Term
| What are the three major types of blood vessels? |
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Definition
- Arteries - distributing systems
- Capillaries - diffusion and filtration
- Veins - Collecting system
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Term
| What is the structure and function of arteries? |
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Definition
Carry blood away from the heart, efferent flow. High pressure vessels with strong vascular walls.
Elastic arteries - conduct, contain an internal elastic layer
Muscular arteries - distribute. Very thick SM tunica media |
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Term
| What is the function of arterioles? |
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Definition
| Controls flow into capillaries. Smooth muscle in the lumen makes it the major site of blood pressure control. RESISTANCE VESSELS. SM present. |
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Term
| What site is the major site of blood pressure control? |
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Definition
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Term
| What is the function of capillaries? |
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Definition
| 'Leaky' vessels allow for nutrient and gas exchange. Exchange vessels. |
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Term
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Definition
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Term
| What is the function of the venules? |
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Definition
| Collect blood from capillaries, coalesce into veins. The postcapillary venules are sites of inflammation. Only possess a tunica externa |
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Term
| What is the function of veins? |
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Definition
| Carry blood back to the heart under low pressure. Large lumens that can greatly expand. Capacitance vessels. |
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Term
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Definition
| Branching of big vessels into smaller vessels. All vessels are arranged in series, except for capillaries which are in parallel. |
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Term
| In the 3 different circuits, which circuit has the most blood? In that circuit, which side has the most blood? |
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Definition
| The venous side of the systemic circuit. |
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Term
| What is the fundamental law of blood vessel branching? |
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Definition
| CSA of a vessel decreases as a result of arborization. However, the total CSA of combined daughter vessels will exceed the CSA of the parent vessel. This is why capillaries have the highest total CSA. |
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Term
| Are there more capillaries present in the systemic circulation or in the lungs? |
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Definition
| In the lungs, have the highest total CSA. |
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Term
| How does CSA relate to velocity? |
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Definition
| v = F/CSA. Therefore velocity is inversely proportional to CSA. Blood flow in the aorta is faster than in a capillary, however aggregate flow in all the capillaries is almost equal to the flow of the aorta. |
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Term
| Which vessels are under high pressure? |
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Definition
| Arteries and arterioles only |
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Term
| How do you calculate mean pressure? |
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Definition
Mean pressure = Diastolic - 1/3(pulse pressure) and pulse pressure = systolic - diastolic)
So MP = diastole - 1/3(Systole - diastole) |
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Term
| Why don't capillaries have a high resistance? |
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Definition
| Even though they have the smallest diameter, they are arranged in parallel. The more vessels in parallel, the smaller the aggregate resistance. |
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Term
| How do the lymphatic vessels work? |
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Definition
| Hydrostatic pressure pushes fluid out of the capillaries. Fluid is taken up by the thoracic duct, connects directly to the left subclavian and then eventually the vena cava. |
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Term
| What are the differences in structure between veins and arteries? |
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Definition
Veins are flat, have a larger lumen, possess a valve to prevent backup.
Arteries only possess an elastic lamina. Also have thicker SM |
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Term
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Definition
| Blood vessels ennervate BV walls in BV that are very thick, such as arteries. |
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Term
| In endothelium, what are permeability barriers? |
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Definition
| tight junctions prevent leaks, though capillaries are intentionally leaky. Also cell surface binding proteins. |
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Term
| In endothelium, what promotes anti-thrombotic activity/prevention of clotting? |
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Definition
- Thrombomodulin - binds thrombin and allows Protein C to bind
- Protein C - Anti-thrombotic and thrombolytic
-TFPI - blocks activity of thrombin and Xa
- tPa - conversion to plasmin, fibrinolytic |
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Term
| In endothelium, what promotes pro-thrombotic activity/clotting? |
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Definition
vWF - allows platelets to bind to injury
PAI - inhibits tPa
Thromboxane - a prostaglandin that promotes aggregation |
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Term
| In endothelium, what are vascular factors? |
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Definition
-PgI2 and prostacyclin - prostaglandins that inhibit aggregation.
- NO - a vasodilator, inhibits aggregation
- EDHF - increases K influx, membrane more difficult to depolarize. |
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Term
| In endothelium, What keeps the surface smooth? |
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Definition
| upregulation of adhesion molecules and chemotactic factors |
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Term
| What receptors are present on endothelium? |
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Definition
| LDL receptors, bradykinin, autonomic. |
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Term
| What type of artery is the aorta? |
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Definition
| An elastic artery. Elastic > smooth muscle. |
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Term
| What is the formula for determining flow? |
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Definition
Flow = change in pressure/resistance
increase in pressure or a decrease in resistance to increase flow.
An increase in pressure shows a nonlinear increase in flow due to elasticity. |
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Term
| What is critical closing pressure? |
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Definition
| As resistance increases, the point at which blood no longer flows. Sympathetic stimulation constricts, increasing pressure. Increases the pressure at which critical closing will occur. |
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Term
| What goes a graph of flow vs resistance and pressure show? |
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Definition
| As you increase pressure, resistance decreases and flow increases. Sympathetic tone increases resistance. |
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Term
| Which vessel has the largest lumen? |
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Definition
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Term
| What are properties of elastic arteries? |
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Definition
| Thick walled and near the heart. Low resistance and high velocity. Not much SNS control. Arteriosclerosis - loss of elasticity. Ex: aorta |
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Term
| What are the properties of muscular arteries? |
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Definition
| Distributing vessels, majority SM with some elastic fibers. Can constrict, with some SNS control. |
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Term
| What are properties of arterioles? |
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Definition
| Mostly SM, significant SNS control. The major resistance vessels. Controls blood flow via resistance, reducing pulsation to a steady flow. |
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Term
| What are some properties of capillaries? |
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Definition
Only posses a tunica intima. Pericytes stabilize wall and control permeability. Mostly tight junctions, some clefts to allow leakage. Astrocytes maintain tight junctions.
