Circulatory System Flashcards
1
Q
What are the four functions of the circulatory system?
A
- Movement of fluids
- Regulation of temperature
- Distribution of molecules (hormones)
- Distribution of cells (immune system)
2
Q
There are two functional components to the cardiovascular system. What are they?
A
- The blood vascular system
- The lymphatic vascular system
3
Q
What are the primary differences between the blood and lymphatic vascular systems?
A
The blood vascular system circulates blood vessels that are pumped by a muscular organ, the heart
The lymphatic vascular system returns and transports lymph without a central pump; smooth muscle in vessel walls move lymph in one direction
4
Q
Describe the common structure of blood vessels.
A
- Tunica intima - inner lining with single layer of flattened epithelial cells (endothelium)
- Tunica media - middle layer, mostly muscular
- Tunica adventitia - outer layer of supporting tissue
5
Q
What are vasa vasorum?
A
Small arteries that run in the tunica adventitia and send arterioles and capillaries into the tunica media to provide nutrient and waste exchange
6
Q
What are vasa vasorum important?
A
Diffusion from the lumen is insufficient to provide the tunica media with nutrition and waste elimination
7
Q
________________ content exhibits the greatest variation from one part of the blood vascular system to the next
A
Muscle content
8
Q
What is blood flow influenced by?
A
By variation in the activity of muscle tissue
9
Q
Is there muscle in capillaries?
A
No
10
Q
Is there muscle in the heart?
A
Yes, it’s literally all muscle
11
Q
The ____________________ is located anterior to the chest wall and connects to the great veins and artiers; it has a free apex and sits in the pericardial sac
A
Heart
12
Q
What are the four histological characteristics of cardiac muscle tissue?
A
Small
Mononucleated
Branched
Intercalated discs
13
Q
What are the four muscular chambers of the heart?
A
Left atria
Right atria
Left ventricle
Right ventricle
14
Q
The ________________ pump blood to the lungers and the body; the __________________ received blood from the lungs and the body
A
Ventricles
Atria
15
Q
Walls of all four heart chambers consist of three major walls or tunics. What are they?
A
- Endocardium
- Myocardium
- Epicardium
16
Q
The _________________________ is a single layer of squamous endothelial cells that sits on a thin layer of loose connective tissue that contains _______________ and collagen fivers and _____________ muscle cells
A
Endocardium
Elastic
Smooth muscle
17
Q
The ______________________ is below the endocardium and connects with the myocardium; it contains small vessels, nerves, and importantly ________________ _____________
A
Subendocardium
Purkinjie Fibers
18
Q
The ___________________ is the thickest of tunics in the heart and consists of _________________ muscle cells; it is much thicker in the ventricles than in the atria
A
Myocardium
Cardiac muscle cells
19
Q
Why does the myocardium have an extensive capillary network?
A
The high oxygen demand of the myocardium
20
Q
The ___________________ is the external layer of the heart and is composed of a simple squamous epithelium (_____________________) and supported by a thin layer of connective tissue
A
Epicardium
Mesothelium
21
Q
The thin layer of connective tissue that supports the epicardium is composed of ____________________ tissue containing _________________ fibers
A
Fibrocollagenous tissue
Elastic fibers
22
Q
What are papillary muscles?
A
Attachments for chordae tendinae (AV valves)
23
Q
Myocardial thickness differs in individuals who are healthy or diseased; _____________________ results from long-standing physical exertion (athletes) and pathology (i.e., hypertension)
A
Hypertrophy
24
Q
Muscle fivers are thicker and the nuclei are ________________ and _______________ in hypertrophied myocardium
A
Larger
Darker
25
The impulse-conducting system of the heart is responsible for what?
Generating the stimulus for contraction and spreading the contraction to the myocardium
26
What are the three major components of the cardiac conducting system?
