Cardiovascular System (Blood Vessels) Flashcards
is the only part of a vessel that is in contact with blood
Tunica intima
Tunica intima is made of ________ called ______ which is continuous with the endocardium of the heart
simple squamous epithelium called endothelium
controls the diameter of the vessel’s lumen
tunica media
involved in the maintenance of normal blood pressure
tunica media
Tunica media is made of ______ and ____
smooth muscle and elastic connective tissue
When the tunica media relaxes, its lumen diameter is high which causes?
vasodilation and decreases the blood pressure
is important to prevent the rupture or bursting of the larger arteries that carry blood under high pressure
Tunica externa
carry blood from the heart to the capillaries
arteries
where the exchange of materials between the blood & tissues take place
capillaries
have higher pressures since they directly arise from the heart
arteries
the pressure generated by the pumping action of the heart
hydrostatic pressure
TRUE OR FALSE: the hydrostatic pressure increases as it gets farther from the heart
FALSE
arteries, as they branch out usually ____ or connect with one another to provide alternate routes for the flow of blood
anastomose
Flow of blood
collateral circulation
the artery which has the highest hydrostatic pressure
aorta
where all the large, medium & small arteries of the systemic circulation arise from
aorta
smallest, almost microscopic, arteries that branch off the small arteries into capillaries
arterioles
its smooth muscles control the amount of blood reaching the capillaries
arterioles
are thin-walled, microscopic vessels (5-10 μm wide) which connect the arterioles & venules (smallest veins)
capillaries
they surround almost every cell in the body, and are highly metabolic
capillaries are more numerous in _____
muscles, liver, kidneys, and nervous system
capillaries are fewer in the _____
tendons and ligaments
capillaries are absent in
covering and lining epithelia, cornea, and cartilage
capillaries are made up of
endothelium
their thin walls permit exchange of substances between blood & interstitial fluid
capillaries
TRUE OR FALSE: the rate of blood flow in
capillaries is fast to permit sufficient time for the exchange of substances
False
refers to the movement of substances between blood & interstitial fluid w/c occurs mostly via diffusion & filtration
capillary exchange
since the O2 level of blood is high, it diffuses from blood to tissue; since CO2 concentration in tissues is high, it moves from tissues to blood
diffusion
occurs in the arterial end of a capillary; the high hydrostatic pressure pushes plasma & dissolved nutrients (glucose, amino acids & vitamins) out of the capillaries & into interstitial fluid
filtration
follows filtration; occurs in the venous end of a capillary; since there is low hydrostatic pressure in this area, the high colloid osmotic pressure exerted by albumin in the blood pulls back most of the pushed fluid from the tissues into the capillaries
reabsorption
What capillary end has higher hydrostatic pressure?
arterial end
the rest of the excess interstitial fluid is absorbed by the
lymphatic system
What do the arterial end of the capillary pushes out to the interstitial fluid?
plasma and dissolved nutrients (glucose, amino acids, and vitamins)
What do the venous end of capillary pushes in?
interstitial fluid or tissue fluid
is swelling caused by too much fluid trapped in the body’s tissues.
edema
carry blood from capillaries back to the heart
veins
TRUE OR FALSE: Veins have thicker tunica media and externa than arteries.
FALSE
What do the tunica intima of veins contain?
valves
when the blood moves toward the heart, their valves will?
open
caused by increased blood pressure in the veins
varicose veins
they are blood reservoirs
veins
when the need for blood arises (e.g. hemorrhage, exercise), the tunica media of the veins ____ to increase venous return to the heart
constrict
small, almost microscopic, veins that carry blood away from the capillaries toward the heart
venules
the largest of all the veins w/c return blood back to the heart
venae cavae
smooth muscles in the tunica media constricts to promote
venous return
the veins _____prevents backflow of blood and promote venous return against gravity
valves
What are the three Mechanisms that promote venous return?
- Vasoconstriction and Venous Valves
- Skeletal muscle pump
- Respiratory Pump
contraction of the skeletal muscles surrounding the veins causes “milking” of the veins between these muscles which squeeze blood towards the heart
skeletal muscle pump
affects veins that pass through the
thoracic cavity
Respiratory pump
this mechanism is based on the alternating compression & decompression of veins
respiratory pump
Explain the mechanism of respiratory pump during inhalation.
during inhalation, the diaphragm moves downward causing a low intrathoracic pressure & high abdominal pressure; this causes the veins in the abdominal cavity to be compressed thus allowing blood to flow into the decompressed thoracic veins
also called hydrostatic pressure
blood pressure
How is blood pressure measured?
millimeters mercury
What is the normal blood pressure in young adult during systole and diastole?
110 mmHg (systole)
70 mmHg (diastole)
What is the blood pressure at the venous ends of the capillaries?
12 to 15 mmHg
When the blood returns to the ____ the blood pressure reaches 0 mmHg
right atrium
What is the normal range for systolic BP in adults
90-120 mmHg
What is the normal range for diastolic BP in adults?
60-80 mmHg
refers to a systemic BP consistently higher than the normal range
hypertension
a lower than normal systemic BP
hypotension
BP depends greatly on the blood volume or the cardiac output w/c is normally about 5 liters
blood volume
What are the determinants of Blood Pressure?
