Unit 4 Cardiovascular/Heart Physiology Flashcards
1
Q
What are the two major divisions of the circulatory system?
A
Pulmonary Circuit
Systemic Circuit
2
Q
What are the three layers of an artery?
A
Tunica Interna
Tunica Media
Tunica Externa
3
Q
What are the two types of arteries?
A
Conducting (Elastic) arteries *Largest
Distributing (Muscular) Arteries
4
Q
What controls Which capillary beds are well perfused?
A
Precapillary sphincters
5
Q
How many capillaries are open at one time?
A
Only 1/4
6
Q
What are the types of capillaries?
A
Continuous
Fenestrated
Sinusoids
7
Q
Continuous Capillaries
A
Occur in most tissues
8
Q
Fenestrated Capillaries
A
Occur in Kidneys and Small Intestine
9
Q
Sinusoid Capillaries
A
Found in Bone Marrow, Liver, and Spleen
10
Q
What are the mechanisms of Venous Return?
A
Pressure Gradient Gravity (Head and Neck) Skeletal Muscle Pump (Limbs) Thoracic Pump Cardiac Suction of expanding atrial space
11
Q
What are the Arterial Sense Organs?
A
Major Arteries above the heart
Carotid Sinuses
Carotid Bodies
Aortic Bodies
12
Q
What are the structures in a Fenestrated Capillary?
A
Endothelial Cells
Filtration pores (Fenestrations)
Basal Lamina
Intercellular Cleft
13
Q
What are the structures in a Sinusoid Capillary?
A
Endothelial Cells Erythrocytes Liver cells Microvilli Sinusoids
14
Q
What are the types of veins
A
Veins
Venules
Venous Sinuses
15
Q
How does the Skeletal Muscle Pump Operate?
A
When the muscle contracts, the valve to the heart opens and can be pumped upwards to the heart. When the muscle is relaxed, the valve is closed.
16
Q
Most Common Circulatory Route
A
Heart-Arteries-Arterioles-Capillaries-Venules-Veins
17
Q
Portal System
A
Hypothalamus-Anterior Pituitary
Found in Kidneys
Between Intestines-Liver
18
Q
How is the heart innervated?
A
Through both sympathetic and Parasympathetic nerves
19
Q
Automaticity
A
The Ability of the heart to self-excite and initiate its own depolarization
20
Q
True or false: The heart contracts in sections.
A
False: The heart contracts as a unit.
21
Q
Intrinsic Conduction
A
The basic contractions, Rhythm, is controlled by the cardiac muscles
22
Q
In-House Conduction
A
The Autorhythmic cells do not maintain a stable resting potential.
23
Q
At what threshold do fast calcium ion channels open (in-house conduction)
A
-40mV
24
Q
What is the sequence of Excitation in the heart?
A
Sinoatrial Node (SA Node) Atrioventricular Node (AV Node) Atrioventricular Bundle (Bundle of His) Right and Left Bundle Branches Purkinje Fibers
25
What is the function of the SA Node in the heart?
Pacemaker
26
What is the function of the SA Node in the heart?
Pacemaker
27
What is the structure of Cardiac Muscle?
Short, branched cells, w/ one central nucleus
28
Intercalated discs
Join Myocytes end to end
29
What allows ions to flow?
Electrical Junctions (GAP Junctions)
30
What type of respiration do Cardiac Muscles use?
Aerobic Respiration
31
True or false: Cardiac muscle cells have small mitochondria
False: They have large mitochondria
32
What are the organic fuels for Cardiac Muscles?
Fatty Acids
Glucose
Ketones
33
True or False: Cardiac cells fatigue easily
False: They are fatigue resistant
34
Systole
Ventricular Contraction
35
Diastole
Ventricular Relaxation
36
What is the action potential flow of a Myocyte?
