Blood Vessel Flashcards

1
Q

Blood Vessel layers

A

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

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2
Q

Blood Vessel vs. Artery

A

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

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3
Q

Cappilaries

A

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

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4
Q

Arteries

A

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)

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5
Q

Types of ateries

A

Elastic Arteries

Muscular arteries

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6
Q

Anastomoses

A

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

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7
Q

Capillaries

A

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

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8
Q

Types of capillaries

A

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

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9
Q

Veins

A

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

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10
Q

Blood distribution

A

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

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11
Q

Capillary exchange

A

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

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12
Q

Bulk flow

A

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

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13
Q

Filtration

A

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

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14
Q

Reabsorbtion

A

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

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15
Q

blood flow

A

Volume of blood flowing through any tissue at a given time

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16
Q

What are the five main types of blood vessels

A
Arteries
arterioles
capillaries
venules 
veins
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17
Q

Tunica interna

A

Inner lining in direct contact of blood

Active role in vessel related activities

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18
Q

Tunica media

A

Muscular and connective tissue layer

Smooth muscle regulates diameter of lumen

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19
Q

Tunica externa

A

Elastic and collagen fibers

Helps anchor vessel to surrounding tissue

20
Q

Elastic arteries

A

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

21
Q

Muscular arteries

A

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

22
Q

Portal vein

A

Blood passes through second capillary bed

Hepatic or hypophyseal

23
Q

Venules

A

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

24
Q

Diffusion

A

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

25
Q

Transcytosis

A

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

26
Q

Net filtration pressure

A

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

27
Q

Starlings law

A

Nearly as much reabsorbed as filtered

28
Q

What are the factors that affect blood flow

A

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

29
Q

What is blood pressure

A

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

30
Q

Vascular resistance

A

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

31
Q

Venous return

A

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

32
Q

Skeletal muscle pump

A

Milks blood in One Direction due to valves

33
Q

Respiratory pump

A

Occurs due to pressure changes in thoracic and abdominal cavities

34
Q

Velocity of blood flow

A

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

35
Q

Circulation time

A

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

36
Q

Control of blood pressure and blood flow

A

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

37
Q

The role of cardiovascular center

A

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

38
Q

The three main types of sensory receptors

A

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

39
Q

Neural regulation of blood pressure

A

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

40
Q

Baroreceptor reflexes in neural regulation

A

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

41
Q

Chemo receptor reflexes in neural regulation

A

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

42
Q

The hormonal regulation of blood pressure: Renin angiotensin aldosterone system

A

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

43
Q

The hormonal regulation of blood pressure: epinephrine and norepinephrine

A

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

44
Q

The hormonal regulation of blood pressure: antidiuretic hormone or vasopressin

A

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

45
Q

Atrial natriuretic peptide

A

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

46
Q

Auto regulation of blood pressure

A

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

47
Q

Circulation

A

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