Cardiovascular System II Flashcards
(94 cards)
1
Q
Events in a cardiac cycle.
A
- Atrial Diastole (Ventricular Filling)
- Atrial Systole
- Isovolumetric Contraction
- Ventricular Systole (Ejection Phase)
- Isovolumetric Relaxation
2
Q
Atrial Diastole
1. Heart is completely ____.
2. Pressure in the heart is ____.
3. AV valves are ____.
4. Blood is flowing passively through the ____ into the ____.
5. Semilunar valves are ____.
A
- Relaxed
- Low
- Open
- Atria > Ventricles
- Closed
3
Q
Atrial Systole
1. Ventricles remain in ____ as the atria ____.
2. Force blood into the ventricles to complete ____.
A
- Diastole, Contract
- Ventricular Filling
4
Q
Isovolumetric Contraction
1. Atrial systole ____, ventricular systole ____.
2. Initial rise in intraventricular pressure ____ the AV valves = prevent backflow of blood into the atria.
3. ____ are completely closed chambers for a moment.
A
- Ends, Begins
- Closes
- Ventricles
5
Q
Ventricular Systole (Ejection Phase)
1. Ventricles continue to ____.
2. Intraventricular pressure surpass the pressure in the ____.
3. Causes the ____ valves to open and blood to be ejected from the ventricles.
4. ____ are relaxed and filling with blood.
A
- Contract
- Major arteries leaving the heart
- Semilunar Valves
- Atria
6
Q
Isovolumetric Relaxation
1. Ventricular diastole ____, pressure in the ventricle ____ below in the major arteries.
2. Semilunar valves ____ to prevent backflow in the ____.
3. ____ are completely closed chambers and intraventricular pressure continues to ____.
4. Atria have been in ____, filling with blood.
A
- Begins, Falls
- Close, Ventricles
- Ventricles, Decrease
- Diastole
7
Q
Two syllables that describe the heart sound.
A
Lub and Dup
8
Q
- Caused by the closing of AV valves.
- Longer and louder.
A
First Heart Sound (Lub)
9
Q
- Caused by the closing of semilunar valves at the end of ventricular systole.
- Short and sharp.
A
Second Heart Sound (Dup)
10
Q
- Abnormal or unusual heart sounds.
- Fairly common in young children with perfectly healthy heart because their heart walls are relatively thin and vibrate with rushing blood.
A
Heart Murmurs
11
Q
- Amount of blood pumped out by each side of the heart in 1 minute.
- Product of the heart rate (HR) and stroke volume (SV).
A
Cardiac Output (CO)
12
Q
- Volume of blood pumped out by a ventricle with each heartbeat.
- Increases as the force of ventricular contraction increases.
A
Stroke Volume
13
Q
Normal resting values for heart rate.
A
75 beats per minute
14
Q
Normal resting values for stroke volume.
A
70 ml per beat
15
Q
Average adult cardiac output: CO = HR x SV
A
5250 ml/min or 5.25 L/min
16
Q
Normal adult blood volume.
A
6000 ml
17
Q
- Cardiac output rises when the stroke volume ____ or the heart beats ____ or both.
- Drops when either both of these factors decrease.
A
Increased, Faster
18
Q
Healthy hearts pumps out about ____ percent of the blood present in its ventricles.
A
60% approximately 70 ml or 2 ounces
19
Q
Three factors that influence stroke volume.
A
- Preload
- Contractility
- Afterload
20
Q
Law of the heart that states critical factor for controlling stroke volume is how much the cardiac muscle is stretched by the filling of the chambers just before they contact.
A
Frank-Starling Law = Preload
21
Q
The more the muscle cells are stretched = the stronger the contraction, and ____ the stroke volume.
A
Higher
22
Q
Two things that influence preload.
A
- Amount of venous return (blood returning to the heart)
- Length of time the ventricles are relaxed and filling (determined by heart rate)
23
Q
Anything that increases the volume or speed of venous return = ____ stroke volume and forces of contraction.
A
Increases
24
Q
____ heartbeat allows more time for the ventricles to fill.
A
Slow
25
____ **speeds** venous return = **increased** heart rate and force.
Exercise
26
Enhanced ____ action of **active skeletal muscles** on the veins help **return blood** to the heart.
Squeezing
27
Plays a major role in **increasing** the venous return.
Muscular Pump
28
1. Might result from **severe blood loss** or an **abnormally rapid heart rate**.
2. **Decreases** stroke volume.
Low Venous Return
29
1. Ability of cardiac muscle to **generate tension**.
2. Influenced by *factors*: **stretch**, amount of **calcium ions** present, **sympathetic** nervous stimulation, **hormones**.
3. As ____ increases, **stroke volume increases**.
Contractility
30
1. **Amount of pressure** the ventricles must **overcome** to eject blood.
