Exam Three: Third Chapter Flashcards
Arteries
carry blood away from heart
Veins
Carry blood back to heart
Capillaries
Connect the smallest arteries to smallest veins
Tunica Interna
lines blood vessels, exposed to blood
repels RBCs and Platelets from adhering
Tunica Media
smooth muscle
Vasomotion, change in diameter for vessels
Tunica Externa
loose connective tissue
anchors blood vessels
3 classes of Arteries (by size)
conducting
distributing
resistance
Aneurysm
weak point in artery or heart wall that ruptures
Carotid sinuses
baroreceptors, in walls of internal carotid artery
Carotid Bodies
chemoreceptors, in branches of internal carotid artery
Aortic Bodies
on wall of aortic arch
Continuous
occurs in most tissue, passage of small solutes
Fenestrated
in organs that require rapid absorption and filtration, passage of small solutes
Sinusoids
liver, bone marrow, and spleen
passage of large solutes
Postcapillary Venules
smallest, receive blood from capillaries
Muscular Venules
receive blood from postcapillary venules
Medium Veins
contain venous valves that stop blood form dropping back
Venous Sinuses
thin walls and NO smooth muscle, NO vasomotion
Large Veins
Smooth muscle in all 3 tunics
Portal System
blood flow through two consecutive capillary networks before returning to the heart
Anastomosis
where two blood vessels meet
Arteriovenous Anastomosis
blood flows directly from artery to vein bypassing capillaries
Venous Anastomosis
Most common, one vein empties directly into another
Arterial Anastomosis
two arteries merge, alternative route for blood supply
blood flow
amount of blood flowing at a given time
Perfusion
flow / given volume or mass of tissue in a given time
Hemodynamic
Physical principles of blood flow
pressure and resistance
Blood Pressure
force blood exerts against vessel wall
Pulse Pressure
difference between systolic and diastolic pressure
MAP
mean pressure one obtains by taking measurements at several intervals during cardiac cycle
Peripheral Resistance
3 variable
Opposition to flow blood encounters in vessels away from the heart
viscosity
vessel length
vessel radius
3 Waves controlling vasomotion
local control
neural control
hormonal control
Mechanisms involved in Capillary Exchange
Diffusion
transytosis
filtration
reabsorption
Edema
main causes
Accumulation of excess fluid tissue
increased capillary filtration
reduced capillary reabsorption
Obstructed lymphatic drainage
Mechanisms of Venous Return
pressure gradient gravity skeletal muscle pump thoracic pump cardiac suction
Low Venous Return
cardiac output is low bc little blood is returning to the heart
Circulatory shock
Cardiac output insufficient to meet body’s metabolic needs
Cardiogenic shock
Inadequate pumping by heart caused by myocardial infarction
Hypovolemic
Most common
Loss of blood volume from trauma, bleeding, ulcers,burns
Instructed venous return
Any object compress a vein and impedes blood flow
Venous pooling
Body has normal total blood volume but too much in lower body
Neurogenic
Loss of vasomotor tone
Septic
Bacterial toxins trigger vasodilation n increase capillary permeability
Anaphylactic shock
Immune reaction that causes histamine release
