Blood Vessel

Question 1

Blood Vessel layers

Answer 1

Tunica Interna: innermost layer
Tunica Media: Middle layer, smooth muscle and elastic fibers
Tunica Externa: outtermost layer

Question 2

Blood Vessel vs. Artery

Answer 2

Artery has large tunica media, smooth muscle,
Artery has more elastic layers
Veins tend to have a larger lumen and main structural feature is the valve, prevents backward flow of blood

Question 3

Cappilaries

Answer 3

One cell thick, endothelium
Surrounded by basement membrane.
Tight and continuous or have holes in them, all depends on where they’re on the body

Question 4

Arteries

Answer 4

Carry blood away from the heart to the tissues
walls are elastic, allowing them to absorb pressure
Because of smooth muscle, they can regulate in diameter( vasoconstriction)

Question 5

Types of ateries

Answer 5

Elastic Arteries

Muscular arteries

Question 6

Anastomoses

Answer 6

Where branches of arteries fuse and move out in different directions
supply the same body region

Question 7

Capillaries

Answer 7

Smallest blood vessels connect arterial outflow and venous return
One cell thick & composed of basement membrane
permit the exchange of nutrients
Found everywhere
Microscopic vessels that connect arterioles and venues
Tunica media and tunica externa

Question 8

Types of capillaries

Answer 8

Three types
Continuous: tight junctions but you can move fluids in between cells, endothelial cells
Fenestrated: Found in kidney and parts of DT, allows some proteins and larger molecules to move out of the blood vessels. have fenestrations or pores
Sinusoid:Wider and more winding, Allow for large plasma proteins to move in and out and some cells too, found in liver and spleen primarily

Question 9

Veins

Answer 9

Veins have little smooth muscle, very thin walls
Have valves
same 3 layers: but
Tunica internal thinner than arteries and with little smooth muscle
and the tunica externa is the thickest layer
Valves fold on tunica international forming cusps

Question 10

Blood distribution

Answer 10

Largest portion of the blood is in the veins and venues,aka blood resiviors. 64%
Heart 7%
Pulmonary 9%
Capillaries 7%
arteries and arterioles 13%
Venoconstruction reduces volume of blood in reservoirs and allows greater blood volume to flow where needed

Question 11

Capillary exchange

Answer 11

The movement of substances between blood and interstitial fluid
Substances cross capillary walls by :
Diffusion
Transcytosis
Bulk flow: movement of fluid under pressure

Question 12

Bulk flow

Answer 12

Passive process in which large number of ions molecules or particles in a fluid move together in the same direction
Based on pressure gradient
More important for regulation of relative volumes of blood and interstitial fluid

Question 13

Filtration

Answer 13

Pressure driven movement of fluid and solutes from blood capillaries into interstitial fluid

Question 14

Reabsorbtion

Answer 14

Pressure driven movement of fluid and solutes from interstitial fluid into capillaries

Question 15

blood flow

Answer 15

Volume of blood flowing through any tissue at a given time

Question 16

What are the five main types of blood vessels

Answer 16

Arteries
arterioles
capillaries
venules 
veins

Question 17

Tunica interna

Answer 17

Inner lining in direct contact of blood

Active role in vessel related activities

Question 18

Tunica media

Answer 18

Muscular and connective tissue layer

Smooth muscle regulates diameter of lumen

Question 19

Tunica externa

Answer 19

Elastic and collagen fibers

Helps anchor vessel to surrounding tissue

Question 20

Elastic arteries

Answer 20

Largest artery’s
largest diameter but walls relatively thin
function as pressure reservoir
help propel blood forward while ventricles relaxing
also known as conducting arteries a.k.a. conduct blood to medium size arteries

Question 21

Muscular arteries

Answer 21

Tunica media contains more smooth muscle and fewer elastic fibers than elastic arteries
walls relatively thick
Capable of great vasoconstriction to adjust rate of blood flow
Also called disturbing arteries

Question 22

Portal vein

Answer 22

Blood passes through second capillary bed

Hepatic or hypophyseal

Question 23

Venules

Answer 23

Thinner walls then arterial counterparts
post capillary venue- smallest manual
Muscular venules have thicker walls with one or more layers of smooth muscle

Question 24

Diffusion

Answer 24

Most important method Substances move down their concentration gradient Substances can cross capillary wall through intracellular clefts fenestrations or through endothelial cells
Post plasma proteins cannot cross except sinusoids, because of blood brain barrier which limits diffusion

Question 25

Transcytosis

Answer 25

Small quantity of material Substances in blood plasma become enclosed Important mainly for large lipid insoluble molecules that cannot cross capillary walls any other way

Question 26

Net filtration pressure

Answer 26

The balance of two pressures Blood hydrostatic pressure and interstitial fluid osmotic pressure Subtracted by Blood call Lloyd osmotic pressure and interstitial fluid hydrostatic pressure

