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The circulatory system

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heart, arteries, capillaries, and veins
What is the blood vascular system made up of?
lymphatic capillaries, lymphatic vessels and lymphatic tissues and organs
What is the lymphatic vascular system made up of?
Medium arteries, small arteries, arterioles, capillaries, venules, small veins, medium veins
Large arteries > _____ > ______> ________> _______> _______> ________> ______ > Large veins
arterioles, capillaries, and venules
What are the make up of microvasculature which is <.1 mm in diameter?
tunica intima, tunica media, and tunica externa
Vessels larger than capillaries are composed of what three layers?
Tunica intima
What is the inner layer of vessel wall?
Tunica intima
What has one layer of endothelial cells (and it's basal lamina) supported by a thin subendothelial layer of loose connective tissue?
tight junctions (variable extensiveness), desmosomes, and gap junctions
The endothelium of the tunica intima is simple squamous epithelium. What type of intercellular junctions does it have?
Edothelial cells
What function to do all of the following? Control and monitor exchange between plasma and interstitial fluid, some contain clotting factor (not in capillaries), production of vasoactive factors (constriction/dilation), continuous anti-thrombogenic lining, conversion of angiotensin 1 > angiotensin II, and synthetic/metabolic activities.
vascular constriction (increase BP)
What does angiotensin II do?
LCT, thin fibers, fibroblasts
What makes up the subendothelium layer of CT in the tunica intima?
internal elastic lamina (layer of fenestrated elastin)
In some vessels, especially larger ones, the tunica intima is separated fromt he tunica media by what?
Tunica media
What is the thickest layer in arteries and is helically arranged layers of smooth muscle and / or elastin sheets?
reticular fibers and GS
What is located in the tunica media in smaller amounts?
Tunica media
What is the thickest layer in arteries?
external elastic lamina
In larger arteries what separates the tunica media from the tunica adventitia?
Tunica externa (adventitia)
What is typically thicker on the venous side and composed of elastic and collagen fibers longitudinally?
Tunica externa
What has blood vessels (vasa vasorum), lymphatic vessels, and nerves (ANS and sensory receptors)?
Elastic, muscular and arterioles (Large, medium and small)
How are arteries classified?
Elastic (large) arteries
What are these examples of? Aorta, common carotid, subclavian, and common iliac. Specialized to accomodate large volume changes and act as a passive auxillary pump.
Muscular (medium) arteries
What type of arteries are most of the named arteries? These aid in regulation of distribution to body regions in response to functional demands.
arterioles (and small arteries)
These are < 1 mm in diameter or even less than 0.5 mm. They regulate distribution to capillary beds and regulate blood pressure.
Internal elastic lamina
What is located in all but smaller arterioles and most prominent in muscular arteries?
Thickest to thinnest
Elastic, muscular and small arteries and arterioles all have endothelium and basal lamina. How does subendothelium progress from elastic arteries to arterioles?
Elastic arteries
What arteries have fenestrated elastin sheets (40-70 layers)? Tunica media
Muscular arteries
What arteries have smooth muscle (up to 40 layers) in the tunica media?
small arteries
What arteries have a tunica media of 3-10 layers of smooth muscle?
arterioles
What arteries have a tunica media of 1-2 layers of smooth muscle?
small arteries and arterioles (elastic and larger muscular arteries)
In what arteries are erternal elastic lamina not present?
Elastic and muscular arteries
In what types of arteries is the tunica adventitia made up of blood vessels, lymphatic vessels and nerves?
Small arteries and arterioles
In what types of arteries is there a thin layer of LCT in the tunica adventitia?
Transitional arteries
What are arteries of mixed types, or elastic to muscular arteries?
smooth muscle and elastic lamellae
Transitional arteries have tunica media with regions of what?
passively
Vessels expand and ______ recoil to move blood along.
Flexibility, elastic (stretch:systole recoil:diastole), smooth muscle in small arteries and arterioles allows for certain distribution and blood pressure changes.
What are the functions of the arterial system?
arterioles
What arteries distribute to the capillary bed?
Muscular arteries
What arteries distribute to a specific region or organ?
ANS motor and visceral sensory
What are the two divisions of innervation to the arterial system?
Parasympathetic (constricts muscle vessels, dilates organ vessels) and sympathetic (opposite)
What is the ANS motor portion or arterial system innervation divided into?
chemoreceptors and baroreceptors
What are the visceral sensory portions of innervation of the arterial system?
tunica intima
In atherosclerosis where are the primary changes?
Atherosclerosis
When do these occur? Proliferation of smooth muscle cells, accumulation of lipids and cholesterol in smooth muscle cells, infiltration of macrophages (foam cells), thickening of CT?
metarterioles
What are a transition vessel between arterioles and capillaries?
single muscle cells
What are spaced at intervals along the length of metarterioles?
regulate blood supply, regulate BP, conserve heat
What are the functions of arteriovenous anastamoses?
Arterial anastomoses
What are direct communication between the arterial and venous systems (bypass capillary beds) and most numerous in the liver, hands, feet, and skeletal muscle?
Capillaries
What have an average diameter 7 to 9 um and <1 mm in length? They are selective barriers and exchange gas, nutrients, and wastes.
Endothelium resting on basal lamina
What is the capillary wall composed that has variable extensiveness of tight junctions?
Endothelial cells
What part of the capillary wall is .2-.4 um thick peripheral to nucleus and may contain actin and myosin and tight junctions that determine the permeability of the vessel?
pericytes
What are occasionally found with their basal lamina in capillaries? They contain contractile proteins and have long cytoplasmic processes.
thin incomplete layer of reticular fibers
What are most capillaries surrounded by?
continuous, fenistrated, and discontinuous sinusoidal
What are the capillary types?
