Lab 2 Flashcards
How much blood do we pump in a minute?
Same for all humans 4.5-5.5 L
Are the following large, medium, or small in diameter size?
- Vein
- Venules
- Capillary
- Artery
- Arteriole
- Vein: Large
- Venules: Medium
- Capillary: Small
- Artery: Large
- Arteriole: Medium
What is an example of vasodilation? Vasoconstriction?
Vasodilation: A because there is an increase in diameter
Vasoconstriction: C because there is a decrease in diameter
Lable the following tunic layers of a blood vessel
- (1) Tunica Interna -> Thin and slick to reduce friction and smooth flow
- (2) Endothelium
- (3) Basement membrane -> consists of extracellular matrix proteins
- (4) Internal Elastic Lamina
- (5) Tunica Media -> Vasoconstriction (blood pressure controls vasodilation and vasoconstriction)
- (6) Smooth muscle
- (7) External Elastic Lamina
- (8) Tunica Externa -> Structure and Support
Discuss Arteries vs. Veins and their correct order in the body’s systems
- Elastic Arteries (large)
- High pressure reservoir function
- Stretchy
- Muscular Arteries (medium)
- Thicker smooth muscle
- Distribute blood grossly
- Less elastic fibers, but both laminae still present
- Arterioles (small)
- No external elastic laminae
- Distribute blood finely
- Capillaries
- Venules
- No internal elastic lamina in venules (but have external)
- Very little amount of muscle
- Veins (don’t really constrict)
- Low pressure reservoir
- No elastic laminae
- Thinner walls overall
- Much larger lumens
- Thunica externia is slightly elastic
- Valves!!! Used to prevent backflow because blood goes against gravity and also veins wouldn’t funtion correctly without them
What are the features of a capillary? And what is their importance?
- Fenestration-tiny holes
- Intracellular Cleft-Holes between cells
- Tight junctions
- Vesicles for transcytosis-invaginations of the membrane
- These are important because they allow the capillaries to exchange nutrients and waste
What are three different types of capillaries?
- Continuous
- Fenestrated
- Sinusoid/Discontinued
What are some features of cardiac muscle histology?
- Cellular features
- Sarcomeres
- Branching
- Intercalated Disks
- Striations
What is the purpose of valves in veins?
They prevent back up. Varicose veins are a good example of this when blood backs up and pools in the vein becoming insufficient and large
Beside your heart, what else pumps blood?
- Muscle Pump
- Respiratory Pump
- When you breathe in it pulls on your thoracic cavity and the heart stretched so more blood can come in and then when it goes back to normal shape it pumps the blood out
- Counterflow
What is pressure? blood pressure? how do we measure blood pressure? what are we actually measuring when we measure blood pressure?
- Pressure is a force distributed over an area
- Blood pressure is pressure pushing on the blood vessel walls
- We measure blood pressure with a sphygmomanometer which is a blood pressure cuff
- When we measure blood pressure we are actually measuring korotkoff sounds
Summarize blood pressure measuring
- At the third step, systole has a turbulant flow
- Fourth step, you’re listening for lack of sound for distole
What does systolic and diastolic pressure mean?
Systolic: arterial pressure when heart is contracting
Diastolic: pressure while heart reflexes (between contractions)
Increasing blood vessel diameter (vasodilation) ___________ resistance and __________ BP
Increasing blood vessel diameter (vasodilation) decreases resistance and lowers BP
Decreasing blood vessel diameter (vasoconstriction) ________ resistance and ________ BP
Decreasing blood vessel diameter (vasoconstriction) increases resistance and raises BP
What is the average blood pressure?
120/80
What is hypertension?
- High blood pressure
- defined as stage 1 hypertension with BP <130/80 (mmHg), htough elevated BP is considered anything above 120/80
- A public health issue due to increasing the risk of heart/cardiovascular diseases (#1 killer in US)
Who is at risk for hypertension?
High risk groups: age groups 40-59 (33.2%), 60 and over (63.1%)
What are symptoms of Hypertension? Does it have symptoms?
Hypertension can be asymptomatic hence being called the “Silent Killer”
- Signs and symptoms includes
- Headache
- Shortness of breath
- Fatigue
- Irritability
- Chest pain
- Vision problems
What are hypertension treatments?
- Lifestyle changes (incorporating exercise, consuming less salt)
- Medications (diuretics, ACE ingibitors, beta blockers)
What are causes and risk factors of primary and secondary hypertension?
What are hypertension complications?
- Uncontrolled hypertension can increase the risk of heart attack (myocardial infarctiob) and stroke due to atherosclerosis
- Damages blood vessels
- Aneurysm (bulging blood vessels)
- Vision loss
- Cognitive impairment
- Heart failure
What is hypotension?
- Low blood pressure
- Defined as BP <90/60 (mmHg)