2. cardiovascular system Flashcards
(67 cards)
1
Q
cardiovascular system
A
- heart, blood vessels, blood
- transport: gases, nutrients, hormones, wastes, heat
- protection: disease, fluid loss (clotting)
2
Q
heart
A
-in a cavity called the mediastinum (=space b/w lungs w/in thoracic cavity)
3
Q
heart structure
A
- coverings=pericardium
- heart wall
- chambers and associated blood vessels
- septa (separate chambers)
- fibrous skeleton
- valves
- cardiac muscle cells
- conduction system
4
Q
coverings = pericardium
A
-double-walled sac surrounding heart
-between pericardium layers = pericardial cavity with serous fluid (lubricates)
-3 layers:
fibrous pericardium
serous pericardial layers - 2 parts
5
Q
fibrous pericardium
A
- outermost layer=dense irregular CT
- anchors to surrounding structures
eg. diaphragm,great vessels (aorta, vena cava, etc)
6
Q
serous pericardium- 2 parts
A
- parietal pericardium
- visceral pericardium = epicardium
7
Q
parietal pericardium
A
fused to fibrous pericardium
fibrous pericardium and parietal pericardium = pericardial sac
8
Q
visceral pericardium
A
=epicardium
-fused to heart surface, so is part of heart wall
9
Q
heart wall
A
3 parts:
epicardium
myocardium
endocardium
10
Q
epicardium
A
stratified squamous epithelium and CT
11
Q
myocardium
A
=cardiac muscle
-arranged in spiral/circular pattern, reinforced with CT
12
Q
endocardium
A
- simple squamous epithelium and CT
- epithelium named endothelium-lines inner surface of heart and all blood vessels
13
Q
Chambers and associated blood vessels
A
right atrium
left atrium
right ventricle
left ventricle
14
Q
right atrium
A
- inferior and superior vena cava
- coronary sinus (posterior)
15
Q
left atrium
A
4 pulmonary veins
16
Q
right ventricle
A
pulmonary trunk-divides to form 2 pulmonary arteries
17
Q
left ventricle
A
aorta
18
Q
septa (separate chambers )
A
inreratrial septum
inter-ventricular septum
19
Q
inreratrial septum
A
separates atria
20
Q
interventricular septum
A
- separates ventricles
- deep to inter-ventricular sulcus (external)
21
Q
fibrous skeleton
A
- CT fibers around the muscle fibers and CT rings b/w atria and ventricles at the coronary sulcus
- allows openings to remain open at all times (valves open and close)
- provides electrical insulation-prevents simultaneous contraction of chambers
22
Q
valves
A
- atrioventricular (AV) valves
- semilunar valves
23
Q
atrioventricular valves
A
*chordae tendineae (CT) attach AV valve cusps to papillary muscles (projections of myocardium)
(prevent eversion of cusps)
-bicuspid (mitral) valve (left side- 2 cusps)
-tricuspid valve (right side- 3 cusps)
24
Q
semilunar valves
A
-3 cusps each
*aortic
(separates left ventricle and aorta)
*pulmonary
(separates right ventricle and pulmonary trunk)
25
cardiac muscle cells
form both contractile myocardium and conduction system
26
cardiac muscle cells similarities to skeletal muscle:
- striated (myofibrils with sarcomeres)
| - has sarcoplasmic reticulum and T-tubules
27
cardiac muscle cells differences to skeletal muscles:
- branched (myofibrils with sarcomeres)
- uninucleated
- intercalated discs=region where two fibers meet
* contain anchoring and gap junctions
28
conduction system
- cardiac muscle cells modified to produce and conduct electrical impulses - DO NOT CONTRACT
- note: electrical signal spreads from conduction system to contractile cardiac cells then they contract
29
conduction system parts
- sinoatrial (SA) node
- atrioventricular (AV) node
- atrioventricular bundle (bundle of his)
- atrioventricular (AV) bundle branches
- purkinje fibers
30
Sinoatrial (SA) node
- in right atrium at base of superior vena cava
| - generates impulses the fastest-sets pace
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atrioventricular (AV) node
-base of right atrium
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atrioventricular bundle (bundle of his)
- superior part of interventricular septum
| - electrically connects atria to ventricles
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atrioventricular (AV) bundle branches
got to each ventricle
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purkinje fibers
-terminal fibers in ventricles only
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circulatory routes
- closed, double circulation
* closed = blood confined to heart and blood vessels
* double = 2 routes (pulmonary and systemic)
- adult circulation and fetal circulation
36
adult circulation
- pulmonary circulation
- systemic circulation
- coronary circulation (visible externally)
37
pulmonary circulation
- right ventricle to lungs by pulmonary arteries (deoxy blood)
- pick up oxygen in lungs by capillaries
- lungs to left atria by pulmonary veins (oxygenated blood)
38
Systemic circulation
-left ventricle to organs by aorta (oxygenated)
-organs remove oxygen by capillaries
-organs to right atrium by superior and inferior vena cava (deoxygenated)
-overall route: left ventricle to right atrium = systemic circulation
*subdivisions/subroutes:
cerebral=brain
hepatic=liver
coronary=heart
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coronary circulation
