EXAM 2 Flashcards
1
Q
Explain the process of action potentials
A
1) A ligand binds with a ligand-gated sodium channel.
2) Na+ diffuses into the cell, depolarizing it.
3) The cell meet its’ sodium threshold voltage and the voltage-gated sodium open depolarizing it further into the potassium voltage threshold. (voltage gated K+ channels begin to open and K+ leaves the cell).
4) (Na+ voltage gated channels close) The K+ voltage gated channels are fully open and the cell repolarizes.
5) K+ voltage gated close slowly as the cell hyperpolarizes.
6) Sodium-Potassium pumps bring the cell back to resting membrane voltage.
2
Q
Changes in membrane potential due to neurotransmitters binding to ligand-gated channels only occur on the _________ and ______ of a neuron.
A
dendrites and soma
3
Q
Explain how the action potentials move through the neuron
A
The action potential begins in the axon hillock and each region begins depolarizing and repolarizing. As the first region’s potassium voltage gated channels are opening the next region’s sodium voltage gated channels are opening. This cycle continues down the axon until it reaches the end and stimulates calcium to activate ligand to transfer to the next neuron, moving the action potentials further.
4
Q
2 types of neurons: the one prior and the one after
A
presynaptic neuron and postsynaptic neuron
5
Q
Name 2 types of neurotransmitters and their functions
A
acetylcholine: stimulates cholinergic receptors
epinephrine: stimulates adrenergic receptors
6
Q
PSP
A
postsynaptic potential: the potential of a post synaptic neuron to create action potentials
7
Q
Explain how action potentials move from the presynaptic neuron to the postsynaptic neuron
A
- Action potential arrives at synaptic knob
- voltage-gated Ca++ channels open and Ca++ enters neuron.
- Ca++ triggers release of neurotransmitter
- Neurotransmitter binds to postsynaptic receptor and creates PSP.
8
Q
What happens to neurotransmitters after creating action potentials?
A
the neurotransmitters have diffused out of the synapse and then return back to the presynaptic neuron through active transport. Then it is degraded.
acetylcholine–> acetylcholine esterase
epinephrine–> monoamine oxidase
9
Q
In order to stop a signal from the brain..
A
Neurotransmitters are no longer put out and therefore there are no action potentials
10
Q
A presynaptic neuron can excite a postsynaptic neuron through…
A
EPSP: excitatory postsynaptic potential
The presynaptic neuron has Na+ enter its cell making it easier to trigger action potential in the postsynaptic neuron.
11
Q
neural integration
A
interactions between circuits of neurons
12
Q
A presynaptic neuron can inhibit a postsynaptic neuron through..
A
IPSP: inhibitory postsynaptic potential
the presynaptic neuron has Cl- entering or K+ leaving and this makes it harder to trigger AP in the postsynaptic neuron
13
Q
______ and ______ “‘fight it out”by simultaneously trying to depolarize and hyperpolarize the membrane. Whether or not postsynaptic neuron fires an AP, depends on how ____ and ___ balance out.
A
EPSP AND IPSP
14
Q
The ________ receives information in the form of action potentials and all of the action potentials are identical.
A
CNS: Central Nervous System
15
Q
How does the CNS interpret information?
A
Neural coding. APs from different neurons mean different things and the neuron can fire many or a few AP’s per second depending on how strong the stimulus.
16
Q
The CNS is made up of the______ and the _______.
A
brain and spinal cord
17
Q
Telencephalon
A
(cerebrum) controls vocabulary, speech, though, judgement, voluntary control, sensory perception, memory, and dreams.
18
Q
Diecephalon
A
(gateway to cerebral cortex (thalamus), hypothalamus, epithalamus).
- controls involuntary functions such as food/water intake/ hormone secretion, cardiovascular regualtion, thermoregulation, sleep wake cycle.
19
Q
Mesencephalon
A
(midbrain, cerebral peduncles, corpora quadrigemina)
- relays info to higher brain centers (unconscious decision)
20
Q
Metencephalon
A
(cerebellum, and pons)
- coordinates movement of skeletal muscle
- aids in learning mortor skills
- remembers how to move
21
Q
Myelencephalon
A
(medulla oblongata)
controls: cardiac center, vasomotor center(vessels), respiratory centers
- sneezing, vomiting, hiccuping, swallowing, sweating
22
Q
Spinal Cord’s function
A
carries most nerves to and from rest of the body
23
Q
Integration center for spinal reflexes
A
- don’t have to think about them
- APs go to sensor–>integration center–>effector before brain is conscious of stimulus
24
Q
The brain and spinal cord make up the CNS and everything else is considered the ____
A
PNS: Peripheral Nervous System
25
afferent fibers (nerves) carry impulses _____ the CNS and are considered ______ neurons.