Question 27

Starlings law

Answer 27

Nearly as much reabsorbed as filtered

Question 28

What are the factors that affect blood flow

Answer 28

A flow is the volume of blood that flows through any tissue in a given period of time Total blood flow is cardiac output Cardiac output depends on pressure differences and resistance to blood flow in specific blood vessels

Question 29

What is blood pressure

Answer 29

Contraction of ventricles generates blood pressure Systolic BP is the highest pressure attained in arteries during systole Diastolic BP is the lowest arterial pressure during distole Pressure falls progressively with distance from left ventricle also depends on total volume of blood

Question 30

Vascular resistance

Answer 30

Opposition to blood flow due to friction between blood and walls of blood vessels Depends on: size of lumen blood viscosity and total blood vessel length

Question 31

Venous return

Answer 31

Volume of blood flowing back to the heart through systemic veins occurs due to pressure generated by construction of left ventricle small pressure difference from venue to right ventricle

Question 32

Skeletal muscle pump

Answer 32

Milks blood in One Direction due to valves

Question 33

Respiratory pump

Answer 33

Occurs due to pressure changes in thoracic and abdominal cavities

Question 34

Velocity of blood flow

Answer 34

Is the speed in cm/sec in inversely related to cross-sectional area it's at its lowest when total cross sectional area is greatest But the flow become slower for their from the heart it's the slowest in the capillaries Aids in exchange

Question 35

Circulation time

Answer 35

The time required for a drop of blood to pass from right atrium through pulmonary and systemic circulation and back to right atrium

Question 36

Control of blood pressure and blood flow

Answer 36

Interconnected negative feedback systems control blood pressure by adjusting heart rate stroke volume systemic vascular resistance and blood volume Some act faster than others Some shorter or longer term

Question 37

The role of cardiovascular center

Answer 37

Occurs in the medulla oblongata Helps regulate heart rate and stroke volume also controls neural. hormona,l and local negative feedback systems that regulate blood pressure and blood flow to specific tissues Happens when groups of neurons regulate heart rate contraction of ventricles and blood vessel diameter Receives input from both higher brain regions and sensory receptors

Question 38

The three main types of sensory receptors

Answer 38

Proprioceptors: another movement of joints and muscles to provide input during physical activity Baroreceptors: that are pressure changes and stretch in blood vessel walls Chemoreceptors: Monitor concentration of various chemicals in the blood

Question 39

Neural regulation of blood pressure

Answer 39

Negative feedback loops from two types of reflexes Baroreceptor reflexes and Chemoreceptor reflexes

Question 40

Baroreceptor reflexes in neural regulation

Answer 40

Pressure sensitive receptors in internal carotid arteries and other large arteries in neck and chest Occurs when blood pressure falls and baroreceptors are stretched less slower rate of impulses to CV CV decreases parasympathetic stimulation and increases sympathetic stimulation

Question 41

Chemo receptor reflexes in neural regulation

Answer 41

Receptors located close to baroreceptors of carotid sinus and aortic arch They detect hypoxia, hyper Capnia, acidosis and send signals to CV CV then increases sympathetic stimulation to arteries and veins producing vasoconstriction and an increase in blood pressure Receptors also provide input to respiratory center to adjust breathing rate

Question 42

The hormonal regulation of blood pressure: Renin angiotensin aldosterone system

Answer 42

In an in angiotensin converting enzyme acts on substrates to produce active hormone angiotensin two This raises BP by vasoconstriction and secretion of aldosterone

Question 43

The hormonal regulation of blood pressure: epinephrine and norepinephrine

Answer 43

Renal medulla releases in response to sympathetic stimulation increase cardiac output by increasing rate in force of heart contractions

Question 44

The hormonal regulation of blood pressure: antidiuretic hormone or vasopressin

Answer 44

Produced by hypothalamus released by posterior pituitary response to dehydration or increased blood volume causes vasoconstriction which releases blood pressure

Question 45

Atrial natriuretic peptide

Answer 45

Released by the cells of atria Lowers blood pressure by causing vasodilation and promoting loss of salt and water in urine reduces blood volume

Question 46

Auto regulation of blood pressure

Answer 46

Ability of tissue to automatically adjust its blood flow to match metabolic demand Also controls regional blood flow in the brain during different mental and physical activities two types of stimuli: physical a.k.a. temperature changes, myogenic responds and vasodilating/vasoconstricting chemicals alter blood vessel diameter

Question 47

Circulation

Answer 47

Important difference between pulmonary and systemic circulation in autoregulatory response - systemic blood vessel walls dilate in response to low O2 to increase O2 delivery - walls of pulmonary blood vessels constrict under low O2 to ensure most blood flows to better ventilated areas of the lungs