cardiovascular vessels 1 Flashcards
(51 cards)
1
Q
Name the 3 layers of an artery
A
- Tunica Interna
- Tunica Media
- Tunica Externa
2
Q
What is the tunica interna
A
- innermost layer of the artery & is in contact with the blood
3
Q
What is the tunica media
A
- middle layer of the artery containing smooth muscle and elastic tissue
4
Q
What is the tunica externa
A
- outermost layer that anchors the vessels
- contains vasa vasorum
5
Q
List 5 types of blood vessels
A
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
6
Q
2 Types of Arteries
A
- Elastic (Conducting)
- Muscular (Distributing)
7
Q
Elastic Arteries
A
- largest arteries in the body
- contain more elastic fibers in the thick tunica media
- include aorta, pulmonary trunk, brachiocephalic, subclavian, common carotid, common iliac
- propels blood onward when ventricles contract
- walls stretch during contraction and close during relaxation to propel blood forward
8
Q
Muscular Arteries
A
- dependent on what the body needs
- contain more smooth muscles giving an ability to contract
- vascular tone maintains pressure and efficient flow
- amount of blood flow decreases in organ and raises BP
- femoral, brachial, axillary, splenic, popliteal
9
Q
Anastemoses Definition
A
Union of 2 or more branches of arteries supplying the same tissue or region
- collateral circulation
10
Q
Arterioles
A
- small arteries
- resistance vessels - vessels constrict, greater friction, more resistance and less blood flow
- vasoconstriction
11
Q
Papillary Sphincter
A
- located at the metarteriole capillary junction
- controls blood flow into the capillary
12
Q
Capillaries Definition
A
- exchange vessels between blood and interstitial fluid
- lack tunica media and externa
- more prominent in kidney, liver, brain, muscle
- absent in cornea, cartilage, lens of the eye, epithelial tissues
13
Q
Capillary Bed
A
- continuous capillaries
- network of 10-100 capillaries increase surface area so cells can rapidly receive oxygen
14
Q
Continuous Capillaries
A
CNS, muscles, skin, lungs
- makes exchange quicker
15
Q
Fenestrated Capillaries
A
- Kidneys, Small Intestine Villi, Choroid Plexus
- little holes in it
16
Q
Sinusoid Capillaries
A
Liver, Spleen, Red Bone Marrow
- allows most exchange
17
Q
Venules Definition
A
- drain the capillaries
- thin walled
- excellent resevoir of blood
18
Q
Postcapillary Venules
A
- exchange of nutrients and wastes
- excellent resevoir of blood
19
Q
Muscular Venules
A
- no exchange occurs
- excellent resevoir of blood
20
Q
Veins Definition
A
- formed from the union of several venules
- thin walls and large diameter
- no smooth muscle or elastic tissue
- have valves to return blood back to the heart
21
Q
Summary of Arteries and Vein
A
22
Q
Blood Distribution Percentages
A
23
Q
Starling Forces
A
- hydrostatic and osmotic pressures determine how much fluid leaves the arterial end of capillary bed and reabsorbed at the venous end
24
Q
Filtration Definition
A
pressure driven movement of fluid from capillaries into interstitial fluid
- BHP and IFOP promote filtration
25
Reabsorption Definition
- pressure driven movement from the interstitial fluid into blood from the capillaries
- IFHP and BCOP promote reabsorption
26
Blood Hydrostatic Pressure
- pushes fluid out of capillaries into interstitial fluid
27
Interstitial Fluid Osmotic Pressure
- pulls fluid out of capillaries into interstitial fluid
28
Blood Colloid Osmotic Pressure
- caused by large proteins in blood
- pulls fluid from interstitial fluid into capillaries
29
Interstitial Fluid Hydrostatic Pressure
- pushes fluid from interstitial fluid back into capillaries
- (negligible)
30
Net Filtration Pressure at Arterial End
10
31
Net Filtration Pressure at Venous End
-9
- more absorption than filtration
32
Starlings Law of Capillaries
- on average about 85% of fluid filtered is reabsorbed
- 15% goes through the lymphatic system
33
Blood Flow Calculation
Flow = Pressure/Resistance
34
3 things that affect resistance
1. Diameter of lumen
2. Viscosity of Blood
3. Length of Vessel
35
Blood Pressure Calculation
BP= Flow x Resistance
36
Blood Pressure
fluid pushing against the wall
- travel from high to low areas
- highest in the aorta and large systemic arteries
37
Systolic Blood Pressure
120mmHg
highest pressure in arteries
38
Diastolic Blood Pressure
80mmHg
- lowest pressure in arteries at the end of ventricle diastole
39
Mean Arteriole Pressure
- average blood pressure in arteries
- MAP= DBP + 1/3 (SBP - DBP)
40
Pulse Pressure
- difference between systolic and diastolic
41
Normal ration of DBP SBP and pulse
3:2:1
42
Blood Pressure in aorta during systole
120mmHg
43
Blood Pressure in Aorta during diastole
80mmHg
44
Blood pressure in arterioles as they pass into the capillaries
35mmHg
45
Blood Pressure in venous ends of capillaries
16mmHg
46
2 additional mechanisms to help return blood to the heart
1. Skeletal Muscle Pump
2. Respiratory Pump
47
What does the skeletal muscle pump
contractions of leg muscles compresses the veins pushing through the veins valves towards the heart
people who walk a lot avoid blood clots (no pooling)
48
What does the respiratory pump
- diaphragm moves down causing a decrease of pressure in the thoracic cavity and an increase in pressure in the abdominal cavity
- veins in abdomen compress and force blood in the lower pressure in the thoracic cavity forces blood from the thoracic veins back to the heart
49
What controls blood pressure
1 Neural
- baroreceptors
- chemoreceptors (aortic arch and carotid sinus)
2. Hormonal
- RAAS system
- epinephrine and norepinephrine
- ADH (all 3 increases BP)
- ANP decreases BP
50
What does a baroreceptor do
senses change in blood pressure
located in aortic arch and internal carotid artery
51
What does a chemoreceptor do
senses change in chemical composition (O2, CO2, pH)