1) toward
| 2) sensory
26
efferent fibers carry impulses ______ the CNS and are considered _____ neurons.
1) away from
| 2) motor
27
The autonomic nervous system is ______ and ______ connections everything except the _______.
1) sensory
2) motor fibers
3) skeletal muscle
28
The autonomic nervous system is made up of two division: the ______ and the _______.
1) sympathetic division
| 2) parasympathetic division
29
Sympathetic division prepares body for ______ and ________ reaction.
1) physical activity
| 2) fight or flight
30
Parasympathetic division gives a ______ effect on many body functions and provides body ________ (resting and digesting).
1) calming
| 2) maintenance
31
The sympathetic and parasympathetic are always active but one is always ________ than the other and they are constantly _________.
1) more active
| 2) titter-tottering
32
In the autonomic nervous system it takes ___ neurons to get from the CNS to an effector. These neurons connect in the ______.
1) two
| 2) ganglia
33
ganglia and ganglion
- a collection of axon terminals synapsing with nerve cell bodies
- an area with many synapses
34
Preganglionic neurons (CNS to ganglion) always release _____.
ACh (acetylcholine)
35
Postganglionic neurons (ganglion to effector) have _____ fibers that usually release ______ or _______ fibers that always release ______.
1) sympathetic, norepinephrine (NE)
| 2) parasympathetic, acetylcholine (ACh)
36
The specific effect of the neurotransmitter depends on what type of receptors are in the membrane of the _____.
effector
37
The sympathetic nervous system does not always stimulate and organ it can also ______ it.
inhibit it
38
Name three body parts that are only affect by the sympathetic nervous system.
skin, adrenal medulla, arteries
39
True or False: Most organs are innervated by both parasympathetic and sympathetic fibers.
True.
40
The sympathetic fibers _____ the heart and parasympathetic _______ it.
1) excites
| 2) inhibits
41
The sympathetic fibers _____ the diaphragm and parasympathetic _______ it.
1) excites
| 2) inhibits
42
The sympathetic fibers _____ the GI tract and parasympathetic _______ it.
1) inhibits
| 2) excites
43
The sympathetic fibers _____ the salivary glands and parasympathetic _______ it.
1) excites
| 2) excites
44
When something is being excited, ______ is entering the cell and it is ________.
1) Na+
| 2) deopolarizing
45
When something is being inhibited, ______ is being released and the cell _______.
1) ACl
| 2) repolarizes
46
Skeletal muscle
- body movement
- facial expression
- breathing
- speech
- under VOLUNTARY CONTROL except diaphragm
47
Cardiac Muscle
- only found in heart and responsible for contractions that pump blood to arteries.
- under INVOLUNTARY control
48
Smooth Muscle
- Digestive system
- squeezes food from one section to another
- also found in iris of eye and hair follicles
- under INVOLUNTARY control
49
Name the four characteristics all types of muscles have in common.
1) excitability
2) contractility
3) extensibility
4) elasticity
50
Excitability
muscle cells produce action potentials
51
Contractility
muscles cell can become shorter
52
Extensibility
muscle cells can be stretched
53
Elasticity
when stretched, muscle cells will return to their original length.
54
Whole skeletal muscles are connected to bones by tough connective tissue called _____.
tendons
55
During _______, the muscle gets shorter, pulls on the tendon, and moves the bone.
contraction
56
Bundles of muscle cells
fascicles
57
The cell membrane of a muscle fiber is called ____.
sarcolemma
58
The cytoplasm of a muscle cell is called_____.
sarcoplasm
59
Within the sarcoplasm, are bundles of proteins called _____.
myofibrils
60
Each myrofibril is made up of many individual overlapping protein strands called ______.
myofilaments
61
The two types of myofilaments are ______ and _____.
thick filaments and thin filaments
62
Thick and think filaments are arranged in over lapping units called a ______.
sacromere
63
The thick and thin filaments _______ _____ ___ ________ and shorten the muscle cell during contraction.
slide past one another
64
thin filaments are made of a protein called_____.
actin
65
thick filaments are made of a protein called_____.
myosin
66
True or False
| Muscle cells and muscle fibers are not the same thing.
False
67
Within the sarcoplasm, there is a complex network of membrane sacs and tubes called the_______.
sarcoplasmic reticulum
68
The sarcoplasmic reticulum is full of _______ ions and lies all around the _______.
1) calcium
| 2) myofilaments
69
The ends of the sarcoplasmic reticulum form large flat sacs called _______.
terminal cisternae.
70
The terminal cisternae of the sarcoplasmic reticulum lie against narrow tubes called _______.
transverse tubules (T tubules)
71
The T-tubules travel from the ______to the surface of the cell directly to the ________.
1) terminal cisternae
| 2) sarcolemma
72
Action potentials that form on the sarcolemma travel down the _______ and cause the _________ to release calcium into the sarcoplasm.