```
Na+ Gates Open
Rapid Depolarization
Na+ Gates Close
Slow Ca2+ Channels Open
Ca2+ channels close, K+ Channels Open
```
37
What are the steps of Electrical activity in the Myocardium?
1- Atrial Depolarization Begins
2-Atrial Depolarization Complete (Atria Contracted)
Ventricles begin to depol. @ Apex; Atria repol. (relax)
Ventricular Depol. complete (contracted)
Ventricles begin to repolarize @ apex
Ventric. Repol. complete (Ventricles Relaxed)
38
1 Cardiac Cycle (Definition)
One Complete Contraction and relaxation of all 4 chambers of the heart
39
1 Cardiac Cycle (Steps)
Atrial Systole; Ventrical Diastole
Atrial Diastole; Ventrical Systole
Quiescent Period
40
Extrinsic Innervation of the heart is controlled by
```
The Autonomic Nervous System
Cardiac Centers in the Medulla Oblongata
Cardioacceleratory Center (Sympathetic)
Cardioinhibitory Center (Parasympathetic)
```
41
The Cardioacceleratory center is in what division of the ANS?
Sympathetic
42
The Cardioinhibitory Center is in what division of the ANS?
Parasympathetic
43
Cardiac Cycle
All Events associated w the blood flow through the heart during one complete heartbeat
Atrial Systole and Diastole
Ventrical Systole and Diastole
44
Systole
Contraction
45
Diastole
Relaxation
46
Blood Flow
The Amount of blood flowing through a tissue in a given time (ml/min)
47
Perfusion
The rate of blood flow per given mass of tissue (ml/Min/g)
48
Blood Pressure
The force that blood exerts against a vessel Wall
49
Systolic Pressure
BP During Ventricular Systole
50
Diastolic Pressure
BP During Ventricular Diastole
51
Normal Value for BP (Young Adult)
120-75 mm Hg
52
Pulse Pressure
Systolic-Diastolic
| Important measure of stress exerted on small arteries
53
Mean Arterial pressure (MAP)
Measurements taken at intervals of cardiac cycle.
Best estimate; Diastolic Pressure +( 1/3 of Pulse Pressure)
Varies w Gravity; Standing 62-head, 180-Ankle
54
True or False: Veins have high blood pressure
False: Veins have no BP because they are so far away from the heart.
55
Hypertension
High BP
56
Hypotension
Low BP
57
Peripheral Resistance (Methods)
```
Blood Viscosity (RBcs and Albumin)
Vessel Length
Vessel Radius (Most powerful influence over flow)
```
58
Ways to regulate BP and Flow
Local Control
Neural Control
Hormonal Control
59
Metabolic theory of autoregulation
Tissue Inadequately perfused, wastes accumulate= Vasodilation
60
Vasoactive Chemicals
Substances that stimulate vasomotion; Histamine; Bradykinin
61
Bradykinin
Stimulates Vasomotion
62
Histamine
Stimulates Vasomotion
63
Reactive Hyperemia
Blood Supply Cut off then restored
64
Methods of Local Control of BP and Flow
Metabolic theory of Autoregulation
Vasoactive Chemicals
Reactive Hyperemia
65
Methods of Neural Control of BP and Flow
Vasomotor Center of Medulla Oblongata
66
The Vasomotor Center of the Medulla Oblongata integrates what 3 Autonomic Reflexes?
