Angiology By Dr Iram

ANGIOLOGY/

circulatory system DR IRAM IQBAL

AIM To describe common features of, cardiovascular system along with types and their different component .

SEQUENCE

Defination  Different types and subtypes of circulatory system 



Components of Cardiovascular System

Anatomy of the Heart and blood vessels  Classifications of blood vessels  Vascular patterns  End arteries  anastomosis 

Association between arteries and veins  Anatomy of the Lymphatic System  Points of clinical significance  Main arteries and veins of the body  conclusion 

Circulatory systems are composed of great numbers of cell lined tubes and spaces which surround and permeate the tissues, providing a continuous perfusion of body fluids. The most extensive of

Circulatory system of the human body are  Vascular

system

 CSF  Perilymph  Various

endocochlear fluids  Ocular aqueous humour  Synovial fluid  The fluids of the coelomic spaces – Pericardial, Pleural and Peritoneal

Vascular System  Cardiovascular

system

 Lymphatic

system

ANGIOLOGY Is the study of cardiovascular system which is one of the major circulatory system of the body.

Cardiovascular system is of three type  Systemic

circulation

 Pulmonary  Portal

circulation

circulation

SYSTEMIC CIRCULATION 1.

Provides the functional blood supply to all tissues of the body.

2. Supplies Oxygen and other nutrients to body tissues and organs. 3. Removes Carbon Dioxide and other wastes.

SYSTEMIC CIRCULATION 

Systemic circulation pathways arise from the aorta and end in the right atrium.

4. Blood always goes through the pulmonary circulation

SYSTAMIC CIRCULATION

PULMONARY CIRCULATION 1..Transports blood (low in oxygen) from the right ventricle to the lungs. 2. Exchange of oxygen and carbon dioxide occurs between alveoli & blood in pulmonary capillaries.

Pulmonary Circulatory Route

Right Atrium Tricuspid Valve Right Ventricle

Pulmonary Semilunar Valve

Pulmonary Arteries Lungs Pulmonary Veins

Left Atrium

HEPATIC PORTAL CIRCULATION

1. The term “PORTAL” is used to refer to veins which carry blood to organs other than the heart. 2. In this case the arterial blood passes through two sets of capillaries finally to be drained into the heart. This takes place at three sites

Hepatic Portal Circulation Route Inferior Vena Cava

Aorta Celiac Artery Digestive Organs Hepatic Portal Vein Liver Hepatic Veins Inferior Vena Cava Right Atrium

Hypothalamo-hypophyseal Circulation One set in hypothalamus. Hypothalamo hypophyseal V ramify into hypophyseal capillaries in pitutiary gland hypophyseal V drain

Hypothalamo - hypophysial portal circulation

Renal postal Circulation  



arterial in type . one set of capillaries is situated between two arteries (a glomeruli between afferent and efferent arterioles ) efferent arterioles divide into 2nd set of capillaries (Peritubular

Blood  Volume

in body is 5 litres, equals about 7% of total body weight.  Composed of plasma and cells.  Plasma / fluid portion : is 91% water and 9% solids {e.g. Proteins, Salts, Products of digestion and waste products. It also contains respiratory gases (O2 and CO2), internal secretions ,enzymes etc} 

Components of Cardiovascular System Heart .



Blood vessels.



Anatomy of the Heart The heart is a funnelshaped, hollow, muscular organ that is responsible for pumping blood to all parts of the body.

The heart is located near the center of the thoracic cavity between the lungs and is contained in the pericardial sac.  The pericardial sac supports the heart and contains some fluid for lubrication. 

 The

broad end, or base, of the heart is also supported by large arteries and veins.  The pointed end, or apex, of the heart is directed

The heart wall is made up of three layers.

Epicardium outer layer of heart wall, which is also the inner layer of epicardial sac; Endocardiu m inner layer that consists of endothelial cells, which line the heart, covers the

• Myocardium – middle

layer composed of cardiac muscle. The cardiac muscle is an involuntary, striated muscle with fibers that intertwine. Therefore, the heart is said to have four chambers (right atrium, right ventricle, left

The AV valves have flaps of tissues, called leaflets or cusps, which open and close to ensure that the blood flows only in one direction and does not backflow into the atriums.

The AV valve on the right side of the heart is called the tricuspid valve because it has three leaflets (cusps). The AV valve on the left side of the heart is called the bicuspid valve (or mitral valve) because it has two leaflets.

The pulmonary valve and the aortic valve prevent blood from back-flowing into their respective ventricles.