```
visible externally
(chart on page 4)
```
40
fetal circulation
- fetus gets O2, nutrients from and expels wastes to mother's blood
- exchange site in the placenta
* blood supplies in close together, but do not mix
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fetal circulation differences from adult circulation
a) umbilical vein (towards the fetal heart)
b) lungs and liver basically non-functional
c) umbilical arteries (away from fetal heart)
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umbilical vein
- towards the fetal heart
| - carries oxygenated blood from placenta to vena cava
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lungs and liver basically non functional
3 shunts to bypass (although some blood flow to these organs for nourishment/growth)
1. ductus venosus
2. foramen ovale
3. ductus arteriosus
44
ductus venosus
- connects umbilical vein (oxy blood) to inferior vena cava (doexy blood) to bypass liver - permits most of the oxygenated blood coming from the placenta to bypass the liver
- oxy and deoxy blood mixes
- mixed blood enters fetal heat by inferior vena cava
45
foramen ovale
-hole in interatrial septum
-allows blood to move from the right to left atrium
(bypass lungs)
46
ductus arteriosus
-connects pulmonary trunk and aorta (bypass lungs)
47
umbilical arteries
- away from fetal heart
| - returns mixed blood to placenta
48
anatomy of blood vessels
- general structure of blood vessels (except capillaries):
1. tunica externa - CT
2. tunica media
* smooth muscle
* elastic fibers (CT)
3. tunica intima/intema
* endothelium-simple squamous epithelium
4. lumen-contains blood (not a layer)
49
blood vessel types (following path from heart and back to heart):
1. arteries
2. arterioles
3. capillaries
4. venules
5. veins
50
arteries
carry blood away from heart (does not refer to oxy of deoxy)
2 types:
elastic arteries
muscular arteries
51
elastic arteries
- elastic CT in all 3 layers
- largest arteries (near heart)
eg. aorta
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muscular arteries
- a lot of smooth muscle
- most arteries
eg. coronary artery
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arterioles
- little arteries
| - regulate blood flow and blood pressure
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capillaries
- only tunica intima-endothelium (on cell layer) + basement membrane
- allow exchange of gases and nutrients
- gaps allow limited fluid and solutes to leak out = interstitial fluid (ISF)
- capillaries unite to form venules
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venules
-intima, thin media, thin externa
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veins
- large lumen
- valves prevent backflow of blood
- thin media-less smooth muscle
* can collapse
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Blood (CT) characteristics
- higher viscosity than water
- 37 degrees c
- ph 7.35-7.45
- 4-6 L in an adult
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blood (CT) composition overview
1. plasma (matrix)
* fluid portion with solutes
2. formed elements
* cellular portion
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plasma (matrix)
```
=blood minus formed elements
-composed of :
H2O-90%
proteins-8%
-albumin-control tissue water balance
-fibrinogen-clot formation
-globulin-antibodies
other solutes-2%
(nutrients, hormones, wastes, electrolytes, gases)
```
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formed elements
1. RBC-erythrocytes
2. WBC-leukocytes
3. platelets
61
RBC- erythrocytes
- hematocrit
- bioconcave disc shape
- anucleate when mature
- life span-120 days
- destroyed in the liver and spleen
- contain hemoglobin
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hemoglobin
- pigment protein
- hemoglobin is broken down to heme and globin
* heme is further broken down to bilirubin
* Fe2- recycled or stored (toxic, so always bound to protein)
* globin to amino acids
i. heme=red pigment-contains iron (Fe)
- attaches and transports O2
ii. globin-protein
- attaches and transport CO2
63
WBC-leukocytes
-nucleated
-life span varies - days to years
-defend against disease
-2 types:
granulocytes
agranulocytes
64
WBC granulocytes
```
includes:
neutrophils 60%
*all phaghocytic (engulf and digest invaders)
*kill bacteria
eosinophils 3%
*attack parasites (eg. worms)
basophils 1%
*release: histamine (increase inflammation) and heparin (decrease local clotting)
```
65
agranulocytes
```
include:
monocytes 5%
*enter tissue + enlarge to become macrophages (phagocytic = big eaters)
lymphocytes 35% immunity
-2 types :
T lymphocytes
*kill infected/diseased cells directly
B lymphocytes
*become plasma cells, produce antibodies (=y globulin)
```
66
Platelets
- fragments of cells called megakaryocytes
- involved in clotting
- life span = ~10 days if not used for clotting
67
Hemopoiesis/Hematopoiesis
-=formation of blood cells
-all blood cells arise indirectly from hemocytoblast (=stem cells) cells in red bone marrow
*red marrow in adult:
axial skeleton
pelvic and pectoral girdles
proximal ends of humerus and femur