Baroreflexes (Dilation and Contraction)
Chemoreflexes
Medullary Ischemic Reflex
67
Baroreflex
Changes in BP detected by stretch receptors (Baroreceptors), in large arteries above the heart
68
Autonomic Negative Feedback Response in Baroreflex Neural Control (Describe it)
An increase in BP causes rate of signals to rise, inhibits vasomotor Center, decreased sympathetic tone, vasodilation causes BP to decrease
Increase in BP causes rate of signals to drop, excites vasomotor center, Increases sympathetic tone, vasoconstriction and BP Increases
69
Neural Control: Chemoreflex
Chemoreceptors in aortic bodies and carotid bodies
| Autonomic Response to changes in blood (like pH)
70
Other Brain Center Neural Control of BP and Flow
Stress, Anger, Arousal can increase BP
71
Other Brain Center Neural Control of BP and Flow
Stress, Anger, Arousal can increase BP
72
Hormonal Control of BP and Flow
```
Angiotensinogen
↓
Renin
↓
Angiotensin I
↓
ACE
↓
Angiotensin II
```
73
Angiotensinogen
Prohormone produced by the Liver
74
Renin
Kidney Enzyme released by Low BP
75
ACE
Angiotensin-Converting Enzyme in lungs
76
ACE Inhibitors
Block the ACE Enzyme, lowering BP
77
Angiotensin II
Very Potent Vasoconstrictor
78
Aldosterone
Mineralocorticoid hormone; Regulates BP, Plasma, Potassium, and Sodium; Adrenal Cortex
79
Atrial Natriuretic Factor
Increases Urinary Sodium Excretion
80
ADH (Antidiuretic Hormone)
Water Retention
81
Epinephrine and Norepinephrine (Hormonal Control of BP and Flow)
Most blood Vessels
- Binds to Alpha-Adrenergic Receptors for Vasoconstriction
Skeletal and Cardiac Muscle blood Vessels
- Binds to Beta Adrenergic Receptors for Vasodilation
82
Cardiac Output
blood pumped out by each ventricle in one minute.
83
Formula for Cardiac Output
Heart Rate (HR) x Stroke Volume (SV)
84
Stroke Volume
Blood Pumped out by one ventricle each beat
85
Stroke Volume Formula
EDV-ESB
86
EDV can be increased by
Longer Ventricular Diastole and/or increase in venous pressue
87
ESV can be increased by
Increased arterial pressure or decreased ventricular contraction
88
What are the three factors affecting Stroke Volume
Preload
Contractility
Afterload
89
Frank-Starling Law of the Heart
The most important factor controlling stroke volume is the PRELOAD
90
______ is the most important factor controlling stroke volume, according to the Frank-Starling Law of the Heart
Preload
91
SV ***Preload***
The Degree to which cardiac muscle cells are stretched before they contract
92
_____ Increases the # of active cross bridges and the force of contraction
Preload
93
In preload, the amount the muscle is stretched is controlled by
Venous Return, increase in volume or speed increases stretch
94
In preload, the amount the muscle is stretched is controlled by
Venous Return, increase in volume or speed increases stretch
95
SV Contractility
An Increase in contractile strength that is independent of muscle stretch and EDV
96
Contractility increases ____ influx from Extracellular Fluids and the Sarcoplasmic reticulum
Ca2+
97
Contractility gives sympathetic stimulation of
Norepinephrine or Epinephrine
98
Contractility gives sympathetic stimulation of
Norepinephrine or Epinephrine
99
Afterload (SV)
The pressure Exerted by arterial blood
100
Ventricles must overcome ______ pressure in order to have maximum stroke volume
Afterload
101
Sympathetic regulation of Heart Rate
Norepinephrine binds to Beta Adrenergic receptors in the heart, accelerating rate to threshold
102
Sympathetic regulation of the Heart Rate enhances ___ Entry, increasing contractility, and the Stroke Volume does not decline (Yet there is a lower EDV
Ca2+
103
Parasympathetic Regulation of the Heart Rate
Hyperpolarizes membranes by opening K+ Channels
| Has very little affect on contractility
104
Vagal Tone
Both Parasympathetic and Sympathetic maintain constant beat
105
Heart Cell Regeneration (Mitosis)
By using DNA samples from many hearts, the researchers estimated that a 20-year-old renews about 1% of heart muscle cells per year and about 45 percent of the heart muscle cells of a 50-year-old were generated after he or she was born.
106
What is the role of the Hypothalamus in the Cardiovascular system?
