Chapter 20 STudy GUide
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What are three kinds of arteries?
- Conducting Arteries
- Distributing Arteries
- Resistance Arteries
What are conducting arteries?
- Also known as elastic or large arteries.
- Biggest Arteries that expand during ventricular to receive blood and recoil during diastole.
What are distributing arteries?
- Known as muscular or medium arteries.
- Also knwon as the intersstate high way that distributes arteries to specific "towns" ( organs )
Example: Brachial, feomoral, renal and splenic arteries.
What are resistance arteries?
- Knwon as small arteries.
- They make up arterioles.
Where do arterioles empty into?
Metarterioles or Capillaries.
What are metaarterioles?
Vessels linking arterioles and cappilarries that contain precapillary sphincter
What are precapilalry sphincters? Where are they found?
Precapillary sphincters are found in the entrances from a metarterioles to a capillary.
They reduce or shut off blood flow to a capillary and diverts blood to tissues or organs elsewhere.
Kinda like the thing on a train track that changes the trains direction.
What are the three types of cappillaries?
- Continuous Capillaries
- Fenestrated Capillaries
What are continous cappillaries?
Capillarries found in most tissues and contain perycttes that contract and regulate blood flow through capillaries.
What are fenestrated capillaries?
Capillaries with filtration pores that allow rapiod passage of small molecules and are important in organs engaging rapid absoprtion and fitlration.
What are Sinusoid cappilarries?
- Known as discontinuous capillaries.
- They're irregular-bloodfilled spaces with twisted, tortuous passageways where larger proteins and blood cells can pass through.
These are also the ways albumin, clotting factors and other proteins synthesized by liver enter the blood.
What are capillary beds?
Network of cappilarries between 10-100 supplied by a single metarteriole.
Materioles continue to become capillarries, and capillaries cointinue as __________ leading directly to a venule.
What do capillaries mepty into?
Distal end of throughfare channels or directly into venules.
How many percent of the blood is found in the veins at rest? At arteries? Pulmonary Circuit? Heart? Capillaries?
- Veins: 64 %
- Artieres: 15%
- Pulmonary Circuit: 9%
- Heart: 7%
- Capillaries: 5%
What are the 5 types of Veins?
- 1. Postcapilalry Venules
- 2. Muscular Venules
- 3. Medium Veins
- 4. Venous Sinuses
- 5. Large Veins
What are poscapilalry venules?
Smallest veins that receive directly from throughfare channels or directly from capillaries and also contain pericytes.
Where do muscular venules receive blood from?
Receive blood from postcapillary venules. They are the 2nd smallest veins.
What are medium veins?
The third smallest vein. Found as the radial and ulnar veins of the forearm as well as the great and lesser sapehnous of the legs.
They contain venous valves.
What are venous valves?
Venous valves are foldings in medium veins that prevents blood from flowing downwards when blood is suppsoe to be going up due to gravity.
What are venous veins?
Veins with especially thin walls. 2nd Largest vein and found in the coronary sinus of the heart and dural sinuses of the brain.
Incapable of vasomotion
What are large veins?
Largest of all veins including the venae cavae, pulmnary veins, internal jugular and renal veins.
Describe the circulatory routes:
Heart -> Arteries -> Metarterioles -> Capillaries/Thoroughfare channels -> Venules -> Large Veins -> Heart
What is a portal system?
Two consecutive capillary networsk blood flows through before returning to the heart. Occurs in the kidneys
What is anastomosis? What are the three types?
A point where two blood vessels merge. Provides alternate routes of passing.
Anteriovenosu ANastomosis - Blood flows directly form an artery into a vein bypassing hte capillaries.
Venous Anastomoses - One vein empties directly into another providing several alternative routes o drainage from an organ
Arterial Anastomoses - two arteries merge providing alternative routes of blood supply to a tissue.
What is blood pressure?
Force that blood exerts agianst a vessel wall.
What is systolic pressure? What is diastolic pressure?
Systolic pressure - PEak arterial Blood preccure attained by ventricular contraction.
Diastolic Pressure - Minmum arterial blood preccure occuring during ventricular relaxation.
How is systolic and diastolic pressure different?
Systolic is measured at the peak of ventricular CONTRACTION.
Diastolic Pressure is measure as the minimum blood pressure at ventricular RELAXATION.
What is the average blood pressure?
120 systolic pressure at 75 diastolic pressure.
What is pulse pressure? How do you calcualte this? What does this calculate?
Pulse pressure is the difference between systolic and diastolic pressure.
You calculate them by subtracting Systolic - Diastolic.
EX: 120/75 BP. 120-75 = 45 mm HG
This calcualtes the maximum stress exerted on small arteries.
What is mean arterial pressure (MAP) ? How is it obtained?
It's another way of measuring stress of n the blood vessels.
You add diastole pressure and one third of the pulse pressure.
Calculate Pulse PRessrue first. 120-75 = 45. Divide this by 3.
Take Diastolic pressure and add that to the Pulse Pressure that was divided by 3.
75+ 45/3 = 62 mm HG
What is peripheral resistance? What are the there factors of this?
Opposition to flow that blood encoutners in vessels away form the heart.
- The three kinds:
- Vessel Length
- Vessel Radius
What is viscosity? How does it affect Peripheral resistance?
- Thickness or stickiness of the blood.
- The more viscosity the more peripheral resistance it has ( flow declines )
How does vesse legth affect perihperal resistance?
The farther the liquid travels the more friction occurs over time hence increasing resistance and reducing blood flow.
How does blood radius affect peripheral resistance?
Vasocontriction - narrows vessels and slows blood flow.
Vasodilation - Increaess blood flow because blood has a greater area to flow through.
How does vasocosntriciton affect blood pressure?
Vasoconstriction increases blood pressure.
How does vasodialtors affect blood pressure?
Decreases blood pressure.
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