Ex phys chapter 6 Flashcards
1
Q
The Major functions of the ____ system are
- Delivers O2, nutrients
- Removes CO2, other waste
- Transports hormones, other molecules
- Temperature balance and fluid regulation
- Acid–base balance
- Immune function
A
Cardiovascular system
2
Q
Name the 3 major circulatory system elements in the body
A
- Heart (the pump)
- Blood vessels (tubes and channels)
- Blood (fluid medium)
3
Q
The heart Generates pressure to
A
drive blood through vessels
4
Q
Blood flow must meet
A
metabolic demands
5
Q
The 4 chambers of the heart are
A
- Right and left atria (RA, LA): top, receiving chambers
- Right and left ventricles (RV, LV): bottom, pumping chambers
6
Q
the membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane is the
A
pericardium
7
Q
The _________ is the potential space formed between the two layers of serous pericardium around the heart. Normally, it contains a small amount of serous fluid that acts to reduce surface tension and lubricate.
A
pericardial cavity
8
Q
______is the serous fluid secreted by the serous layer of the pericardium into the pericardial cavity
A
Pericardial fluid
9
Q
Which half of the heart carries out the following tasks:
- Pumps deoxygenated blood from body to lungs
- Superior, inferior vena cava → RA → tricuspid valve → RV → pulmonary valve → pulmonary arteries → lungs
A
Right Heart: pulmonary circulation
10
Q
Which half of the heart carries out the following tasks?
- Pumps oxygenated blood from lungs to body
- Lungs → pulmonary veins → LA → mitral valve → LV → aortic valve → aorta
A
Left Heart: systemic circulation
11
Q
What is cardiac muscle called?
A
Myocardium
12
Q
_____ has most myocardium
A
Left Ventricle
13
Q
_____ -Must pump blood to entire body
- Thickest walls (hypertrophy)
- ____ hypertrophies with exercise and with disease
- But exercise adaptations versus disease adaptations very different
A
left ventricle
14
Q
Myocardium is only 1 type fo muscle fiber and it’s similar to type ____
A
1
15
Q
_______ is
- High capillary density
- High number of mitochondria
- Striated
A
Myocardium
16
Q
_________ hold cells together
A
desmosomes
17
Q
_______ rapidly conduct action potentials
A
Gap junctions
18
Q
________ ________ cells
- Large, long, unbranched, multinucleated
- Intermittent, voluntary contractions
- Ca2+ released from SR
A
Skeletal muscle
19
Q
_____ cells
- Small, short, branched, one nucleus
- Continuous, involuntary rhythmic contractions
- Calcium-induced calcium release
A
Myocardial
20
Q
Right coronary artery
- Supplies ________
- Divides into _______ & ______
A
- right side of heart
- marginal, posterior inter-ventricular
21
Q
Left (main) coronary artery
- Supplies ________
- Divides into _____ & _______
A
- left side of heart
- circumflex, anterior descending
22
Q
Atherosclerosis →
A
coronary artery disease
23
Q
___ ___ is when special heart cells generate and spread electrical signal
A
Spontaneous rhythmicity:
24
Q
The following all help carry out:
- Sinoatrial (SA) node
- Atrioventricular (AV) node
- AV bundle (bundle of His)
- Purkinje fibers
A
Spontaneous rhythmicity
25
Electrical signal spreads via
gap junctions
26
The Intrinsic heart rate (HR): is
100 beats/min
27
____ : initiates contraction signal
- Pacemaker cells in upper posterior RA wall
- Signal spreads from SA node via RA/LA to AV node
- Stimulates RA, LA contraction
SA node
28
_____ : delays, relays signal to ventricles
- In RA wall near center of heart
- Delay allows RA, LA to contract before RV, LV
- Relays signal to AV bundle after delay
AV node
29
______ : relays signal to RV, LV
- Travels along inter ventricular septum
- Divides into right and left bundle branches
- Sends signal toward apex of heart
AV bundle
30
_____ : send signal into RV, LV
- Terminal branches of right and left bundle branches
- Spread throughout entire ventricle wall
- Stimulate RV, LV contraction
Purkinje fibers:
31
when the Heart initiates its own electrical impulses:
intrinsic control
32
HR and force of contraction altered by extrinsic systems:
Parasympathetic nervous system
Sympathetic nervous system
Endocrine system (hormones)
33
Parasympathetic Nervous System Originated from the ____ and reaches heart via
brain stem
| vagus nerve
34
vagus nerve is also known as the
(cranial nerve X)
35
Parasympathetic Nervous System carries impulses to the ___ & ___ nodes
SA, AV
36
When Parasympathetic Nervous System carries impulses to the SA & AV nodes:
- Releases ________, hyperpolarizes cells, slows spontaneous depolarization
- Decreases ___ & force of contraction
acetylcholine, Heart rate
37
parasympathetic nervous system decreases HR below intrinsic HR.
