area where thin and thick filaments overlap

195
Q

What is the H zone?

A

Central region of A band, consists only of thick filaments

196
Q

What is the M line?

A

Proteins form the attachment site for thick filaments, equivalent to z disk for thin filaments

197
Q

The I band has ____ only

A

actin

198
Q

The H zone has _____ only

A

myosin

199
Q

The M line is where ___ is linked with accessory proteins

A

myosin

200
Q

The A band is where ___ and ____ overlap

A

actin, myosin

201
Q

Glucose is stored as glycogen in the _____

A

sarcoplasm

202
Q

The force generated by a contracting skeletal muscle is referred to as ?

A

muscle tension

203
Q

What is the sliding filament model in muscle contraction?

A

The sarcomere shortened during contraction. As contraction takes place, actin and myosin do not change length, but instead slide past one another

204
Q

What is a neuromuscular junction?

A

Point of synaptic contact between somatic motor neuron and individual muscle fibre

205
Q

What is excitation-contraction coupling?

A

An action potential initiated in the skeletal muscle fibre results in an increase in intracellular Ca2+

206
Q

What are the brain regions involved in voluntary movements?

A

Primary motor cortex, corticospinal tract, upper motor neuron, alpha motor neuron

207
Q

What are the 5 components of the primary motor cortex?

A

Basal ganglia, premotor cortex, thalamus, cerebellum, midbrain

208
Q

What is the corticospinal tract?

A

Descending tract (ventral and interior lateral white matter)

209
Q

What is an upper motor neuron?

A

Brain to brainstem or spinal cord

210
Q

What is an alpha motor neuron?

A

Spinal cord (or brainstem) to muscle

211
Q

What is a motor unit?

A

A single motor neuron and all the muscle fibers it innervates

212
Q

Alpha-motor neurons are ___, ______ axons

A

large, myelinated

213
Q

Each axon branches and innervates ?

A

several muscle fibres

214
Q

The number of muscle fibres/motor unit varies. ____ for delicate and precise work, ____ for powerful, less precise contractions

A

<10, >100s

215
Q

What is superoxide dismutase?

A

Enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide

216
Q

What is ALS?

A

A neurodegenerative motor neuron disease. Upper and/or lower motor neurons degenerate leading to muscle atrophy and weakness from disuse

217
Q

What are the 3 components of a neuromuscular junction?

A
  1. Presynaptic motor neuron filled with synaptic vesicles
  2. The synaptic cleft
  3. The postsynaptic membrane of the skeletal muscle fibre
218
Q

Somatic motor neuron branches at its _____ end

A

distal

219
Q

The neuromuscular junction consists of 3 structures: ?

A
  1. Axon terminals
  2. Motor end plates on the muscle membrane
  3. Schwann cell sheaths
220
Q

What is a motor end plate?

A

The region of sarcolemma at the neuromuscular junction

221
Q

What is the purpose of junctional folds?

A

Increase surface area on sarcolemma

222
Q

Motor neuron vesicles contain _____, muscle sarcolemma contains ?

A

acetylcholine, nicotinic acetylcholine receptors

223
Q

What is the extracellular matrix?

A

meshwork of proteins and proteoglycans

224
Q

Nicotinic Acetylcholine receptors are members of cys-loop receptor family of ligand gated ion channels; classified as a _______ ____ _____

A

Monovalent cation channel

225
Q

The opening of ACh receptor requires __ acetylcholine molecules

A

2

226
Q

Na+ entry through nACh generate an _______ ___-____ _____ that spreads to adjacent voltage Na+ channels on the sarcolemma and initiates an action potential

A

excitatory end-plate potential

227
Q

Once APs stop firing in the alpha motor neuron acetylcholine in the synaptic cleft must be removed, what are the 2 options?

A
  1. Diffused away
  2. Broken down to acetate and choline by the enzyme acetylcholinesterase
228
Q

Choline is transported back into the motor neuron and combined with acetyl CoA by the enzyme ? to make acetylcholine

A

choline acetyltransferase

229
Q

What does autoimmune mean?