1) t-tubules
| 2) sarcoplasmic reticulum
73
Calcium in the sarcoplasm causes the ____ to change shape and trigger muscle _______.
1) myofilaments
| 2) contraction
74
A sarcomere is the functional unit of a muscle cell. They are formed by....
repeating units of thick and thin filaments that run end to end, along the length of the muscle cell.
75
An indivudal myosin molecule look like a little ______. The head of the myosin molecule is hindged and can _______.
1) golf club
| 2) move back and forth
76
The thin filaments are made from different proteins. The long string of bead like molcules is called _____. Each individual bead is _______.
1) F actin
| 2) G actin
77
On a think filament each molecule of G actin has an _______ that the myosin heads can bind to.
active site
78
When the muscle is relaxed, long chains of _____ cover the active sites on the G actin of the thin filament.
tropmyosin
79
Small proteins called ____ are attached along the length of the tropomyosin chains.
troponin
80
When calcium is present inside the sarcoplasm, the calcium binds to _____, causing it to change shape.
troponin
81
As the troponin molecules change shape, they ....
drag the tropmyosin chain off of the active sites.
82
Skeletal muscle is made to contract when neurons from the ____ stimulate the muscle cells.
CNS
83
Neurons that stimulate muscle cells are called ______.
motor neurons
84
A motor neuron travels from the CNS and synapses with a muscle cell. The synapse between a motor neuron and a muscle is called the __________ ______.
neuromuscular junction
85
Explain the process of how the CNS stimulates muscle contraction by eventually releasing calcium from the sarcoplasmic reticulum.
1. Action potentials arrive at synaptic knob and opens voltage-gated Ca++ channels.
2. Calcium ions diffuse into synaptic knob.
3. Ca++ binds with protein to move Synaptic vesicles they then release ACh.
4. ACh binds to receptors on the sarcolemma
5. Ion channel of ACh receptors opens. Na+ enters, K+ leaves sarcoplasm through same channel, creating the end-plate potential (EPP).
6. EPP excites voltage-gated ions channels in other regions of sarcolemma. Diffusion of Na+ and K+ through their separate channels depolarizes membrane and initiates AP in muscle fiber.
7. APs propagated down T-tubles to interior muscle fiber.
8. Terminal cisternae release Ca++ into sarcoplasm.
86
Inside of your calls, calcium often acts as a ___ that activates some sort of _______ machinery.
1) key
| 2) protein
87
True or False:
| There is a higher calcium concentration outside of your cells than on the inside.
True
88
Synaptic Vesicles
sacs made from membranes.
| - Ca++ activates them to move and they release ACh into cell membrane
89
The tiny space between the neuron and the muscle cell membranes.
synaptic cleft
90
End Plate Potential (EPP)
the intial depolarization and repolarization the opening of the ACl receptor creates that triggers the voltage-gated sodium channels to open.
91
Put the following events in order:
a. action potential travels down T-tubules
b. active sites on G actin exposed
c. calcium binds to troponin
d. calcium released from sarcoplasmic reticulum
e. heads of myosin molecules attach to active sites on G actin
f. tropomyosin pulled away from active sites on G actin
g. troponin
a. action potential travels down T-tubles
d. calcium released from sarcoplasmic reticulum
c. calcium binds to troponin
g. troponin changes shape
f. tropomyosin pulled away from active sites on G actin
b. active sites on G actin exposed
e. heads of myosin molecules attach to active sites on G actin
92
Identify the neurotransmitter released into the neuromuscular junction by the motor neuron.
ACh
93
What allows the myosin head to bind to the active site?
An ATP molecule bends the head back and as soon as tropomyosin has moved from the active site, the head springs forward from the ATP hyrdrolyzing into ADP + P
94
Cross-Bridge formation
the action of the myosin heads springing up and attaching to the active site on G actin
95
Explain the cycle of the myosin binding and unbinding to the active site. How long will this cycle continue?
1. ATP molecule bends head back
2. (CROSS-BRIDGE FORMATION)ATP--> ADP+P and the head springs forward and binds to active site.
3. (POWER STROKE)The myosin releases the ADP+P and the head flexes further, making the filament shorter
4. Myosin remains flexed and bound to ac5. tive spot until another ATP molecule binds to it.
5. ATP binds to myosin and the head goes back to its intial position, ready to repeat the cycle.
-The cycle will continue as long as the G actin is exposed.
96
True or False:
| You can choose to stop sending action potentials down your motor neurons.
TRUE
97
When the muscles cells relax, the sarcomeres within each muscle cell......
return to their original length
98
Describe the process of muscle relaxation.
