i Flashcards
Primary organ of the cardiovascular system
Heart
- It is a four-chambered, hollow, muscular organ that is slightly larger than a man’s closed fist.
- It lies in the anterior medial area of the chest, posterior to the ribcage.
- It is surrounded by a thin fluid-filled sac called the pericardium and its walls have three distinct layers.
- It has two sides, a right and a left.
- It is a double-pump system
Heart
A a medial muscular wall that separates the left and right chambers from each other by partitions
Septa (singular, septum)
A thin fluid-filled sac surrounding the heart
Pericardium
Three layers of the heart
Epicardium, Myocardium, Endocardium
Layer: thin outer layer
* thin, serous (watery) membrane that is continuous with the lining of the pericardium
* covers the heart and attaches to the pericardium
Epicardium
Layer: middle muscle layer
* thick layer of cardiac muscle
* contracts to pump blood into the arteries
Myocardium
Layer: thin inner layer of the heart
* thin layer of epithelial cells that is continuous with the lining of the blood vessels
* lines the interior chambers and valves
Endocardium
- Upper chambers on each side of the heart
- singular (atrium)
- receiving chambers
Atria
- Lower chambers
- pumping or delivering chambers
Ventricles
The valves at the entrance to the ventricles. They are also attached to the walls of the ventricles by thin threads of tissue called chordae tendineae, which keep the valves from flipping back into the atria
Atrioventricular valves (AV)
Chamber: Receives deoxygenated blood from the body via both the superior (upper) vena cava and inferior (lower vena cava) and pumps it into the right ventricle
Right atrium
Chamber: Receives blood from the right atrium and pumps it into the pulmonary artery, which carries it to the lungs to be oxygenated
Right ventricle
Chamber: Receives oxygenated blood from the lungs via the pulmonary veins and pumps it into the left ventricle
Left atrium
Chamber: Receives blood from the left atrium and pumps it into the aorta. The walls of this are nearly three times as thick as those of the right ventricle owing to the force required to pump the blood into the arterial system
Left ventricle
These are valves that exit the ventricles; they are crescent-shaped like a half moon
Semilunar valves
Valves:
* Blood flows from this through the Mitral valve and in the left ventricle
Blood Vessels:
* Oxygenated blood comes from the lungs and enters the heart from the Pulmonary veins
Left atrium
Valves:
* Blood is pumped from this through the Aortic valve and into the aorta
Blood Vessels:
* Oxygenated blood leaves the heart from the Aorta
Left ventricle
Valves:
* Blood flows from this through the Tricuspid valve and into the right ventricle
Blood Vessels:
* Deoxygenated blood enters the heart from the Vena cava (superior and inferior)
Right atrium
Valves:
* Blood is pumped from this through the Pulmonary valve and into the pulmonary artery
Blood Vessels:
* Deoxygenated blood exits the heart through the Pulmonary artery towards the lungs
Right ventricle
The left and right ventricles are surrounded by a large layer of cardiac muscle which allows the pumping mechanism of the heart to exist
* it occurs as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body
cardiac cycle
Two phases of the cardiac cycle:
Systole and Diastole
It occurs when the heart contracts to pump blood out. The semilunar valves are open while the atrioventricular valves are closed. The aortic valve allows blood to be pumped from the left ventricle into the aorta. The pulmonary valve allows blood to be pumped from the right ventricle into the pulmonary artery.
Systole
It occurs when the heart relaxes after contraction. The atrioventricular valves open while the semilunar valves are closed. The mitral valve (bicuspid) allows blood to enter from left atrium into the left ventricle. The tricuspid valve allows blood to enter from the right atrium into the right ventricle.
Diastole
What valve is open in systole?
Semilunar valves
What valve is closed in systole?
Atrioventricular valves
What valve is open in diastole?
Atrioventricular valves
What valve is closed in diastole?
Semilunar
What is responsible for the delivery of oxygen and nutrients to all the tissues of the body to maintain their function and homeostasis?
Blood
- It is the movement of blood from the heart to the surrounding tissues and organs, and back to the heart.