A

body produced antibodies that bind to ACh receptors

230
Q

What is Myasthenia gravis?

A

Means severe weakness of muscle, and is a disorder of neuromuscular transmission

231
Q

Action potentials propagate from the sarcolemma to the interior of muscle fibres along the ?

A

Transverse tubule network

232
Q

Sarcolemma penetrates into the muscle fibre in the form of __-____ and wrap around each ______ in specific regions

A

T-tubules, myofibril

233
Q

The ultimate intracellular signal that triggers contraction in all muscle types is a rise in ?

A

intracellular calcium [Ca2+]i

234
Q

Depending on the muscle type, Ca2+ can enter the sarcoplasm from the extracellular space via ?

A

Voltage gated Ca2+ channels or can be released into the sarcoplasm

235
Q

T-tubules penetrate the muscle fibre and surround the myofibrils at 2 points in each sarcomere: ?

A

At the A band and I band junctions

236
Q

Along its length the tubules are associated with 2 cisternae to form a “?”

A

triad

237
Q

What is a DHP receptor?

A

L-type Ca2+ channel, it is voltage sensitive

238
Q

What is a RyR?

A

Ryanodine receptor, it is a Ca2+ release channel on SR

239
Q

Besides mechanically, ryanodine receptors can also be activated by ____?

A

Ca2+

240
Q

An increase in [Ca2+]i triggers contraction by removing the inhibition of ?

A

cross bridge cycling

241
Q

Ca2+ binds low affinity sites on troponin C which induces a conformational change in the ?, which causes the troponin complex and the tropomyosin to move, revealing the ?

A

troponin complex, myosin binding site on the actin

242
Q

Order these statements in the proper order:
1. Myosin hydrolyzes ATP. Energy from ATP rotates the myosin head to the cocked position. Myosin binds weakly to actin
2. Myosin releases ADP at the end of the powerstroke
3. ATP binds to myosin. Myosin releases actin
4. Power stroke begins when Pi is released

A

3, 1, 4, 2

243
Q

The release of Pi strengthens the bond between ___ and ___

A

actin, myosin

244
Q

What is a power stroke?

A

A conformational change in which the myosin head returns to its un-cocked state and while doing so pulls the actin filament generating force and motion

245
Q

The termination of contraction requires the removal of ?

A

Ca2+

246
Q

Once the AP has subsided, Ca2+ must be removed so that the myosin binding site on actin can be converted by _______

A

tropomyosin

247
Q

Ca2+ can be removed to the extracellular space by the ? or by the ?

A

Na-Ca exchanger, Ca2+ pump which uses ATP

248
Q

_______ and _____ maximize Ca2+ uptake by the SR

A

Calsequestrin, calreticulin

249
Q

Order these statements according to Ca2+ reuptake into the SR:
1. Ca2+ is bound in the SR by calreticulin and calsequestrin
2. Na-Ca exchanger and Ca2+ pump in the plasma membrane both extrude Ca2+ from the cell
3. Ca2+ pump sequesters Ca2+ within the SR

A

2, 3, 1

250
Q

Elastic recoil of titin and other connective tissues causes sarcomeres to ?

A

return to initial resting position

251
Q

What is rigor mortis?

A

Development of rigid muscle several hours after death, Ca2+ leaks into the sarcoplasm ad binds troponin

252
Q

Why does ATP production stop and cause rigor mortis?

A

Ca2+ cannot be removed (SERCA pump needs ATP), ATP needed to release myosin head from actin, and so it remains in latched cross bridge formation until muscles begin to deteriorate

253
Q

Ca2+ reuptake into the SR is mediated by?

A

the sarcoplasmic and endoplasmic reticulum Ca2+-ATPase (SERCA)-type Ca2+ pump

254
Q

In terms of the timing of E-C coupling, there is a ? between motor neuron AP and muscle fibre AP, and there is a ? between muscle fibre AP and contraction time when Ca2+ is being released and binding troponin

A

slight delay, delay

255
Q

Muscles need a steady supply of ___ to function

A

ATP

256
Q

What are all 3 instances in muscles where ATP is required?

