Circulatory System (Exam II) Flashcards by Annabella Moody

Primary function of the circulatory system

transport O2 (to tissue)
transport CO2 (to tissue)
transport nutrient (to tissue)
transport metabolic waste (from tissue)

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Secondary functions of the circulatory system

Thermoregulation
Transport of immune cells
Transport of hormones

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Vascular system consisting of heart and blood vessels

Blood vascular system

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Two components of the circulatory system

Pulmonary circulation
Systemic circulation

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Describe the route of pulmonary circulation

Right atrium —> Right ventricle —> Pulmonary artery —> lungs —> pulmonary vein —>Left atrium

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Describe the path of systemic circulation

Left atrium —> left ventricle —> aorta —> rest of body

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Extravascular fluid

Lymph

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Passive drainage system for returning extravascular fluid (lymph) to blood vascular system

Lymph vascular system

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The lymph vascular system lacks:

An intrinsic pump

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Due to absence of pump, the lymph vascular system relies on: (2)

Muscle contraction
Body movement

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Type of circulatory system humans have

Closed

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The closed circularity system is divided into pulmonary circulation that occurs on the _____ side of the heart and systemic circulation that occurs on the _____ side of the heart

Pulmonary (right side)
Systemic (left side)

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The two major types of circulatory system

Open
Closed

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Circulatory system in which there are no vessels but contains a heart that pumps fluid around to circulate in body and bathes tissues

Open

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Limiting factor of an open circulatory system

Body size

(Once you exceed certain body size, it becomes less efficient especially in lower extremities)

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Circulatory system in which the blood is contained within vessels/plumbing of the body

Closed

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The systemic circulatory system takes _____ and distributes it to rest of body

Oxygenated blood

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Blood vessels of the circulatory have a common basic structure with:

Three concentric layers

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The three concentric layers of the blood vessels are commonly referred to as:

Tunics

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Innermost vascular tunic

Tunica intima

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Type of cells comprising the tunica intima

Simple squamous endothelial cells lining lumen

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Describe thickness of tunica intima

1-2 cells thick; very thin

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The tunica intima forms a ______ supported by _____

Semi-permeable barrier
Basement membrane

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Specialized discontinuous junctions contained between the endothelial cells of the tunica intima

Fascia occludens

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Function of the fascia occludens of the tunica intima

Allow WBC to extravasate

Tunica intima contains variable amounts of

Subendothelial connective tissue

If present, separates the tunica intima and a tunica media

Internal elastic lamina

Makes up the internal elastic lamina

Elastic fibers

Higher variable middle layer (vascular tunic)

Tunica media

Tunica media is comprised of

Smooth muscle cells Fibroblastic connective tissue

In arteries, the tunica media is:

Thickest of layers

In arteries, the tunica media may contain:

Reticulin (type III collagen) Elastic fibers

In veins, the tunica media tends to be:

Thinner

What is Reticulin

Type III collagen

If present, located between tunica media and tunica adventitia

External elastic lamina

What two layers may or may not be present in a vessel

Internal & external elastic lamina

Describe arrangement of elastic fibers in external elastic lamina

Not well organized

determines if an inner or outer elastic lamina will be present

Size of vessel

Outermost layer (vascular tunic)

Tunica adventitia

Vascular tunic comprised of loose fibroblastic connective tissue

Tunica adventitia

Tunica adventitia contains

Loose fibroblastic connective tissue Fibroblasts Collagen Elastic fibers Smooth muscle cells

Describe thickness of tunica adventitia in arteries

Thin

Describe thickness of tunica adventitia in veins

Thickest

In larger vessels, tunica adventitia may contain:

Vasa vasorum

Small blood vessels that supply the tunica media and tunica adventitia in both large arteries and veins

Vasa vasorum

Types of nerves contained within the tunica adventitia

Autonomic nerves

The autonomic nerves of the tunica adventitia

Nervi vasculares

Responsible for smooth muscle contraction in vessel wells (vasoconstriction & vasodilation)

Nervi vasculares

Two functions of the Nervi vasculares

Vasoconstriction Vasodilation

Most common fiber of tunica adventitia

Fibroblasts

Decrease in lumen diameter due to the action on smooth muscle of tunica media by sympathetic post-ganglionic nerve fibers

