test 2 review Flashcards
(220 cards)
the job of arteries is to transport ? blood ? ? the heart
oxygenated, away from
arteries branch into ? which control blood ? and ? thru the body
arterioles, flow, pressure
veins carry ? blood ? the heart
deoxygenated, toward
? are tiny blood vessels with thin walls, primarily functioning to exchange nutrients, ?, and ? products between the bloodstream and surrounding tissues by allowing substances to diffuse through their single layer of endothelial cells
capillaries, oxygen, wastes
? arteries are
Act as ? reservoirs by expanding during systole and recoiling during diastole. w/o pressure smoothing effects of elastic arteries, walls of arteries throughout body would experience higher ?
elastic, pressure, BP
? Arteries
Also called distributing arteries because they deliver blood to body organs
Account for most of named arteries
Have thickest tunica ? with more smooth muscle
Active in ? and ? to shunt blood to most needed areas
muscular, media, vasoconstriction, vasodilation
The ? system functions primarily to drain excess fluid from ? throughout the body, returning it to the bloodstream, while also playing a crucial role in the ? system by filtering out harmful substances and producing WBC’s to fight infection
lymphatic, tissues, immune
Tunica ?
? layer that is in “intimate” contact with blood
Contains endothelium, simple squamous epithelium, which lines lumen of all vessels and is continuous with endocardium
Tunica intima is flat and slick surface to reduce ?
intima, innermost, friction
Tunica ?
middle layer composed mostly of circular smooth muscle and sheets of elastic CT
Sympathetic vasomotor nerve fibers innervate smooth muscle of tunica media controlling ? or ?.
maintains BP and circulation
↑ Sympathetic stimulation ↑ constriction (vasoconstriction)
↓ Sympathetic stimulation ↓ constriction and BV dilates (vasodilation)
media, vasoconstriction, vasodilation
Tunica ?
outer layer of wall
Also called tunica ?
Composed mostly of loose collagen fibers that ? and reinforce BV wall
Tunica externa infiltrated with
1. Sympathetic Nerve fibers
2. Lymphatic vessels
3. Elastic CT
4. Vasa ? = BVs to nourish BV wall; system of tiny blood vessels to nourish outermost external layer of BV wall; whereas, the lumen of BV obtains nutrients directly from blood in lumen
externa, adventitia, protect, vasorum
? capillaries are most common
Abundant in ?, muscles, lungs, and ?
Least permeable but have intercellular ? to ↑ permeability
these capillaries in the brain form the blood brain barrier because they lack intercellular clefts and are totally enclosed with continuous tight junctions
continuous, skin, CNS, clefts
? capillaries
Have large fenestrations or pores that ↑ permeability
Fenestrations plus intercellular clefts ↑ permeability
Found in areas involved in filtration as in the ?, absorption as in ?, and in endocrine tissue for hormone ?
Fenestrations are “Swiss cheese-like holes” that tunnel through endothelial cells for ↑ permeability
fenestrated, kidneys, intestines, secretion
? capillaries
Most ? and occur in limited locations
Found only in the liver, bone marrow, and ?
these capillaries have large intercellular clefts, fenestrations, few tight junctions, and
larger lumens. These characteristics allow large molecules and cells (RBCs, WBCs, Platelets) to
pass across wall
In the Liver and Spleen, Sinusoidal capillaries are lined with ? to capture and
destroy foreign invaders
sinusoidal, permeable, spleen, macrophages
? venules drain blood from the capillaries and allow for diffusion of nutrients to the tissues
postcapillary
? are blood reservoirs that return blood toward the heart
Veins form when ? converge and BVs have all three tunics
Veins have
1. Thinner walls than arteries
2. Larger lumens than arteries
3. Lower BP than arteries
Veins are called Capacitance Vessels or Blood Reservoirs
Their large lumen makes veins good storage vessels
Veins have
Lower ? than in arteries
The large-diameter lumens offer little resistance; ↑ lumen diameter ↓ resistance
Veins have structural adaptation to ensure blood returns to heart at the same rate that the
blood is pumped out of heart
Veins have ? that prevent ? of blood and compensate for low venous BP
Venous valves are most abundant in veins of ? and absent in thoracic / ? veins
veins, venules, BP, valves, backflow, limbs, abdominal
What are examples of Venous Sinuses?
1. ? sinus of the heart
2. Dural sinuses of the brain
What are characteristics of Venous Sinuses?
? veins with extremely ? walls
Composed only of ?
Supported by ? that surround them rather than additional tunics
Dural Venous Sinuses are supported by dura mater and receive CSF
coronary, flattened, thin, endothelium, tissues
What is Blood flow?
? of blood flowing through a ? or an ?
Blood flow is the entire circulation in given period measured in ml/min
Blood flow under resting conditions is relatively constant. Blood flow (does/does not) vary based on needs
volume, vessel, organ, does
What is Blood Pressure (BP)?
BP = ? of blood exerted on wall of BV
BP is Ventricular ? pressure/Ventricular ? pressure
1. Normal BP of adult = ?
2. BP newborn baby = ?
3. Hypertension = ?
force, systolic, diastolic, 120/80, 90/55, 140/90
What is Resistance?
? to blood flow
Measurement of the amount of ? blood encounters in BV
Most friction is encountered in systemic circulation, we call peripheral Resistance
Three important Sources of Resistance
1. Blood ?
2. Total blood vessel ?
3. Blood vessel ?
opposition, friction, viscosity, length, diameter
What is Blood Viscosity?
? or “?” of blood due to formed elements and plasma proteins
Blood is more viscous than water, so blood flows ? than H₂O under same conditions
thickness, stickiness, slower
How does Blood Viscosity Affect Resistance?
↑ Blood Viscosity ↑Resistance: ? for molecules to be able to slide past each other and more difficult to keep blood moving (Think milkshake vs. water)
↑ Blood Viscosity ↑ Resistance ↓ ? ?
? = ↑ viscosity ↑ resistance ↓ blood flow
↓ RBC count = ? ↓ viscosity ↓ resistance ↑ blood flow
harder, blood flow, polycythemia, anemia
How does Blood Vessel Length Effect Resistance?
Longer the blood vessel length, more ? encountered, greater the ? encountered
↑ BV length ↑ Resistance ↓ Blood Flow (easier to drink through a shorter straw)
Infant’s BV lengthen as grow into adulthood so R and BP increases
Why does BP ↑ with age? ↑ BV length, ↑ R, ↑ BP
Why does obesity ↑ BP? ↑ ? ? to service adipose tissue ↑ R, ↑ BP
friction, resistance, BV length
How does Blood Vessel Lumen Diameter Effect Resistance?
Blood vessel diameter has greatest influence on resistance
1. Constrict BV… ? Resistance
2. Dilate BV… ? Resistance (That’s why a wider straw is easier to drink from)
increased, decreased
Fluid close to BV wall is slowed by ? and blood moves more slowly along the wall than in
middle of tube
Fluid in center of the BV lumen does not encounter ? of the BV wall and moves
freely and ?. This is called ? flow.
The smaller the tube diameter, the greater the friction and the greater the ?
friction, friction, faster, laminar, resistance