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AND VASCULAR SYSTEMS

BLOOD TRANSFUSIONS

Objectives Functions of vessels Layers in vascular walls Classification of vessels Components of vascular walls Control of blood flow in microvasculature Variation in microvasculature Blood barriers Introduction Multicellular Organisms Need 3 Mechanisms ------1. Distribute oxygen, nutrients, and CARDIOVASCULAR SYSTEM

2. Collect waste

3. Transport waste to excretory organs

CARDIOVASCULAR SYSTEM Cardiovascular System

Component function - Produce (systole)

Elastic - Conduct blood and maintain pressure during diastole

Muscular arteries - Distribute blood, maintain pressure

Arterioles - Peripheral resistance and distribute blood

Capillaries - Exchange nutrients and waste

Venules - Collect blood from ()

Veins - Transmit blood to large

Reservoir Larger veins - receive lymph and return blood to Heart, blood reservoir Cardiovascular

System Heart produces blood pressure (systole)

ARTERIOLES – PERIPHERAL RESISTANCE Vessels are structurally adapted to physical and metabolic requirements. Vessels are structurally adapted to physical and metabolic requirements. Cardiovascular System

Elastic arteries- conduct blood and maintain pressure during diastole

Cardiovascular System

Muscular Arteries - distribute blood, maintain pressure

Arterioles - peripheral resistance and distribute blood

Capillaries - exchange nutrients and waste

Venules - collect blood from capillaries (edema)

Cardiovascular System Veins - transmit blood to large veins reservoir Larger veins - receive lymph and return blood to heart, blood reservoir

Volume: 5-6 l = 12-13 pints/ person Classification of Vessel

Size (caliber) Prominent structures in wall Function Layers In Vascular Wall

Layer Composition (Subendothelia ct. )

Tunica media (elastic lamellae, external elastic lamina)

Tunica Adventitia (longitudinal smooth muscle, ) Layers in vascular wall

Muscular

Tunica Intima

Tunica Media

Tunica Adventitia Tunica Intima

Tunica Media

Tunica Adventitia Elastic artery (human )

Tunica Intima

Tunica Media

Elastic Arteries Elastic Artery

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Lots of elastic tissue to help maintain pressure during diastole Elastic artery Muscular artery

Tunica Intima

Tunica Media

Tunica Adventitia Muscular artery (smooth muscle cells in tunica media)

Arteriole

Arterioles

Arteriole

Arteriole - -

Capillary

Capillary Pericyte UT 166

VENULE Venule Venule Collect blood from capillaries (edema)

Arteriole

Capillary

Venule Venule

Venule

Note difference in density of smooth muscle cells. Venule

Muscular Artery Small Large Vein

Large Vein 196 TUNICA INTIMA

TUNICA MEDIA

TUNICA ADVENTITIA

Cardiac Muscle Cardiac Muscle

Intercalated disc Cardiac muscle

Intercalated disc Fascia Adherens Maculae Adherens Gap junctions Lateral portion

Intercalated Disc

Cardiac Muscle is Striated Muscle

Cardiac Muscle

Cardiac Muscle - Diad

Cardiac Muscle mitochondria

Cardiac Muscle

PURKINJE FIBERS Cardiac Muscle PURKINJE FIBERS PURKINJE FIBERS

PURKINJE FIBERS

Vasa Vasorum VESSEL OF VESSELS

THE CORONARY ARTERY IS A VASA VASORUM CONTROL OF BLOOD FLOW: TONE MUSCULAR ARTERY

Tone – state of partial contraction of smooth muscles in arteries and veins that reduces the caliber of the lumen. Innervations of Normal No smooth muscle cells nervous nervous of blood vessels control control controls the tone. Control Of Blood Flow Through Microvasculature

Arterioles

Precapillary sphincters

Metarterioles Arteriolar Functions

Allow sufficient pressure for flow through capillaries Low enough pressure to prevent damage Constant intermittence of blood flow to capillary beds

Autoregulation - smooth muscle cells in arterioles and in pre-capillary sphincters respond to metabolic needs, low o2 tension, then relax  increased blood flow (independent of nervous system)

