Functional cell Ajith Sominanda Department of Anatomy Faculty of Medicine University of Peradeniya.
Ajith Sominanda Department of Anatomy. Lecture outline Why a circulatory system ? Arrangement of the...
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Transcript of Ajith Sominanda Department of Anatomy. Lecture outline Why a circulatory system ? Arrangement of the...
Cardio Vascular System
(Circulatory system)Ajith SominandaDepartment of Anatomy
Lecture outlineWhy a circulatory system ?Arrangement of the CVSVascular tree-Gross AnatomyCVS histology
Circulatory system; Why?
Amoeba in motion
Circulatory system; Why?
Circulatory system; Why?
Functions of circulatory system
Transport of materials and cells by continuous movement of blood GasesNutrientsWaste productsComponents of immune and endocrine system
Thermoregulation
Components of human circulatory systemBlood vascular system
(closed) HeartArteries and arterioles
(conduction / distributing vessels)Capillaries (exchange vessels)Venules and veins (capacitance
vessels)
Lymph vascular system (open)LymphaticsLymph nodes
Pulmonary circulation Heart: left
chambers (oxygenated blood)
Heart: right chamber s (De-oxygenated blood)
Conducting vessels
Arterioles
Exchange vessels
(Capillaries)
Venules
Lymph nodes
Lymphatics
Capacitance vessels(Veins)
Distributing vessels
Vascular tree- Gross anatomy
Overall arrangement
Aorta(2-2.5 cm)
Large and medium
size arteries
(100-200)
Arterioles(4 * 106 )
(<300 µm)
Capillaries(16 * 106 )
(7 µm)
LV
RV
RA
Arch of aortaSuperior vena
cava
Pulmonary artery
Intercostal vessels
Inferior vena cava
Heart, great vessels and circulation in thorax
Heart, great vesselsCirculation in axilla and upper arm
Pulmonary artery
Left bronchus
Subclavian artery &
vein
Axillary artery &
vein
Brachial artery &
vein
Common carotid arteries
External & internal carotid
arteries
Arch of aorta
Circulation in head & neck
Circulation in abdomen, upper and lower limbs
Abdominal aorta
Common iliac artery
External & internal iliac
arteries
Femoral artery
Radial & ulnar arteries
Branching patterns of arterial tree
1. Terminal branches
2. Co-lateral branches
1. End-to-end anastomosis1. Vaginal artery-ovarian artery2. Left gastro epiploic arteries3. Ulnar artery and superficial palmar branch of
radial artery
2. Anastomosis by convergenceVertebral arteries forming basilar artery
3. Transversal anastomosis1. Between anterior cerebral arteries2. Between radial and ulnar at wrist3. Between posterior tibial and peroneal arteries
Anastomosis of arteries
Venous systemSuperficial veins
Deep veins Venae comitantes
Valves & Venous
drainage
Venous system: problemsFailed superficial veins:
’’Varicosities’’Obstructed deep veins:
’’Deep vein thrombosis (DVT)’’
CVS Histology
General arrangement of cardio-vascular tissues
(CARDIO VASCULAR TUBE)
’’ Tunic = coat ’’
1. Tunica externa / adventitia
2. Tunica media
3. Tunica intima
Vasa vasorum
(Vessels of vessels)
Nervi vasorum
(Nerves of vessels)
Has three-layered structure
General arrangement of cardio-vascular tissues
Heart Arteries Capillaries Veins
Note the changes occurring in the wall of the structures
Structure for Function !The heart is a (muscular) pump !
Heart
1. Endocardium (Tunica intima)
2. Myocardium (Tunica media)
3. Epicardium / viceral pericardium (Tunica adventitia)
Cardiac wall consists of three layers:
1. Endothelium (single layer of flattened epithelial cells)
2. Sub-endothelial connective tissue
Heart• Endocardium
Tunica intima
1. Consists of cardiac muscle fibers (Cardiocytes) arranged in a network ’’ Syncytium’’
2. Cardiocytes have central nucleus and are connected by junctional complexes ’’intercalated discs’’
3. Mitochondria and sarcoplasmic reticulum are abundant in cytoplasm
4. Muscle contractions are Strong , continuous and inherent
Heart• Myocardium
Heart• Cardiocyte-Ultra structure
Transverse junctional complexes (Intercalated discs)
Striations
Longitudinal junctional complexes(GAP junctions)
Heart• Epicardium
1. Consists of flattened epithelium (Mesothelium) that secretes serous fluid into pericardial space
2. Epithelium is supported by Sub-endothelial connective tissues
3. Contains coronary vasculature
Heart Arteries Capillaries Veins
Arterial tree• Arteries conduct and distribute blood to periphery
Blood pressure
Vascular anatomy
High pressure tubal system for conduction of blood to periphery
Low pressure tubal system for drainage of blood
Exc
han
ge
syst
em
Structural adaptation for Function !
Conform to the three-layered tissue arrangement
Main types of vessels in arterial system1. Large elastic arteries
(Aorta , Brachiocephalic, common carotid, subclavian & common iliac arteries)
2. Medium-sized muscular arteries(Intercostal, axillary, radial arteries)
3. Arterioles
Arterial tree
• Elastic arteries
1. Tunica media contains large amounts of fenestrated sheaths of elastin and lesser amounts of collagen and smooth muscle cells
2. Tunica adventitia contains collagen tissues
Arterial tree
• Muscular arteries
1. Tunica intima has three layers:1. Endothelium2. Sub endothelial connective tissues3. Internal elastic lamina (sheath of
elastin)
2. Tunica media has thick layer of smooth muscle cells
3. Larger vessels have external elastic lamina
Arterial tree
• Arterioles
1. Arterioles are final branches of arterial system that regulate blood flow to capillary bed
2. Tunica media has concentric layers of smooth muscles
3. Innervated by sympathetic nerves and control the vascular tone
Arterial tree
• Arterioles and micro circulation
Arterial tree
Arteriloes
Venule
Sympathetic nerve
Pre-capillary spincters
1. Continuation of endothelium
2. No smooth muscle and adventitial layers
3. Occasion pericytes are found
Capillaries: the exchange compartment
Capillaries: different types
1. Continuous
2. Fenestrated
3. Discontinuous
Q: List the sites where different capillary types are found
Venous system• Veins & venules
Venules (Post capillary, Muscular & Collecting venules)
Capillaries
Veins
• Has relatively Large lumen & thinner wall • Elastic and muscular components are much less prominent compared to arteries•Acts as reservoirs of blood; Capacitance vessels
Lymph vascular system
• Reuptake excess tissue fluid that accumulates in ECS
• Similar to venous system
Things that are good to read (know) !
Formation of EdemaThickening of arterial walls i.e.
Arteriosclerosis & AtherosclerosisEndothelium and inflammationEndothelium and blood coagulationBiology of vessel formation and tumors
(tumor angiogenesis )
References1. Wheaters functional histology2. Histology and cellbiology by Abraham L
Kierszenbaum3. Grays Anatomy4. WWW.
The ENDThank you