1. Sinoatrial node
2. Atrioventricular node
3. Atrioventricular bundle of His
27
Cells and fibers of the impulse-conducting system are modificed cardiac muscle cells functionally integrated by ____________ \_\_\_\_\_\_\_\_\_\_\_\_\_
Gap junctions
28
The impulse rate of the conducting system is controlled by the __________________ nervous system
Autonomic
29
Describe the steps of the impulse-conducting system of the heart.
1. The SA node in the right atrium generates the impulse
2. The impulse spreads to the AV node in the right atrium
3. The impulse is passed along the conducting fibers of the AV bundle of His, which divide into the left and right bundle branches that become the Purkinjie Fibers
30
What are the steps of the impulse conducting system?
31
The atrioventricular bundle of His splits into the left and right _______________ \_\_\_\_\_\_\_\_\_\_\_\_\_ that become the ______________ \_\_\_\_\_\_\_\_\_\_\_ that run beneath the endocardium and penetrate the myocardium
Bundle branches
Purkinjie fibers
32
The bundle branches are separated from myocardial fibers by a ______________ layer; they are specialized conducting fibers that contain few myofibrils and abundant ________________ granules and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Fibrous
Glycogen
Mitochondria
33
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ _________________ are the terminal branches of the AV bundle branches located in the subendocardial connective tissue
Purkinjie fibers
34
What are the histological and structural characteristics of Purkinjie fibers?
Purkinjie fibers are large modified cardiac muscle fibers that cluster together in groups with one to two nuclei per cell
They contain a pale-staining central area with red stains on the cell periphery representative of myofibrils
35
Do Purkinjie fiber contain T-tubules and intercalated discs? If not, how do they communicate and connect with each other?
No, they are connected by desmosomes and gap junctions
36
The heart has four valves. What are they?
1. The mitral valve
2. The tricuspid valve
3. The aortic valve
4. The pulmonary valve
37
The mitral and tricuspid valves control blood flow from the ______________ to the \_\_\_\_\_\_\_\_\_\_\_\_\_
Atria
Ventricles
38
The aortic and pulmonary valves control blood flow out of the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Ventricles
39
\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ______________ can be thought of as double-sided flattenings of the basic cardiovascular histological layers with different histological profiles to match their different physiological roles
Heart valves
40
What are the specialized features of heart valves?
They are primarily composed of a tough, specialized tunica intima in the absence of other vascular layers; the endothelium is continuyous with that of the cardiac wall while the collagenous layer toughens and becomes highly fibrous
41
Heart valves are primarily composed of a tough, specialized ______________ \_\_\_\_\_\_\_\_\_\_\_\_ in the absence of other vascular layers; the \_\_\_\_\_\_\_\_\_\_\_\_\_\_is continuous with that of the cardiac wall while the _______________ layer toughens and becomes highly \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Tunica intima
Endothelium
Collagenous
Fibrous
42
Identify the blood vessel tunic:
–1 layer endothelial cells
–Supported by subendothelial CT layer (Loose CT) with occasional smooth muscle cells
Tunica intima
43
What do the tunicas intimas of the arteries have that those of veins?
In arteries, the internal elastic lamina separates the intima from the media
44
Identify the tunic of the blood vessel:
–Middle layer
–Concentric layers of smooth muscle cells
Tunica media
45
What do the tunica media of arteries contain that veins do not?
A thinner external elastic lamina that separates the media from the adventitia
46
Identify the blood vessel tunic layer:
–Type 1 collagen and elastic fibers
–Gradually continuous with stromal CT of organ through which the vessel runs
Tunica adventitia
47
Large vessels usually have ______________ \_\_\_\_\_\_\_\_\_\_\_\_\_ or "vessel of the vessel" and a network of __________________ sympathetic nerve fibers to control \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Vasa vasorum
Unmyelinate
Vasoconstriction
48
What is the function of the arterial system?
