Chapter 20 STudy GUide

• Conducting Arteries
• Distributing Arteries
• Resistance Arteries

• Also known as elastic or large arteries.
• Biggest Arteries that expand during ventricular to receive blood and recoil during diastole.

• 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.

• Knwon as small arteries.
• They make up arterioles.

Metarterioles or Capillaries.

Vessels linking arterioles and cappilarries that contain precapillary sphincter

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.

• Continuous Capillaries
• Fenestrated Capillaries
• Sinusoids

Capillarries found in most tissues and contain perycttes that contract and regulate blood flow through capillaries.

Capillaries with filtration pores that allow rapiod passage of small molecules and are important in organs engaging rapid absoprtion and fitlration.

• 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.

Network of cappilarries between 10-100 supplied by a single metarteriole.

Thoroughfare channel

Distal end of throughfare channels or directly into venules.

• Veins: 64 %
• Artieres: 15%
• Pulmonary Circuit: 9%
• Heart: 7%
• Capillaries: 5%

• 1. Postcapilalry Venules
• 2. Muscular Venules
• 3. Medium Veins
• 4. Venous Sinuses
• 5. Large Veins

Smallest veins that receive directly from throughfare channels or directly from capillaries and also contain pericytes.

Receive blood from postcapillary venules. They are the 2nd smallest 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.

Venous valves are foldings in medium veins that prevents blood from flowing downwards when blood is suppsoe to be going up due to gravity.

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

Largest of all veins including the venae cavae, pulmnary veins, internal jugular and renal veins.

Heart -> Arteries -> Metarterioles -> Capillaries/Thoroughfare channels  -> Venules -> Large Veins -> Heart

Two consecutive capillary networsk blood flows through before returning to the heart. Occurs in the kidneys

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.

Force that blood exerts agianst a vessel wall.

Systolic pressure - PEak arterial Blood preccure attained by ventricular contraction.

Diastolic Pressure - Minmum arterial blood preccure occuring during ventricular relaxation.

Systolic is measured at the peak of ventricular CONTRACTION.

Diastolic Pressure is measure as the minimum blood pressure at ventricular RELAXATION.

120 systolic pressure at 75 diastolic pressure.

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.

It's another way of measuring stress of n the blood vessels.

You add diastole pressure and one third of the pulse pressure.

120/75 BP.

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

Opposition to flow that blood encoutners in vessels away form the heart. 

• The three kinds:
• Viscosity
• Vessel Length
• Vessel Radius

• Thickness or stickiness of the blood.
• The more viscosity the more peripheral resistance it has ( flow declines )

The farther the liquid travels the more friction occurs over time hence increasing resistance and reducing blood flow.

Vasocontriction - narrows vessels and slows blood flow.

Vasodilation - Increaess blood flow because blood has a greater area to flow through.

Vasoconstriction increases blood pressure.

Decreases blood pressure.