Receives signal information from the Aortic bodies
107
What is the role of the Medulla Oblongata in the Cardiovascular System?
Helps Determine if BP and O2 are within range. (O2 of interstitial fluid of the brain)
*O2 Sensitivity
108
What controls which capillary beds are perfused?
Precapillary Sphincters
109
If a capillary sphincter is shut off, how does the tissue stay alive?
Diffusion keeps the tissue alive
110
Closed Precapillary sphincters will result in low _____
Perfusion
111
Sinusoid capillaries are found in the
Red bone Marrow (Produces RBCs)
| Liver and Spleen (Break down RBCs and recycle them)
112
Fenestrated Capillaries are found
In the Urinary system (For Filtration)
| Glomeruli in the Kidneys
113
Continuous Capillaries are found
```
Endothelial tissue (Continuous)
Diffusion can occur
```
114
Tunica Externa
Outside layer of arteries
| Fibrous connective tissue
115
Tunica Media
```
Middle layer of arteries
Smooth muscle (Varies on location) *Sympathetic Only
```
116
Vasoconstriction ___ BP
Increases
117
Vasodilation ____ BP
Decreases
118
Tunica Interna
internal layer of arteries
Simple Squamous endothelium
In All vessels + Heart
Diffuson, Filtration, & Exchange occur in this layer)
119
What are the larges arteries
Conducting (Elastic)
120
What is the distributing process for Renal Arteries
Rena Artery
Large Arteriole
Very Small Arteriole
Capillary Bed (Only Tunica Interna) (Exchange occurs)
121
Veins have _____ Blood Pressure
Very Low
122
What keeps blood going towards the heart in veins?
Valves
123
What area has more valves int he veins than the torso and head?
Appendages
| Gravity would make it harder for blood to go up, so valves keep the blood from going back down
124
In the thoracic pump, an increase in Volume will result in a ______ in_____
Decrease in Pressure
125
Automaticity (Autorhythmicity)
The ability to self-excite and intiate their own depolarization
126
True or false:
| The heart contracts in sections
False: The heart contracts as a unit
127
The autorhythmic cells do not maintain stable _______-
Resting Potential
128
@-40 mV, What occurs in the SA Node
The threshold is reached, and fast calcium ion channels open
129
SA Node depolarization is like a
Disco Ball
130
The SA Node sends the action potential to the surrounding tissue and constantly
Depolarizes and repolarizes
131
True or False: As the SA Node keeps depolarizing and repolarization, there is no refractory period
False: There is no refractory period
132
What are the proteins involved in Cardiac Cells
```
Troponin
Tropomyosin
Titin
**Cross-Bridging**
Actin
Myosin
```
133
What is the structure of Cardiac Muscle
Short, branched cells; One central nucleus
Sarcoplasmic reticulum, Large T-Tubules
Admit More Ca2+ from the Extracellular fluid
134
Gap Junctions
Channels connecting two or more cardiac cells (All interconnected) to one another)
135
Metabolism of Cardiac Muscle
```
Aerobic Respiration
Rich in Myoglobin and Glycogen
Large Mitochondria
Organic Fuels: Fatty Acid, Glucose, Ketones
Fatigue Resistant
```
136
Heart attacks come from
Blockage in a coronary artery. The Blockage causes an oxygen deficit and the tissue begins to die
137
What is the Action Potential of a Myocyte (Myocardia)
-55 mV
138
How are Slow Ca2+ gates used in the Action Potential of Cardiac Cells
They are used to slow and prolong the Action Potential for all cells to promote contraction
139
How is contraction promoted in Cardiac Cells?
Ca2+ is bonded, Cross Bridges are formed, and contraction is occurring
140
What is a Quiescent period of Contraction in the Cardiac Cycle?
A pause in contraction before the next one.
141
What is the best area for listening to a heartbeat on the body?