To distribute blood from heart to capillary beds throughout the body
49
The pumping action of heart produces pulsatile blood flow in arterial system: the contraction of ventricles is known as ______________ (blood forced into arteries and arterial walls expand), and the recoil of the arterial walls is known as \_\_\_\_\_\_\_\_\_\_\_\_\_
Systole
Diastole
50
What regulates the flow of blood to organs and tissues?
The diameter of the distributing vessels
51
The arterial system vessel walls conform to the general three-tunic structure but are characterized by increased ___________________ and a thicker ______________ \_\_\_\_\_\_\_\_\_\_\_\_\_ wall relative to lumen diameter
Elastin
Smooth muscle
52
There are three types of arterial vessels. What are they?
Elastic artery
Muscular artery
Arteriole
53
The ______________ arteries are the major distribution vessels of the arterial system; they help stabilize blood flow and include the aorta, brachopephalic trunk, common cartoid artery, subclavian artery, and large pulmonary arteries
Elastic
54
The tunica media of elastic arteries contain many _______________ fibers
Elastic fibers
55
How is the tunica intima of elastic arteries different from those of muscular arteries?
The tunica intima of elastic arteries is much thicker than those of muscular arteries
56
The aorta is a prime example of an elastic artery. The tunica intima is composed of a single layer of flattened endothelial cells that are supported by a layer of ___________________ tissue rich in \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_; its subendothelial supportive tissue contains _______________ and ________________ cells that are structurally similar to smooth muscle cells
Collagenous
Elastin
Fibroblasts
Myointimal cells
57
The subendothelial layer in the elastic artery, the aorta, contains two cell types. What are they?
Fibroblasts
Myointimal cells (similar to smooth muscle cells)
58
The _____________ \_\_\_\_\_\_\_\_\_\_\_ of elastic arteries is broad and extremely elastic, and the ____________ \_\_\_\_\_\_\_\_\_\_\_\_\_ of elastic arteries is collagenous with small vasa vasorum, which penetrate the outer half of the tunica media
Tunica media
Tunica adventitia
59
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ arteries are the main distributing branches of the arterial tree
Muscular
60
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ arteries have very thin intimas with adventitia layers of various thickness
Muscular
61
Whereas elastic tissue is found nearly throughout elastic arteries, how is elastic tissue organized in muscular arteries?
Elastic tissue is concentrated into two well defined elastic sheets:
Internal elastic lamina (IEL) (between the intima and media)
External elastic lamina (EEL) (between media and adventitia)
62
What are some examples of muscular arteries?
Radial
Femoral
Coronary
Cerebral
63
Small muscular arteries have a thin but distinct _________________________ but little or no _____________________ while their medias contain three to 10 layers of smooth muscle with nearly no ________________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Internal elastic lamina
External elastic lamina
Elastic fibers
64
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ contain only one to two layers of smooth muscle and are the primary site of vascular resistance
Arterioles
65
Explain the flow of blood from aorta to capillary.
Elastic artery
Large muscular artery
Small muscular artery
Large arteriole
Small ateriole
Capillary
66
As muscular arteries merge into larger arterioles and smaller arterioles, there is a gradual loss of the ______________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ ______________ and a reduction in the number of ____________ \_\_\_\_\_\_\_\_\_\_\_ in the \_\_\_\_\_\_\_\_\_\_\_\_\_\_
Internal elastic lamina
Muscle layers
Media
67
Larger arterioles have only __ to __ layers in their medias with very thin _______________ that are sometimes indistinguishable from the surrounding collagenous fibrous tissue
Two to three
Adventitia
68
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ are thin-walled vessels forming interconnected networks for the exchange of gases, fluids, nutrients, and metabolic wastes
Capillaries
69
How is the blood flow of capillaries regulated?
Via the arterioles and precapillary sphincters
70
To what do capillaries drain into?
Postcapillary venules
Collecting venules
Small muscular venules
71
What blood vessels are the only ones that permit exchange?
