Vessels and Circulation #1 Flashcards
Circulation that consists of left atrium, left ventricle, and all named arteries and veins blood travels through until it comes back to the heart (not including right atrium)
Systemic Circulation
high pressure circulation system
systemic
Circulation that consists of right atrium, right ventricle, and all named arteries and veins that blood travels through until it comes back to the heart (not including left atrium)
Pulmonary Circulation
low pressure circulation system
pulmonary
3 classes of blood vessels
Arteries, Capillaries, and Veins
carry blood from heart and become progressively smaller as they travel farther from heart
Arteries
Arteries branch into these smaller vessels
Arterioles
where gas and nutrient exchange occurs between tissue cells and blood
Capillaries
carry blood to heart and become progressively larger as they merge and travel closer to heart
Veins
Veins receive blood from these small branches of vessels
Venules
site where two or more arteries or veins merge to supply the same body region
Anastomosis
provide alternate blood supply routes to body tissues or organs
Arterial Anastomoses
Which type of vessel forms many more anastomoses than the other?
Veins form more
When there is only one pathway through which blood can reach an organ.
End Arteries
Two examples of end arteries
Renal Artery and Splenic artery
Arteries that do not form and anastomoses
End Arteries
When an artery will travel with the corresponding vein because they service the same body region and tend to lie next one another
Companion vessels
Both arteries and veins walls have three layers called what
Tunics
The tunics surround this inside space of the blood vessel through which blood flows
Lumen
The innermost layer of a blood vessel wall
Tunica intima
What layer of a blood vessel wall has structural differences between veins and arteries? What is the structural difference?
The Tunica intima in the veins has one-way valves which are not seen in arteries
What is the tunica intima composed of?
Endothelium and a subendothelial layer (thin layer of connective tissue)
The middle layer of the blood vessel wall
Tunica media
What is that tunica media composed of?
Circularly arranged layers of smooth muscle cells
In the blood vessel tunics what causes the smooth muscles to contract, resulting in narrowing of the blood vessel lumen? What is the term for this action?
Sympathetic innervation causes vasoconstriction
What is the term or when the smooth muscle fibers relax in the blood vessel tunics and result in widening the blood vessel lumen?
Vasodilation
The vasomotor center, responsible for vasoconstriction and vasodilation, resides where the brain?
Medulla oblongata
The outermost layer of a blood vessel wall
Tunica externa
What is the tunica externa composed of?
Connective tissue that contains elastic and collagen fibers
Which is the thickest tunic in arteries? In veins?
Arteries= tunica media, veins= tunica externa
Very large blood vessels require their own blood supply to and through which Tunica in the form of a network of small arteries?
Tunica externa
This is narrower in an artery than in a vein of the same size
The lumen
Arteries tend to have more what in all their tunics? What does this mean?
They have more elastic and collagen fibers which means that artery walls remain open (patent) and can spring back to shape
Vein walls tend to do what if there’s no blood in them?
Collapse
Capillaries contain only which tunic?
Tunica intima
The tunica intima of capillaries consist of what?
A basement membrane and endothelium only
Capillaries containing only the tunica intima allow for easier what?
Exchange of materials between the blood in the vessels and the interstitial fluid
What is the scientific name for tissue fluid?
Interstitial fluid
What is the primary function of capillaries?
Exchange of materials
If the veins collapsed and there is severe hypotension, what life-saving procedure can be done?
Intraosseous infusion (IO)
In general, as an artery’s diameter decreases, there is a corresponding decrease in what? And a relative increase in what?
A decrease in the amount of elastic fibers and a relative increase in the amount of smooth muscle
What are the three basic types of arteries?
Elastic arteries, muscular arteries, and arterioles
Which type of artery is the largest, with diameters ranging from 2.5 to 1 cm?
Elastic arteries
Elastic arteries have a large proportion of what throughout all three tunics, especially in this layer?
Elastic fibers, especially in the Tunica media
The abundant elastic fibers within elastic arteries allow them to do what?
Stretch when a heart to ventricle ejects blood into it
What is responsible for the forwarding propulsion of your arterial blood?
Ventricular systole and the elastic recoil of the arterial walls
Name six elastic arteries
Aorta, pulmonary, brachiocephalic, common carotid, subclavian, and common iliac arteries
Elastic arteries branch into what?
Muscular arteries
This type of artery typically has diameters ranging from 1cm-3mm
Muscular arteries
Unlike elastic arteries, how are the elastic fibers within muscular arteries arranged?
They are confined to 2 laminar rings (one ring between the tunica intima and media, and the second between the Tunica media and externa)
Most of the named arteries belong to which category?
Muscular arteries
Muscular arteries branch into what?
Arterioles
These are the smallest arteries, what diameters ranging from 3 mm to 10 µm
Arterioles
Which layer of muscular arteries are proportionately thicker, with multiple layers of smooth muscle? This results in a better ability do what?
thicker tunica media gives them a better ability to vasoconstrict and vasodilate
How do larger arterioles and smaller arterioles differ?
Larger arterioles have all three tunics, whereas the smallest arterioles have fewer
What do arterioles regulate by vasoconstricting or vasodilating?
Arterial blood pressure AND blood flow through capillaries
What connects arterioles to venules?
Capillaries, the smallest blood vessels
The average capillary diameter is just slightly larger than what? What does this mean?
The diameter of a single erythrocyte; erythrocytes must travel single file through each capillary
What causes blockages and infarctions in body organs, such as the spleen and brain, due to narrow vessel diameter?
Sickle cell disease
Sickle cell disease is caused by inheritance of a gene for what abnormal protein?
Hemoglobin (hemoglobin–S)
Functional units of the cardiovascular system
Capillaries
Three different structural types of capillaries
Continuous capillaries, fenestrated capillaries, and sinusoids
What is the most common type of capillaries, composed of endothelial cells that form a complete, continuous lining and are connected by tight junctions?
Continuous capillaries
This type of capillary makes passing materials through endothelial cells or the intercellular clefts to and from the surrounding interstitial fluid possible
Continuous capillaries
This type of capillary is seen where a great deal of fluid transport occurs between the blood and interstitial fluid of the tissues? Name three locations
Fenestrated capillaries (have fenestrations within each endothelial cell) can be seen in the intestines, endocrine glands, and kidneys.
What is meant by fenestration?
An opening in the surface of structure, as in a membrane
Which type of capillary tend to be wider, larger vessels with openings that allow for transport of larger materials, such as proteins or cells? Where can they be found?
Sinusoids are found in the bone marrow, the spleen, the anterior pituitary, the liver, and several other locations.
Compared with the corresponding artery, vein walls are relatively ______, and the lumen is ______.
Thin; larger
Veins function as? Meaning what?
Blood reservoirs. At rest, the body’s veins hold about 60% of the body’s blood.
What type of organ is the spleen?
Lymphoid
Why is there very little pressure in veins?
Because most of the pressure has dissipated after traveling through the smaller arteries and capillaries
What is the smallest type of vein called? What happens when it’s diameter is greater than 100 µm?
venule; it becomes a vein
What do the smallest venules do? Do they have all three tunics?
The smallest venules drain capillaries. Only the largest venules have all three tunics.
Smaller and medium sized veins typically travel with which arteries? Largest veins?
Smaller and medium-sized veins typically travel with muscular arteries, while the largest veins travel with elastic arteries
Formed primarily of tunica intima and strengthened by elastic and collagen fibers, these prevent blood from pooling in the limbs and assist blood moving back to the heart
One way valve in veins
Describe the “skeletal muscle pump” process
Nearby skeletal muscles squeeze veins when they shorten and contract, propelling the blood superiorly.
Venous return is assisted by what two processes?
The Skeletal Muscle Pump and the Respiratory Pump
When a person inhales, the diaphragm contracts and increases the pressure in the abdominal cavity, which helps propel blood into the thoracic cavity. When a person exhales, the diaphragm relaxes and decreases the volume of the thoracic cavity, which increases the intrathoracic pressure, moving blood from the thoracic cavity into the heart. In addition, intra-abdominal pressure decreases, allowing more blood to move from the lower limbs into the abdominal vessels. What is this process known as?
The respiratory pump
How does activity level affect blood flow through veins?
Blood flows well through veins when persons are active and blood has a tendency to pool in the leg veins when persons are inactive or bedridden.
Oxygenated blood leaves the left ventricle of the heart and enters the:
ascending aorta
These emerge immediately from the wall of the ascending aorta (just superior to aortic semilunar valve) and supply the heart.
left and right coronary arteries
The ascending aorta curves towards the left side of the body and becomes the:
aortic arch
3 main arterial branches emerge from the aortic arch
brachiocephalic trunk, left common carotid artery, and the left subclavian artery
The brachiocephalic trunk bifurcate into the:
Right common carotid artery and right subclavian artery
Supplies arterial blood to the right side of the head and neck
Right common carotid artery
Supplies arterial blood to the right upper limb and some thoracic structures
Right subclavian artery
Supplies arterial blood to the left side of the head and neck
Left common carotid artery
Supply arterial blood to the left upper limb and some thoracic structures
Left subclavian artery
sudden decelerations can damage the aortic arch or descending thoracic aorta in what ways?
Aortic transactions (typically fatal, DRT) and aortic dissections (90% fatal, very painful, typically between the tunica media and intima)
What is the term for stationary blood clot?
Thrombi
What is the term for mobile blood clot?
Emboli
What is the fatal condition resulting from an embolus encountering its first capillary beds?
Pulmonary embolism
Interruption of blood flow in these arteries causes loss of consciousness
Left and right common carotid arteries
At the superior border of the thyroid cartilage each common carotid artery divides into what? Which structures do they supply blood to?
External carotid artery (structures external to the skull) and internal carotid artery (internal skull structures)
What structure at which bifurcation contains baroreceptors?
The carotid sinus where the common carotid arteries bifurcate
Pressure sensors which monitor blood pressure, and when stimulated, cause slowing of the heart, vasodilation, and a fall in blood pressure
Baroreceptors in the carotid sinus
The external carotid artery extended upward along the side of the neck and head and branches to form this artery that pulsates vigorously when persons have a headache
Superficial temporal artery
Name 4 vessels that supply blood to the cranium
Internal carotid artery, vertebral arteries, basilar artery, and the circle of Willis
These arteries emerge from the subclavian artery and traveled through the transverse foramina of the cervical vertebrae before entering the skull through the foramen magnum, where they merge to form the:
Vertebral arteries merge to form the basilar artery
An important anastomosis of arteries around the sella turcica. Name its function.
The circle of Willis equalize blood pressure in the brain and can provide collateral channels should one vessel become blocked
Blood flow to the circle of Willis is contributed by the inflow of blood from branches of what 2 arteries?
Vertebral arteries and the carotid arteries
The aortic arch curves and project inferiorly as this artery that extends several branches to supply thoracic organs and the thoracic wall. Name three organs that it supplies blood to.
The descending thoracic aorta branches to supply blood the lungs, esophagus, and diaphragm.
The bronchi, bronchioles, and connective tissue of the lungs are supplied by three or four small arteries that emerge as tiny branches from the anterior wall of the descending thoracic aorta
Bronchial arteries (part of systemic circulation)
Several small arteries emerge from the anterior wall of the descending thoracic aorta and supply the esophagus
esophageal arteries
Supplies arterial blood to the abdominal portion of the esophagus
Left gastric artery
Arterial blood is supplied to the diaphragm by which three paired vessels and where do they arise/emerge from?
Superior phrenic arteries (descending thoracic aorta), musculophrenic arteries (branches of subclavian arteries), and inferior phrenic arteries (descending abdominal aorta).
When the descending thoracic aorta extends inferior to the diaphragm, it is renamed and extended branches to supply the abdominal wall and organs
Descending abdominal aorta
Name the three UNPAIRED arteries that you emerge from the anterior wall of the descending abdominal aorta to supply the G.I. tract
Celiac trunk, superior mesenteric artery, and inferior mesenteric artery
Which branch of the descending abdominal aorta is surrounded by the largest autonomic nerve plexus. Name the three branches that emerge from this arterial trunk.
The celiac trunk, located immediately inferior to the aortic opening through the diaphragm, is surrounded by the celiac plexus, or solar plexus. The left gastric artery, splenic artery, and common hepatic artery all emerge from this arterial trunk.
Supplies the lesser curvature of the stomach and extends some branches to the esophagus
Left gastric artery
Supplies the spleen, part of the stomach, And the pancreas
Splenic artery
Supplies the liver, gallbladder, part of the stomach, the duodenum, And the pancreas
Common hepatic artery
Name the sources of arterial blood to the pancreas
Splenic artery, Common hepatic artery, And superior mesenteric artery
Located immediately inferior to the celiac trunk. Supplies most of the small intestine (excluding duodenum), the pancreas, and the proximal portion of the large intestine
Superior mesenteric artery
The most inferior of the three unpaired arteries that arise from the descending abdominal aorta. Emerges from the aorta at about the level of the L3 and supplies part of the transverse colon, part of the descending colon, sigmoid colon, and rectum.
Interior mesenteric artery
Name the three PAIRED arterial branches that emerge from the sides of the descending abdominal aorta.
Middle suprarenal arteries, Renal arteries, and gonadal arteries
Supplies each adrenal gland with arterial blood
Middle suprarenal arteries
Supplies arterial blood to each kidney
Renal arteries
Supplies arterial blood to each gonad (testes in males, ovaries in females)
Gonadal arteries
At the level of L4 the descending abdominal aorta bifurcates into:
The left common iliac artery and right common iliac artery
Each common iliac artery further divides into what? What did they supply?
Internal iliac artery (pelvic and perineal structures) and external iliac artery (lower limb)
Where does the diameter of the descending abdominal aorta diminish and contain lesser amounts of elastin than the thoracic aorta?
As it nears the bifurcation to form the iliac arteries
How is blood flow through the upper limb and lower limb similar?
Supplied by a main arterial vessel which bifurcates at the elbow/knee, arterial and venous arches in hand/Foot, superficial and deep networks of veins
Main arterial vessels of the upper limb. Where did they emerge?
Left subclavian artery (directly from aortic arch) and right subclavian artery (division of brachiocephalic trunk)
After the subclavian artery passes over the lateral border of this landmark, what is it renamed?
First rib, axillary artery
When the axillary artery passes the inferior border of this muscle what is it renamed?
Teres major muscle, brachial artery
This artery travel along the medial side of humerus, and is often use to monitor blood pressure with a sphygmomanometer and stethoscope. Branches of this artery supply blood to most of the brachial muscles
Brachial artery
At this landmark, the brachial artery divides into what two arteries? Where did they travel?
Cubital fossa, ulnar artery (medial side of forearm) and radial artery (lateral side of forearm)
Hospital workers often use this artery in the lateral wrist for collecting arterial blood for blood gas analysis in hospitalized patients
Radial artery
Both the ulnar and radial arteries supply the muscles and structures the forearm and wrist before they do what?
Anastomose and form two arches in the palm
Name the two arches in the palm and which artery primarily formed them
Superficial Palmar Arch (ulnar artery) and Deep Palmar Arch (Radial artery)
Emerge from the arches in the palm to supply arterial blood to the fingers
Digital arteries
What is the source of bleeding in a pelvic fracture? How can it be controlled?
The internal iliac artery, controlled by realignment of bones
A sign of what disease was found at the left contour of the aortic bifurcation in the Iceman? What artery was hit by the fatal arrow?
Atherosclerosis, left subclavian artery
Einstein died of this
Ruptured abdominal aortic aneurysm
The main arterial supply for the lower limb
External iliac artery
The external iliac artery travels inferior to this landmark, where it is renamed what?
The inguinal ligament, femoral artery
The femoral artery initially passes through what area on the upper medial portion of the thigh? What is significant about this area?
The femoral triangle, it is an arterial pressure point, may obtain blood samples for arterial blood gases, and can palpate the femoral artery.
Emerges from the femoral artery to supply the hip joint and many of the thigh muscles
Deep femoral artery
The femoral artery passes into this region where it is renamed what? What structures does it supply?
Region behind the knee, popliteal artery, the knee joint and muscles in this region
The popliteal artery divides into what? What do they supply?
anterior tibial artery (anterior compartment of the leg) and posterior tibial artery (posterior compartment)
The posterior tibial artery extends a branch called what? What does it supply?
Fibular artery (lateral compartment)
The posterior tibial artery continues on the plantar side of the foot where branches into what?
Medial plantar artery and lateral plantar artery
The anterior tibial artery crosses over the anterior side of the ankle where is renamed what?
The dorsalis pedis artery (dorsal pedal artery)
The most distal portion of the circulatory system
Dorsal pedal artery
Palpation of this can provide information about circulation of the foot and in general
Dorsal pedal artery
The dorsalis pedis artery and a branch of the lateral plantar artery unite to form:
Plantar arch of the foot
Extends from the plantar arch and supply the toes
Digital arteries