Highest regeneration capacity in the capillaries. |
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Term
| What are the different types of capillaries? |
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Definition
- Continuous - least permeable and most common. Few intracellular clefts
- Fenestrated - larger pores allowing more permeability. Important for filtration in the kidney
- Sinusoidal - Most permeable with large clefts, important in the liver. |
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Term
| How does the capillary bed control local blood flow? |
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Definition
| If no oxygen is needed, sphincters close and blood goes through anastomosis and thoroughfare channel |
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Term
| How does the structure of the venous system differ from arteries? |
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Definition
| Mostly tunica externa. Thin walls with large lumen. Venules are porous with no elasticity. Veins have 3 layers but little elasticity and SM, large amount of collagen. SNS stimulation causes contraction and displacement of blood. Presence of valves prevent backflow. |
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Term
| What are the 3 mechanisms to increase venous return? |
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Definition
- SNS - Contracts vessels to squeeze blood up and valves prevent backflow.
- Muscular pump - contracting skeletal muscle squeezes vein
- Respiratory pump - inhale to create pressure in the abdomen drawing blood up.
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Term
| What is angiogenesis and vasculogenesis? What are treatments involving angiogenesis? |
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Definition
| Growth of new blood vessels. Vasculogenesis is angiogenesis in fetal development. Stimulate angiogenesis when collateral blood flow is needed in ischemia. Prevent in cancer. |
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Term
| What are the steps in angiogenesis? |
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Definition
1)Injury of a BV releases growth factors 2)GFs bind to receptors on ENDOTHELIUM on prexisting BVs 3)Endothelium is activated, release matrix metallo-proteanases 4) MMPs dissolve holes in surrounding basement membrane 5) Endothelium divides and sprouts into holes
6) Integrins/adhesion molecules serve as grappling hooks
7) MMPs dissolve tissue in front of new BV 8) Endothelium forms BV tube, connect to form loops, and are stabilized by SM and pericytes.
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Term
| What are 4 important components in angiogenesis? |
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Definition
Vascular endothelial growth factor (VEGF) - stimulates angiogenesis by signaling endothelium to reproduce and migrate
Fibroblast Growth Factor - growth of endothelium, fibroblasts, and smooth muscle
Angiopoietins - form mature blood vessels and stabilize them
MMPs - form holes in basement membrane and allow sprouting. |
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Term
| What are the components of the axial skeleton? |
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Definition
| The skull, the ribs and sternum, the spine, and the sacrum. |
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Term
| What are the bones of the appendicular skeleton? |
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Definition
- Arms - Clavicle and scapula, humerus, Radius and ulna (Ulna towards pinkie), carpals/metacarpals/phalanges.
- Legs - Pelvic bones and girdle, femur, patella, tibia (large) and fibula, tarsals/metatarsals/phalanges
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Term
Where is blood pressure measured?
What are the other major arteries of the arm? |
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Definition
At the brachial artery
Axillary -->Brachial --> Radial and Ulnar (ulnar towards pinkie) --> palmar arches and digital arteries |
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Term
| What is the nomenclature for abdominal arteries? |
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Definition
Above the diaphragm -- thoracic aorta
Below the diaphragm -- abdominal aorta
Into the legs: Common Iliacs
Branches off of abdominal aorta:
Celiac trunk - splits off into gastric, splenic, and hepatic arteries
Renal artery
Superior and inferior mesentary - Small and large intestine respectively. |
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Term
What is the nomenclature of the arteries of the legs/feet?
What branch can be palpated for a pulse in the feet? |
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Definition
Common iliac --> Internal and external iliac --> Femoral artery --> Popliteal artery --> Anterior/posterior tibial artery and fibular artery --> Plantar artery --> Dorsal pedis and plantar arch.
The dorsal pedis can be palpated for blood flow. |
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Term
What are the veins of the head?
Which vein is a sign of heart problems? |
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Definition
| The brachiocephalic vein branches into the subclavian and the large internal jugular. The external jugular runs just below the surface of the neck. Visible distension is a sign of heart problems. |
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Term
What are the veins of the arm?
Which veins are superficial/can you draw blood from? |
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Definition
Subclavian --> Axillary --> Brachial --> Radial and ulnar veins, palmar venous arches and digital veins
Superficial veins: Cephalic vein, Median antebrachial vein, Basilic vein. Blood may also be drawn from the median cubital vein. |
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Term
| What is the nomenclature of veins in the abdomen? |
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Definition
The common iliac leads into the inferior vena cava.
The mesenteric and celiac veins empty into capillary beds in the liver called the hepatic portal system/sinusoids, then empty out the hepatic vein. Capillary --> Vein --> Capillary --> Vein
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Term
| What is the nomenclature of the veins in the leg/feet? |
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Definition
Iliac --> Femoral --> Popliteal --> Tibial and fibular --> Dorsal pedis vein and arch
Saphenous veins are superficial, responsible for varicose veins. |
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Term
| What arteries are most commonly palpated for blood flow? |
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Definition
- Posterior tibial artery
- Right Common Carotid
- Brachial artery
- Radial artery
- Femoral artery
- Dorsal Pedis
- Popiteal artery
- Facial and temporal artery
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