A
  1. Myosin ATPase (contraction)
  2. Ca2+ ATPase: SERCA (relaxation)
  3. Na+K+ ATPase ( after AP in muscle fibre)
257
Q

What are the 2 main sources of ATP for muscles?

A
  1. Free intracellular ATP
  2. ATP formed from phosphocreatine
258
Q

One glucose molecule can then be broken down to pyruvate by glycolysis resulting in the production of __ ATP molecules

A

2

259
Q

Glycolysis takes place in the _____ of muscle

A

sarcoplasm

260
Q

What is muscle fatigue?

A

A decrease in muscle tension as a result of previous contractile activity that is reversible with rest

261
Q

What is Central fatigue?

A

The feeling of tiredness and a desire to cease activity, it preceded physiological cell fatigue

262
Q

Low __ from acid production during ____ _____ may influence the sensation of fatigue perceived by the brain

A

pH, ATP hydrolysis

263
Q

What is peripheral fatigue?

A

Failed excitation-contraction coupling at the T-tubule, and an accumulation of phosphate, acid and ADP

264
Q

What are the possible problems that causes peripheral fatigue?

A
  1. Problems with excitation-contraction coupling
  2. At the T-tubule, with repeated AP firing, K+ builds up in the T-tubules changing the threshold
  3. Within the muscle fibres, buildup of inorganic phosphate
265
Q

What are the different accumulation theories in terms of muscle fatigue?

A

Troponin C leads to decreased Ca2+ sensitivity
Myosin head leads to the release of Pi and ADP
Sarcoplasmic reticulum leads to reduced Ca2+ reuptake and release

266
Q

What are the two classification of skeletal muscle?

A

Maximal velocity of shortening (fast or slow)
The primary pathway they use to form ATP (oxidative or glycolytic)

267
Q

The velocity of shortening is dependent on ? and differs with ?

A

ability to hydrolyze ATP, different isoforms of myosin heavy chain

268
Q

Slow fibres contain _____ with _____ ATPase activity and is considered Type __

A

myosin, slower, I

269
Q

Fast fibres contain _____ with _____ ATPase activity and is considered Type __

A

myosin, faster, II

270
Q

Fibres containing a large amount of mitochondria have a high capacity for ____ metabolism, and are classified as ____ fibres

A

aerobic, oxidative

271
Q

Fibres containing a small amount of mitochondria but have a large store of glycogen, are classified as ____ fibres

A

glycolytic

272
Q

There are 3 types of skeletal muscle fibres: ?

A

Type I: slow-oxidative fibre
Type IIA: fast-oxidative- glycolytic fibre
Type IIX: fast-glycolytic fibre

273
Q

What are the determinants of force on a muscle cell?

A

Fibre diameter, fatigability, initial resting length, frequency of activation

274
Q

What are the determinants of force on an entire muscle?

A

Number of muscle cells activated

275
Q

Muscle length influences tension development by determining ?

A

the degree of overlap between actin and myosin filaments

276
Q

The amount of tension developed is ? to the number of cross bridges formed

A

directly proportional

277
Q

The force developed by a muscle fibre is increased by the summation of ?

A

multiple twitches

278
Q

A single action potential in a single muscle fibre results in ?

A

an individual muscle twitch

279
Q

Does a single twitch represent the maximal force that a muscle fibre can develop?

A

No

280
Q

If a subsequent action potential occurs before the muscle fibre is allowed to relax, a more forceful contraction occurs due to ?

A

summation of single twitches

281
Q

How is summation possible?

A

A single AP does not cause release of the entire Ca2+ store from the SR. A second AP causes a second wave of Ca2+ that may keep additional troponin complexes activated allowing for more cross bridges to be formed so Ca2+ remains elevated for a longer period of time

282
Q

What is tetanus?

