Veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology transport deoxygenated blood and waste products from capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries: Histology in the periphery back to the heart. Veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology are capacitance vessels Capacitance vessels Veins: Histology, meaning that they can stretch significantly, increasing the volume of fluid they can hold without significantly increasing their pressure. Veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology respond to stimulation from the ANS ANS The ans is a component of the peripheral nervous system that uses both afferent (sensory) and efferent (effector) neurons, which control the functioning of the internal organs and involuntary processes via connections with the CNS. The ans consists of the sympathetic and parasympathetic nervous systems. Autonomic Nervous System: Anatomy, as arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology do, but to less of an extent. The effects of either venoconstriction or venodilation, however, impact venous capacitance. As veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology constrict, capacitance goes down, forcing more blood back to the heart (i.e., increasing venous return), which in turn affects the amount of blood that can be pumped out of the heart on the next heartbeat. Thus, changes in venous capacitance can significantly affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) output (CO). These effects can be plotted on graphs known as venous function curves.
Last updated: 4 Dec, 2021
Veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology are tubular collections of cells that transport deoxygenated blood and waste products from capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries: Histology in the periphery of the body back to the heart.
Pressure in the venous system is too low to spontaneously push blood against gravity; moving blood against gravity up to the heart requires:
Muscle
pump
Pump
ACES and RUSH: Resuscitation Ultrasound Protocols and venous valves:
As
skeletal muscles
Skeletal muscles
A subtype of striated muscle, attached by tendons to the skeleton. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
Muscle Tissue: Histology surrounding a vein contract, they compress the vessel, forcing the blood to move forward.
One-way valves
One-way valves
Veins: Histology within the
veins
Veins
Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia.
Veins: Histology prevent back-
flow
Flow
Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls.
Vascular Resistance, Flow, and Mean Arterial Pressure and ensures blood only flows in one direction.
Venous pressure:
Smooth muscle in vein walls can contract or relax, changing the luminal diameter within a vein. Sympathetic stimulation causes venoconstriction, reducing venous capacitance and forcing more blood back to the heart. This increases
preload
Preload
Cardiac Mechanics, which in turn can increase
stroke volume
Stroke volume
The amount of blood pumped out of the heart per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
Cardiac Cycle and
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) output (CO).
Venous function curves (also known as systemic vascular function curves) plot central venous pressure Central venous pressure The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity. Central Venous Catheter ( CVP CVP The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity. Central Venous Catheter) against CO.
Cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) output:
Central venous pressure Central venous pressure The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity. Central Venous Catheter:
Example of a venous function curve:
Central venous pressure
Central venous pressure
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter (
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter) is plotted along the Y-
axis
Axis
The second cervical vertebra.
Vertebral Column: Anatomy and
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) output (CO) is plotted on the X-
axis
Axis
The second cervical vertebra.
Vertebral Column: Anatomy. There is an inverse linear
relationship
Relationship
A connection, association, or involvement between 2 or more parties.
Clinician–Patient Relationship between the 2 variables until a CO is reached, at which point
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter drops to 0 (because
veins
Veins
Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia.
Veins: Histology have the ability to collapse).
Venous function curve shape:
Mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion systemic filling pressure ( mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion circulatory pressure)
Factors affecting the shape/location of the curve:
Venous function curve showing the effects of systemic vascular resistance Vascular Resistance The force that opposes the flow of blood through a vascular bed. It is equal to the difference in blood pressure across the vascular bed divided by the cardiac output. Vascular Resistance, Flow, and Mean Arterial Pressure (SVR) increasing
Image by Lecturio.Venous function curve showing the effects of systemic vascular resistance Vascular Resistance The force that opposes the flow of blood through a vascular bed. It is equal to the difference in blood pressure across the vascular bed divided by the cardiac output. Vascular Resistance, Flow, and Mean Arterial Pressure (SVR) decreasing
Image by Lecturio.Venoconstriction:
Combined venous/
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) function curve illustrating the
equilibrium
Equilibrium
Occurs when tumor cells survive the initial elimination attempt These cells are not able to progress, being maintained in a state of dormancy by the adaptive immune system. In this phase, tumor immunogenicity is edited, where T cells keep selectively attacking highly immunogenic tumor cells.This attack leaves other cells with less immunogenicity to potentially develop resistance to the immune response.
Cancer Immunotherapy point between
central venous pressure
Central venous pressure
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter (
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter) and
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) output (CO):
A
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter of 2
mm
MM
Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies.
Multiple Myeloma Hg and a CO of 5 L/min is the functional average for most people.
Clinical scenario #1: MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction leading to a decrease in inotropy
Venous function curves illustrating how the body can increase blood volume to compensate for a decrease in inotropy:
(Left) When inotropy is decreased,
central venous pressure
Central venous pressure
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter (
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter) increases, whereas
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) output (CO) decreases. However, expanding the intravascular volume can compensate for these changes to improve CO (right).
Clinical scenario #2: hemorrhage
Venous function curves illustrating how an increase in inotropy (i.e., contractility) compensates for a decrease in blood volume:
(Left) When volume is decreased,
central venous pressure
Central venous pressure
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter (
CVP
CVP
The blood pressure in the central large veins of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
Central Venous Catheter) decreases along with
cardiac
Cardiac
Total Anomalous Pulmonary Venous Return (TAPVR) output (CO). However, increasing inotropy can compensate for these changes to improve CO (right).