Lab: Blood Vessels Flashcards
Arteries carry blood _____ from the heart
away
Veins carry blood _______ the heart
toward
Capillaries enter into
Venules
Capillaries
Site of exchange of nutrients, wastes, and gases
Very small
Forms when smaller venules merge
veins
Arteries branch into smaller…
arterioles
In which vessel does each heart beat create a surge of pressure?
artery
Which vessel maintains it’s round shape even when empty due to it’s muscle?
arteries
Vasoconstriction
Decreases diameter
Vasodilation
Increased diameter
Arteries have input from the _______ nervous system
Sympathetic
Relatively thin-walled vessel
Vein
Vessel with relatively low blood pressure
Vein
Vessel with steady blood flow
Vein
Vessel that expands easily and collapses when empty
Vein
Do veins or arteries have a greater capacity for blood?
Veins
5 ways of venous return to the heart
- Pressure gradient
- Gravity
- Skeletal muscle pump
- Respiratory pump
- Cardiac suction
Veins contain valves to…
prevent back flow
Veins contain valves to…
prevent back flow
3 layers of the blood vessel wall
- Tunica interna (intima)
- Tunica media
- Tunica externa (adventitia)
Components to the tunica interna
- Endothelium (simple squamous) (innermost)
- Basement membrane
- Internal elastic lamina
Only found in arteries because it allows for recoil and return to normal shape after stretch
Elastic lamina
Tunica media components
- Smooth muscle
- External elastic lamina(artery)
What is key to regulating diameter of a vessel?
External elastic lamina
Outer layer that provides support and protection of veins and arteries
Tunica externa
What fibers make the tunica externa?
Elastic and collagen fibers
What is the thickest layer in a vein?
Tunica externa
In veins, what layer creates the valves?
Tunica interna
What is the thickest layer in an artery?
Tunica media
Which vessel contains a majority of blood and serves as a reservoir?
Vein
Types of arteries
- Elastic arteries
- Muscular arteries
- Arterioles
Which type of artery has a large diameter?
Elastic arteries
Which type of artery has a high amount of elastic fibers?
Elastic artery
The aorta is an example of which type of artery?
Elastic artery
Which type of artery has a small diameter?
Muscular artery
Which type of artery has a high smooth muscle fiber content?
Muscle artery
Which type of artery controls the blood flow into capillaries?
Arterioles
Which type of artery regulates blood pressure?
Arterioles
What vessel is made from a thing single endothelial layer?
Capillaries
Which vessel is only wide enough for 1-2 RBCs?
Capillaries
The thin walls of a capillary allows for exchange of nutrients, wastes, and gases between _______ and _______ _____
Blood
Interstitial fluid
3 types of capillaries
- Continuous
- Fenestrated
- Discontinuous
Intercellular clefts
Space between cells
Fenestrations
Pores in plasma membrane by a thin membrane
Where can continuous capillaries be found?
Most tissue and organs.
Ex. Lungs + brain
Which type of capillary is least permeable?
continuous capillaries
What can pass the intercellular clefts of a continuous capillary?
- small solutes
- diffusion of gases
Continuous capillary characterisitics
- Tight junctions
- Narrow intercellular clefts
- Least permeable
Fenestrated capillaries characteristics
- Fenestrations
- Rapid passage of small molecules
Location of fenestrated capillaries
Organs with rapid absorption
Ex. Kidneys, endocrine glands, small intestine
Discontinuous capillary characterisitics
- Endothelial cells separated by wide gaps
- No basal lamina
- Most permeable
What can pass through discontinuous capillaries?
Large molecules such as protein and blood cells
Location of discontinuous capillaries
Liver
Bone marrow
Spleen
Pituitary gland
Vessel that connects 2 capillary beds in series
Portal
Vessel that allows for an alternate route of blood flow in case main route is blocked/damaged
Anastomosis
Large, short vessel that immediately branches
Trunks
There are several superficial veins found in the body. What purpose might these serve?
Thermoregulation
Primary venous drainage of thoracic organs
Azygos system
What receives blood from the hemiazygous vein and the accessory hemiazygos vein before emptying into the superior vena cava?
Azygos vein
What is an example of a venous anastomoses
Azygos vein
What is the function of hepatic portal circulation?
To filter our nutrients from digested food and to carry them through our circulation
Neutrophil differential count
60-70%
Eosinophil differential count
2-4%
Basophil differential count
less than 0.5%
Lymphocyte differential count
25-33%
Monocyte differential count
3-8%