A+P chap 19 blood vessels

What are the three types of blood vessel

Arteries, vein and capillaries.

How are the different blood vessel types similar? Compared structure and function.

All are made from a three-layered structure. All form a closed transport system to move blood and remove waste.

How are different blood vessel types different (Arteries)

Thick and highly muscular. Made to handle high pulsing blood.

How are different blood vessel types different (veins)

Thinner with larger lumens made to carry lower pressure high volume of blood.

How are the different blood vessels types different (capillaries)

Are thin and are made to exchange nutrients and gases between blood and tissues.

Which vessel types bring blood towards the heart?

Veins

Which vessel types take blood away from the heart?

Arteries

What are the three main tunics (layers) of arteries and veins?

Tunica initma, tunica media, and tunica externa.

What are the main functions of tunica intima

Innermost layer that lines lumen providing smooth surface

What are the main functions of tunica media

increased and decreases the diameter of the vessel

What are the main functions of the tunica externa

Protects, reinforces, and anchors vessel to surrounding structures

What tissue type makes up the tunica initma

Made from endothelium and a subendothelial layer

What tissue type makes up the tunica media

Made from smooth muscles and elastic fibers.

What tissue types make up the tunica externa

Made from collagen fibers

Which tunica has the most elastic fibers

Tunica media

Define vasoconstriction

Decreased diameter of blood vessel

Define vasodilation

Increased diameter of a blood vessel

Structure and function of the elastic arteries

Pressure reservoirs that stretch and recoil to conduct blood flow. Not much use of smooth muscle.

Structure and function of the muscular arteries

Distribute blood to organs. Has more smooth muscle and less eastin than elastic arteries.

Structure and function of artrioles

Controls the blood flow into capillary beds (tissues). Made from smooth muscles with almost no elastin.

At what location does the exchange of nutrients and gases occur?

Happens in all tissues besides for cartilage, epithelia, cornea, and lens

Which types of vessels are most involved in this exchange?

Capillaries

What are the three types of capillaries?

Continuous, fenestrated, and sinusoid.

What distinguishing features are found in continuous capillaries

They are the most common and least permeable

What distinguishing features are found in fenestrated capillaries

They are involved in active filtration, absorption, and secretion (and therefore more permeable).

What distinguishing features are found in the sinusoid capillaries

The least common and is the most permeable due to having gaps between cells and an incomplete basement membrane

Where are capillaries NOT found

Cartilage, epithelia, cornea, and lens

How do terminal arterioles help to regulate blood flow through a capillary bed?

Control the blood flow by either dilating or constricting

Where are sinusoid capillaries found?

Liver, bone marrow, spleen, and adrenal gland

What are varicose veins and what causes them?

Swollen, twisted, and enlarged veins. Caused by Obesity, pregnancy, and long periods of sitting and standing

People in which professions are at higher risk of developing varicose veins

Nursing

What units are used for flow and pressure

Flow uses mL per minutes and pressure uses mmHG

How are blood flow and pressure related?

Blood flow is directly proportional to blood pressure

How are blood flow and resistance related?

Blood flow is inversely proportional to resistance

What is the most important factor in regulating resistance

Vessel diameter

What are the other factors of regulating resistance

Total blood vessel and blood viscosity

Define vasomotion

The spontaneous contraction and relaxation of the vascular smooth muscle cells within the walls of small arteries

Which vessels have the highest blood volume?

Veins have the highest blood volume

Which vessel has the highest blood pressure? The lowest?

Arteries have the highest blood pressure and veins have the lowest pressure.

Where is blood flow the fastest? The slowest?

Arteries have the fastest flow while capillaries have the slowest

What is systolic pressure and what is the normal average in adults

Results of pressure from left ventricle contraction. The average pressure is 120

What is diastolic pressure and what is normal average in adults?

Results of left ventricle relaxation. Normal is 80.

How do you obtain the value for the pules pressure

Difference between systolic and diastolic

In what locations can you a pulse pressure

Superficial temporal artery, facial artery, common carotid artery, brachial artery, radial artery, femoral artery, popliteal artery, posterior tibial artery, and dorsalis pedis artery

What are the three major factors that influence blood pressure

Cardiac output, resistance, and blood volume

Why is it important for blood flow to be slow through sinusoid capillaries

Because of the structure, more time is required to for efficient exchange

How is cardiac output related to blood pressure

Increased cardiac output is caused by increased heart rate/stroke volume which raises blood pressure

How is peripheral resistance related to blood pressure

As peripheral resistance increases, blood pressure increases

What are the two anatomical systems that mediate short-term regulation of blood pressure

Neural and endocrine

Through changes in which two variables does short-term regulation of blood pressure occur

Resistance and cardiac output

What change stimulates baroreceptors?

An increase in blood pressure

When baroreceptors are activated, what effect does that have on blood vessels and on the heart

Cardiac output decreases and the blood vessel go through vasodilation

What are two stimuli for chemoreceptors

Stimulated by an increase in CO2, decrease in pH, and decrease in O2

When chemoreceptors are activated, what effect does that have on blood vessels and on the heart

Cardiac output is increase and vasoconstrictions is increased

What are the major causes hypertension

Heredity, diet, obesity, age, diabetes, stress, smoking, and hyperthyroidism

What are the major causes of hypotension

Heredity causes chronic hypotension. Hemorrhage and anaphylatic shock causes acute hypotension

What is an aneurysm? Is it more likely to be caused by hypotension or hypertension?

An abnormal bulge of an artery caused by a weak spot. It is more likely to be caused by hypertension.

What is edema and what causes it?

It is an excess volume in interstitial fluid. It is caused by incompetent venous valves (usually in lower limbs), localized vascular blockage, congestive heart failure, and high blood volume

What is tissue perfusion

Tissue perfusion is blood flow through the tissue

What are the four main events that occur during tissue perfusion

Delivery of oxygen and nutrients, removal of carbon dioxide and waste, gas exchange (lungs), nutirent absorption (GI tract), and urine formation (kidneys)

How is the rate of blood flow regulated by extrinsic factors

Endocrine and sympathetic nervous systems are mediators that act on the arteriole smooth muscle, redirecting flow to tissue with the greatest needs

How does gas exchange occur across capillaries?

Diffusion, bulk flow, and vesicular transport

In what ways are various (lipid-soluble or water-soluble) nutrients transported across capillaries?

Exit from the capillary arterial end and entry into the venous end

Is the net filtration pressure higher at the arterial or venous end of a capillary bed

Arterial end of the capillary bed

Is the capillary hydrostatic pressure higher in the direction of bulk flow across capillaries

Higher in the arterial end of the capillary bed

What are the two factors forces that determine the direction of bulk flow across capillaries

Hydrostatic pressure and colloid osmotic pressure

Dose osmotic pressures normally change as blood passes through a capillary bed

Blood colloid pressure remains relatively constant