- It includes all arteries that carry oxygenated blood from the left ventricle to systemic capillaries, as well as the veins and venules that return deoxygenated blood to the right atrium after flowing through body organs.
Systemic circulation
What is the color of the blood leaving the aorta and flowing through the systemic arteries?
Bright Red
What is the color of the blood as it loses of its oxygen and picks up carbon dioxide?
Dark Red
It is is the movement of deoxygenated blood from the heart and towards the lungs where gas exchange occurs. The blood then returns to the heart oxygenated.
Pulmonary circulation
They are tube-like structures capable of expanding and contracting and consist of three types.
Blood vessels
What are the three types that blood vessels consist of?
Capillaries, Arteries, Veins
These are microscopic blood vessels through which materials are exchanged between blood and tissue cells. These tiny hair-like vessels cover every organ and structure throughout the body. Every cell in the body must be able to make contact with this to receive oxygen and nutrients and rid itself of waste products.
* tiny: smallest - metabolic exhange
* has three types: continuous, fenestrated, sinusoid
Capillaries
These carry blood away from the heart. They carry oxygenated blood (except for the pulmonary artery). They have thick elastic walls that expand and contract. These can be felt to have a “pulse” when a wave of blood is pushed through. The lumen (the hollow passageway) of this is narrower than the vein.
* Alis- away: thicker walls; O2; “pulse”
Artery
Smaller arteries
Arterioles
What can be felt to have in an artery when a wave of blood is
pushed through?
“pulse”
Is the lumen of the artery narrower or wider than the vein?
Narrower
These transport blood towards the heart. These carry deoxygenated blood (except for the pulmonary veins). They have thinner walls and area not as elastic.They also have small valves which prevent the backflow of blood
* Valik-towards; thinner walls; CO2
Veins
Smaller veins?
Venules
Three layers of the blood vessels
- Tunica intima
- Tunica media
- Tunica externa
Layer of the blood vessel:
* Innermost layer (towards the lumen)
* Comprised of a single layer of endothelial cells
Tunica intima
Layer of the blood:
* Middle layer
* Comprised of smooth muscle cells, elastic and connective
tissue
* The layer is much thicker in arteries, and veins have fewer elastic fibers
Tunica media
Layer of the blood:
* Outermost layer
* Also known as the tunica adventitia
* composed entirely of connective fibers and surrounded by an external elastic lamina which functions to anchor vessels with
Tunica externa
Three types of capillaries:
Continuous, fenestrated, sinusoid
Type of capillary:
* most common type
* junctions to prevent fluid leakage
* mass cross via transfusion
Continuous Capillary
Type of capillary:
* tight junctions
* fenestrations
* allow greater exchange of materials
* endocrine glands, intestinal walls, colloid plexus
Fenestrated Capillary
Type of capillary:
* discontinuous
* organs where exchange of macromolecules occur
* bone marrow
Sinusoid Capillary
Two groups of the veins of the arm
Deep and Superficial
Except for the axillary veins, these are arranged in pairs, one on either side of the various arteries
Deep veins
- This is a direct continuation of the basilic vein, crosses the axilla and becomes the subclavian vein at the outer border of the first rib. Its branches correspond to those of the axillary artery, except for the thoracoacromial, which joins the cephalic vein.
- They receives the brachial veins in the lower portion of the axilla and the cephalic vein in the upper portion of the axilla.
Axillary Vein
These veins of the upper limb are the veins selected for most elective venipuncture.
Superficial veins
From the palmar aspect of the hand, most blood flows to the ——— of the hand, especially through the intercapitular veins that lie between the heads of the ——– bones (aka knuckles) and around the margins of these heads.
Dorsum; metacarpal
Two major veins arise from this dorsal venous network:
Cephalic vein & basilic vein
Dorsal venous network: Major vein:
* This arises from the radial aspect of this network
* side of thumb
Cephalic vein
Dorsal venous network: Major vein:
* This rises from the ulnar side
* side of pinky; near the body
Basilic vein
Factors [judgment of the site for venipuncture]:
- patient’s age
- diagnosis
- type of tests
- current condition
- volume of sample needed
- current therapy
- condition of the superficial veins
- relationship of the vein to other anatomic structures
- duration of the venipuncture
- body physique (size) of the patient
- type of intravenous procedure
The most common site for venipuncture:
Antecubital area
This area is located at the bend of the elbow also called the antecubital fossa.
antecubital area
Antecubital means?
