L3: Cardiovascular system Flashcards
What does CVS consist of?
Consists of: heart, blood vessels & blood.
What does CVS transport? and what does blood transport?
It transports blood to and from the tissues.
Blood transports O2 & nutrition to tissues for metabolism & transports CO2 & wastes from tissues to lung & kidney for elimination
What is the site of the heart?
-in the middle of the thorax above the diaphragm.
-extending slightly to the left.
What is the size of the heart?
about the size of an individual’s closed fist.
What are the general features of the heart?
-It is surrounded by a thin membrane called pericardium
- It is divided into 4 chambers
-Interatrial septum separates 2 atria
- An interventricular septum separates 2 ventricles
There are 2 types of valves: Atrioventricular and semilunar
What are the chambers of the heart? and what are the structures associated with atria?
It is divided into 4 chambers:-
1) The upper 2 champers are right & left atria, each atrium has an ear-like projection called the auricle
2) The lower 2 champers are right & left ventricles
What are the types of Valves?
There are 2 types of valves:
1) Valves ( ) atria & ventricles “cuspid valves” or “atrioventricular valves”
2) Valves at the base of large vessels leaving the ventricles “Semilunar valves”
where and when does blood flow through vessels?
blood passes from the heart in arteries, through tissues in capillaries & back to the heart in veins
What are the types of circulations?
Systemic, pulmonary, and portal
Systemic circulation
Oxygenated blood is pumped from the left ventricle to the aorta where it is distributed to various parts of the body through arteries, arterioles, and finally the capillaries in the tissues.
Deoxygenated blood from the capillaries passes into small veins then large veins and finally returns to the right atrium via the superior and the inferior vena cava
Pulmonary circulation
Deoxygenated blood passes from the right atrium into the right ventricle.
Then pumped to the pulmonary trunk then to lungs through two pulmonary arteries, arterioles and finally capillaries around the alveoli; where carbon dioxide is eliminated and the blood is oxygenated.
Oxygenated blood from the capillaries passes into venules, veins, then to the left atrium via four pulmonary veins.
Then passes from the left atrium into the left ventricle.
Portal circulation
Circulation of the blood between two sets of capillaries.
-One in the digestive tract: Venous blood from the stomach, intestines, pancreas, and spleen does not return directly to the heart, but it drains into the liver via the portal vein.
-One in the liver: In the liver, the portal vein breaks up finally into the 2nd set of capillaries (liver sinusoids), which drain into the heart via the hepatic veins and inferior vena cava
What are blood vessels?
The channels through which the blood is moved.
What are the types of blood vessels?
arteries, veins, and capillaries.
What are arteries?
Vessels or tubes carry blood away from the heart & distribute it to various tissues by their branches
What are the types of arteries?
-arterial anastomosis
-end arteries
-wavy(tortuous arteries)
What is the definition of arterial anastomoses?
The terminal branches of arteries communicate with those of adjacent arteries.
What are the sites of arterial anastomosis?
Around joints of limbs.
In hand & foot.
At the base of the brain.
In abdomen ( ) stomach & intestine
What is the importance of arterial anastomosis?
Provides a collateral circulation if an artery becomes occluded to maintain blood flow to the area
What is the definition of end arteries?
arteries whose terminal branches do not anastomose adjacent arteries
What are the sites of end arteries?
Retinal
Renal, splenic.
Cerebral, coronary, and pulmonary arteries.
What is the importance of end arteries?
Their occlusion disrupts blood supply to their organs; resulting in ischemia and infarction
What is the definition of wavy arteries?
arteries which have wavy course mostly as they supply expansile or moving organs
What are the examples of wavy arteries?
facial artery
Lingual artery
Uterine artery
Splenic artery
What are veins?
Vessels or tubes carrying blood towards the heart & they have tributaries
Wat are the types of veins?
Pulmonary and systemic
Pulmonary veins
Return oxygenated blood from lung to left atrium
Systemic veins
-Return deoxygenated blood from body to right atrium In limbs & neck, veins have valves to ensure unidirectional flow of blood.
-Divided into 3 sets:
1) Superficial veins: in the superficial fascia
2) Deep veins: accompany arteries
3) Dural sinuses: inside skull ( ) 2 dural layers
Compare between arteries and veins?
-DIRECTION of carrying of the blood (away-to)
-TYPE of carried blood (oxy-de) “except pulmonary”
-WALLS (rich in SM and EF - poor) (thick wall and narrow lumen - reverse)
-presence of VALVES (no-yes)
-BRANCHES or TRIBUTARIES (branch - tributaries)
What are the types of connections between arteries and veins?
1-capillaries
2-AV Shunts
3-blood sinusoids
capillaries
-Simple vascular endothelial networks between arterioles & venules in tissues
-Their walls are very thin to allow the exchange of oxygen, nutrients & wastes between blood & tissue.
-Cartilage, cornea & epidermis of skin are devoid of (without) capillaries
What is the definition of AV Shunts?
Direct communications ( ) arterioles & venules proximal to capillaries so, blood passes directly from arterial to the venous side without passing in capillaries
What are the sites of AV shunts?
The dermis of the skin (to regulate body temperature)
The auricle of ear, Tip of the Tongue, Nose, Lips Intestine (to regulate the rate of absorption)
The erectile tissue of sex organs (to regulate erection)
What are blood sinusoids?
Wide tubular spaces lined incompletely with phagocytic cells
What are the sites of blood sinusoids?
liver, spleen & bone marrow
What is the definition of the lymphatic system?
considered a part of both the circulatory & immune systems.
What are the components of the lymphatic system?
-lymph
-lymphatic vessels
-lymphoid tissue
What is the function of the lymphatic system?
drainage of extracellular tissue fluid to the blood stream, this fluid is called lymph (clear water)
removal of cellular debris & microorganisms
What are the components of the lymphatic system?
-lymph capillaries
-lymph vessels
-lymph ducts
-lymph nodes
-lymphoid tissues
Lymph cappilaries
network of fine blind end capillaries
drain lymph from extracellular spaces of tissues
What are lacteals?
lacteals are a special type of lymph capillaries that receive absorbed fat from the small intestine.
Lymph vessels
lymph capillaries join to form thin-walled lymph vessels
have numerous valves allowing lymph to pass in one direction
lymph within vessels passes in stations of lymph nodes
lymphatics carry lymph to lymph node are called afferent lymphatics
lymphatics that carry lymph away from L N are called efferent lymphatics
areas with no lymphatics: teeth, bone marrow, cornea & CNS
Lymph ducts
lymphatic vessels unite to form lymph duct
-right lymph duct:
drains lymph from the right side of head, neck, thorax & right upper limb
it end in junction ( ) right subclavian & right internal jugular v.
-thoracic duct:
drains rest of body
begins in the abdomen as cisterna chyli & ascends through the thorax
it ends in junction ( ) left subclavian & left internal jugular v.
What is the definition of lymph nodes?
small oval bodies of lymphatic tissue along lymph vessels through which lymph is filtered on its way to the venous system
What are the important groups of lymph nodes?
axillary: for upper limb & breast
cervical: for head & neck
mediastinal: for thorax
iliac: for the pelvis
aortic: for abdomen
What is the function of lymph nodes?
filtering station as they prevent microorganisms & foreign bodies in lymph from entering the blood.
formation of lymphocytes
formation of antibodies
What are lymphoid tissues?
❖ collection of lymphoid tissue other than lymph nodes eg: palatine tonsils, adenoid, thymus & spleen
What is the function of lymphoid tissues?
defense mechanism for the body.