- Intrinsic HR: ___ beats/min
- Normal resting HR (RHR): ___ to __beats/min
- Elite endurance athlete: ___beats/min
- 100
- 60-80
- 35
38
the sympathetic nervous system has opposite affects of the
parasympathetic system
39
When the sympathetic Nervous system Carries impulses to SA, AV nodes:
- Releases ______, facilitates depolarization
- Increases __, force of contraction
- Endocrine system can have similar effect (epinephrine, norepinephrine)
- norepinephrine
| - HR
40
when the sympathetic nervous system Increases HR above intrinsic HR:
Determines ___ during physical, emotional stress
Maximum possible HR: ___beats/min
- HR
| - 250
41
Electrocardiogram is a recording of
hearts electrical activity
42
electrocardiogram is a Diagnostic tool for
coronary artery disease
43
What are the 3 phases of electrical activity?
- P wave: atrial depolarization
- QRS complex: ventricular depolarization
- T wave: ventricular repolarization
44
___ is the All mechanical and electrical events that occur during one heartbeat
Cardiac Cycle
45
relaxation phase of heart:
- Chambers fill with blood
- Twice as long as systolic phase
Diastole:
46
contraction phase:
Systole:
47
1/3 of cardiac cycle
Ventricular systole
48
Relaxation begins
- Ventricular pressure drops
- ______ valves close
- Atrioventricular valves open
- Fill 70% passively, 30% by atrial contraction
- At end, blood in ventricle = _____ _____ _____ (EDV)
- Semilunar
| - end-diastolic volume
49
Stroke volume (SV):
volume of blood pumped in one heartbeat
50
Stroke volume (SV): volume of blood pumped in one heartbeat
- During _______, most (not all) blood ejected
- EDV – ESV = ___
- 100 mL – 40 mL = ___ml
- Systole
- SV
- 60 ml
51
Ejection fraction (EF):
percent of EDV pumped
52
```
Ejection fraction (EF): percent of EDV pumped
SV / EDV = ___
60 mL/100 mL = 0.6 = 60%
Clinical index of heart contractile function
```
-EF
53
Cardiac output:
Total Volume of blood pumped per minute
54
(Q•) represents
cardiac output
55
Q• = HR x ____
RHR ~___beats/min, standing SV ~70 mL/beat
70 beats/min x 70 mL/beat = 4,900 mL/min
Use L/min (4.9 L/min)
- Stroke Volume
| - 70
56
resting cardio output is ____ to ____ L/min
4.2-5.6
57
average total blood volume is
~5 L
58
Total blood volume circulates once every ______
minute
59
_____carry blood away from heart
Arteries:
60
______ control blood flow, feed capillaries
arterioles:
61
______ site of nutrient and waste exchange
Capillaries:
62
______ collect blood from capillaries
Venules:
63
_____ carry blood from venules back to heart
Veins:
64
___ ______ (_____)
- Highest pressure in artery (during systole)
- Top number, ~110 to 120 mmHg
Systolic pressure (SBP)
65
______ ______ (______)
Lowest pressure in artery (during diastole)
Bottom number, ~70 to 80 mmHg
Diastolic pressure (DBP)
66
______ ______ _____ (____)
Average pressure over entire cardiac cycle
MAP ≈ 2/3 DBP + 1/3 SBP –
120/80 mmHg – MAP = 93mmHG
Mean arterial pressure (MAP)
67
____ ____ is required by all tissues
blood flow
68
______: force that drives blood flow
pressure
69
pressure is:
-Provided by ____ contraction
-Blood flows from region of high pressure (_______) to region of low pressure (_______)
-Pressure gradient = MAP 100 mmHg in aorta – 0 mmHg in RA = 100 mmHg
Re
- heart
- LV, arteries
- veins, RA
70
______ force that opposes blood flow
Resistance:
71
easiest way to change flow is to
change vascular resistance
72
vascular resistance changes can be made through
- Vasoconstriction (VC)
- Vasodilation (VD)
- Diverts blood to regions most in need
73
_______ are resistance vessels
arterioles
74
Arterioles: resistance vessels
- Control systemic ______
- Site of most potent ____ &____
- Responsible for ____ to ____% of MAP drop from LV to RA across entire CVS
- resistance
- \VC and VD
- 70 to 80%
75
Blood flow =
ΔP/R
76
ΔP
- Pressure gradient that drives flow
| - Change in P between LV/aorta and vena cava/RA
77
in the equation Blood flow = ΔP/R:
| R=
Small changes in arteriole radius affect R
| VC, VD
78
in the distribution of blood, blood flows to where:
