Lecture 10- Circulatory System Flashcards Preview

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Flashcards in Lecture 10- Circulatory System Deck (54)
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1
Q
What are the subsystems of the circulatory system?
A
- cardiovascular
- lymphatic
2
Q
A person develops a thrombus in their femoral vein. If the clot breaks off, where will it most likely end up?
A
Lungs
3
Q
Where does the blood from the femoral vein enter the heart?
A
Right atrium then eventually will get stuck in the capillaries of the lung. Pulmonary embolism
4
Q
What would happen if there was a clot in the left atrium?
A
- Could go to the brain and cause stroke
- infarction in kidney or liver
5
Q
The wall of the hear is composed of 3 layers. Which layer will be the thickest?
A
Myocardium (the muscle)
6
Q
Which part of the heart will have the thickest myocardium?
A
Left Ventricle
7
Q
What type of tissue lines the endocardium?
A
simple squamous endothelial layer (loose CT with smooth muscle)
8
Q
What makes up the sub- endocardium?
A
connective tissue with arteries, veins, nerves, and Purkinje fibers
9
Q
What is the role of the endothelial layer lining in the endocardium?
A
- acts as a barrier between blood and heart
- nonthrombogenic surface (no clots)
- modify cardiac performace
10
Q
What is the role of collagne in the endocardium and subendocardium?
A
support and strength
11
Q
What is the function of Purkinje fibers?
A
Muscle cells that are specialized for impulse conduction instead of contraction
12
Q
How do Purkinje fibers differ from myocytes?
A
- Purkinje fibers are fewer and towards the periphery. Lots of glycogen and mitochondria
- myocytes are dense and full of myofibrils
13
Q
Describe the conduction system of the heart
A
1) SA node initiates impulse to atria
2) Atrial contraction
3) AV Node sends impulse to ventricles (through bundle of His)
4) Ventricles contract
14
Q
A 67-year-old male had a dental procedure which caused a transient bacteremia (bacteria in the blood). This precipitated infective endocarditis (inflammation or infection of the endocardium) because they already had damage to which of the following?
A
Endothelial layer of the endocardium. There is no barrier for the bacteria.
15
Q
While infective endocarditis can occur in the heart chambers, it most commonly occurs on the valves of the heart. Why?
A
- vegetations develop in areas of high pressure through a narrow space to low pressure
- valves are covered by endothelial layer
- turbulent flow--> epithelial damage
16
Q
What type of tissues make up the valves of the heart?
A
Dense irregular CT
17
Q
A person had a myocardial infarction which damaged an area of the ventricles containing purkinje fibers. This most likely caused:
A
Cardiac arrhythmia
-Purkinje fibers affect the conduction of impulse
18
Q
What is the epicardium?
A
The external tissue layer surrounding the pericardium or pericardial sac
19
Q
Describe the two layers of the epicardium?
A
- external layer is simple squamous layer of mesothelium
- internal layer is loose CT with adipocytes, coronary arteries, veins, and autonomic nerves.
20
Q
What makes up the serous pericardium?
A
- visceral layer
- parietal layer
- external fibrous pericardium
* simple sqaumous epithelial tissue that secretes fluid into space.
21
Q
What type of tissue makes up the fibrous pericardium?
A
Dense, fibrous CT
22
Q
What is the function of the pericardium?
A
- fixes the heart in the chest cavity
- protection against infection
- provides lubrication for the heart when it beats or moves
23
Q
A 65-year-old male presents to the emergency department with chest pain and difficulty breathing. Testing reveals that he has a pericardial effusion. This is caused by fluid building up in which location around the heart?
A
Between the visceral pericardium and the parietal pericardium
24
Q
What are the walls of the arteries?
A
- Tunica intima
- Tunica media
- Tunica adventitia or externa
25
Q
What type of tissue is the endothelium?
A
Simple squamous epithelium
26
Q
What is the function of the epithelium?
A
- selective barrier
- nonthrombogenic barrier
- modulates blood flow
27
Q
What is the Tunica intima?
A
- endothelium and underlying basal lamina
- subendothelial layer of CT
- internal elastic lamina
-fenestrations for rapid diffusion
28
Q
What is the Tunica media?
A
- circumferentially arranged smooth muscle with variable amounts of elastic fibers, reticular fibers, proteoglycans and glycoproteins
- external elastic lamina
- constrict or dilate corresponding to smooth muscle
29
Q
What is the Tunica adventitia?
A
- dense irregular CT (Collagen and elastin)
- fibroblasts!
- larger arteries contain vasa vasorum (blood vessels, nerves to adventia and media)
30
Q
What is the main type of collagen in tunica adventitia?
A
Type I
31
Q
How do systemic arteries differ from systemic veins?
A
Arteries are subjected to a much higher pressure than veins
32
Q
Are the layers of walls for veins the same as the arteries?
A
Yes
33
Q
How do the walls of veins differ from the walls of arteries?
A
Veins have:
- one way valves
- thinner smooth muscle layer
- adventitia is thicks
- more extensive vasa vasorum
34
Q
What are the conductance vessels?
A
- large, elastic arteries (aorta)
- muscular arteries (medium sized arteries)
35
Q
What are the resistance vessels?
A
Small arteries and arterioles
36
Q
What is the function of large elastic arteries like the aorta?
A
- Conduct blood
- Help store energy generated by the heart's contraction
37
Q
Describe systole of the aorta.
A
- aorta expands or distends
- facilitated by elastic fibers, limited by collagen fibers
- systolic pressure is not too high
38
Q
Describe diastole of the aorta.
A
- elastic recoil
- Diastolic pressure is not too low
39
Q
If elasticity of the aorta is reduced, what happens to systolic and diastolic pressure?
A
Systolic pressure is higher and diastolic pressure is lower
40
Q
What type of cells are the predominate constituent of tunica media in muscular arteries?
A
Smooth muscle cells
41
Q
What is the function of muscular arteries?
A
- Conduct blood
- large elastic and muscle arteries are considered conductance vessels or distributing arteries
42
Q
What is the function of arterioles?
A
Control the amount of blood going into the capillary
- arterioles dilate
- more blood
- responsible for relative blood flow to an organ at any given mean arterial pressure
- help determine mean arterial pressure
43
Q
What happens to resistance to blood flow if an arteriole dilates?
A
Resistance decreases
44
Q
What makes up a capillary? (2)
A
- endothelial layer
- basal lamina
45
Q
What is the function of capillaries?
A
Gas, nutrient, waste product exchange between blood and tissues
46
Q
What are the three types of capillaries?
A
- continuous (no holes)
- fenestrated (small holes)
- sinusoid (big holes)
47
Q
What is the most common type of capillary?
A
continuous capillary
48
Q
How does material go from the lumen of the capillary to the interstitial space?
A
Diffusion, paracellular transport, transcytosis (type depends on number of tight junctions)
49
Q
What is the advantage of the fenestrae?
A
more rapid, easier exchange of substances
50
Q
What is unique about a sinusoid capillary?
A
- much larger than the other capillaries
- both the endothelial layer and basal lamina have large holes
51
Q
Where are the venules located?
A
After the capillaries
52
Q
What is the venule wall like?
A
Gradually develops a tunica media
53
Q
What is different between arteries and veins? (4)
A
1) Small/medium arteries have thicker media
2) Large veins have thicker adventitia
3) Arteries are under higher pressure
4) Veins have valves
54
Q
A 44-year-old female has Marfan syndrome (mutation in the FBN1 gene, which encodes for fibrillin-1). She is at an increased risk for the development of an aneurism (weakened blood vessel wall) in:
A
Aorta (most elastic)