1. Signals stop arriving from motor neuron
2. ACh release ceases
3. ACh dissociates from receptors on sarcolemma
Fee ACh broken down by ACh esterase or are reabosrbed by synaptic knob
4.Calcium ions transported back into sarcoplasmic reticulum
5. Calcium ions dissociate from troponin by ATP driven Ca pumps actively transporting Ca back into sarcoplamic reticulum.
6.Tropomyosin blocks active sites
99
How is calcium removed from the inside of the motor neuron during muscle relaxation?
ATP driven Ca++ pumps in the neuron memebrane actively transport any calcium in the cytoplasm out of the cell.
100
Idenitfy 3 ways ACh is cleared from the synaptic cleft of the neuromuscular junction.
1) the enzyme acetylcholineeterase (AChE) breaks down free ACh molecules
2) Actively transported into the synaptic knob of the membrane.
3) Some ACh molecules just diffuse away
101
How is calcium removed from the sarcoplasm of the muscle cells during relaxation?
ATP driven calcium pumps actively transport Ca++ out of the sarcoplasm and back into the sarcoplasmic reticulum.
102
Name the four chambers the heart is comprised of.
right atrium
left atrium
right ventricle
left ventricle
103
The right atrium is separated from the right ventricle by the __________.
The left atrium is separated from the left ventricle by the ____________.
right atrioventricular valve (AV)
| left atrioventricular valve (AV)
104
Blood from the body cells enters the right atrium through the ________ and _____________.
superior vena cava and the inferior vena cava
105
Blood from the lungs enters the left atrium through the ________.
pulmonary veins
106
When the atria contract, blood is forced into the _________.
ventricles
107
When the ventricles contract, the ________ prevent blood from flowing backward into the atria.
Atrioventricular (AV) valves
108
When the right ventricle contracts blood flows through the ___________ and into the _____________ toward the lungs.
pulmonary semilunar valve
| pulmonary artery
109
When the left ventricle contracts blood flows through the ______ and into the _______ toward the rest of the body's cells.
aortic semilunar valve
| aorta
110
The semilunar valves prevent blood from flowing back into the ventricles as the ventricles _______.
relax
111
Blood that is low in oxygen is carried to the heart by 2 large veins. One is called the ________ and the other is called the __________.
superior vena cava
| inferior vena cava
112
The superior vena cava carries blood from the _____ and _______ to the heart.
head and shoulders
113
The inferior vena cava carries blood from the ______ and the _______ to the heart.
abdomen and lower limbs
114
Blood that is high in oxygen is carried to the heart by the ____________.
pulmonary veins
115
Blood from the superior and inferior vena cava flows through the __________ of the heart and then through the __________ into the ______.
1) right atrium
2) right AV valve
3) right ventricle
116
Blood from the pulmonary veins flows through the _______ of the heart and then through the _______ into the _______.
1) left atrium
2) left AV valve
3) left ventricle
117
Explain how the first heart beat is produced.
* NOTE that both right side and left side of the heart are both doing the following and create the first heart sound at the same time.
1) The right of the heart fills from bottom to top. (first the right ventricle then the right atrium).
2) Right atrium contracts, forces more blood into right ventricle.
3) Right ventricle contracts and blood tries to squeeze back into right atrium
4) RIGHT and LEFT AV valve close at the same time and cause the first heart sound!
118
What valves produce the first heart sound?
the RIGHT and LEFT ventricles close simultaneously and create the first heart sound.
119
Explain how the second heart beat is produced.
* NOTE that both the right side and the left side of the art are both doing the following and create the second heart sound at the same time together.
1) Right and left ventricle contract building more and more pressure in the ventricles.
2) Pressure becomes so great the pulmonary and the aortic semilunar valve are forced open.
3) Blood is squeezed out of the ventricles through the valves into the pulmonary artery and the aorta.
4) As the ventricles relax, blood starts to flow backwards into the ventricles. Both the pulmonary semilunar and the aortic semilunar valve close simultaneously and create the second heart sound!
120
Blood in the pulmonary artery is carried to the lungs. In the tiny blood vessels of the lungs, ______ enters the bloods and ______ leaves. The blood is now high in ______, an as it leaves the lungs, it enters the _______.
1) oxygen
2) carbon dioxide
3) pulmonary veins
121
TRUE OR FALSE
| The aorta is the largest artery in the body.
TRUE.
122
Blood in the aorta is carried to all of the body cells except the ______. In the tiny blood vessels that deliver blood to the body cells, _______ leaves and blood and _______ enters. The blood is now _____ in oxygen, and as it leaves the body cells, it will ultimately enter the ________ or the _______.