The pulmonary valve is located between the right ventricle and the pulmonary artery. The aortic valve is located between the left ventricle

A group of cells called the sinoatrial node (SA node) control the beat of the heart by sending out electrical signals to make heart pump. Blood the supply of heart The heart wall is supplied . by the coronary arteries and the cardiac veins

Coronary Circulation Pattern Aorta Coronary Arteries Myocardium

Coronary Circulation Pattern Aorta Coronary Arteries Myocardium Cardiac Veins Coronary Sinus Right Atrium

Vessel Wall

 (intima)  Endothelial cell resting on basement membrane  Sub endothelial ells  internal elastic lamina 

Tunica media  middle

layer  usually thickest; smooth muscle, collagen, some elastic 

(tunica adventitia)  outermost

layer  External elastic lamina  loose connective tissue with vasa vasorum and nerve

BLOOD VESSELS

Arterioles

Veinules

Histological Structure of Blood Vessels 

Notes

Muscular arteries

Classification of Blood Vessels

A. Anatomical Classification: Based upon structure of tunica media and diameter of blood vessels. B. Functional Classification 4. Conduction vessels. 5. Distribution vessels 6. Resistance vessels 7. Exchange vessels

1. Large sized/Elastic/Conduction vessels. (73000micro m or 30mm) 2. Medium sized/Muscular/Distribution vessels. (1000- 3000micro m) 3. Small sized/Muscular/Distribution vessels. (50-1000micro m) 4. Muscular arterioles/Resistance vessels. (50-100 micro m) 5. Terminal arterioles/Resistance vessels (50 micro m)

7. Capillarie/Exchange vessels. (5 micro m) 8. Venules/Exchange vessels.(2030micro m) 9. Post capillary venules/Exchange vessels. (20-30 micro m) 10. Small sized muscular vein/Capacitance vessels. 11. Medium sized muscular

BLOOD VESSELS

COMPARISON OF ARTERIES, CAPILLARIES, & VEINS Arteries & Arterioles Tunica Media

Capillarie s Tunica Intima (Blood)

Tunica Adventitia

Veinules & Veins

Avascular Structures : 

   

cartilage. stratified epithelium. cornea. hair . nails.

CAPILLARIES  Diameter

(5 micro

m)  Endothelium Continuous

(muscles, lungs, CNS) Fenestrated(80100nm), gallbladder ,intestine) Discontinuous

Discontinuo us 

liver, bone marrow, spleen irregular blood-filled spaces; some have extra large fenestrations, allow proteins and blood cells -

VASA VESORUM (vessels of vessels)  Arteries

and veins

with a diameter greater than 1 mm are supplied by small vessels called Vasa vesorum.

Vascularity 

Cellular tissues are vascular.



Glands are very vascular (Kidney, Suprarenal, Thyroid and Renal) C.T. are only slightly vascular Loose and dense fibrous tissues have a very less blood supply. Fat and bone have a fair supply. Hyaline cartilage, cornea & epidermis ,nail & hair are non vascular. Nervous tissue Gray matter of brain and spinal medulla, being cellular, is more vascular than the white matter and the peripheral nerve.





VEINS Tunica intima Little more than endothelium

Tunica media Thin layer of smooth muscle

Tunica adventitia Thickest layer

Veins  lower

blood pressure: 10mmHg with little fluctuation  thinner walls, less muscular and elastic tissue  expand easily, have high capacitance  venules more porous than capillaries

VENOUS PUMP 



Valves - formed from folds of tunica intima prevent backflow of blood in veinules & veins. Function like semilunar valves forcing blood to flow against gravity

VENOUS PUMP 

Skeletal muscles pressing against walls of veins provide force to move blood from one valve through the next toward the heart.

Valves are absent in veins of < 2 mm in diameter, Vena Cava, hepatic, renal, uterine ovarian, cerebral, spinal, pulmonary and 

 There

are no functioning valves in the Portal System and only rarely do those (2 or 3) in the cardiac veins function.  Valves are most numerous in the veins of the limbs and they are commonly placed just distal to the mouth of a tributary

arteries End End arteries are arteries that do not anastomose with neighboring arteries except through terminal capillaries.  Obstruction of such an artery is likely to lead to local death, resulting in the case of the:  cerebral artery, in paralysis  central artery to the retina, in blindness  branch of the renal or splenic artery, in death of a segment of the kidney or spleen  several adjacent end arteries of the gut, in gangrene

Anastomoses

Arteries

do not always end in arterioles and capillaries . They may unite

Arterial anastomosis Communication between two vessels through collateral channels. May occur between arteries, between veins, between arterioles and venules

Arterial anastomosis Heterocladic & homocladic  End to end  Collateral anastomosis  Convergence anastomosis  Transverse anastomosis  Potential (at capillary

1. Arterial Anastomosis 

Arterial anastomosis provide alternate (collateral) ways for tissues to receive Oxygen and nutrients if one artery is shut off.



The circle of Willis is an example of Anastomoses which reduce the chance of an interruption to the supply of O2 to the brain.