it's needed most
79
When blood flows to where it's needed most its:
- Often, regions of ↑ _______ → ↑ blood flow
- Other examples: blood flow changes after eating, in the ____
- metabolism
| - heat
80
at rest Q=
5L/m
81
When at rest kidneys receive ___% of Q and skeletal muscles receive __% of Q
- 50%
| - 20%
82
During heavy exercise Q• =
25 L/min
83
Exercising muscles receive ____ % of Q• via VD
80
84
During heavy exercise;
| Flow to liver, kidneys _____ via VC
decreases
85
Intrinsic Control of Blood Flow is defined as:
Ability of local tissues to constrict or dilate arterioles that serve them
86
The purpose of intrinsic blood flow is to
alter regional flow depending on need
87
the three types of intrinsic control are:
- Metabolic
- Endothelial
- Myogenic
88
Metabolic mechanisms (VD)
-Buildup of local metabolic by-products
– ↓ O2
– ↑ CO2, K+, H+, lactic acid
89
Endothelial mechanisms (mostly VD)
- Substances secreted by vascular endothelium
| - Nitric oxide (NO), prostaglandins, EDHF
90
Myogenic mechanisms (VC, VD)
-Local pressure changes can cause VC, VD
| – ↑ P → ↑ VC, ↓ P → ↑ VD
91
Extrinsic neural control of blood flow:
- Upstream of local, intrinsic control
| - Redistribution of flow at organ, system level
92
Sympathetic nervous system innervates smooth muscle in arteries and arterioles
-Baseline sympathetic activity → vasomotor tone
– ↑ Sympathetic activity → ↑ __
– ↓ Sympathetic activity → ↓ __ (passive VD)
VC
93
At rest, veins contain ____ blood volume
2/3
94
At rest, veins contain 2/3 blood volume
- High _____ to hold blood -volume
- Elastic, balloon-like vessel walls
- Serve as blood ____
- capacity
| - reservoir
95
Venous reservoir can be liberated, sent back to heart and into arteries through
- Sympathetic stimulation
| - Venoconstriction
96
the blood volume distribution at rest:
- 13% arteries
- 7% heart
- 7% arterioles and capillaries
- 64% veins
- 9% pulmonary
97
Integrative Control of Blood Pressure:
Blood pressure maintained by autonomic reflexes
98
Baroreceptors:
- Sensitive to changes in arterial ____
- Afferent signals from baroreceptor to ____
- Efferent signals from ____ to heart, vessels
- Adjust arterial pressure back to _____
- pressure
- brain
- brain
- normal
99
Upright posture makes venous return to heart more
difficult
100
Three mechanisms assist venous return
- One-way venous valves
- Muscle pump
- Respiratory pump
101
3 major functions of Blood
- Transportation (O2, nutrients, waste)
- Temperature regulation
- Acid–base (pH) balance
102
Blood volume: _ to _ L in men, - to - L in women
- 5-6
| - 4-5
103
Whole blood = _____ + ______
plasma + formed elements
104
Plasma ___ to ___% of blood volume
55-60%
105
plasma:
- Can _____ by 10% with -dehydration in the heat
- Can ______ by 10% with training, heat acclimation
- 90% water, 7% protein, 3% nutrients/ions/etc.
- decrease
| - Increase
106
Formed elements
- Red blood cells (_____ 99%)
- White blood cells (_______:
- erythrocytes
- leukocytes
- Platelets
107
Formed elements make up ___to __% of blood
(40-45% of blood volume)
108
Hematocrit =
total percent of volume composed of formed elements
109
red blood cells without a nucleus:
cannot reproduce
110
Red Blood Cells:
- Replaced regularly via:_____
- Life span ~ __ months
- Produced and destroyed at equal rates
- hematopoiesis
| - 4
111
Hemoglobin:
-Oxygen-transporting protein in red blood cells
| 4 O2 / hemoglobin
112
Hemoglobin
-Oxygen-transporting protein in red blood cells
(___ O2 / hemoglobin)
-Heme (pigment, iron, O2) + globin (protein)
-250 million hemoglobin/red blood cells
-Oxygen-carrying capacity: ___ mL O2 / 100 mL blood
- 4
| - 20
113
Blood Viscosity:
Thickness of blood due to red blood cells
114
Blood viscosity:
- Thickness of blood (due to red blood cells)
- Twice as viscous as _____
- Viscosity ↑ as _______ ↑
- water
| - hematocrit
115
- Plasma volume must ↑ as red blood cells ↑
- --Occurs in athletes after____ , acclimation
- --_______ and viscosity remain stable
- --Otherwise, blood flow or O2 transport may _____
- training
- hematocrit
- suffer