2. Determined by the **blood pressure** in the **pulmonary trunk** and **aorta** pressing back on the semilunar valves.
3. To pump blood, ventricles must generate a force **greater than** the ____.
4. If ____ **increases**, stroke volume will **decrease** as it will be difficult for the ventricles to pump blood.
Afterload
31
Stroke volume tends to be relatively ____ in **healthy people**.
Constant
32
When **blood volume drops** suddenly or when heart has been seriously **weakened**, stoke volume ____ and cardiac output is maintained by a ____ heartbeat.
Declines, Faster
33
**Rate of heart contraction** can be changed temporarily.
Autonomic Nerves
34
Most important **external** influence on **heart rate**.
Activity of the Autonomic Nervous System
35
**Modify** heart rate.
1. Chemicals
2. Hormones
3. Ions
36
1. During times of physical or emotional stress, the nerves of the sympathetic division **strongly stimulate the SA and AV nodes** and **cardiac muscle** itself.
2. Heart beats more **rapidly**.
Neural (ANS) Controls
37
1. A **faster blood flow** increases the rate at which fresh blood flow **reaches body cells**, more ____ and ____ are made **available** to them during periods of **stress**.
2. When demand declines, the heart ____.
1. Oxygen and Glucose
2. Adjusts
38
Nerve fibers that **slow and steady the heart**, giving it more time to **rest** during noncrisis times.
Parasympathetic nerves, primarily vagus nerve fibers
39
**Mimics sympathetic nerves** and is released in response to **sympathetic** nerve stimulation.
Epinephrine
40
A **thyroid hormone** that **increases** heart rate and contractility.
Thyroxine
41
1. ____ level of **ionic calcium** in the blood **depresses** the heart.
2. ____ level of **blood calcium ions** causes **prolonged** contractions that the heart may stop entirely.
1. Reduced
2. Excessive
42
**Ions** that **modify** heart activity.
Sodium and Potassium Ions
43
Causes the heart to **beat feebly** and **abnormal** heart rhythms appear.
Deficit in Potassium Ions
44
*Physical factors* that influence **heart rate**.
1. Age
2. Gender
3. Exercise
4. Body Temperature
45
Resting heart rate is **fastest** in the **fetus**.
140 to 160 beats per minute
46
Average adult **heart rate** is faster in **females**.
72 to 80 beats per minute
47
Average adult **heart rate** in **males**.
64 to 72 beats per minute.
48
**Increases** heart rate by **boosting the metabolic rate** of heart cells.
Heat
49
Directly **decreases** heart rate.
Cold
50
**Pumping action** of the heart maintains a **balance** between ____ and ____.
Cardiac Output and Venous Return
51
1. Occurs when **pumping efficiency of the heart is reduced** so that circulation is inadequate to meet tissue needs.
2. Reflects **weakening** of the heart, **hypertensive** heart disease, or **multiple** myocardial infarctions.
3. Heart **pumps weakly** and is nearly worn out.
4. Results in **lower** stroke volume.
Congestive Heart Failure (CHS)
52
**Left heart fails** and **unable to eject** returning blood into the systemic circulation.
Pulmonary Congestion
53
**Become swollen with blood** as blood **backs up** in the lungs and **pressure** within them **increases** and fluid **leaks** into the lung tissue.
Pulmonary Edema
54
**Right side of the heart fails** as blood backs up in the systemic circulation.
Peripheral Congestion
55
Blood circulates **inside** the blood vessels forming a **closed transport system**.
Vascular System
56
Proved that **blood** move in **circles**.
William Harvey
57
As the **heart beats**, it **propels** blood into the ____ **leaving** the heart.
Large Arteries
58
As the **large arteries branch**, blood moves into successively smaller and smaller arteries and then into the ____.
Arterioles
59
**Arterioles feed** the ____ in the **tissues**.
Capillaries
60
**Clusters** of capillaries that are **drained by venules**.
Capillary Beds
61
**Drain the capillary beds** which in turn empty into veins that merge and empty into great veins.
Venules
62
**Conducting** vessels.
Arteries and Veins
63
1. Extend and branch through the tissues and **connect smallest arteries to the smallest veins** and directly serve the needs of the body cells.
2. Only through their **walls** that **exchanges** between tissue cells and blood can **occur**.
Tiny Hairlike Capillaries
64
**Red** indicates ____ which is the **normal status** of blood in most body's **arteries**.
Oxygen-rich Blood
65
**Blue** indicates ____which is **carbon-dioxide** rich blood, the **normal** status of blood in most of the **veins**.
Oxygen-poor Blood
66
An **exception** wherein **oxygen-poor blood** is carried.
Pulmonary Trunk
67
An **exception** wherein **oxygen-rich blood** is transported back to the heart.
Pulmonary Veins
68
**Walls of blood vessels** have *three layers* or ____.
Tunics
69
1. **Lines the lumen** or interior of vessels.