“in front of the elbow”
Fossa means?
a shallow depression
- It is the shallow depression in the arm that is anterior to (in front of) and below the bend of the elbow.
- It is the first choice location for venipuncture because several major arm veins lie close to the surface in this area, making them relatively easy to locate and penetrate with a needle.
antecubital (AC) fossa
These major superficial veins are referred to as —?
antecubital veins
Two basic vein arrangements:
H- and M-shaped patterns
- It is displayed by approximately 70% of the population and includes the median cubital vein, cephalic vein, and basilic vein.
H-Shaped Antecubital Veins
Median cubital vein, Cephalic vein, Basilic vein
H-Shaped Antecubital Veins
H-Shaped Antecubital Veins: Part?
* Located near the center of the antecubital area, it is the preferred vein for venipuncture in the H-shaped pattern.
* It is typically larger, closer to the surface, better anchored, and more stationary than the others, making it the easiest and least painful to puncture and the least likely to bruise.
Median cubital vein
H-Shaped Antecubital Veins: Part?
* Located in the lateral aspect of the antecubital area, it is the second choice vein for venipuncture in the H-shaped pattern. It is often harder to palpate than the median cubital but is fairly well anchored and often the only vein that can be palpated (felt) in obese patients.
Cephalic vein
H-Shaped Antecubital Veins: Part?
* A large vein located on the medial aspect (inner side) of the antecubital area, it is the last-choice vein for venipuncture in either venous distribution pattern. It is generally easy to palpate but is not as well anchored and rolls more easily, increasing the possibility of accidental puncture of the anterior or posterior branch of the medial cutaneous nerve (a major nerve of the arm) or the brachial artery, both of which commonly underlie this area. Punctures in this area also tend to be more painful.
Basilic vein
The veins that form in this include the cephalic vein,
median vein, median cephalic vein, median basilic vein, and basilic vein.
M-Shaped Antecubital Veins
Median vein, Median cephalic vein, Median basilic vein
M-Shaped Antecubital Veins
M-Shaped Antecubital Veins: Part?
* Also called the intermediate antebrachial vein
* The first choice for venipuncture in the M-shaped pattern because it is well anchored, tends to be less painful to puncture, and is not as close to major nerves or arteries as the others, making it generally the safest one to use.
Median vein
M-Shaped Antecubital Veins: Part?
* Also called the intermediate cephalic vein
* The second choice for venipuncture in the M-shaped pattern because it is accessible and is for the most part located away from major nerves or arteries, making it generally safe to puncture. It is also less likely to roll and relatively less painful to puncture.
Median cephalic vein
M-Shaped Antecubital Veins: Part?
* Also called the intermediate basilic vein
* The last choice for venipuncture in the M-shaped pattern (even though it may appear more accessible) because it is more painful to puncture and, like the basilic vein, is located near the anterior and posterior branches of the medial cutaneous nerve and the brachial artery.
Median basilic vein
True or False:
* According to CLSI, although the larger and fuller median, median cubital, cephalic, and median cephalic veins are used most frequently, veins on the back of the hand and wrist are also not for venipuncture
False, veins on the back of the hand and wrist are also
acceptable for venipuncture
- These are veins that run down the middle of the hand
- can also be used for intravenous infusions as well as for drawing blood if the antecubital vein isn’t accessible
- Hand veins aren’t as large as the veins in the forearm and antecubital fossa.
Dorsal Metacarpal Veins
- Because of the potential for significant medical complications such as phlebitis or thrombosis, veins of these organs must not be used for venipuncture without permission from the patient’s physician.
- Puncture of the femoral vein is performed only by physicians or specially trained personnel.
Leg, Ankle, and Foot Veins
- These are not used for routine blood collection.
- Punctures of these requires special training to perform, is more painful and hazardous to the patient, and is generally limited to the collection of arterial blood gas (ABG) specimens for the evaluation of respiratory function.
Arteries