A

A maintained contractile response to repeated stimuli

283
Q

What is unfused tetanus?

A

Reached steady state of contraction but stimuli are far enough apart that the muscle fibre slightly relaxes between stimuli

284
Q

What is fused tetanus?

A

The stimulation rate is fast enough that the fibre does not relax, instead it reaches maximum tension and remains there

285
Q

One way to increase tension developed by a single muscle fibre is to increase ?

A

the rate at which action potentials occur in the fibre

286
Q

In a whole skeletal muscle force may be increased by the recruitment of additional ?

A

motor units

287
Q

What is a motor neuron pool?

A

The group of all motor neurons innervating a single muscle

288
Q

What is the size principle?

A

As the stimulus onto the motor neuron pool increases, additional larger motor neurons are recruited

289
Q

In a large-diameter motor neuron, Rm is ___ and conduction velocity is ___

A

low, high

290
Q

In a small-diameter motor neuron, Rm is ___ and conduction velocity is ___

A

high, low

291
Q

All muscle fibres within one motor unit are ? type

A

the same

292
Q

Smaller motor neurons innervate ____ muscle fibres and constitute _____ motor units

A

smaller, smaller

293
Q

In a whole skeletal muscle force may be increased by summing contractions of ______ ____

A

multiple fibres

294
Q

Small motor neurons tend to innervate the ____ number of (_____ diameter) muscle fibres (slow-oxidative) constituting ____ motor units

A

least, small, small

295
Q

Intermediate size motor neurons tend to innervate an ____ number of (_____ diameter) muscle fibres (fast-oxidative-glycolytic) establishing ____ sized motor units

A

intermediate, medium, intermediate

296
Q

Large motor neurons tend to innervate a ____ number of (_____ diameter) muscle fibres (fast-glycolytic) making up ____ motor units

A

large, large,large

297
Q

What is asynchronous recruitment?

A

During submaximal contraction the CNS modulates firing rates of upper motor neurons to allow different motor units to maintain contraction in order to prevent fatigue

298
Q

What is tension?

A

The force tending to pull the attachment points of a muscle toward one another

299
Q

What is isotonic contraction?

A

The muscle contracts, shortens, and creates enough force to move a load

300
Q

What is isometric contraction

A

The muscle contracts but does not shorten. The force created cannot move a load

301
Q

What is concentric contraction?

A

Where the muscle shortens while generating force

302
Q

What is eccentric contraction?

A

Muscle lengthens while generating force and acts to decelerate the joint at the end of a movement

303
Q

How do the sarcomeres shorten during isometric contraction without the muscle changing length?

A

Elastic elements in tendons, elastic and connective tissue in and around muscle fibres

304
Q

What is the proper order of these statements: ?
1. Isometric contraction: muscle has not shortened
2. Muscle at rest
3. Isotonic contraction: the entire muscle shortens

A

2, 1, 3

305
Q

How has skeletal muscle increased ATP synthesizing capacity?

A

Increase in mitochondria size and number, increased capillary density, increase in glycolytic enzymes

306
Q

There is a ______ remodeling of muscle mass

A

constant

307
Q

Changing rates of contractile ____ _____ and ____, regulated by pathways that are influenced by mechanical stress, physical activity, availability of nutrients, growth factors and age

A

protein synthesis, degradation

308
Q

To increase muscle mass, _____ ____> _____ ____

A

protein synthesis, protein degradation

309
Q

There are 2 proposed mechanisms by which muscle mass may be increased: ?

A
  1. Hypertrophy (increased diameter)
  2. Hyperplasia (increased number)
310
Q

What are myosatellite cells?

A

Involved in muscle repair and may form new fibres

311
Q

Satellite cells migrate to the damaged region and, depending on the severity of the injury, ____ to the existing muscle fibre to cause regeneration

A

fuse

312
Q

When skeletal muscle is subjected to an overload stimulus, it causes perturbations in muscle fibres and the related extracellular matrix. This sets off a chain of myogenic events that ultimately leads to: ?

