Vasculature Flashcards
What are the vessel wall layers?
innermost-tunica intima
middle- tunica media
outermost- tunica externa
what is the function of the tunica intima?
it facilitates smooth blood flow and plays a role in vessel permeability
What is the function of the tunica media?
allows for vasoconstriction and vasodilation
What is the function of tunica externa?
consists of areolar CT with collagen and elastic fibers which anchor the vessel to surrounding organs
Which vessel has thicker tunica media?
arteries
Which vessel has thicker tunica externa?
veins
What are elastic arteries?
they are nearest to the heart and responsible for conducting the blood from the heart to the smaller artery branches.
Name the major elastic arteries
aorta, pulmonary trunk, common carotid, and common iliac arteries
What are muscular arteries?
distributing arteries, medium sized blood vessels that distribute blood to organs and tissues throughout the body. These vessels have more muscle fibers than other arteries
Name a few muscular arteries
radial, brachial, and femoral arteries
What are arterioles?
the smallest arteries. They branch off from arteries and lead to capillaries. They are vital in regulating blood flow and pressure.
What are capillaries?
The smallest vessels. They connect arterioles to venues. The exchange vessels that are responsible for delivering nutrients to and removing wastes from the tissues
What are continuous capillaries?
They have no breaks or spaces between cells, they are connected by tight junctions. The most common type of capillary in the body and serve most organs including muscles, skin, and lungs
What are fenestrated capillaries?
Tiny blood vessels with small pores that allow substances to move in and out of the capillaries. Found in kindeys, small intestines, and pancreas
What are sinusoidal capillaries?
Also known as discontinuous capillaries. They regulate bp and perfusion in the liver. Found in liver, spleen, bone marrow and lymph nodes.
What are venules?
The smallest veins, they receive blood from thoroughfare channels and capillary beds. Venules merge, forming veins
What are veins?
blood vessels that conduct blood toward the heart
What are anastomoses?
blood vessels that bypass the capillary beds and where two or more arteries converge to supply the same area
Which type of blood vessels have valves to keep deoxygenated blood flowing in the correct direction?
veins
Which type of blood vessels have the smallest diameter?
capillaries
Which type of blood vessels have the thickest walls?
Elastic arteries
Which type of blood vessels have the thinnest walls?
capillaries
Which type of blood vessels has the highest pressure?
arteries have the highest pressure because they carry blood away from the heart, which pumps it forcefully
Why do you draw blood from the vein?
because they have much lower pressure, making it safer
What type of blood travels through arteries?
arteries carry oxygen rich blood away from the heart to the body’s tissues
What type of blood travels through veins?
veins carry oxygen poor and carbon dioxide rich blood towards the heart
What type of blood travels through capillaries?
capillaries carry both oxygenated and deoxygenated blood
What is the direction of blood flow through arteries?
away from the heart
What is the direction of blood through veins?
Towards the heart
What is the direction of blood through capillaries?
arterioles to capillaries to venules
after blood flows out of an artery, which vessel type comes next until you are back to the heart?
arteries–>arterioles–> capillaries–> venules–> veins –> heart
What is capillary exchange?
the process where substances are transferred between the blood and tissues
What are the different ways fluids move across capillary walls?
filtration, reabsorption, hydrostatic pressure, osmotic pressure, net filtration pressure
Define filtration
Movement of fluid in capillaries (arterial end)
Define reabsorption
The movement of material from the interstitial fluid into the capillaries (venous end)
Define hydrostatic pressure
pushes fluid out of capillaries
What is osmotic pressure?
Pulls fluid back into the capillaries
Define hemodynamics
The forces and factors that drive blood circulation and direct how blood is circulated throughout your body
What is blood pressure?
The force exerted by circulating blood on the walls of blood vessels. Controlled by cardiac output, blood volume, and resistance
What is vascular resistance?
The opposition to blood flow. It increases with vessel lenght and decreases with vessel diameter
Describe how venous return works
The amount of blood returning to the heart via veins. Influenced by pressure differences between the veins and the right atrium
What are the common pulse points?
Temporal artery, facial artery, common carotid artery, brachial artery, radial artery, femoral artery, popliteal artery, posterior tibial artery, dorsalis pedis artery
What are the factors that control blood pressure?
Cardiac output
blood volume
vascular resistance
vessel elasticity
hormones
neural control
How do you measure blood pressure?
Wrap BP cuff around upper arm
Inflate to about 30mmHg above expected systolic pressure
Place stethoscope on inner elbow
Slowly deflate cuff whil listening to sounds
First sound is systolic pressure
Sound disapears is diastolic pressure
What is the hepatic portal system?
specialized circulatory pathway that carries blood from digestive organs to the liver for processing before being sent to the systemic circulation.
Returns blood from the digestive organs to the liver for nutrients to be processed and harmful agents removed before the blood returns to the heart.