1) lungs
2) oxygen
3) carbon dioxide
4) high
5) superior or the inferior vena cava
123
The portion of the pathway that carries blood to and form the lungs is called the _______.
pulmonary circuit
124
The portion of the pathway that carries blood to and from the rest of the body cells is called the ______.
systemic circuit
125
Arteries move blood ______ the heart.
away from
126
Veins move blood ________ the heart.
toward
127
The differences between arteries and veins
Arteries
- thicker
- more blood pressure
- carry blood away from heart
Veins
- thinner
- less blood pressure
- carry blood to the heart
128
As the heart beats, it creates ______ pressure changes in the arteries closet to the heart. These changes become ____ and _____ in blood vessels further away from the heart.
1) larger
| 2) smaller and smaller
129
When the heart muscle is contracting, the phase of the cardiac cycle is called ______.
systole
130
When the heart muscle is relaxing between heart beats, this phase of the cardiac cycle is called _______.
diastole
131
The blood pressure in the arteries _____ during systole and _____ during diastole.
1) rises
| 2) falls
132
When measuring blood pressure from a large artery, there are two pressures to measure: the _______ (while the heart is contracting) and the _______ (in between heartbeats) pressure.
1) systolic
| 2) diastolic
133
Explain how blood pressure is measured
1) A sphygmomanometer is placed on the brachial artery
2) The sphygmomanometer in inflated and occludes artery and the blood flow creates a muffled tapping sound called "sounds of Korotkoff"' the pressure measured at the beginning of this sound is the systolic pressure
3) When this sound first disappears as the sphygmomanmeter deflates, the pressure measured at this time is the diastolic pressure.
134
Bloods pressure is recorded as the _______ over ______ pressure. In healthy adults, this is aprroximately _______ mm Hg.
systolic/diastolic
| 120/80
135
Homeostatis
the tendency for any living organism to maintain a fairly stable internal environment, even when the external environment is changing.
ex: shivering, sweating, urinating
136
TRUE OR FALSE
| The internal environment of your body is always stable.
FALSE
137
Your body maintains homeostasis with ____________, which are self-correcting systems that do not allow your internal environment to fluctuate outside a set of limits.
negative feedback loops
138
Blood pressure is monitored by specialized nerve cells called ________. They are found in the ______ arteries ______ to your heart.
1) baroreceptors
2) large
3) closest
139
If blood pressure is increasing--->baroreceptors generate ______ APs.
If blood pressure is decreasing--->baroreceptors generate _____ APs.
The APs travel ___ sensory neurons to the _____.
1) more
2) fewer
3) up
4) brain
140
At the base of the brain(medulla oblongata), are circuits of neurons that can adjust blood pressure, The ________ can increase and decrease heart rate. The ______ can adjust the diameter of the blood vessels.
1) cardiac control center
| 2) vasomotor center
141
____________ is when blood vessels become narrower and _____ is when blood vessels become wider.
1) vasoconstriction
| 2) vasodilation
142
Name the 2 parts of the cardiac control center.
cardioacceleratory center and the cardioinhibitory center
143
The neurons of the cardioacceleratory center stimulate motor neurons that cause the heart to beat ______ and _____. These motor neurons are _______.
1) faster and harder
| 2) sympathetic
144
The neurons of the cardioinhibitory center stimulate motor neurons that cause the heart to beat ______. These motor neurons are _________.
1) slower
| 2) parasympathetic
145
The baroreceptors, medulla oblongata, and heart and blood vessels form a _______ that can regulate ________.
1) negative feedback loop
| 2) blood pressure
146
Explain how the negetive feedback loop for blood pressure decreasing blood pressure when there has been an increase in blood pressure.
Increase in Blood Pressure
1) Baroreceptors fire APs more often
2) Cardioacceleratory center neurons generate fewer AP, heart beats slower
2) Cardioinhibitory center neurons generate more AP, heart beats slower
2) Vasomotor center neurons generate fewer APs, blood vessels vasodilate
3) Blood pressure decreases
147
Explain how when there is a decrease in blood pressure how the negative feedback loop increases blood pressure.
Decrease in Blood Pressure
1) Baroreceptors fire APs less often
2) Cardioacceletory center neurons generate more APs, heart beat increases.
2) Cardioinhibitory center neurons generate less APs, heart beat increases.
2) Vasomotor center neurons generate more APs, blood vessels vasoconstrict.
3) Blood pressure increases
148
The heart contains many autorhythmic cells. If a cell is authorhythmic, it can.....
spontaneously produce action potentials at regular intervals.
149
Heart muscle cells are called _________.
cardiac myocytes
150
The action potentials that cause the cardiac myocytes to contract in a coordinated fashion are able to travel rapidly from cell to cell, because _______ connect the cardiac myocytes of the heart to one another.
intercalated disks
151
Intercalsted disks occur at the ends of the cells. Intercalated disks have three characteristics: _______,_______, and __________.
interdigitatating folds, mechanical junctions, and gap junctions
152
The interconnecting folds of a cell membrane of cardiac myocytes are called ________.
interdigitating folds
153
_________ are made from strong proteins that bind adjacent cardiac myocytes together at the intercalated disks, and prevent them from tearing apart as the heart beats.
mechanical junctions
154
________ are places in the intercalated disks where the cytoplasm of one cardiac myocyte, actually connects to, and is continuous with the cytoplasm of an adjacent cardiac mycocyte.