Aerobic exercises promote collateral circulation .This could prevent or reduce

End to end anastomosis

Collateral anastomosis

Convergence anastomosis

Transverse anastomosis

Potential anastomosis

2.Arterio-venous anastomosis (vascular shunts)  The

blood is not allowed to

pass through the capillaries, rather the blood of arterial tree bypasses the capillary beds and sinusoids and enter directly into the venous

i..Preferential thorough fare channels: Terminal arteriovenular anastomosis.  Side branches  Functional micro circulatory unit  found in almost all the sites of body  Control of blood flow

Direct communication b/e branches of ii..the Simple arteriovenous smallanastomosis muscular arteries and vein.  Innervated by sympathetic nerve fibres  When patent the blood is bypassed to exclude the capillary bed from the circulation for the 

iii.Glomera In the skin of hands and feet (especially digital pads and nail beds) anastomosis form a large number of small units termed “glomera”. They are deep in the corium; each “glomus” has one or more afferents arteries, stemming from branches of cutaneous arteries approaching

Veno-venous anastomosis External Iliac Great Saphenous Femoral Popliteal

Anterior Tibial

Posterior Tibial Great Saphenous Dorsal Venous Arch

Anatomy of the Lymphatic System LYMPHOID SYSTEM The lymphoid system drains surplus fluid from the extracellular spaces to the bloodstream. ♦ The lymphoid system also constitutes a

Functions of the lymphatic system: •Drainage of surplus tissue fluids, and leak plasma proteins to the blood stream. •Removal of debris from cellular decomposition and infection. • absorb fatty acid and transport fat to circulatory system, and •produce immune cells (lymphocytes, monocytes,

Lymphatic System: Lympha = pure, clear water  Important

components of the lymphoid system are  networks of lymphatic capillaries,  lymphatic

plexuses;  lymphatic vessels;  lymph;  lymph nodes;  lymphocytes

Starling hypothesis

Starling hypothesis

Starling hypothesis 

e fluid and electrolytes entering the extracellular spaces from the blood capillaries is also reabsorbed by them. However, as much as 3 L each day fails to be reabsorbed by the blood capillaries. Furthermore, some plasma protein leaks into the extracellular spaces, and material originating from the tissue cells that cannot pass through the walls of blood capillaries, such as cytoplasm from disintegrating cells, continually enters the space in which the cells live. If this material were to accumulate in the extracellular spaces, a reverse osmosis would occur, bringing even more fluid and resulting in edema (an excess of interstitial fluid, manifest as swelling). However, the amount of interstitial fluid remains fairly constant under normal

Blood fluid escapes through the thin-walled capillaries into spaces between body tissue cells. Lymph vessels, which have very thin walls, pick up these fluids

The lymph vessels join to form larger ducts that pass through lymph nodes (or glands). Each lymph node has a fibrous outer covering (capsule), a

Lymph nodes filter foreign substances, such as bacteria and cancer cells, from the lymph before it is re-entered into the blood system through the larger veins. Lymph nodes, which are scattered among the lymph vessels, act as the body’s first defense against infection.

Each lymph node has its own blood supply and venous drainage. The lymph nodes usually have names that are related to their location in the body.

When a specific location gets infected, the lymph nodes in that area will enlarge to fight the infection. If the lymph node closest to an infected area is unable to eliminate the infection, other lymph nodes in the system will attempt to fight the infection.

This is particularly critical in the case of cancer, which can be spread from its point of origin to all parts of the body through the lymphatic system.

Clinical notes  Atherosclerosis  Varicose

veins  Lymphangitis  Lymphadenitis  Lymphography  Spread of cancer

VARICOSE VEINS 1. Veins that are stretched, dilated & overfilled with blood due to incompetent valves 2. Contributing causes: Weak valves or veins - (heredity) Excessive weight Excessive standing, straining Inadequate exercise Increased intra-pelvic pressure pregnancy, constipation

VARICOSE VEINS

MAJOR ARTERIES OF THE BODY

Brachiocephalic Ascending Aorta

Aortic Arch Thoracic Aorta

Abdominal Aorta

Celiac

ARTERIES OF THE LEG External Iliac

Internal Iliac Femor al Popliteal (behind knee)

Anterior Tibial

Posterior Tibial (behind Tibia)

ARTERIES OF THE HEAD & NECK

ARTERIES OF THE ARM & SHOULDER Subclavia n

Axillary

Brachia l Radil Ulnar

ARTERIES OF THE HEART

Aort a

Pulmonary Artery

Coronary Arterie

MAJOR VEINS OF THE BODY

MAJOR VEINS OF THE HEAD & NECK

MAJOR VEINS OF ARM & SHOULDER Cephal icBrachi al

Radial

Subclavi an Axilla y Basil ic Median Cubital Ulna r

MAJOR VEINS OF THE LEG External Iliac Great Saphenous Femoral Popliteal

Anterior Tibial

Posterior Tibial Great Saphenous Dorsal Venous Arch

MAJOR VEINS OF THE ABDOMEN

Inferior Vena Cava Renal

Hepatic Veins Renal Inferior Vena Cava

Common Iliac Internal Iliac External Iliac

Common Iliac Internal Iliac External Iliac

MAJOR VEINS OF THE HEART Superior Vena Cava

Pulmonary Veins Inferior Vena Cava

Coronary Sinus Cardiac Veins

CONCLUSION

REFERENCES

 Gray’s

Anatomy (37 th edition).  Grant’s method of Anatomy. (10 th edition).  Clinical Anatomy by Richard S. Snell, (7 th edition).  Clinical oriented Anatomy(klm)6th edt