Module 6 Circulatory System Flashcards
What is the function of the Circulation system?
To Transport blood + nutrients to all parts of the body.
To continually perfusion, oxygenate, and nourish all vital organs in the body.
Remove wastes including CO2
The heart is the main pump of the body, where is it located?
Lies in the mediastinum, behind the sternum.
-between ribs 2 to 6
Approx 2/3 of is left on the midline, the other 1/3 is to the right.
Where does the heart lay on posterior lay?
T5 - T8
Where does the Apex and base of the heart lie?
Apex = on the diaphragm, pointing left.
Base = just below the second rib.
Blood vessels: where does blood flow for Arteries/arterioles?
Carry blood away from the heart.
The exception is the pulmonary artery which carries deoxygenated blood from the right side of the heart to the lungs for oxygenation
Blood vessels: where does blood flow for veins/venues?
Carry blood toward the heart
The exception is the pulmonary veins.
Blood vessels: where does blood flow for Capillaries?
microscopic vessels that carry blood from arterioles to venues.
What are 4 types of Arteries?
Elastic (conducting arteries)
- Aorta + big branches
Muscular (distributing) arteries
- Cary blood further away from heart
- Think Brachial
Arterioles (resistance) vessels
- Regulate blood flow to end organs + tissues
- Regulates BP
Metarterioles
- Connect arterioles and capillaries
Which vessel does primary gas/nutrient exchange occur?
Occurs within capillary beds/networks.
They carry blood from arterioles to venues.
Microscopic is size? - one RBC at a time
Arterioles + capillaries + Venules = microcirculation.
What are 3 types of Capillaries?
Continuous capillaries
Fenestrated capillaries
Sinusoid
Why are Veins and venues referred to as Capacitance vessels?
They have the capacity to take on large volumes of blood without rupture
It is a reflection of their ability to stretch.
Recall, they use valves to keep blood moving.
what are the 3 main layers to a vessel structure?
(vessel it refers to veins or artery’s
Tunica external - found in all arteries and veins
Tunica media - found in all arteries and veins
Tunica intima - found in all blood vessels, only layer present
Vessel structure: What are Endothelial cells?
What are its 3 functions?
Endothelial cells are lining that cover blood vessels in the entire vascular tree—capable of self reproduction
(1) They provide a smooth luminal surface that protects intravascular coagulation.
(2) Intercellular clefts, cytoplasmic pores, and fenestrations allow exchange to occur between blood and tissue fluid
(3) capable of secreting a number of substances (NO)
Vessel structures: what is the composition of Elastic fibres and what is its main function?
Elastic fibres are composed of insoluble protein called elastin—form elastic networks.
They can stretch up 100% under physiological conditions.
Their function is to help regulate BP by creating passive tension.
Vessel structures: What are smooth muscle fibres located and their purpose?
Smooth muscles are present in all segments of vascular system expect capillaries, and few in veins.
Most numerous in elastic and muscular arteries
They exert active tension in vessels when contracted
They’re directly connected to the autonomic nervous system
Collagen fibers what is the range they can stretch under physiological conditions?
2-3%
What is the function of Collagen fibers?
To strengthen and keep lumen of vessels open.
What are 2 types of ciruclation?
Systemic circulation
Pulmonary circulation
What is systemic circulation?
carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body.
course description
blood flows from the left ventricle of the heart through blood vessels to all parts of the body (except gas exchange tissues of lungs) and back to the right atrium
What is pulmonary circulation?
the system of transportation that shunts de-oxygenated blood from the heart to the lungs to be re-saturated with oxygen before being dispersed into the systemic circulation
Course description
: venous blood moves from right atrium to right ventricle to pulmonary artery to lung arterioles and capillaries, where gases are exchanged; oxygenated blood returns to left atrium by pulmonary veins; from left atrium, to the left ventricle.
Main arteries give off branches, which continue to rebranch, forming arterioles and then capillaries:
what is the terminal (end) arteries function?
supplies the only supply of oxygen or nutrients to a particular area or organ
What is Arterial anastomoses? why would they form?
IMPORTANT.
The merger of one artery directly into another.
They form in response to disease (to bypass a blocked artery for ex.)
Why is arterial anastomoses important?
Allows for collateral circulation (protective function;allows detours)
What is Arterio-venous anastomoses?
IMPORTANT
basically, SHUNTS
that occur when blood flows from an artery directly into a vein.
Where does blood from the head, neck, upper extremities, and thoracic cavity (except lungs) drain into?
The superior vena cava
Where does venous blood from
thoracic organs drain into?
directly into superior vena cava or azygo vein.
Venous blood from the lower trunk, lower extremities, hepatic portal circulation renal system drain into?
the inferior vena cava
hepatic portal circulation
the venous system that returns blood from the digestive tract and spleen to the liver
(where raw nutrients in blood are processed before the blood returns to the heart).
Veins from the spleen, stomach, pancreas, gallbladder, and intestines send blood to the liver by the ___?
Hepatic portal vein
The hepatic veins function and relation to the inferior vena cava?
The hepatic vein drains blood from the liver into the inferior cava
The blood in the liver comes from capillary beds (mix of venous and arterial)
What are the 2 main functions of blood?
Delivery and pickup transport medium.
Body head regulation
What enables blood to absorb large quantities of heat? And why is it important?
A high specific heat capacity and conductivity.
It is important because it allows blood to transfer heat from core to surface for dissipation.
Blood volume varies by size of person, what is the aprox. average of blood in a adult male?
5 L
What is the general composition of whole blood?
55% plasma
45% formed elements.
What is composition of plasma?
Protein (7%)
Water (91%)
other solutes (2%)
what are the 4 proteins found in blood?
Albumins (57%)
Globulins (38%)
Fibrinogen (4%)
Prothrombin (1%)
In blood, what are the 5 solutes found in water
Ions
nutrients
waste products
gasses
regulatory substances
Of a persons total body weight, what is the division between blood and other fluids +tissues?
Not as important?
Blood = 8%
Other fluids/tissues = 92%
what is a hematocrit?
Important.
The percentage of RBC in your blood.
45% of it is in formed elements.
What is the makeup of formed elements?
Platelets [Thrombocytes]
Leukocytes [WBC]
Erythrocytes (majority) [RBC]
What are the 5 things that make up Leukocytes in your blood?
Slide 33.
Neutrophils (60-70%)
Lymphocytes (20-25%)
Monocytes (3 -8%)
Eosinophils (2-4)
Basophils (0.5 - 1%)-