A

Increase in size of sarcomeres and number of myosin and actin
Increased number of sarcomeres within a muscle length, increased myofibrils
Increased sarcoplasmic storage (glycogen)

313
Q

Several studies show a greater rate of myofiber hypertrophy for Type __ fibers in comparison to Type __ and is genetically predetermined

A

II, I

314
Q

What is skeletal muscle atrophy?

A

Protein degradation > protein synthesis, and can occur due to disuse

315
Q

What is cachexia?

A

Weakness and/or wasting due to chronic disease

316
Q

Cardiac muscle is made up of _____ ____ (myocardial muscle cells) which are ______, branched cells and usually contain a ____ ____

A

cardiac myocytes, shorter, single nucleus

317
Q

Cardiac muscle is interconnected by _____ _____: ______ link mechanically, and ___ ______ link them electrically

A

intercalated disks, desmosomes, gap junctions

318
Q

Like skeletal muscle, cardiac muscle is ____ and has ____ containing a similar array of ____ and ___ filaments

A

striated, sarcomeres, thick, thin

319
Q

Cardiac muscle has less abundant but larger __-_____ in comparison to skeletal muscle

A

T-tubules

320
Q

Cardiac muscle has ___ amounts of sarcoplasmic reticulum and requires the entry of ?

A

smaller, extracellular Ca2+

321
Q

Approximately 1% of myocardial cells are specialized non-contracting _____ cells (pacemakers) that generate action potentials spontaneously. This depolarization begins in the _____ ___ (main pacemaker of the heart). They are ____ and contain ___ contractile fibres

A

autorhythmic, sinoatrial node, smaller, few

322
Q

Autorhythmic have an ____ resting membrane potential of -60mV, they never truly rest

A

unstable

323
Q

HCN channels open from ___ to nearly ___ and allow a net influx of Na+, causing the cell to become depolarized

A

-60, -40

324
Q

HCN channels close and __-___ Ca2+ channels open, allowing Ca2+ to flow in, further depolarizing the cell to reach threshold

A

T-type

325
Q

Once reaching threshold __-___ Ca2+ open allowing an influx of Ca2+, causing the depolarizing spike of the action potential

A

L-type

326
Q

HCN channels are only in ________ cells

A

autorhythmic

327
Q

Order these statements in regards to APs in contractile myocardial cells:
1. Once the adjacent cell reached threshold voltage gated Na+ open causing the Na+ spike of action potential
2. There is a brief repolarization from fast K+ channels before the Ca2+ influx through the L-type Ca2+ channels occurs and the fast K+ channels close leading to a sustained depolarization
3. Ions that entered from an AP are transferred to adjacent cells through gap junctions leading to depolarization of the adjacent cell
4. The positive voltage change of the AP slowly opens L-type Ca2+ channels
5. Once the Ca2+ channels close, slow K+ channels repolarize the cell

A

3, 1, 4, 2, 5

328
Q

Long action potential duration prevents ?

A

summation of contraction

329
Q

In cardiac muscle L-type Ca2+ channels (DHP receptors) are not _____ coupled to _______ receptors therefore Ca2+ entry is necessary for contraction

A

mechanically, ryanodine

330
Q

Although removal of Ca2+ to extracellular space is slightly more important in cardiac muscle, ? is still the primary mechanism

A

reuptake into the SR

331
Q

In cardiac muscle the SERCA pump is regulated by ?