Gap Junction
155
Gap junctions connect the cardiac myocytes together _______, so that action potential traveling across the membrane of one cardiac myocyte can quickly crossover to the next cell. This is how it is possible for all of the muscle cells to....
1) electronically
2) This makes it possible for all the myocytes of the atria to contract together and then for all of the cell of the ventricles to contract together.
156
There are 2 types of the cardiac myocytes: ______ and _______.
contractile myocytes and the cells of the cardiac condution system
157
contractile myocytes
- the heart cells that actually contract and push blood through the heart.
- most of the heart is composed of contractile myocytes
158
The cardiac conduction system
- system of cells in heart that are specialized for generating action potentials and transmitting those APs rapidly across the heart.
- all of these cells are authorhythmic
159
sinoatrial node (SA node)
- a cluster of cells on the right atrium near the superior and inferior vena cava.
- the cells of the SA node depolarize more rapidly than any of the other cells so their action potentials set the pace for the rest of the cardiac conduction system
- SA node is referred to as the pacemaker of the heart
160
Atrioventricular node (AV node)
cluster of cells between the atria and the ventricles that transmit action potentials from the atria down to the ventricles.
161
Purkinje fibers (subendocardial fiber)
branch extensively and help deliver the APs to all the contractile myocytes and cause ventricles to contract.
162
Explain how the cardiac conduction system makes the heart contract.
1) SA node's APs spread across the atria andthe atria contracts
2) The AV node transmits APs from the atria down to the ventricles.
3) After leaving AV node, APs travel through the AV bundle toward ventricles
4) The AV bundle brakes of into 2 pathways to the right and to the left
5) At the bottom of the heart the AV bundles branch of into the Purkinje Fibers and these fibers deliver the APs to all the contractile myocytes and the ventricles contract
163
TRUE OR FALSE:
For the most part, the cells of the atria do not share gap junctions with the cells of the ventricles, except in one area.
TRUE
164
As cardiac action potentials travel through the cardiac conduction system and contractile myocytes of the heart, the action potentials cause very small, and very brief changes in the distrubtion od ions through the extraceullar fluid. These changes can be measured as _______ changes between different parts of your body.
tiny voltages
165
An ________ is the machine used to produce a picture of the small voltage changes in your body due to cardiac action potentials.
electrocardiograph
166
An ___________ is the picture, display, or print out of the small voltage changes across the body that are caused by the cardiac action potentials.
electrocardiogram (ECG or EKG)
167
The atria are slightly tilted toward the right side of the body. If the extracellular fluid around the atria has ______ charge compared to the extracellular fluid in the rest of the body, then we can measure a small voltage difference between the ___ side of the body and the _____ side of the body or even between the ___ of the body and the ____ of the body. A ____ is measure of these small changes in voltage.
1) negative
2) right
3) left
4) top
5) bottom
6) ECG
168
ECG
| The P wave is caused as....
cardiac APs depolarize the cells of the atria
169
ECG
| The QRS complex is caused as....
cardiac action potentials depolarize the cells of the ventricles
170
ECG
| The T wave is caused as the cell of the....
ventricles go through the repolarization phase of the cardiac action potential.
171
The time between the individual waves of an ECG is also of interest to physicians because it shows how...
quickly action potentials are moving from one part of the cardiac conduction system to the next.
172
ECG
| The P-Q segment (interval) is the time from the...
end of the P wave to the beginning of the ORS complex, and is equal to the time between atrial depolarization and ventricular depolarization
173
The ________ and ________ of each wave within the ECG is affected by the condition of the cardiac muscle tissue.
shape and spacing
174
A healthy ECG shows a ___________.
normal sinus rhythm
175
TRUE OR FALSE
An ECG is not a record of the muscle contraction, but rather an electric signal that follows depolarization and repolarization.
TRUE
176
If a person has ________, some part of the cardiac conduction system is failing to properly transmit action potentials.
heart block
177
First degree heart block
- cardiac conduction system is slow to transmit APs from the atria to ventricles
- may be caused by damage to AV node or AV bundle
- the ECG would display a longer than usual P-Q interval
178
Second degree heart block
- cardiac conduction system transmits only some of the APs
- may be caused by more severe damage to the AV node or AV bundle
- the ECG displays P waves that are followed by QRS complexes and then some P waves that are not followed by QRS complexes
179
Third degree heart block (complete heart block)
- AV node or AV bundle are not transmitting any APs
- some cell of the cardiac conduction system in the ventricles take over and are the pacemaker for ventricles (ectopic pacemaker) but they depolarize and repolarize at a slower rate than the SA node
- the ECG will display a deformed QRS complex
180
Ectopic pacemaker
- pacemaker cells outside of the SA node
| ex: 3rd degree heart block
181
Fibrillation
- no coordination of the heartbeat
- the cells of the atria may be fibrillating or the cells of the ventricles may be fibrillating or both.