- blood volume
- Pumping Action of the Heart
- Blood Viscosity
- Peripheral Resistance
the more are the formed elements, the greater the blood viscosity
Blood Viscosity
refers to the opposition to blood flow due to friction bet. blood & the walls of the blood vessels
Peripheral Resistance
enzyme released by kidneys to the bloodstream in responseBP,
renin
a plasma protein synthesized by the liver which splits to become angiotensin I in the presence of renin in the blood
angiotensinogen
released by the lungs; converts angiotensin I to angiotensin II
angiotensin-converting enzyme (ACE)
Angiotensin II has two actions what are these?
vasoconstriction and release of aldosterone
hormone released by the zona glomerulosa of the adrenal cortex; causes Na+ reabsorption & blood volume
aldosterone
Differentiate Aldosterone from Antidiuretic hormone
Aldosterone increases sodium reabsorption in the kidney while antidiuretic hormone increases water reabsorption
a continuous vessel divided into sections that are named anatomically: ascending aorta, aortic arch, thoracic aorta, & abdominal aorta
aorta
first division of the aorta w/c curves upward from the left ventricle of the heart
ascending aorta
the only branches of the ascending aorta; they supply the myocardium of the heart
right and left coronary arteries
second division of the aorta w/c arches to the left from the ascending aorta
aortic arch
what are the three branches of aortic arch?
brachiocephalic artery
left common carotid artery
left subclavian artery
Aortic arch supplies what part of the body?
head, neck, and upper extremities
where the baroreceptors & chemoreceptors that help regulate BP could be found
aortic arch
third division of the aorta w/c plunges downward from the aortic arch through the thorax following the spine
thoracic aorta
what part of the bodies do the thoracic aorta supply blood to?
skin, muscles and bones of the trunk, diaphragm, and esophagus
last division of the aorta w/c passes through the diaphragm from the thoracic aorta into the abdominopelvic cavity
abdominal aorta
What parts of the body does the abdominal aorta supply blood to?
abdominopelvic cavity and lower extremities
are the terminal branches of the abdominal aorta w/c supply blood to the lower extremities
right and left common iliac arteries
where the temporal pulse could be
palpated
superficial temporal artery
where the carotid pulse could be palpated
common carotid artery
should not be palpated together as doing so may interrupt blood flow to the brain
common carotid artery
where the brachial pulse could be palpated
brachial artery
commonly used for assessing blood pressure
brachial artery
where the radial pulse could be palpated
radial artery
commonly used for assessing pulse rate & for withdrawing an arterial blood specimen
radial artery
where the femoral pulse could be palpated
femoral artery
commonly used entry site for cardiac catheterization to gain access to the coronary arteries
femoral artery
where the popliteal pulse could be palpated
popliteal artery
where the posterior tibial pulse could be palpated ( just behind the medial malleolus)
posterior tibial artery
where the dorsalis pedis pulse could be palpated ( just on top of the foot over the 1st metatarsal & medial cuneiform)
Dorsalis pedis artery
returns blood from the head, neck, thorax & upper limbs to the right atrium of the heart
superior vena cava
returns blood from the abdomen, pelvis & lower limbs to the right atrium
inferior vena cava
a superficial vein that descends vertically through the neck on the surface of the sternocleidomastoid muscle
external jugular vein
External jugular vein first drains blood to the _____ before it reaches to the superior vena cava
subclavian vein
distention of this vein may
indicate circulatory overload
external jugular vein
commonly used site for administering substances intravenously or for withdrawing venous blood specimen
median cubital vein
a superficial vein on the upper limb specifically on the antecubital space
median cubital vein
longest vein in the body
great saphenous vein
ascends along the medial side of the entire limb to empty into the common iliac vein which is a direct tributary of the inferior vena cava
great saphenous vein
a union of arteries at the base of the
brain around the pituitary gland
circle of Willis
an important arterial anastomosis which facilitates continuous blood supply to the brain by providing more than one route for blood to reach brain tissue in case of a clot or impaired blood flow in the system
circle of Willis
unites the brain’s anterior & posterior blood supplies provided by the internal carotid & vertebral arteries which are branches of the aortic arch
circle of willis
What are the blood vessels that unite in the circle of Willis?
Posterior communicating artery
Anterior communicating artery
posterior cerebral artery
anterior cerebral artery
a vein that carries blood
from one capillary network to another
portal system
formed by the union of the splenic & superior mesenteric veins w/c receives blood from the capillaries of the digestive organs and delivers it to the liver
hepatic portal vein
exists only in the fetus & contains special structures that allow the developing fetus to exchange materials with its mother
fetal circulation
the fetus obtains O2 & nutrients from & eliminates CO2 & other wastes into the
maternal blood
a pancake-shaped organ at the end of the umbilical cord through which O2 & nutrients are obtained from the mother’s uterus
placenta
carries O2-rich blood to the fetus from the placenta
umbilical vein
carries O2-poor blood from the fetus back to the placenta
umbilical arteries
blood from the umbilical vein bypasses the ______by flowing through the ductus venosus w/c drains into the inferior vena cava
immature fetal liver
blood bypasses the immature fetal lungs by flowing from the pulmonary trunk through the _______ to the aorta
ductus arteriosus
blood also bypasses the fetal lungs by flowing from the right to the left atrium through the ________ (an opening in the interatrial septum)
foramen ovale
after birth, the fetal circulation converts into _______ when the functions of the lung & liver begin
postnatal circulation
the remnant
of the ductus venosus
ligamentum venosum
the
remnant of the ductus arteriosus
ligamentum arteriosum
the remnant of the
foramen ovale
fossa ovalis