A

phospholamban

332
Q

When phosphorylated: Ca2+-pump inhibition is removed, enhancing ? and ________

A

relaxation rates, contractility

333
Q

Rate and amount of Ca2+ uptake is increased, causing ? and a ____ store of Ca2+ for subsequent contractions

A

quicker relaxation, larger

334
Q

Frequency summation in individual fibres and multiple fibre recruitment are used for regulating force generation in ______ muscle

A

skeletal

335
Q

In cardiac muscle an increase in intracellular Ca2+ in the cardiac myocytes enhances ______ ______

A

contractile force

336
Q

Cardiac muscle is capable of _____ single twitch contractions

A

graded

337
Q

If cytosolic Ca2+ is low some actin remains covered by
_______

A

tropomyosin

338
Q

Cardiac muscle generates a greater force when slightly ______

A

stretched

339
Q

The heart has neuronal input that modifies _______/_______

A

conduction, contraction

340
Q

The heart is innervated by the ______ nervous
system

A

autonomic

341
Q

The ______ increases heart rate/conduction and contractility (autorhythmic and contractile); The ________ decreases heart rate/conduction (autorhythmic)

A

sympathetic, parasympathetic

342
Q

Order these statements in order of the Sympathetic modulation of Contraction:
1. Phosphorylation of SERCA increases the speed of Ca2+ re-uptake which increases Ca2+ storage
2. Increases rate of myosin ATPase
3. Phosphorylation of ryanodine receptors enhances sensitivity to Ca2+, increasing release of Ca2+ from the sarcoplasmic reticulum
4. Phosphorylation of Ca2+ channels increases calcium conductance during action potentials

A

4, 3, 2, 1

343
Q

Skeletal length tension relationship explained by degree of overlap between ?

A

thick and thin filaments

344
Q

A slightly stretched sarcomere increases the Ca2+ sensitivity of the ______. A stretched sarcomere has a ______ diameter which may reduce the distance that Ca2+ needs to diffuse increasing ______ of cross-bridge cycling

A

myofilaments, decreased, probability

345
Q

A slightly stretched sarcomere puts additional ____ on stress-activated Ca2+ channels, increasing Ca2+ entry from ______ space and increasing Ca2+ induced Ca2+ release

A

tension, extracellular

346
Q

Heart rate is under _____ control

A

tonic

347
Q

Why is heart hate considered under tonic control?

A

Autorhythmic cells can be modulated by sympathetic and parasympathetic neurons

348
Q

With no autonomic stimulation, autorhythmic cells of the SA node have an intrinsic firing rate of ?

A

~90 action potentials per minute

349
Q

At resting heart rate of ? parasympathetic is
dominant

A

70-72 BPM

350
Q

Parasympathetic neurons containing ACh mainly innervate the ? influencing autorhythmic myocardial cells, decreasing the frequency of action potentials (aka decreasing ____ ___).

A

SA and AV node, heart rate

351
Q

ACh acts on _____ ____ cholinergic receptors opening K+ channels and closing T-type Ca2+ channels and HCN channels

A

muscarinic (M2)

352
Q

Since the pacemaker activity does not usually reside within the AV node, these mechanisms act at the AV node to decrease ______ ____

A

conduction velocity

353
Q

In HCN channels there is a ____ rate of depolarization. Slower depolarization requires more _____ to reach threshold

A

decreased, time

354
Q

In K+ (GIRK) channels there is a ____ shift in maximum diastolic potential. Starting from a more negative value, ___ requires more time to reach threshold.

A

negative, Vm

355
Q

In T-type Ca2+ channels there is a _____ shift in the threshold. Reaching a more positive threshold requires more ____

A

positive, time

356
Q

_____ _____ receptors can be activated by NE released from sympathetic neurons or epinephrine from the adrenal medulla

A

Beta1 adrenergic

357
Q

Increased Na+ conductance through HCN channels and Ca2+ through T-type channels causes: ?

A

Cells reach threshold more rapidly
Decreased level of repolarization

358
Q

______ muscle must operate over a range of lengths

A

Smooth

359
Q

______ muscle layers may run in several directions

A

Smooth

360
Q

______ muscle contract and relax much more slowly

A

Smooth

361
Q

______ muscle uses less energy to generate and maintain force

A

Smooth

362
Q

______ muscle can sustain contraction without fatigue

A

Smooth

363
Q

______ muscle contraction initiated electrically or chemically

A

Smooth

364
Q

______ muscle controlled by autonomic nervous system

A

Smooth

365
Q

______ muscle’s Ca2+ from extracellular space and/or SR

A

Smooth

366
Q

______ muscle Ca2+ initiates cascade eventually turning on myosin ATPase

A

Smooth

367
Q

______ muscle is spindle-shaped, uninucleate cells

A

Smooth

368
Q

______ muscle is troponin & T-tubules absent

A

Smooth

369
Q

intermediate filaments (non-contractile) and dense bodies
(similar to z-lines) form extensive cytoskeletal structure in _____ musle

