Vessels and Circulation Flashcards
What is systemic circulation
From the left ventricle through the circulatory system and back to the right atrium
what is pulmonary circulation
Right ventricle through lungs and into left atrium
what is an anastomosis
Site where two or more vessels merge to supply the same body region
what are arterial anastomoses
Ways to proved alternate blood supply routes to tissues or organs
What are anatomical end arteries
vessels whose terminal branches do not anastomose.
What happens in the event that anatomical end arteries become blocked
The tissues will be deprived of oxygen and an “infarct” develops (ex. Kidneys, spleen, brain)
What are functional end arteries
Anastomoses are so small that arteries may be considered end arteries (ex. coronary arteries)
Do Veins or Arteries tend to form more anastomoses
Veins form many more anastomoses
what are the three layers of tunica
Tunica intima, Tunica media, Tunica externa
Tunica intima
Innermost layer of a blood vessel wall
composed of a layer of simple squamous epithelium, called endothelium
Tunica Media
Middle layer of blood vessel wall
composed of circularly arranged layers of smooth muscle cells under autonomic control
fxn: in vasocontriction and vasodilation
Tunica Externa
Outermost layer of the blood vessel wall
composed of an areolar CT that contains elastic and collagen fibers and nerve fibers
fxn: helps anchor the vessel to other tissues, protects, and supports vessel
what is the tunica externa composed of
Areolar CT that contains elastic and collagen fibers and nerve fibers
What is the function of the Tunica Externa
Helps anchor the vessel to other tissues, protects, and supports vessel
What is the Vasa Vasorum
Small blood vessels that supply the cells of the blood vessel wall
which has a wider lumen diameter a artery or a vein
Vein (note that they are often collapsed though)
Which has a larger general wall thickness an artery or a vein
Artery is thicker than comanion vein
What is the cross-sectional difference between an artery and a vein
Artery retains circular X-sectional shape
Vein X-section tends to flatten and collapse
Which tunic is thickest in an Artery
The Tunica Media
Which tunic is thickest in a Vein
Tunica Externa
Which has more elastic and collagen fibers in the tunics an artery or vein
Artery
Which has a higher blood pressure an artery or vein
Artery
Systemic Arteries carry what kind of blood
Oxygenated blood to body tissues
Pulmonary arteries carry what kind of blood
Deoxygenated blood to the lungs
What are the three basic types of arteries
Elastic, Muscular, and arterioles
What characteristics change as an artery decreases in diameter
corresponding decrease in the amount of elastic fibers
relative increase in the amount of smooth muscle
What is the typical size of an elastic artery
1-2.5 cm diameter
Elastic arteries are known as what
Conduncting arteries
Where are elastic arteries typically located
Near the heart
Elastic arteries have a high proportion of what thoughout there tunica media
elastic fibers
what are some examples of elastic arteries
Aorta, Pulmonary arteries, brachiocephalic trunk, common carotid and iliac
what results in smooth flow of blood through elastic arteries
Passive accommodation
what are two properties of elastic arteries
Dampen BP changes associated with heart contraction
passive accommodation results in smooth flow of blood
What is the size of muscular arteries
0.3-1.0 cm
Where are muscular arteries located
distal to elastic arteries
where are elastic fibers in the muscular arteries found
Restricted to the internal and external elastic lamina
What is the size of arterioles
10.0 micrometers to 0.3 cm
In arterioles how many layers of smooth muscle are in the tunica media
Generally 6 layers, loss of layers with decreasing size
Are arterioles under autonomic control
Yes
what are some common arterial disorders
Arteriosclerosis, atherosclerosis, hypertension, aneurysms
What is arteriosclerosis
Hardening of the arteries
What is atherosclerosis
Fatty deposits and occlusion
A slow, complex disease in which fatty deposits (called plaque) build up in the inner lining of an artery, eventually causing it to narrow and restrict blood flow
What are aneurysms
ballooning and/or rupture of the vessel
What are risk factors for Atherosclerosis
Genetics, hypercholesterolemia, sex (male), age, smoking, hypertension
what are some treatments for atherosclerosis
Angioplasty and surgery
Ways to treat an aneurysm
ballooning of the vessel
What are the smallest blood vessels
Capillaries
what do capillaries connect
arterioles to venules
what is the diameter size of capillaries
slightly larger than diameter of single erythrocytes
what layers due capillaries contain
Only Tunica Intima, but this layer consists of a basement membrane and endothelium only
What is the function of capillaries
Allow gas and nutrient exchange between the blood and the body tissues to occur rapidly
What is a metarteriole
true capillaries branch off metarteriole. It feds the capillary beds
Pre-capillary sphincter
Controls blood flow from the metarteriole into the capillaries
do capillaries function independently
No!