Continuous
What capillary type is the typical capillary found in muscles, CT, exocrine glands, and nervous tissue?
Continuous
What capillary type has endothelial cells that have a complete layer of cytoplasm, frequent pinocytotic vesicles and tight junctions making them less permeable? Also continuous basal lamina.
Fenestrated (visceral)
What capillary types have fenestrae (pores) 60-80 nm, and are found in areas involved in rapid interchange of substances between tissues and blood? (ie kidney, intestine)
Continuous and fenestrated
What two types of capillaries have continuous basal lamina?
Discontinuous sinusoidal
What capillary type is found in the liver, spleen, and bone marrow and are 30-40 um in diameter, slowing longitudinal flow?
Discontinuous sinusoidal
What capillary type has fenestrations without diaphragms, lacks intercellular junctions, and allows for easy exchange between blood and extravascular space?
Discontinuous sinusoidal
What capillary type has macrophages outside the endothelium and reticular fibers?
exchange of materials yet selective barrier
What is the main function of capillaries? This is done by the following: Diffusion and active transport (small molecules), intercellular clefts (hyrophilic molecules; histamine increases permeability), pinocytotic vesicles (endocytosis / exocytosis), fenestrations (non-selective; in some capillaries)
larger, thinner, less, higher, less, less
In veins, the lumen is ____ than arteries, wall is _____, pressure is _____, ______ concentration of CT, _____ smooth muscle, and tunics are ______ distinct.
Tunica adventitia
What is the thickest layer of tunica in the veins?
valves
What assist blood flow through veins and have endothelium covering and thin layer of CT with high elastic fiber content?
Valves
What are most numerous in medium and large veins of the LE and lower trunk?
Skeletal muscle contraction
What is essential for blood flow?
Venules
What are < 1 mm in diameter and exchange between blood and tissue fluid? Also susceptible to histamine.
Small and medium veins
What are 1-9 mm in diameter and are cutaneous and deeper veins of the extremeties?
Large veins
What are these examples of? Inf vena cava, portal, splenic, superior mesenteric, external iliac, etc.
Absent to thick (all have endothelium with basal lamina)
How does subendothelium change from venules to large veins? Tunica intima
thinnest incomplete layer to still only having a few layers of smooth muscle
How does the Tunica media change from venules to large veins?
Venules
What type of veins have a tunica adventitia of longitudinally arranged collagen and reticular fibers?
increase, increase
As diameter of a vein increases, the number of elastic fibers ______. Thickness will ______ from small to large veins.
Small, medium, and large veins
What veins have tunica adventitia of longitudinally arranged smooth muscle?
cardiac muscle
What do the largest veins contain in the tunica adventitia?
endocardium (internal), myocardium (middle), epicardium (external)
What are the three layers of the heart wall?
Endocardium
What layer of heart wall has endothelium with basal lamina and subendothelium: LCT?
Subendocardium
What layer of the heart wall connects endocardium to myocardium and contains veins, nerves, and branches of the impulse conducting system of the heart (SA and AV nodes, AV bundle)?
Myocardium
What layer of the heart wall is thickest and consists of cardiac muscle cells?
Myocardium
What part of the heart wall is thicker in the ventricles, but in the atria there are elastic fibers between cardiac muscle fibers?
Purkinje cells
What are specialized cardiac muscle cells?
Subepicardium
What layer of the heart wall attaches epicardium to the myocardium and has LCT, vessels, nerves, and adipose tissue?
Epicardium
What is a mesothelial covering of simple squamous epithelium supported by a thin layer or loose CT? This layer is a moist serosal membrane.
Fibrous skeleton
What part of the heart provides attachment for cardiac muscle and valves and is located at the atrial end of the interventricular septum?
DCT and some fibrocartilage
What is the fibrous skeleton made up of?
Cardiac valves
Wht have a central core of dense fibroelastic connective tissue covered by an endothelial layer?
annuli fibrosi of the fibrous skeleton
What are the bases of cardiac valves attached to?
Impulse conducting system
What is modified cardiac muscle innervated by the ANS and located in the subendocardium until near termination in the ventricular myocardium?
Sinoatrial node
What is modified cardiac muscle surrounding nodal artery and acts as a pacemaker providing spontaneous depolarization?
Sinoatrial node, AV node, and AV bundle
What make up the impulse conducting system?
Atrioventicular node
What is modified cardiac muscle and large arterioles?
Atrioventricular bundle (of His) (to ventricle myocardium)
What consists of left and right bundle branches and has large modified cardiac muscle cells called purkinje cells?
Sympathetic, parasympathetic and sensory
What are the components of neural innervation of the heart?
more
Are lymphatic capillaries more or less permeable than most blood capillaries?
lymph nodes, antigens
Lymph is filtered in _____ along the path of lymph vessels; an immune response can be triggered in response to ______.
blindly, larger, lack
Endothelial tubes of lymphatic capillaries begin ____, their diameter is _____ than blood capillaries, and they ____ fenestrations and tight junctions.
microfibrils
What are lymphatic capillaries held open by?
walls, valves
Lymphatic vessels resemble veins but have thinner _____ and more ____.
Lymphatic ducts (thoracic and right lymphatic ducts)
What are the largest lymph vessels called?
Lymph nodes and nodules
What filter lymph before fluid is returned to blood vascular system?