Download Cardiovascular system1

Cardiovascular system
Heart
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The size of persons fist
Less than 500gm in weight.
Apex at the level of 5th intercostals space
Base is where great vessels emerge, beneath 2nd rib
Receive 5% of cardiac output.
Pericardium
Serous membrane, formed of two layers
Visceral layer: on external surface of the
heart.
Parietal thick layer, protect heart, anchor
it to surrounding structures like
diaphragm, reinforced superficially by
dense connective tissue
Lubricating serous fluid secreted by
visceral layer is present pericardial
membrane
The wall of the heart
Is formed by three layers
Outer layer epicardium (visceral pericardium)
Middle layer myocardium which is thick bundle of
cardiac muscle twisted into ring like arrangements
It is reinforced internally by dense fibrous connective
tissue called skeleton of the heart
Deep layer endocardium thin glistening sheet of
endothelium enclose the heart and continuous with
great vessels in and out
Chambers of the heart
Two atria, receiving chambers, thin
wall.
Two ventricles are discharging
chambers, thick wall
The left ventricle form the apex
The right ventricle form anterior
surface.
Septum divides heart to RT, lt
halves.
Interatrial, interventricular septum.
• Heart is double pump
• RT is the pulmonary circuit. It
receives oxygen poor blood by
superior and inferior vena cava,
and pumps it through pulmonary
trunk, which divides into RT, lt
pulmonary arteries.
• The four pulmonary veins return
blood to the heart.
Aorta: pump blood through systemic circulation to the
body.
Heart
Body
Heart
A left ventricle is thicker than right ventricles.
Atrioventricular valves
Tricuspid between RT atrium, and RT ventricle
Mitral between lt atrium and ventricle
They prevent back flow of blood to atria as they are one
way valve,mitral valve have two cusps (bicuspid)
Chordae tendineae (heart strings) anchor the heart to wall
of ventricles
Semilunar valves: guard the arteries which leave the heart
Pulmonary valve: guard pulmonary
artery which leave RT ventricle
Aortic valve: guard the aortic artery
which leave lt ventricle
Each valve has three cusps
Blood supply to the heart
The right and left coronary arteries
They arise from ascending aorta
The right coronary give posterior
interventricular, and marginal
The left coronary give anterior
interventricular and circumflex
arteries
Angina pectoris
Myocardial infarction
Major arteries of systemic
circulation
Aorta
Arise from the left ventricle.
It is the largest artery in the
body.
Start as the ascending aorta,
then continue as aortic arch,
curve downward as
descending aorta, ends in
the diaphragmatic opening by
becoming abdominal aorta.
Branches of the thoracic
aorta
Branches of ascending aorta:
Rt and left coronary arteries
Branches from aortic arch
Brachicephalic, lt common
carotid, lt subclavian
arteries
Brachiocephalic artery divides
in to RT common carotid, RT
Subclavian arteries behind
Rt sternoclavicular joint.
Common carotid artery
divides into:
External, and internal carotid
arteries at level of thyroid
cartilage C4
External carotid artery is the
artery to the neck, supply face
tongue, thyroid.
Internal carotid artery supplies
the brain.
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Subclavian artery gives
vertebral artery to the
brain.
Continue as axillary artery in
axilla, then brachial artery
in the arm, divide into
radial and ulnar arteries at
elbow joint.
Abdominal aorta give
Celiac trunk to supply liver,
spleen, stomach
Superior and inferior
mesenteric arteries to
large and small bowel
RT,and LT renal arteries to
kidneys
Gonadal arteries to ovaries
and testes
Abdominal aorta ends at level
of L3-L4 by dividing into RT
and lt common iliac arteries.
Common iliac artery divides
into external and internal iliac
arteries.
Internal iliac artery supply
pelvic organs.
External iliac artery continue
as femoral artery in thigh, then
popliteal artery in back of
knee, then divide into anterior
and posterior tibial arteries in
the leg.
Major veins of systemic
circulation
Superior vena cava for upper part of
the body, head neck, and upper
limb
Inferior vena cava for lower part of
the body, abdomen pelvis and
lower limb.
Veins of clinical importance
Cephalic, and basilic veins, at
lateral and medial aspect of
fore arm, median cubital
vein at elbow region
connect the two; deep to it
is the brachial artery.
External and internal jugular
veins from head and neck
Great saphenous vein begins
at in front the medial
malleolus, and end in
femoral vein.
Hepatic portal vein drain the
digestive system to liver
Circle of Willis
Arterial blood supply to the brain
15% of cardiac output
The grey matter contain more
capillaries than white matter
Formed by
• Internal carotid artery
• Vertebral artery
Internal carotid artery, of common
carotid artery inter the skull
through temporal bone (carotid
canal)
ICA divides into
• Anterior cerebral artery
• Middle cerebral artery
• Vertebral arteries, enter skull
through foramen magnum
Right and left vertebral arteries,
which are branches of subclavian
arteries, join to form basilar
artery, which divide into two
posterior cerebral arteries
Basilar artery supply blood to
cerebellum, and brain stem
The anterior and posterior blood
supply are united by small
communicating arteries
Circle of Willis
Posterior cerebral artery supply,
center of vision, smell, thalamus,
and mid brain
Anterior cerebral artery supply
motor and sensory areas of lower
limbs
Middle cerebral artery supply motor
and sensory areas of rest of the
body
Hepatic portal circulation
Portal vein
 Is formed by union of
Superior mesenteric vein and Splenic vein
behind neck of pancreas
 Portal vein blood contain nutrients from
digestion in the gut, and deliver them to
liver, some of nutrients are stored or
processed
 Blood leave the liver through hepatic
veins which drain into inferior vena cava.
Hepatic portal circulation
Superior mesenteric vein drain
blood from small bowel
Inferior mesenteric vein drain the
colon in to Splenic vein.
STRUCTURE OF BLOOD
VESSELS
• Endothelium
• Smooth muscle
• Connective tissue
• Collagen fibers
• Elastic fibres
• Tunica intima
• Tunica media
• Tunica adventitia
MUSCULAR ARTERY
ARTERIOLE
CAPILLARIES
STRUCTURE OF VEINS