Blood Vessels

Question 1

Name the different types of blood vessels and the order in which they appear:

Answer 1

Arteries (conducting/distributing vessels)
Aterioles (resistance vessels) - control BP
capillaries (exchanges vessels)
Venules (collecting vessels)
Veins (capacitance vessels ) storage of blood

Question 2

Name the 3 common layers found in blood vessels and give a basic description:

Answer 2

1) tunica intima - inner most. Direct contact with blood, epithelial lining

2) tunica media - binds inner and outer together

3) tunica externa - protective sheath. Anchor system - blood vessels stay in their position

Question 3

Properties and function of arteries:

Answer 3

Divided in to muscular and elastic arteries
Muscular are more in abundance - same size as a medium vein
Elastic eg aorta or carotid - wider in diameter

Carry blood from heart to body
Thick muscular to elastic tunica media able to accommodate high pressure chances
Able to propel blood onwards
Can even out pressure changes
Can vasodilate and vasoconstrict in response to stimulation
Able to constrict following damage

Question 4

Structure of arteries -

Answer 4

Tunica intima, media and externa
Tunica media made up of smooth muscles
External elastic membrane between media and externa
Larger radius to offer little resistance to blood flow
Have collagen fibres for tensile strength
And elastic fibres to provide elastic recoil
Smooth muscle fibres help regulate flow

Question 5

Properties, structure and function of arterioles -

Answer 5

Smallest branches of arteries
Led into capillaries
Les that 13nm in diameter
Les elastic and collagen fibres
More smooth muscle which helps blood redistribution - have sphincters
Resistance vessels - regulate arteriole BP

Question 6

Properties of capillaries -

Answer 6

Smallest vessels with thin walls
Microscopic capillary networks permeate all active tissues
Only tunica intima
Exchange vessels of cardiovascular system
Materials diffuse between blood and interstitial fluid
Where the arterial and venous systems meet

Question 7

Properties of venules -

Answer 7

Diameter - 1nm
Smallest branches of veins
Allows blood to return from the capillary bed to the venous system
Have the same function as veins
Thin tunica media and thicker tunica externa and intima

Question 8

Properties and function of veins -

Answer 8

Regulate and return blood to the heart (venous return)
Same 3 layers - much thinner walls
Unable to withstand high pressures
Requires skeletal muscle pump to assist venous return
On way valves prevent backflow and aid venous return
Capacitance vessels - large radius and little musculature
Reservoir for blood
Tunica externa is the thickest layer

Question 9

Equation for blood pressure -
Main factors influencing blood pressure are…

Answer 9

Blood pressure = cardiac output * peripheral resistance

Main factors:
Cardiac output
Peripheral resistance (how much pressure is in vessels)
Blood volume

Question 10

Blood pressure values
High -
Pre high -
Normal -

Answer 10

High - systolic 140 or above
Diastolic 90 or above

Pre high - (normally caused by stress or exercise) \
Systolic 121-139 or diastolic between 81-89

Normal - systolic 120 or less AND
Diastolic 80 or less

Question 11

What is hypertension ?
Essential hypertension -
Secondary hypertension -

Risk factors -
Lifestyle factors -

Answer 11

BP greater than 140/90mmHg
Essential - aka primary. Most common. Abnormally high BP not as a result of a medical condition. Caused by obesity, smoking, fam history etc

Secondary - due to a medical condition
Risk factors - genetics, environmental, race, age, gender, pathology

Lifestyle - smoking, diet (salts and fats), alcohol, sedentary lifestyle, obesity, stress

Question 12

Symptoms of hypertension -

Management of hypertension -

Answer 12

Normally only present once its really severe, therefore vessels are already heavily damaged

Management - lifestyle changes
Medication - ACE inhibitors - impact adrenal glands to decrease BP through hormonal regulation
B blockers
Calcium channel blocker and diuretics - SM of blood vessel to promote vasodilation and decrease peripheral resistance

Question 13

Consequences of LT hypertension -

Answer 13

Damages tunica intima, therefore clots may form
Blood vessel damage - arteriosclerosis
Heart attack or heart failure
Kidney failure

Question 14

Pathologies of the arterial walls - (there’s 3)

Answer 14

Arteriosclerosis - hardening and loss of elasticity of large and medium arteries

Arteriolosclerosis - hardening and loss of elasticity of arterioles

Atherosclerosis - hardening of an artery due to the deposition of an atherosclerotic plaque

Question 15

Consequences of artherosclerosis -

Answer 15

Tear in artery wall
Cholesterol deposits and fats deposits therefore reducing diameter of artery

Question 16

Aneurysm -

Answer 16

Excessive localised enlargement of an artery caused by weakness in the arterial wall
Common locations - aortic aneurysm and cerebral aneurysm

Question 17

Deep vein thrombosis -

Answer 17

Thrombus (blood clot) formed in large veins
Risk factors - family history, immobility, recent surgery and obesity
Symptoms - discolouration, pain,, swelling and homan’s test

Question 18

Varicose veins -

Answer 18

Bulging veins
Irregular blood flow due to warped valve and dilated vein
Vein walls are thin and skin will protrude

Question 19

Chronic venous insufficiency-

Answer 19

Symptoms - leg swelling, skin colour and texture changes
Venous ulcers

Causes - faulty valves and varicose veins

Question 20

Constituents of blood
Average how many litres in the body?
What are the two sub groups that make up blood?

Answer 20

4-6 litres in body
Plasma - mainly water, around 55%
Formed elements, around 45%

Question 21

Constituents of blood
What makes up plasma?
What makes up formed elements?

Answer 21

Plasma: plasma proteins 7%
Other solutes 1%
Rest is water as plasma is mainly comprised of water

Formed elements: RBC’s 95.8%
WBC’s 0.1%
Platelets 4%

Question 22

What is plasma?
What proteins make up plasma ?

Answer 22

Similar to, and exchanges fluids with interstitial fluid (fluid between blood vessel and surrounding cells) - extracellular fluid
92% water and small amount of electrolytes
6-8% plasma proteins
- albumin (egg whites)
-fibrinogen (clotting)
-globulins - immunoglobulins

Waste products, nutrients, vitamins, hormones and gases are also present

Question 23

What is the main difference between plasma and interstitial fluid?

Answer 23

Interstitial fluid has no proteins

Question 24

Formed elements:
1) red blood cells -

Answer 24

Disc shaped - thin in middle and thicker at edge (bioconcave disc shaped)
Lack nuclei, therefore cannot reproduce
Lack mitochondria, therefore rely on energy from other sources
And lack ribosomes
Contain haemoglobin - each carry 4x 02 molecules
Go through apoptosis

Question 25

Formed elements:
2) white blood cells -

Answer 25

Mainly found in lymphatic tissue/ connective tissue proper
Role in inflammation and the immune response
Have nuclei and other organelles
Less than 1% in blood

Question 26

Formed elements
Type of WBC’s - granulocytes:

Answer 26

Nucleus will show under microscope
- neutrophils - phagocytosis of bacteria/pus formed
- eosinophils - allergic reactions, defence against parasites, control inflammation
- basophils - allergic reactions - inflammatory reactions

All are non-specific immunity

Question 27

Formed elements - types of WBC’s
Agranulocytes -

Answer 27

Nucleus will not show up under a microscope
- lymphocytes - immunity, T and B cells. Specific immunity
- monocytes - phagocytosis of large particle pathogens. Attract immune system cells
Non-specific immunity