Vasoconstriction

Vasoconstriction is due to the action of what nerve fibers

Sympathetic, post-ganglionic

Three debated causes of vasodilation

1- absence/inhibition of sympathetic stimulation 2- accomplished via indirect parasympathetic innervation 3- when oxygen tension in cells is low causing smooth muscle to relax

When endothelial cells to release NO which secondarily causes smooth muscle to relaxe- this is an example of vasodilation caused by

Indirect parasympathetic innervation

In response to low oxygen tension smooth muscle in walls of arterioles:

Relax, causing vasodilation

Specialized sensory receptors located in the walls of blood vessels (2)

Baroreceptors Chemoreceptors

Specialized sensory receptor located in the carotid sinus and aortic aortic arch; detect BP

Baroreceptors

Baroreceptors detect blood pressure by:

Detecting stretch in walls of blood vessel

Specialized sensory receptor located at bifurcation of carotid aorta and in aortic bodies in aortic arch; function to detect changes in O2, CO2 and pH

Chemoreceptors

Chemoreceptors function by:

Detecting changing in composition of blood (O2, CO2, pH)

How do chemoreceptors monitor pH

Monitoring hydrogen ion concentration

System that conducts blood AWAY from the heart and TO the capillary bed

Arterial system

System that returns blood FROM capillaries and TO the heart

Venous system

Cyclical pumping of the heart causes:

Pulsatile blood flow

Contractions of the ventricles

Systole

Systole causes

Pressure wave

Relaxation of the heart

Diastole

Diastole causes:

Decrease in pressure

Normal blood pressure

120/80 mm Hg

Expansion and recoil of _____ maintains BP

Elastic arteries

Regulation of BP is accompanied by changes in:

Diameter of blood vessels

Regulation of blood pressure is accompanied by changes in diameter of blood vessels; it occurs via _____ control of _______ in vessel walls

Sympathetic control Smooth muscle

Arteries contain large amounts of ____ and ____

Elastin Smooth muscle

In arteries the vessel wall is _____ relative to lumen diameter

Thick

Two arteries that carry unoxygenated blood

Pulmonary Umbilical

Determines the name of the vessel

Direction of blood flow relative to the heart

Causes an ejection of blood volume in the heart

Systole

A drop in BP is commonly seen in what phase of BP

Diastole

In the case of elastic arteries, the large volume of elastin in the walls of these vessels minimizes ____ and encourages ____

Expansion Elastic recoil

Large amounts of collagen and elastin in the arterial wall promotes a more:

Rigid vessel

When blood vessels constrict, pressure:

Increases

When blood vessels relax, pressure:

Decreases

BP throughout the body is regulated by change in diameter and vessel size- accomplished by sympathetic control of smooth muscle in the:

Tunica media

Size of elastic arteries

Greater than 1 cm in diameter

Large conducting blood vessels; receive blood directly from heart

Elastic arteries

Examples of elastic arteries (4)

1- aorta 2- common carotid 3- subclavian 4- pulmonary

Elastic arteries contain sheets of elastic tissue in the:

Tunica media

In elastic arteries, the sheets of elastic tissue in the tunica media helps to maintain:

BP between systole and diastole

Thickest layer of elastic artery

Tunica media

Elastic arteries possess both:

Internal & external elastic lamina

If the blood vessel takes up the entire side it’s most likely:

Elastic artery

Diameter of muscular arteries

2-10nm in diameter

Medium-sized distributing arteries

Muscular arteries

Arteries that have more smooth muscle and less elastin the tunic media when compared to elastic arteries

Muscular arteries

Thickest layer in muscular artery

Tunica media

A muscular artery contains a distinct _____ ; while a larger muscular artery may also contain ____

Internal elastic lamina External elastic lamina

Diameter of arterioles

10-100 micrometers

Vessels containing relatively little smooth muscle

Arterioles

Tunica media of arterioles is around:

2-3 cells thick

Absent in arterioles

Elastic laminae

Terminal branches of arterial system supply:

Capillaries beds

Arterioles provide the major sites of:

Vasoconstriction & vasodilation

Arterioles regulate distribution of capillaries via:

Pre-capillary sphincter

Intermittent rings of smooth muscle within walls of arterioles

Pre-capillary spinchters

Small diameter arterioles, intermediate in size between arterioles and capillaries

Metarterioles

Metarterioles are in between size of:

Arterioles & capillaries

In general, the amping of smooth muscle _____ with increase in diameter of vessel (& relative amount of connective tissue ____)

Increases Decreases

Last blood vessels you would see before capillary begins

Metaarterioles

In a Metarterioles, the tunica media has become so thin that it is no longer ______

Continuous

Concerned with exchange of gases, fluids, nutrients, metabolites and waste products

Microcirculation

Components microcirculation is concerned with (exchange of)

Gases Fluids Nutrients Metabolites Waste products

Microcirculation occurs primarily within ____ but also includes ___ & ____

Capillaries Arterioles & venules

Thin walled vessels aroun 8-10 micrometers in diameter

Capillaries

Capillaries are lined by thin _____ layer of ____ cells

Single Endothelial

Capillaries are supported by (2):

Basal lamina Small # of pericytes

Regulate blood flow to capillaries to themselves

Arterioles

Major sites of exchange of nutrients and oxygen in tissues; very thin walled vessels

Capillaries

Generally, fluid leaves circulatory system in:

Capillaries

Capillaries lack ____ & _____ so they are nothing more than tunica intima with some pericytes and collagen

Tunica media Tunica adventitia

Derived from same precursor cells as endothelial cells

Pericytes

Pericytes can differentiate into: (following injury)

Endothelial cells Smooth muscle cells

Capillaries do not exhibit ______ themselves

Vasomotor activity

Vasodilation & vasoconstriction accomplished via smooth muscle contraction in arterioles & pre-capillary sphincters result in:

Passive change in capillary diameter

Types of capillaries

1- continuous 2- fenestrated 3- discontinuous

Type of capillary where endothelium forms continuous lining

Continuous capillary

Most common type of capillary

Continuous

Locations of where you may find continuous capillaries (3)

1- muscle 2- lung 3- CNS

Type of capillary where the endothelium forms a continuous lining to prevent lymph from leaking out

Continuous

Type of capillary in which the endothelial cells possess pores or fenestrae within cells

Fenestrated capillary

In fenestrated capillaries, where are the fenestrae located in relation to the endothelial cell

Within

Capillaries allowing for large molecule weight molecules to pass through the endothelial lining or with hormones - you want them to leave the vessel and go to surrounding tissue

Fenestrated

Location fenestrated capillaries may be found (2)

1- endocrine system 2- GI tract

Type of capillary in which basal lamina is NOT continuous

Discontinuous capillary

Type of capillary in which the endothelial cells are separated by large gaps BETWEEN cells

Discontinuous

Most leaky type of capillary

Discontinuous

Discontinuous capillaries may form large open spaces called:

Sinusoids

Location discontinuous capillaries may be found (4):

1- liver 2- spleen 3- bone marrow 4- Inn

Transport across capillaries may occur via: (3)

Fenestrae Transcytosis Diapedesis

Label the type of capillary and label A, B, C

1- continuous 2- fenestrated 3- discontinuous A- junction B- fenestra C- spaces

System that functions as low pressure collecting system for returning blood from capillary beds to heart

Venous system

Venous system contains vessels with ____ walls and ____ relative luminal diameter in comparison to corresponding arteries

Thinner Larger

In the venous system there are few layers of smooth muscle in _____ compared to similar sized arteries

Tunica media

The thickest layer in veins

Tunica adventitia

Prevents back flow in veins (especially in limbs and thorax)

Valves

Valve failure in legs results in:

Varicose veins

Why is there a higher likelihood of stagnation in the veins (versus the arteries)

Gravity

Because of _____ its okay to remove veins, the blood will just go to a different vein route

Collateral circulation

Small veins

Venules

Lack elastic lamina and potentially even tunica media (in the smaller ones)

Venules

Around 10-50 micrometers in diameter; both tunica media and adventitia is reduced or absent

Post-capillary venules

Post-capillary venules is the preferential site for:

Diapedesis

Venules drain into larger ______ then into ______

Collecting venules Muscular venules

Type of venule with thin smooth muscle layer in tunica media

Muscular venules

Type of substances that act on venules

Vasoactive substances

Examples of vasoactive substances (2)