Left Posterior
142
Extrinsic innervation in the Cardiovascular System
```
Controlled by Autonomic NS
Cardiac Centers(Medulla)
Cardioacceleratory Center (Sympathetic)
Cardioinhibitory center Parasympathetic)
Vasomotor Center (Sympathetic Only, Blood Vessels)
```
143
Cardiac Output
Blood Pumped OUt by each ventricle in one minute
144
EDV
Ending Diastolic Volume: How much blood is in the left ventricle in complete relaxation
145
ESV
Ending Systolic Volume: How much blood is left after contraction
146
EDV can be increased by
Larger Ventricular Diastole and/or increase in venous pressure (Relax Longer, More Blood)
147
An increase in EDV will result in
An increase of the time in diastole
| Increase in Venous Pressure
148
ESV can be increased By
Increased Arterial pressure or decreased ventricular Contraction
149
In regards to ESV and EDV, the goal is to
Decrease ESV, so the goal is to overcome ESV.
| When there is a high aortic pressure, the ventricle has to work harder
150
What are the three factors affecting Stroke Volume
Preload
Contractility
Afterload
151
EDV is also know as _____. and Means?
Preload
| Means Put as much blood into the Ventricle as possible
152
Preload
The Degree to which cardiac muscle cells are stretched before they contract
153
Result of PReload
Increase Number of Active Cross-Bridges,
| Increase the Force of Contraction
154
In Preload, the amount the muscle is stretched is controlled by
Venous Return, increase in volume or speed, increase in stretch
155
Preload requires
Optimal length in sarcomere
Increase time for SR to release Ca2+ into the cell
Open Ca2+ Gates for influx of extracellular Ca2+ to bond Troponin
Increases # of Cross-Bridges
156
Contractility requres
Increase in contractile strength that is independent of muscle strength and EDV
157
Increases Ca2+ Influx from ECF and SR w/ Sympathetic Stimulation od Norepinephrine and Epinephrine
Contractility
158
Norepinephrine and Epinephrine bond to Beta 1 adrenergic receptors, resulting in Ca2+ Ion Influx
Contractility
159
Afterload EDV Requires
Pressure Exerted by Arterial Blood
Ventricles Mus overcome the pressure in addition to have max Stroke Volume
Keep as low as possible for high Cardiac Output
160
What was used in Vietnam degrades the tissue of the heart?
Agent Orange
161
What was used in Vietnam degrades the tissue of the heart?
Agent Orange
162
How is the heart Rate regulated?
Parasympaathetic
Hyperpolarizes membranes by opening K+ Channels
Little Affect On Contractility
163
Vagal Tone
Bosh Sympathetic and Parasympathetic NS maintain constant beat
164
The Vagus Nerve innervates what sections of the heart?
SA Node and AV Node
165
Blood Flow
Amount of blood flowing through a tissue in a given time (mL/Min)
166
BP
Force that blood exerts against a vessel wall
167
High PErfusion occurs (With without) Capillary Blocks
Without
168
Low Perfusion occurs *With Without) Capillary Blocks
With
169
An Increase in perfusion occurs in areas with ____ Metabolism
High
170
A Decrease in Perfusion occurs in areas with ___ Perfusion
Low
171
BP is measured
On the Systole of the Left Ventricle
| Measured as itis coming out of the heart
172
In the Urinary System, the filtration rate is compromised during Hypertension. Why?
The Filtration rate in the kidneys is too fast. It results in low nutrient Reabsorption
173
In the urinary system, the filtration rate is compromised during Hypotension. Why?
Filtration rate is too slow, and the organism becomes toxic
174
Between Hypertension and Hypotension, which is more dangerous to the body?
Hypotension is more dangerous to the body because it affects the brain and kidneys most negatively
175
IN reference to peripheral resistance, vasodilation will give what result to the Blood pressure?
Lower Blood Pressure
176
IN reference to peripheral resistance, vasoconstriction will give what result to the Blood pressure?
