Chapter 20 Flashcards
vessels are composed of 3 layers called
tunics
name the 3 tunics
tunica intima
tunica media
tunica externa
lumen
space inside each vessel
the endothelium of tunica intima is
simple squamous epithelium
in which layer of tunica are the smooth muscle cells with elastic fibers?
tunica media
function of tunica externa
protection
tunica media is thicker in
arteries
tunica externa is thicker in
veins
which vessel have valves?
artery or vein
vein
the lumen is narrowed in
arteries or veins
arteries
which vessel has less elastic and collagen fibers?
veins
what happen if the lumen diameter of an artery decrease?
elastic and collagen fibers decrease
smooth muscle cells increase
types of arteries
elastic or conducting
muscular
arterioles
e.g of elastic arteries
aorta, pulmonary trunk, common carotid, common iliac
muscular arteries distribute blood to _____ body regions
specific
muscular arteries allows more:
vasoconstriction and vasodilatation
name the two elastic layers in muscular arteries
internal elastic layer
external elastic layer
e.g. of muscular arteries
brachial artery, coronary arteries
types of capillaries
continuous
fenestrated
sinusoid
continuous capillaries have ______ allowing small particles to pass through
intercellular clefts
where are the continuous capillaries found?
muscle, skin, lungs, CNS
fenestrated capillaries have ______ allowing the movements of smaller plasma proteins
fenestrations (pores)
where are the fenestrated capillaries found?
intestine
kidney
capillary beds are bed by
metarteriole
distal part of a metarteriole
thoroughfare channel
vasomotion
cycle of contracting and relaxing of precapillary sphincters
pathways of blood vessels
simple
alternative:
arterial anastomosis
venous anastomosis
arteriovenous anastomosis
portal system
sequence of portal system pathway
artery
capillary bed
portal vein
capillary bed
vein
blood flow is fastest in _____ arteries
elastic
bulk flow
fluid flow down gradient pressure
filtration
fluid OUT of blood
occurs in arterial end
reabsorption
fluid back into blood
occurs in venous end
chemical that alter blood flow
vasoactive chemicals
vasodilators
dilate arterioles
relax sphincters
increase flow into capillary beds
vasoconstrictors
constrict arterioles
contraction of sphincters
decrease flow into capillary beds
blood pressure
force against the vessel wall
blood pressure in higher in _____ and lower in ______
arteries, veins
systolic pressure
pressure when the ventricle contracts
120 mmHg
diastolic pressure
pressure when the ventricle relax
80mmHg
pulse
same as heartbeat
formula for pulse pressure
systolic - diastolic pressure
men arterial presssure formula
systolic pressure + 1/3 pulse pressure
venous return depends on
skeletal muscle pump
respiratory pump
resistance is affected by
viscosity
lumen length
lumen size
blood pressure depends on
cardiac output
resistance
blood volume
two parts of cardiovascular center
cardio center
vasomotor center
cardiac center
influences blood pressure by the cardiac output
vasomotor center
influences blood pressure by vessel diameter (resistance)
origin of sympathetic pathways
cardioacceleratoy
increases cardiac output and blood pressure
cardioinhibitory
decreases cardiac output and blood pressure
baroreceptors
receptors for blood pressure
chemoreceptors reflexes stimules
high CO2
low pH
low O2
high blood pressure
location of chemoreceptors
aortic arch uses via vagus nerve
carotid bodies uses via glossopharyngeal nerve
angiotensin II _____ blood pressure
increases or decreases
increases
where is inactive angiotensinogen made?
liver
renin is released by the
kidney in response to low blood pressure
renin converts ______ to _____
angiotensinogen, angiotensin I
Angiotensin I is converted to angiotensin II by
angiotensin-converting enzyme (ACE) located in the lungs
how does angiotensin II raise blood pressure?
vasoconstriction
stimulates thirst center
decreases urine formation
stimulation of release of aldosterone and antidiuretic hormone (vasopressin)
function of atrial natriuretic peptide (ANP)
decreases blood pressure
vasodilation
increases urine output
internal thoracic artery becomes
superior epigastric artery
internal jugular vein becomes
brachiocephalic vein
hemiazygos and accessory hemiazygos veins are in the _____ side
right
azygos are in the _____ side
left
celiac trunk branches into
left gastric artery
splenic artery
common hepatic artery: hepatic artery proper, gastroduodenal artery
great saphenous vein originates in _____ ankle and drains into _____ vein
medial, femoral
small saphenous vein originates in _____ ankle and drains into the _____ vein
lateral, plopiteal
Exchange processes that occur in capillaries include ______
diffusion
bulk flow
vesicular transport
The arteries that supply the mammary gland and anterior thoracic wall are the
internal thoracic arteries
The bronchial arteries that supply the bronchi, bronchioles, and connective tissue of the lungs emerge as tiny branches from the anterior wall of the ______.
descending thoracic aorta
The left and right bronchial veins drain into the ______.
azygos venous system
Which paired arterial branches emerge from the sides of the descending abdominal aorta?
middle suprarenal arteries
gonadal arteries
renal arteries
In general, as an artery’s diameter decreases, the artery walls show
+ smooth muscle
- elastic fibers
Blood velocity is measured in _________ and is generally _________ related to total cross-sectional area of blood vessels.
cm/s
inversely