- ECG is not readable and resembles a squiggly line
182
Defibrillator
machine that delivers an electric shock to the heart to stop fibrillation
183
Cardiac Output (CO)
the amount of blood your heart is pumping out each minute
184
Cardiac Output depends on two factors:
1) how many times the heart beats each minute
| 2) how forcefully the heart contracts with each beat
185
Stroke Volume (SV)
The amount of blood ejected from the heart with each individual contraction.
186
Heart Rate (HR)
how often the heart beats each minute
187
Cardiac Out put is equal to...
CO=HR*SV
188
The ________ is constantly regulating cardiac output by adjusting heart rate and stroke volume.
cardiac control center
189
Anything that affects how fast the heart is beating is said to have a __________ ______.
chronotropic effect
190
Anything that affects how forcefully the heart muscle contracts is said to have an
inotropic effect
191
The cardiac control center is part of the ________ nervous system.
autonomic
192
The cardiac control center receives ________ _____ from baroreceptors monitoring blood pressure, _________ monitoring the oxygen and carbon dioxide of your blood, and _________ monitoring the activity and position of your limbs.
1) sensory (afferent) input
2) chemoreceptors
3) proprioreceptors
193
When an organ is innervated by autonomic motor neurons, it always take 2 motor neurons to reach from the CNS to the organ. The autonomic motor neurons connect to one another in a collection of synapses called a _________.
ganglion
194
A ___________ conducts action potentials from the CNS to the ganglion, where it synapses with a posganglionic neuron.
preganglionic neuron.
195
The ___________ conducts action potentials from the ganglion to the organ (effector).
postganglionic neuron
196
The sympathetic and parasympathetic branches of the autonomic nervous system have separate ___________ and _______, and separate ______.
1) bundles of preganglionic and postganglionic neurons
| 2) ganglia
197
The motor neurons that travel from the cardioacceleratory center to the heart are part to the ______ branch of the autonomic nervous system.
sympathetic
198
The motor neurons that travel from the cardioinhibitory center to the heart are a part to the ________ branch of the autonomic nervous system.
parasympathetic
199
All preganglionic motor neurons (CNS to ganglion) release the neurotransmitter ________.
ACh
200
Cardiac Physiology
The dendrites and cell bodies of the postganglionic neurons are covered with receptors that bind with ACh molecules. Protein receptors that bind with ACh are called ___________.
cholinergic receptors
201
Cardiac Physiology
When ACh binds with the cholinergic receptors the ________ open and ______ flows into the postganglionic cells allowing it to depolarize and repolarize.
1) sodium channel
| 2) sodium
202
The ganglia of the __________ motor neurons are usually very close to the spinal cord. the ganglia of the _________ motor neurons occur close to or ar even part of the organ being innervated.
1) sympathetic
| 2) parasympathetic
203
Sympathetic postganglionic neurons usually release the neurotransmitters ____________.
norepinephrine
204
Parasympathetic postganglionic neurons always release __________.
acetylcholine (ACh)
205
In the heart, sympathetic and parasympathetic postganglionic neurons form _____________ with the cell of the SA node.
neuromuscular junctions
206
The cells of the SA node are covered with both _______ and _______ receptors.
cholinergic and adrenergic
207
__________ receptors are membrane proteins that have the right shape to bind molecules of norepinephrine.
Adrenergic
208
In the heart, the ________ receptors are part of the sodium channels and the ______ receptors are part of potassium channels.
1) adrenergic
| 2) cholinergic
209
When postganglionic sympathetic motor neurons release ________, it binds to adrenergic _______ channels on the cells of the SA node and causes those cells to __________. This causes the cells of the SA node to generate APs more frequently and the heart beats _______. Norepinephrine, plus other chemcals such as epinephrine, will also make the contractions _______ by causing their ______ channels to stay open longer, this increasing the amount of _____ in the cytoplasm of the muscle cell.
1) norepinephrine
2) sodium
3) depolarize
4) faster
5) stronger
6) calcium
7) calcium
210
When postganglionic parasympathetic motor neurons release ______________, it binds to the cholinergic ________ channels on the cell of the SA node, and the cells _________. This causes the cells of the SA node to generate _______ APs, and the heartbeat becomes ________. ACh will _______ the strength of each contraction of cardiac muscle cells by causing their ____ channels to close faster, thus decreasing the amount of _____ in the cytoplasm of the muscle cell.