Higher BP
177
Medullary Ischemic Reflex
Low O2 in the tissue
| Detects when O2 Surrounding the tissue and uses a baroreflex to adjust naturally
178
Baroreflex
Changes in BP are detected by stretch receptors (Baroreceptors) in large arteries above the heart
179
Autonomic Negative Feedback Response (Part 1)
A Rise in BP causes the rate of signals to rise inhibits vasomotor center, decrease in sympathetic tone, causes BP decrease and Vasodilation to occur
180
Autonomic Negative Feedback Response (Part II)
A Decrease in BP causes the rate of signals to drop, excites vasomotor Center, increases sympathetic tone, Vasoconstriction, and increases BP
181
An Increase in BP results in:
INhibited Vasoconstriction; Relaxation of smooth muscle, and Lowers BP
182
A Decrease in BP results in:
Excites Vasoconstriction, Increases BP
183
Chemoreflex
Chemoreceptors in aortic bodies and carotid bodies increase cardiac output and respiratory rates
184
Medullary ISchemic Reflex increases
Respiratory Rates
185
Other ways BP and Flow Can be regulated
Stress, Anger, Arousal (Limbic System)
186
if paracrine level is too high in the cardiovascular system, what occurs.
Local Control is no longer effective and Hormonal response will be required.
187
Vasoactive Chemicals
Substances that stimulate vasomotion, histamine, and bradykinin
188
Reactive Hyperemia
Blood Supply Cut off, then restored
189
Aldosterone increases what in the Kidneys?
Sodium Channels in the Ascending Limb, Stimulating an increase in Na+ Reabsorption (Loop of Henle), in the interstitial Fluid
190
Hormonal Control of BP and Flow
Kidney releases Renin (Enzyme)
Triggers Angiotensin I
Triggers Angiotensinogen in the Liver (Prohormone)
Goes through Pulmonary Circuit and releases ACE(Angiotensin Converting Enzyme)
ACE Converts to Angiotensin II (Vasoconstricting hormone)
Vasoconstriction occurs and BP increases
Stimulates adrenal Cortex to secrete Aldosterone
Aldosterone increases Soduim Channels in the Ascending Limb
Hypothalamus gives Thirsty Signal
Antidiuretic Hormone released by osterior Pituitaru
Stimualtes Aquaporin added to distaltubule
Atrial Natriuretic Factor INcreases Urinary sodium excretion)
191
The Descending Limb on the Kidney is impenetrable to
Ions
192
90% of the H2) in the kidney is secreted in the
Ascending Limb
193
At the loop of Henle, what occurs
Na+, CL- are secreted and it's impenetrable to Water
194
The bladder only holds 1% of water
True
195
What works in opposition of Aldosterone
Atrial Natriuretic Factor
196
Neural Control of BP and Flow
Vasomotor Center of the Medulla Oblongata Integrates 3 Autonomic Reflexes
Baroreflexes
Chemoreflexes
Medullary Ischemic Reflex
197
When Water and Carbon Dioxide Form to Make Carbonic Acid, What additional reaction occurs?
The Carbonic Acid is converted into H+ and HCO3
198
Metabolic Theory of Autoregulation
Tissue inadequately perfused, wastes accumulate, resulting in vasodilation (Uses Paracrines for Local Communication)
199
Vasoactive Chemicals
Substances that stimulate vasomotion, Histaine, and Bradykinin
200
True or false: There are millions of Nephrons per Kidney
True
201
Juxtaglomerular Apparatus(Baroreceptors)
Macular Densa
Mesangial Cells
Granular Juxtaglomerular Cells
202
How Many Arterioles are in the Kindey
5
203
Increase in BP: Vasoconstriction in the nephron (Afferrent)in the Kidney
Slows Pressure
204
Increase in BP: Vasodilation in the Nephron (Efferent)
Slows Pressure