2. **Thin layer of endothelium** (*squamous epithelial cells*) resting on a **basement** membrane.
3. Its cells **fit closely** together and form a **slick** surface = **decreases friction** as blood flows through the vessel lumen.
Tunica Intima
70
1. **Bulky middle layer** made up of mostly **smooth muscle** and **elastic fibers**.
2. Some of the large arteries have **elastic laminae** (*sheets of elastic tissue*)
Tunica Media
71
1. Controlled by the **sympathetic nervous system**.
2. **Active** in changing the **diameter** of vessels.
3. **Vessels constrict** = blood pressure *increases*, **vessels dilate** = blood pressure *decreases*.
Smooth Muscle
72
1. **Outermost** tunic.
2. Composed largely of **fibrous connective tissue**.
3. **Support** and **protect** the vessels.
Tunica Externa
73
1. **Walls** are much **thicker** than veins.
2. **Arterial tunica media** is much thicker.
3. Carry blood **away** from the heart.
4. **Expland** as blood is forced into them and **recoil** passively as the blood flows off into the circulation during **diastole**.
5. Walls must be strong and stretchy to **take continuous changes in pressure** without stretching out permanently.
Arteries
74
1. Carry blood **toward** the heart.
2. Pressure in them tends to be **low** at all time.
3. Have **thinner** walls.
4. Modified to ensure that the amount of blood returning to the heart (**venous return**) **equals** the amount being pumped out of the heart (**cardiac output**) at any time.
5. **Lumens** are much **larger** than arteries.
6. Thinner tunica media but **thicker tunica externa**.
7. Have **valves** to prevent backflow of blood.
Veins
75
1. **Enhances** venous return.
2. Muscles surrounding the veins **contract and relax**, blood is ____ through the veins toward the heart.
3. **Drop in pressure** that occurs in the ____ just before we ____ causes the **large veins** near the heart to ____.
4. Helps **return** blood to heart.
1. Skeletal Muscle Activity or Muscular Pump
2. Squeezed or Milked
3. Thorax, Inhale, Fill
4. Respiratory Pump
76
**Transparent walls** of the capillaries are only ____ cell layer thick = **tunica intima**.
One
77
Because of this **exceptional thinness**, substances are exchanged ____ between the blood and tissue cells.
Easily
78
**Flow of blood** from an anteriole to a venule through a **capillary bed**.
Microcirculation
79
Branches into **10 to 20 capillaries** which are the **exchange vessels** which drain into a **postcapillary venule**.
Terminal Arteriole
80
If the **terminal arteriole** is ____, blood **enters** the capillary bed and **exchange occurs**.
Dilated
81
If the **terminal arteriole** is ____, **no blood flows** through the capillary bed.
Constricted
82
**Serous membranes** holding the **intestines** in place where the **special capillary beds** are found.
Mesenteries
83
Found in **capillary beds**.
1. Precapillary Sphincters
2. Vascular Shunt
84
1. **Regulate blood flow** in the capillary bed.
2. When **relaxed or open**, blood flows through the **capillaries** and takes part in **exchanges** with cells.
3. When **contracted or closed**, blood flows through the **shunt** and **bypasses** the cells in that region.
Precapillary Sphincter
85
A **vessel** that **directly connects** the **arteriole** and **venule** at opposite ends of the bed.
Vascular Shunt
86
1. Common in people who **stand for long periods** of time and in **obese** individuals.
2. *Common factors* = **pooling of blood** in the feet and legs and **inefficient venous return** resulting from inactivity or pressure on the veins.
3. **Overworked** valves give way and veins become twisted or dilated.
Varicose Veins
87
1. **Serious complication of varicose veins**.
2. **Inflammation** of a vein that results when a **clot** forms in a vessel with **poor** circulation.
Thrombophlebitis
88
1. Along with **clot detachment**, is a common **consequence** of **thrombophlebitis**.
2. Life-threatening condition in which the **embolism lodges** in a vessel in the lung.
Pulmonary Embolism
89
**All venous blood** must pass through the ____ circulation **before traveling** through the ____ again.
Pulmonary, Body Tissues
90
1. **Largest artery** of the body.
2. In adults, about the **size of a garden hose** and an **internal diameter** equal to the diameter of your **thumb**.
3. **Leaves the left ventricle** of the heart.
4. **Decreases** only slightly as it runs to its **terminus**.
5. Named either for their **location** or **shape**.
Aorta
91
Aorta that **springs upward** from the **left ventricle** of the heart.
Ascending Aorta
92
Aorta that **arches to the left**.
Aortic Arch
93
Aorta that **plunges downward** through the **thorax** following the **spine**.
Thoracic Aorta
94
Aorta that pass through the **diaphragm** into the **abdominopelvic cavity**.
Abdominal Aorta