What is the Thoroughfare channel
The continuation of the metarteriole through the capillary bed from arterial end to Venous end
True capillaries are branches off what
The metarteriole
What are the three basic kinds of capillaries
Continuous capillaries, fenestrated capillaries, Sinusoids (discontinuous capillaries)
what type of capillary is the most common
Continuous capillaries
where are continuous capillaries located
Muscle, skin, lungs, CNS
Where are menstruated capillaries located
GI tract, kidney, endocrine glands
Where are sinusoid (discontinuous capillaries) located
Suprarenal glands, spleen, liver, anterior pituitary
systemic veins carry what kind of blood
Deoxygenated blood to the right atrium
Pulmonary veins carry what kind of blood
Oxygenated blood to the left atrium of the heart
Veins hold what percent of the body’s blood when at rest
60%
Veins function as blood ______
Reservoirs
Blood pressure is substantially _______ by the time blood reaches the veins
Reduced
Walls of veins are relatively ______ and the vein lumen is ______
Thin, Large
Venules merge to form
Veins
A Venule becomes a Vein when
its diameter is greater than 100 micrometers
The Tunica media of veins is composed of
little muscle and is mostly elastin
What is the thickest layer of a vein
The Tunica Externa
Veins have _____ walls and _____ muscle than arteries
Thinner, less
what is the function of valves in veins
To prevent blood from pooling in the limbs and to prevent blood blackflow
Numerous _____ along a veins length assist in moving blood back to the heart
Valves
Many deep veins pass between what
Skeletal muscle groups
what is the purpose of deep veins passing between skeletal muscle groups
Skeletal muscle contract causing the veins to be squeezed thus help pump blood toward the heart
What does the skeletal muscle pump refer too
The contraction of skeletal muscle leading to the squeezing and pumping of deep veins
What are Varicose Veins
Dilated, tortuous veins
most common in lower limbs
What are the causes of varicose veins
Valves are nonfunctional causing blood to pool
can be caused by genetics, aging, stress (standing , pregnancy, obesity)
What is Sclerotherapy
a treatment used for Varicose Veins
irritant injected into smaller veins to cause scarring and closure
What are some ways to treat Varicose Veins
Sclerotherapy, Vein ablation
What are some clinical observations for chronic venous insufficiency
Skin discoloration, eczema, induration, venous ulcers, varicose vein rupture, leg swelling
Caused by incompetent venous valve- leading to venous congestion and high pressures within the superficial veins
where is a DVT most common
in sural (calf) or femoral (thigh) region
what is the most serious complication of a DVT
PE
what is another name for a blood clot
Thrombus
risk factors for DVT
Pregnancy, Economy class syndrome Poor blood circulation (heart failure, increased blood thickness, small blood clots, prolonged immobilization) Venous injury (Surgery, Trauma) Increased blood clotting (anti-clotting factor deficiencies, autoimmune disorders, certain cancers, platelet disorders)
How is a DVT treated
With Anticoagulants
What is blood pressure
force/unit area in mmHg applied to walls of blood vessels
what is systolic BP
during ventricular contraction (120mmHg)
What is Diastolic BP
During Ventricular relaxation (70mmHg)
What is pulmonary circulation
responsible for carrying deoxygenated blood from the right side of the heart to the lungs, and then returning the newly oxygenated blood to the left side of the heart
In pulmonary circulation the arteries carry what
deoxygenated blood
In pulmonary circulation the veins carry what
oxygenated blood
blood is pumped out of the right ventricle into the ____
Pulmonary trunk
When does cardiopulmonary circulation end
when blood enters the aorta
Does pulmonary circulation provide blood to the lung tissues
No
Describe the flow of blood through the pulmonary circulation
right ventricle—> pulmonary trunk—–> pulmonary arteries—–> lungs—–> pulmonary veins—–>left atrium
List the branches of the Aorta in relation to the left ventricle
Coronary arteries, Brachiocephalic (right common carotid, R subclavian), Left common carotid (left internal carotid, let external carotid), Left subclavian, Thoracic aorta (above the diaphragm)
The brachiocephalic has two main branches what are they
Right subclavian (Right vertebral and right axillary), Right common carotid (right internal carotid and right external carotid)
what is Bifurcation
Division of something into two branches or parts
explain the Bifurcation of the Aorta
descending aorta brances at the common iliac artery, then into the internal iliac artery and external iliac artery
Explain the main path of lower extremity venous return
external iliac and internal iliac ——-> the common iliac —–> to inferior vena cava
where does the ascending aorta start
aortic orifice
Where does the ascending aorta end
T4/5 sternal angle
Where does the aortic arch start
T4/5
Where does the aortic arch end
T4
Where does the aortic arch reach
T3/4
What gives oxygenated blood to the lung tissues
Bronchial arteries
Head and neck arterial supply is derived form either ___ or ______
common carotid artery or vertebral artery
The common Carotid artery supplies oxygenated blood to
neck, face, and anterior brain
The Vertebral Artery supplies blood to
The posterior brain
The vertebral artery is a branch off what artery
The subclavian artery
what arteries arise int he carotid triangle
Superior thyroid artery ascending pharyngeal artery lingual artery facial artery occipital artery
What are the branches off the external carotid artery
Superior thyroid artery, ascending pharyngeal artery, lingual artery, facial artery, occipital artery
Posterior auricular artery
Terminal branches ( maxillary artery, and superficial temporal artery)
What are the two terminal branches of the external carotid artery
maxillary and superficial temporal artery
What is the cerebral arterial circle (circle of Willis)
an important anastomosis of arteries around the sella turcica
What forms the cerebral arterial circle (circle of Willis)
formed form posterior cerebral arteries and posterior communicating arteries (branches of the posterior cerebral arteries), internal carotid arteries, anterior cerebral arteries, and anterior communicating arteries (which connect the two anterior cerebral arteries).
What is the function of the cerebral arterial circle (circle of Willis)
Equalizes blood pressure in the brain and can provide collateral channels should one vessel become blocked
Branches of the external Carotid Artery
Superior thyroid artery, superior laryngeal artery, suprahyoid artery, lingual artery, ascending pharyngeal artery, facial artery, maxillary artery, posterior auricular artery, superficial temporal artery
The Coeliac trunk is located at
T12
The superior mesenteric artery is located at
L1
The Inferior mesenteric artery is located at
L3
The bifurcation of the descending aorta is located at
L4