Capillaries
72
There are two main types of capillaries. What are they?
Continuous
Fenestrated
73
Flow in capillaries is by arterioles and muscular sphincters called ______________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_
Precapillary sphincters
74
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ are composed of a single layer of endothelial cells rolled up in the form of a tube
Capillaries
75
Thin walls and slow blood flow favors _____________ in capillaries
Exchange
76
Does blood move fast or slow in capillaries?
Slow
77
What are pericytes?
Pericytes are contractile cells that wrap around the endothelial cells of capillaries and venules that regulate capillary blood flow, the clearance and phagocytosis of cellular debris, and the permeability of the blood–brain barrier
78
What are the functions of pericytes?
To regulate the flow of blood in capillaries, the clearance and phagocytosis of cellular debris, and the permeability of the blood-brain barrier
79
Where are pericytes embedded?
The basement membrane
80
How do pericytes communicate with endothelial cells?
Direct physical contact
Paracrine signaling
81
Most regions of the body are supplied by ____________________ capillaries that contain a complete lining, where they regulate the exchange of material, and maintain a distinct continuity with endothelial cells
Continuous capillaries
82
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ capillaries contain "windows" or pores that permit the rapid exchange of water and solutes
Fenestrated
83
Where are fenestrated capillaries found?
In tissues where rapid interchange of substances occurs between the tissues and blood (e.g., kidney, intestine, choroid plexus, endocrine gland)
84
The _______________ system of the cardiovascular system is the low pressure component that carries blood from capillaries back to the right atrium of the heart
Venuous
85
How does blood flow against gravity in the venuous system?
Contractions of smooth muscle in vein walls and the external compression of veins by surrounding skeletal muscle
86
How is backflow prevented in the venuous system?
The presence of valves
87
Why is it important to move (in regards to the venuous system)?
Skeletal muscle compression of veins assists in blood flow
88
While veins maintain the general three-layer structure of blood vessels, how do they differ from arteries?
They have less elastic and muscular components
89
Which system contains a larger portion of blood: the arterial or venuous system?
Venuous
PV = nRT
(Less pressure = more volume)
90
What are venules?
The smallest venous vessels that collect blood from capillary beds
91
What is a characteristic feature of all venules?
Large diameter of the lumen compared to the overall thinness of the wall
92
The transition from capillaries to _______________ occurs gradually and the immediate _______________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ are structually similar to capillaries but with larger diameters
Venules
Postcapillary venules
93
Postcapillary venules converge into larger __________________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ that have more contracile cells
Collecting venules
94
Venules become surrounded by recognizable tunica medias with two or three smooth muscle layers and are called __________________ venules
Muscular
95
Blood entering veins is under very low \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Pressure
96
How does blood move towards the heart in veins?
Via contraction of the tunica media and external compressions from surrounding muscles and organs
97
\_\_\_\_\_\_\_\_\_\_\_\_\_\_ project from the tunica intima to prevent the back flow of blood
Valves
98
Most veins are ____________ or _____________ veins and are usually located in parallel with corresponding muscular arteries
Small
Medium
99
What are the primary differences between venules and veins?
Venules contain a clealy difined intimal layer but no elastic fibers; the tunica media contains one to two smooth muscle layers
Veins have a thicker muscular wall with poorly developed internal elastic lamina
100
In \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_-sized veins the tunica intima is hard to discern and the tunica media is compared to an artery
Medium
101
Medium-sized veins have two to four layers of smooth muscle fibers arranged circumferentially, and the ____________ \_\_\_\_\_\_\_\_\_\_\_\_\_ is usually the thickest layer
Tunica adventitia
102
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ veins are big venous trucks paired with elastic arteries close to the heart
Large
103
Large veins have a well-developed tunica intima but a relatively thin _______________ \_\_\_\_\_\_\_\_\_\_\_\_\_\_ with few layers of smooth muscle and abudant connective tissue
Tunica media
104