Endothelium - active cell

Has enzymes and receptors Transport without much energy Flat for less turbulence

Negatively charged surface Not wetable surface

Methods of transport through capillary walls

Diffusion

Vesicle transport

Channels between junctions

Types of capillaries & basal lamina characteristics

Capillaries basal lamina examples of locations

Continuous complete muscle, testis, brain, Thymus

Fenestrated complete , adrenal

Discontinuous incomplete or liver, , bone Or sinusoidal lacking marrow

MUSCLE GLOMERULUS LIVER Continuous

Fenestrated

Sinusoidal Continuous

Fenestrated

Fenestrated Sinusoidal

Continuous (gut)

Sinusoidal

Angiogenesis – growth of blood vessels Mesenchymal cells

Endothelial cells Smooth muscle cells

Fibroblasts

Angiogenesis Vascular Valves Location - medium caliber veins (especially extremities) Collecting and lymphatic ducts

Function - insure unidirectional flow

Composition flap or leaflet which are folds of The intima with reinforcements of connective tissue Vascular Valve

Heart

Heart

Internodal connections Congestive Heart Failure

Congestive heart failure (CHF), or heart failure, is a condition in which the heart can't pump enough blood to the body's other organs. This can result from narrowed arteries that supply blood to the heart muscle — coronary artery disease

• Past heart attack, or myocardial infarction, with scar tissue that interferes with the heart muscle's normal work • High blood pressure • Heart valve disease due to past rheumatic fever or other causes • Primary disease of the heart muscle itself, called cardiomyopathy. • Heart defects present at birth — congenital heart defects.

Congestive Heart

Failure

• Infection of the heart valves and/or heart muscle itself — endocarditis and/or myocarditis • The "failing" heart keeps working but not as efficiently as it should. People with heart failure can't exert themselves because they become short of breath and tired. • As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing congestion in the tissues. Often swelling (edema) results. Most often there's swelling in the legs and ankles, but it can happen in other parts of the body, too. Sometimes fluid collects in the and interferes with breathing, causing shortness of breath, especially when a person is lying down. • Heart failure also affects the kidneys' ability to dispose of sodium and water. The retained water increases the edema.

Variations in the Microvasculature Common Arteriole  Capillary  Venule

Shunts Arteriole   Venule

Artery  av shunt  Vein

Variations in the Microvasculature Venous portal system Capillary  Portal Vein  Capillary

Arterial portal system Capillary  Portal Arteriole  Capillary Generic function of any Portal System Venous portal system Arterial portal system Function of portal system? Modify local blood composition with first capillary modifying blood composition and second distributing modified blood locally for benefit of target cells/tissues Arterial portal system

Capillary  Portal Arteriole  Capillary

Blood barriers

Type Source of Barrier

Blood-brain Zonula Occludens of endothelium

Blood-thymus Zonula Occludens of endothelium and sheath of epithelial reticulum

Blood-testis Occluding junctions between sertoli cells in Seminiferous tubules Typical Endothelial Tight Junction and Marginal Fold Blood-Brain Barrier

Typical Blood-Thymus Barrier

Zonula Occludens of endothelium and sheath of epithelial reticulum

Occluding junctions between sertoli cells

Blood-testis barrier occluding junctions between sertoli cells in seminiferous tubules

Lymph vessels

Functions return protein, fluid, and blood cells

Lymph vessels

Functions return protein, fluid, and blood cells Transport secretions (hormones, antibodies) Transport fat (neutral fat)

Lymph vessels

Transport across transit vesicles

Capillaries Intercellular junctions Lymph vessels Lymph flow – Compression of lymphatic vesicles (muscles, pulsating blood vessels) Unidirectional flow – Controlled by valves Flow rate – Remarkably rapid Anchoring device – Vessels open

Age-related and/or disease- related changes in blood vessels

Defect cause elastic lamellae (hardening of replaced by other arteries) connective tissue elements

Atherosclerosis patchy, irregular (heart attack and thickening of intima stroke)

Function / actions of lysosomes

Unprogrammed cell death

Damage/death to cardiac cells in ischemia associated with myocardial infarctions

Function / actions of lysosomes PRE-STENT

POST-STENT Summary Vessels are structurally adapted to physical and metabolic requirements. Summary Vessels are structurally adapted to physical and metabolic requirements. Can you identify these?

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