A

smooth

370
Q

In ______ muscle, thin filaments are anchored to the cell membrane or dense bodies.

A

smooth

371
Q

Smooth muscle myosin has _____ heads all along its length

A

hinged

372
Q

Smooth muscle has functional variability, and its categorized by: ?

A
  1. Location
  2. Contraction pattern
  3. Communication with neighboring cells
373
Q

In humans smooth muscle can be divided into 6 major
groups: ?

A
  1. Vascular: blood vessel walls
  2. Gastrointestinal: walls of digestive tract and associated organs
  3. Urinary: wall of bladder and ureters
  4. Respiratory: airway passages
  5. Reproductive: uterus in females and other reproductive structures in males and females
  6. Ocular: iris and ciliary body
374
Q

Contraction pattern in smooth muscle can be divided into 4 patterns: ?

A
  1. A phasic smooth muscle that is usually relaxed
  2. A phasic smooth muscle that cycles between contraction and relaxation
  3. A tonic smooth muscle that is usually contracted
  4. A tonic smooth muscle whose contraction is varied as needed
375
Q

Communication with neighboring cells is divided into 2 categories: ?

A
  1. Unitary (single unit) smooth muscle: contains jab junctions similar to cardiac muscle cell. Allows coordinated contraction, and is often referred to as visceral smooth muscle
  2. Multiunit smooth muscle: not electrically coupled. Electrical isolation of cells allows for finer motor control
376
Q

Smooth muscle may contract in response to _______ _____ or ________ ______

A

synaptic transmission, electrical coupling

377
Q

Smooth muscle can be innervated by multiple neurons, capable of releasing different ______

A

neurotransmitters

378
Q

Receptor subtype differences in muscle (α-adrenergic: ? vs β-adrenergic: _____ _____)

A

Gi vessel constriction, airway dilation

379
Q

Circulating hormones, stretch and local factors, including paracrine signals, acidity, oxygen and carbon dioxide concentration, and osmolarity, can also alter smooth muscle _____

A

tension

380
Q

Action potentials can be initiated by _____, ______, or ______ stimulation

A

neural, hormonal, mechanical

381
Q

Slow wave potentials fire _____ _____ when they reach threshold, but pacemaker potentials always ______ to threshold

A

action potentials, depolarize

382
Q

Smooth muscle cells produce a wide range of membrane potentials (Vm) and in some smooth muscle Vm oscillations can lead to tonic contractions in the absence of ?

A

action potentials

383
Q

Action potentials usually do not occur in _____ smooth
muscle.

A

multiunit

384
Q

Autonomic neurons create a local depolarization that spreads _______ (graded fashion) throughout the muscle fibre triggering ?

A

electrotonically, Ca2+ entry

385
Q

Autonomic AP initiation (spikes or plateaus) and Spontaneous AP (slow wave, pacemaker) are for _____ _____; but, graded potentials are for ________

A

single units, multi units

386
Q

Contraction due to electrical signaling is known as _________ coupling

A

electromechanical

387
Q

Both extracellular entry and intracellular release of Ca2+ activate contraction and cytosolic [Ca2+]i is increased by three different mechanisms:

A
  1. Ca2+ entry through voltage gated channels or ligand gated ion channels
  2. Ca2+ release from the SR (Ca2+-induced Ca2+ release from RyR, IP3 Ca2+ release from IP3R)
  3. Ca2+ entry through voltage-independent channels (store operated Ca2+ channels, stretch activated channels)

BMSC 207 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions