Flashcards in Vascular system Deck (61):
Who is credited with ‘discovering’ the vascular system?
What are the 2 subsystems within the vascular system?
The cardiovascular system and the lymphatic system
What 3 things comprise the cardiovascular system
Heart, Blood vessels, and Blood
What three things make up the lymphatic system?
Lymph tissue/nodes, Lymph vessels, and Lymph
What is the only liquid tissue in the body?
How much blood is in the average human body?
~5.1 liters in volume (5-6 liters)
What is blood composed of?
Liquid plasma (55%), Erythrocytes (RBCs) (45%) Leukocytes (WBC)
The cardiovascular system begins and ends at the ______
What are the three major types of blood vessels?
Arteries (blood leads away from the heart), Veins (blood leads towards the heart), Capillaries (exchange)
What are the outermost, middle, and innermost layers of blood vessels?
Tunica Adventitia, Tunica Media, Tunica Intima
Which layer of the blood vessels is made mainly of collagen and elastin?
Which layer of the blood vessels is composed of endothelium?
Which layer of the blood vessels is made mainly of muscle?
Tunica media, Used for vasoconstriction/vasodilation
What is the effect on blood pressure in vasoconstriction?
Raise in blood pressure
Muscles of the blood vessels are controlled by what?
The ANS (visceral efferent)
Is the tunica media thicker (more muscular) in arteries or veins?
Do arteries or veins have more elastin? Why?
Arteries have more elastin, Due to the extremely high pressure coming from aorta, arteries are elastic (esp near the aorta) to even out the pressure to maintain a constant pressure throughout the system
What is the correct order of vessels from arteries to veins?
Elastic ArteriesMuscular Arteries ArteriolesTerminal ArterioleMatearteriole CapillariesPostcapillary VenuleSmall VeinsLarge VeinsHeart
Where does the lymphatic system empty into the cardiovascular system?
What are the 4 parts of the aorta?
Ascending, Arch, Thoracic, Abdominal
Where does the Brachiocephalic artery lead?
To the head and arms
What are the two parts of the carotid artery?
-Internal and external
-Between the two is where the body detects blood pressure
What are the main arteries we should be familiar with?
Aorta, Brachiocephalic, Carotid, Subclavian, Axillary, Brachial, Radial, Ulnar, Common Iliac, Internal Iliac, External Iliac
Are veins or arteries more rigid?
•Veins have more elastin
How much of your blood is in the venous system at any given time?
What mechanisms do veins use ass assistance for getting blood back to the heart?
.Valves: prevent backflow
•Skeletal Muscle: squeeze the vein, increasing pressure
•Pressure changes in thorax (breathing)
What are the main veins we should be familiar with?
Superior Vena Cava, right and left Brachiocephalic, internal and external Jugular, Subclavian, Axillary, Cephalic, Basilic, Azygos, Hemiazygos, Inferior Vena Cava, Common Iliac, Internal Iliac, External Iliac
Where do the exchange of oxygen and nutrients take place?
What are the different kinds of capillaries?
continuous, fenestrated, sinusoid
Allow exchange of water and some ions (small things)
Found in skin and at blood-brain barrier
Larger luminal; more exchange
Found in pancreas, endocrine glands, glomerulus, other places where you want to secrete
Allow movement of very large molecules
Found in liver, spleen, bone marrow, lymph nodes
Areas of filtration
How many RBCs can fit through a capillary bed at once? Why?
•Only one at a time, single file
•Slows them down, maximize time and surface area to exchange
What is the main difference between the types of capillaries?
•How leaky they are
•Continuous least leaky; sinusoid most leaky
What are the different ways blood vessels anastomose, or connect, to one another in the body?
•Arteriovenous: direct connection bw arteries/veins
•Arterial: collateral circulation, Many tissues richly supplied with several arteries; branches join and communicate directly
Do arteries have vales?
•NO; flow can therefore be bidirectional—follows a pressure gradient (highlow)
What is the purpose of collateral circulation?
•To allow constant uninterrupted flows to the areas they supply
•Alternative channels when one usual channel is blocked.
Does not work if circulation is cut off before the branching point.Does not work if alternative channel cannot supply enough blood.Keeps tissues alive.not present everywhere*
What are arteriovenous anastomoses and in what situations are they used?
•A direct connection between arteries and veins.Precapillary sphincters form a cuff, blood is shunted (avoids capillary beds). Occurs in the skin, mucosa, organs, glands
•Occurs when nutrients/energy is better spent elsewhere.Time of stress (fight or flight), don’t need as much blood in intestines when not eating, etc
What is a true end artery and what are some examples?
•An artery that does NOT anastomose with other arteries.
EX: Central artery of the retina, Splenic artery (curled like a pig tail), Proper hepatic artery
What is a functional end artery and what are some examples?
•An artery that DOES anastomose with other arteries but does NOT allow for sufficient collateral circulation. E.g. not enough blood flow
•EX: arteries that supply the brain and heart
Why is the fetal circulatory system different?
Don’t need lungs in utero
Where is blood reoxygenated in the fetal system?
The umbilical cord
What are the unique parts of the fetal system and what are their adult counterparts? What was their purpose in the fetal system?
•Foramen ovale Fosso ovales (hole seals itself, becomes a small divot). Hole in wall between right atrium to left atrium; right heart goes to lungs
•Ductus venosa ligamentum venosum.Bypasses liver
•Ductus arteriosa ligamentum arteriosa.Going from pulmonary trunk directly to aorta bypassing lungs
•Umbilical vein ligamentum teres.Brings blood back up to heart from mother
What is the lymphatic system composed of?
•Organs:Bone, Thymus, Spleen, Lymph nodes, Tonsils
•Smaller disseminated groups:
Mucosa associated lymphatic tissue
Who ‘discovered’ the lymphatic system?
What is the function of lymph nodes?
Store cells and filter out bacteria and other unwanted substances to purify the lymphatic fluid
What is the function of the spleen?
Stores and purifies blood
What are the cells of the lymphatic system (lymphocytes), and what do they do?
•T cells(Manage the immune response,Attack and destroy foreign cells,Mature in (T)hymus)
•B cells(Produce plasma cells, which secrete antibodies,Antibodies immobilize antigens,Mature in (B)one marrow)
What are the primary responses of the lymphatic system?
initial encounter with antigen
-Non-bacterial invasion(T cells initially attack foreign invaders, T-helper cells signal immune system to invaders
-Bacterial invasion(Antigen binds to a receptor on a specific B lymphocyte(plasma cell—bacterial infections), Makes more plasma cells specific for antigen (and also memory B cells)
What are the secondary responses of the lymphatic system?
next exposure (can be years later)
Memory B cells mount quick response and make more plasma cells
Both T and B cells make memory cells
What is conferred immunity?
-Free antibodies transferred to baby via breast milk
-Only lasts for about 6 months
What are the characteristics of lymphatic collecting vessels? Compared to blood vessels.
•Have the same three tunics as veins
•Have thinner walls
•More internal valves than veins
•Anastomose more frequently
•Collective vessels in the skin travel with superficial veins
•Deep vessels travel with arteries
•Nutrients are supplied from branching vasa vasorum
What is the vasa vasorum?
•Very tiny; vessel of the vessels
•Feed large arteries (the outermost layer),Large arteries need supplemental source of nutrients
______ collect extravenous fluid, and after filtration returns it to blood vessels.
52. LYMPHATIC CIRCULATION—THOARCIC DUCT (left/most of body)/RIGHT LYMPHATIC DUCT
Where does the right lymphatic duct empty its contents into the circulatory system?
Right subclavian vein
Where does the thoracic duct empty its contents into the circulatory system?
Into the left subclavian vein
What are lacteals?
•Lymphatic vessel in small intestine that sucks up fat
•Presence of lipids gives lymph a “milky” appearance
Why do lymph nodes have many afferent vessels and only one efferent vessel?
•Slows down the flow of lymph—creates a traffic jam
•Lots of T cells present, this gives them more time/chance to filter
•If it’s too slow, though, you might get sick (“sitting in own filth”)
Why do we need lymph nodes to concentrate antigens? Why not just use blood?
•Brings antigen in a closer approximation/higher concentration
•There are approximately 60,000 miles of blood vessels—chance of running into antigens much lower in circulatory system
•Think of it like an enzyme lowering the activation energy