1) acetylcholine
2) postassium
3) hyperpolarize
4) fewer
5) slower
6) decrease
7) calcium
8) calcium
211
Chemoreceptors
-specialized neurons that sense the chemical composition of your blood, such as oxygen, and carbon dioxide levels
212
Proprioreceptors
sensory neurons that deliver info about the position and activity of the limbs.
213
The order of events from the beginning to the end of a single heartbeat is called the ______
cardiac cycle
214
Quiescent Period
- both the atria and the ventricle are in diastole
1) blood from the vena cavas flow through right atrium, as the blood from pulmonary veins flows through left atrium
2) blood blows thtough AV valves and then into ventricles
3) the heart fills from bottom to top
215
Atrial Systole
- everything that happens as the atria contract
- SA node depolarizes and APs spread across atria (P wave)
- atria contract and force more blood into ventricles
216
Isovolumetric contraction of the ventricles
- everything that happens during ventricular systole
- atria relax (atrial diastole) as cardiac action potential travels from the AV node, to AV bundle, to bundle branhces, to Purkinje fibers and over the ventricles, causing ventricles to deolarize (QRS complex)
- ventricles contract and blood tries to squeeze back into atria
- right and left AV valves close at same time creating the first heat sound
- ventricle continue to contract, pressure becomes greater and greater until the pulmonary semilunar valve and the aortic semilunar valve are forced open
217
Ventricular ejection
- everything that is happening during ventricular systole, but now the semilunar valves are open
- blood is squeeze out of right ventricle through pulmonary semilunar valve and into pulmonary artery
- at the same time blood is squeeze out of left ventricle, through the aortic semilunar valve and into aorta.
218
Isovolumetric relaxtion
- everything that happens in the heart as the ventricles relax but the semilunar and AV valves are all closed.
- as ventricles relax, blood starts to flow backward so the pulmonary and aortic semilunar valve close. They close at the same time creating the second heart sound
- during this time the AV valves are also closed, ventricles continue to relax and pressure drops and AV valves pop open
- blood is again flowing through the atria and into the ventricles (quiscent period)
219
Functions of Blood Vessels
1) distribution of blood
- selective delivery to tissues in need
- return to heart
2) blood pressure
- exert force to alter pressure
- must withstand changes in pressure
3) exchange
- deliver oxygen and nutrients
- remove carbon dioxide and other waste
220
Arterioles
- small arterial branches
| - resistance vessels
221
capillaries
-exchange vessels
222
venules
collects from capillary beds
223
veins
- return blood to heart
| - capacitance vessels
224
TRUE OR FALSE
| all organs do not receive similar concentrations of oxygen and nutrients
FALSE
225
Vessels contain the following: ______, _______< and _________.
muscle fibers, elastic fibers, and collagen (provide flexibility, strength, and control
226
Arteries have more _____ and elastic fibers ______.
1) muscle
| 2) recoil
227
Veins are ______ and have more_______
1) thinner
| 2) stretch
228
Capillaries are the ______ and have no ______. They also permit ________.
1) thinnest
2) muscle
3) diffusion
229
Capillaries are arranged in ______ so they have a lot of ________ and can easily flow with less ______ and it promotes ________.
1) beds
2) surface area
3) pressure
4) exchange
230
Beds are perfused as needed. Only ____% of beds are perfused at rest.
25
231
Venous Pressure
- very low
- 18mmHG in venules and 2mmHg in vena cava before entering right atrium
- the blood pressure will determine return
- affects CO
- if blood pressure is too low for return then CVO will be reduced.
232
Blood Distribution Percentages:
| Heart, Arteries, Capillaries, Veins
Heart- 7%
Arteries- 13%
Capillaries- 7%
Veins- 64%
233
Venous reserve is ___%
20%
- skin, liver, lungs,
- can divert in case of need or hemorrhage
234
Vericose Veins
- blood pools in lower limbs and veins stretch
| - valves can break or separate
235
Skeletal muscle pump
- helps develop pressure when standing
- must counter force of gravity
- muscles squeeze vessels to develop pressure
- valves direct flow toward heart
236
Respiratory pump
- important when exercising
- inhaling expands thoracic cavity
- pressure drops blood flows toward vena cava and heart
237
Blood
-fluid component of cardiovascular system
238
Blood functions
1) transport
- gases, nutrients, hormones, metabolic waste
2) Regulates pH and ion composition of interstitial fluids,
3) Restricting fluid loss at injury site
- clotting
4) Defense
- white blood cells provide immune function
5) Temperature
- redistribute heat
239
Blood sampling
-diagnostic tool
- can collect blood from any vessel for analysis
(veins preferred but arterial puncture needed to examine blood gases).