Histamine Serotonin

Vasoactive substances ____ intercellular spaces

Enlarge

Ultimately vasoactive substances

Increase permeability of vessel

smallest venules located immediately after capillary bed

Post-capillary venules

Downside of vasodilation in venules

Leakiness= edema

Large and medium sizes veins

Muscular veins

Small muscular veins may or may not contain

Internal elastic lamina

Medium muscular veins contain only:

Internal elastic lamina

Large muscular veins contain:

Internal & external elastic lamina

_____ in the tunica media of veins controls luminal diameter of muscular veins and venules

Smooth muscle

To determine difference between muscular artery and vein, you look at:

Wall thickness Lumen diameter

Direct connections between arterial & venous system

AV shunts

AV shunts bypass:

Capillary bed

AV shunts are a type of:

Anastomoses

AV shunts are commonly found in _____ and function in _____

Skin Thermoregulation

Vein or artery directly connecting two capillary beds

Portal vessels

Example of portal vessels

Hepatic portal vein

____ of the venous portal system connects the capillary bed of the small intestine to the capillary bed of the liver

Hepatic portal vein

The idea is that in AV shunts, blood detours around capillary bed to:

Preserve heat

When endothelial vessel is damaged, cholesterol adheres to exposed proteins to form a:

Cholesterol patch

once the endothelium has healed (after vessel damage and formation of cholesterol patch)

Cholesterol patch is reabsorbed

When endothelium of vessel is damaged, cholesterol adheres to:

Exposed proteins

After healing of damaged endothelial vessel the cholesterol is phagocytosed by:

Macrophages

After healing and after the cholesterol is phagocytosed by macrophages, further phagocytosis occurs by:

Endothelial & subintimal cells

The endothelial & subintimal cells that later phagocytose the cholesterol patch form

Foam cells

Type of cells composing foam cells

Endothelial & subintimal

Purpose of formation of choleserol patch following damage of endothelium

Prevents initiation of clotting cascade

Following damage endothelium of vessel, if inflammatory response becomes chronic this results in (condition):

Atherosclerosis

In atherosclerosis the plaque can be:

Generalized or focal

If you have high cholesterol, and the cholesterol patch persists, the macrophages come in and try to engulf the cholesterol, but there is so much cholesterol that the macrophages have to recruit other cells to come in, and these different cells have:

Cholesterol vacuoles

In atherosclerosis all the recruited cells with cholesterol vacuoles begin to take on the appearance of:

Brown fat

When the cholesterol patch persists (in case of atherosclerosis) we get the development of:

Foam cells

Minimizes the effects of atherosclerosis

Vitamin C

In the later stages of atherosclerosis, you get the proliferation of ____ cells and formation of ____

Smooth muscle cells Fibrous connective tissue capsule

In atherosclerosis, the formation of the connective tissue capsule around the plaque is formed by fibroblasts migrating in and producing ______ around the edges of the plaque

Collagen

The presence of collagen around the plaque in atherosclerosis, results in the limited ability for _____ and ___ to get into the plaque, ultimately resulting in _____ and ____

Oxygen & nutrients Necrosis & secondary calcification

In atherosclerosis the necrosis and and secondary calcification is also known as

Hardening of artery

In atherosclerosis, as plaque thicken and enlarge the vessel lumen size decreases and you get corresponding:

Elevated systolic BP

Atherosclerosis is often associated with what condition:

Hypertension

Most common cause of ischemic heart disease

Atherosclerosis

In ischemic heart disease (due to atherosclerosis) the lumen of the coronary artery may decrease by:

90%

Gradual narrowing of lumen in vessel

Stenosis

Gradual narrowing (stenosis) of vessel by plaque

Thrombosis

Thrombosis can also be referred to as ___ of a vessel

Occlusion

As plaque enlarges or if endothelium is damaged it exposes:

Underlying collagen

Decreased oxygen uptake by tissue

Anoxia

When heart becomes anoxic the resulting chest pain:

Angina

______ formation initiates the clotting cascade

Thrombus

Broken off piece of thrombus

Embolus

If piece of thrombus breaks off this causes:

Thromboembolic disease

Sudden occlusion by embolus results in:

