Chapter 20 Q&A

What are the three layers of blood vessel walls called?

Tunica interna, tunica media, tunica externa.

What is the main function of the tunica interna (intima)?

Lines the blood vessel and is exposed to blood; site of material exchange.

What are elastic arteries also known as?

Conducting arteries.

Name an example of a conducting artery.

Pulmonary artery, aorta, or common carotid artery.

Which type of artery distributes blood to specific organs?

Muscular (distributing) arteries.

What do arterioles control?

The amount of blood to various organs.

What connects arterioles to capillaries?

Metarterioles.

What type of capillaries are characterized by tight junctions and intercellular clefts?

Continuous capillaries.

Where are fenestrated capillaries found?

Kidneys and small intestine.

What do sinusoids allow the passage of?

Larger molecules such as proteins and blood cells.

What are veins considered in terms of their function?

Capacitance vessels.

How is arterial blood pressure measured? and with what measurments?

Using a sphygmomanometer at the brachial artery. Systolic/Diastolic Pressure

What is the formula for Mean Arterial Pressure (MAP)?

Diastolic pressure + 1/3 pulse pressure.

What are the three factors that influence peripheral resistance?

Blood viscosity, blood vessel length, and blood vessel radius.

How does blood vessel radius affect blood flow?

Larger radius increases blood flow; smaller radius decreases blood flow.

What does vasomotion refer to?

Changes in vessel radius, including vasoconstriction and vasodilation.

What is the primary physiological purpose of vasoreflexes?

Increase or decrease blood pressure and flow rate.

What drives filtration at the capillary level?

Blood (hydrostatic) pressure.

What is edema a result of?

Increased hydrostatic pressure, decreased colloid osmotic pressure, or blockage of lymph drainage.

Define hypertension according to the lecture notes.

Chronic resting blood pressure greater than 140/90.

What risk factors are linked to primary hypertension?

Heredity, race, gender, aging, stress, obesity, lifestyle, and smoking.

What type of hypertension results from identifiable disorders?

Secondary hypertension.

What is a common cause of secondary hypertension?

Kidney disease, atherosclerosis, or hyperthyroidism.

What is the function of the coronary arteries?

Supply blood to the heart muscle.

What is the purpose of the pulmonary circuit?

Exchange CO2 for O2 in the lungs.

From which arteries does blood primarily supply the brain?

Internal carotid and vertebral arteries.

What is the significance of the hepatic portal system?

Receives blood from the digestive tract to allow the liver to process and detoxify nutrients.

What is the largest blood vessel in the body?

Inferior vena cava.

What are the superficial veins of the upper limb called?

Cephalic vein, basilic vein, and median cubital vein.

Where does the great saphenous vein empty?

Into the femoral vein.

What occurs to peripheral resistance when blood vessel length increases?

Peripheral resistance increases; blood flow decreases.

What is a characteristic of resistance arteries?

They control blood flow to specific tissues and organs.

What major blood vessels drain the head and neck region?

Internal jugular and external jugular veins.

What kind of capillary allows rapid exchange of small molecules due to its filtration pores?

Fenestrated capillaries.

What happens when vascular resistance increases?

Blood pressure rises.

Name one treatment for hypertension.

Weight loss, exercise, dietary changes, or medication.

formula for Cardiac Output

CO = HR x SV.

What are the 3 main circulatory routes

Simplest pathway, portal system and anastomosis

Simplest Pathway: Most common route

Heart-arteries-arterioles-capillaries-venules-veins-back to heart

Portal System

Blood flows through 2 consectuive caplarillary netowrks before returning to heart

ex. btw intestines and liver

Anastomosisis

artery directly to vein: fingers, toes, ears; reduces heat loss

calculate pulse pressure

PP= SP-DP

what is perfusion

the RATE of blood flow per given mass of tissue

What is blood flow and perfusion determined by?

Blood pressure and resistance

Chronic resting BP for Hypotension

90/60

Chronic resting bp for Normal

120-135/75

Chronic resting bp of 140/90

Hypertension

Peripheral resistance: Higher Viscosity equals…

lower blood flow

Peripheral resistance: Blood Vessel length:- Higher distance

Lower blood flow

Peripheral resistance: Blood vessel radius:- Lower/smaller radius =

lower blood flow

% of cases/ risk factors and treatment for primary Hypertension

90%, Lifestyle and genetics; weight management, low sodium diet, physical activity

% of cases/risk factors and treatment for secondary Hypertension

(10%) caused by another disease like kidney disease, adrenal gland disorder, or sleep apnea; address other disease, lifestyle modifications

three factors that affect peripheral resistance

Blood Vessel radius, Blood vessel length, Viscosity

Two purposes of vasomotion

Baroreflex and Chemoreflex

What is vasomotion

change in vessel radius+ vasoconstriction and vasodilation

What would the baroreceptors do to the cardiac center and the vasomotor center if there was an INCREASE in blood pressure?

BAroreceptors would signal cardiac center to decrease HR by increasing parasympathetic(vagal) activity

What would the baroreceptors do to the cardiac center and the vasomotor center if there was a DECREASE in blood pressure? 

Vasomotor center would increase vasoconstriction to increase blood pressure

What would the chemoreceptors in the medulla do in response to ê blood flow to brain (ischemia)?

Vasomotor center:

Vasoconstrict to increase BP

Cardiac center:

Send signals to CC to stim sympathetic fiber to increase HR and contraction force

List the factors that lead to EDEMA (fluid accumulation in the body)

• Increased Hydrostatic pressure

• Decrease colloid osmotic pressure

• Blockage of drainage to lymph capillaries