Acute ischemic event

During an acute ischemic event, what two symptoms present:

Anoxia Angina

If ischemia is untreated, resulting in death of portion of muscle this is called:

Myocardial infarction

Death of muscle by ischemia

Myocardial infarction

In myocardial infarction what cells are terminally differentiated

Myocytes (cardiac muscle cell)

Because myocytes are terminally differentiated, they are unable to:

Regenerate

Due to the myocytes inability to regenerate, if a portion of heart muscle dies, we need:

Fibroblasts to produce collagen

Problem with fixing gap in cardiac muscle with collagen rather than muscle:

Collagen isn’t as stretchy like the original muscle was

All healing during MI has occur via:

Fibrosis

Due to the connective tissue replacement (collagen), the loss of contractility results in:

Decreased or partial loss of function

During prolonged ischemia, in addition to MI ____ can also be affected

Heart valves

Inflammation ad thickening of AV valves often associated with valvular incompetence leads to

Increased turbulence & regurgitation

When inflammation and thickening of the AV valves occurs leading to increased turbulence and regurgitation, this leads to what conditions

Vegetative endocarditis Thromboembolic disease

Similar to MI excepting for it affects the brain

Stroke

In a stroke, issues occur because _____ are terminally differentiated

Neurons

cell cycle stage are both myocytes and neurons stuck in

The loss of neurons caused by inability to receive oxygen & nutrients ultimately results in:

Cerebral infarct

Cerebral infarct basically means our cells are ____ and we have a _____

Dead Loss of function

Determines the symptoms and severity of clot in a stroke

Location of clot

Occurs when blood vessels dilate to form thin-walled, balloon-like regions

Aneurism

Aneurisms are common in the:

Aorta Brain

Middle-aged Asian women are at an increased risk of developing ____ (numerous bleeding little blood vessels) and the effect can be cumulative over time

TIAs

The lymph vascular system is structurally similar to:

Veins

Lymph vascular system is structurally similar to veins, but the endothelial cells are:

Thinner and have greater permeability

Lymph endothelial cells are highly active in:

Phagocytosis

The lymph vascular system has a very thin:

Tunica media

_____ are present in the lymph vascular system

Valves

May or may not be present in lymph vascular system

Pericytes & basement membrane

Excess fluid the lymph vascular system drains

Lymph

The lymph vascular system is responsible for drainage of lymph from ______ and returns it to _____

ECS Bloodstream

Lymph is formed as a result of:

High hydrostatic pressure & arterioles

In arterioles, the high hydrostatic pressure exceeds the ____ exerted by plasma proteins

Colloidal on oncotic pressure

In the lymph vascular system, when the high hydrostatic pressure in arterioles exceeds the colloidal oncotic pressure exerted by plasma proteins, this results in leakage of (what & where):

water, electrolytes, & plasma proteins from capillaries into ECS

Lymph is very high in

Protein

ECS is drained by a series of:

Interconnected, blind-ending tubules

ECS is drained by a series of interconnected, blind-ending tubules called:

Lymphatics

The lymphatics converge on the:

Thoracic duct & right lymphatic duct

Largest lymph vessel in body

Thoracic duct

Thoracic duct & right lymphatic duct both contain:

Tunica media

Lymph returns to the bloodstream at junction of:

Left internal jugular vein & left subclavian vein

Because the lymph vascular system relies on body movement and contraction of skeletal muscle, immobility may lead to:

Peripheral edema (swollen feet)

Interspersed along lymph vessels

Lymph nodes

Contain lymphoid tissue for antigenic sampling & recognition; activation of immune cells and production of antibodies

Lymph nodes

Asymmetrical lymph draining is important in:

Tumor metastasis

Thin walled, lack blood, contain smooth, eosinophilic, proteinaceous fluid (lymph), occasional WBCs

Lymph nodes

The basement membrane in lymph nodes is ____ or ____

Rudimentary or absent

Antigen sampling —-> immune activation —-> _______

Lymph trap

In some areas of the body, especially the _____ lymphatic drainage is asymmetrical

Thorax

Disease due to fallarid worm- they like the inguinal lymph nodes & obstruct the return of lymph to the periphery:

Elephantiasis

Circulatory System (Exam II) Flashcards

(253 cards)