Circulatory System general anatomy topic, with clinical anatomy. UG Topic for seminars.

1. Circulatory
System

2. Components
Of Circulatory
System
• Heart
• Arteries
• Veins
• Capillaries

3. • Carries blood from heart.
• Have branches.
• Large artries are made of
elastic tissues.
• Minute branches are called
artrioles.
• Ageion = vessel.
Arteries

4. Veins
• Carry blood to heart.
• Veins have tributaries.
• Have venules.
• Large veins unite to
form Venae cavae

5. Capillaries
• Network of capillaries.
• Comes in intimate contact with tissues.
• Exchange of nutrients & metabolites.
• Capillaries are replaced by sinusoids in certain
organs
• eg: Liver, Spleen.

6. Five Types Of
Blood
Vessels
[Based on
functions]
• Distributing Vessels
• Resistance Vessels
• Exchange Vessels
• Reservoir Vessels
• Shunts

7. Types of
Circulation of
Blood
Systemic Circulation : From Left
ventricle to Right Atrium through various
parts of body.
Pulmonary Circulation : From Right
ventricle to Left Atrium through lungs.
Portal Circulation : Blood passes
through two sets of
capillaries before draining into systemic
vein. Portal Vein & Capillaries or
Sinusoids

8. Arteries
Carries Blood from the Heart

9. Characteristic
Features of Arteries
• Arteries are thick walled.
• Cranium & Vertebral Canal
are thin walled.
• Lumen is smaller than
accompanying veins.
• Arteries have no valves.
• An artery is usually
accompanied by veins, nerves
& lymphatics.

10. Types of Arteries & Str
• Large arteries of elastic type. Eg : Aorta & its
main branches.
• Medium & small arteries of muscular types. Eg :
Ulnar, radial, formal.
• Smallest arteries of muscular type are called
arterioles.

11. Nerve supplies of arteries
• The skeletal muscle vessels – cholinergic sympathetic nerves.
• The Exocrine gland vessels - Parasympathetic nerves.
• The cutaneous vessels.

12. Veins
Carries Blood towards Heart

13. Characteristic
Features
• Thin walled & has a larger Lumen.
• Have valves to maintain unidirectional flow.
• Valves are absent in : veins less than 2mm, In vena
cave, hepatic, renal, utrine, overian, cerebral, spinal
& pulmonary.
• Muscular & elastic tissue are less.
• Have dead spaces.

15. Venous System
Caval System :
Portal System :
• Includes superior & inferior caval veins.
• Veins associated with caval system are : Emissary vein of cranial cavity
• 2 set of capillaries Eg : Hepatic portal system
• Capillaries can join to form portal veins.
• Branches into sinusoids & veins
• Hypophyseal portal system

16. Emissary
vein
 Helps in lowering intracranial
pressure.
 Causes infections from outside to
enter inside cranial cavity.

17. Structure of Veins
• Usual made of three coats, coats are ill-defined.
• The muscle and elastic tissue content is poor.
• The smooth muscle is altogether absent in veins of
maternal part of placenta, cranial venous sinuses and
pial veins, retinal veins, veins of cancellous
bone, venous spaces of the corpora cavernosa and
corpus spongiosum.

18. Blood & Nerve
Supply of Veins
• Large veins are supplied with nutrient vessels called vasa
vasorum.
• Vessels may penitrate up to intima.
• Nerves are distributed as in arteries but fewer in number.

19. Factors Helping in Venous
Return
• Overflow from the capillaries.
• Negative intrathoracic pressure.
• Gravity helps venous return in the upper part of the body.
• Arterial pulsations.
• Venous valves prevent any regurgitation.

20. Capillaries

21. Sinusoids
• Sinusoids are larger, irregular, vascular spaces.
• Sinusoids differ from capillaries in the following respects.
• Their lumen is wider (upto 30micron) & irregular.
• Their walls are thinner & incomplete.
• They may connect arteriole with venule or venule with venule.

22. Cavernous Tissue
• These are seen in penis & clitoris.
• These Spaces are blood filled space.
Angiosomes
• It is 3d block of tissue
• These are coupled by an artery & vein.
• Composed of skin, fascia, muscle, bone.
• Neighbouring are linked by "choke" vessels.

23. Angiosomes

24. Anastomoses
Cross Connection b/w
adjacent openings

25. Types of
Anastomoses
 Arterial anastomoses
 Venous anastomoses
 Arteriovenous anastomoses
(Shunt)

26. Arterial Anastomoses
Actual Arterial Anastomoses
 Arteries meet end to end.
 True Anastomosis.
 Eg: Palmar arch, plantar arch, Circle of Willis,
Labial branches of facial arteries.
Potential Arterial Anastomoses
 Takes place b/w the terminal arterioles.
 Dilate only gradually.
 Eg: Coronary arteries.

30. Venous
Anastomoses
• B/w the veins or tributaries of
veins.
• Eg: Dorsal venous arches of
hand & foot.

31. Arteriovenous
Anastomoses (Shunt)
• Communication b/w artery & vein.
• Serves during active phase of organs.
• Shunt vessels may be straight or coiled.
• Has thick muscular coat of sympathetic system.
• Three types of Shunt :
Simple str => skin of nose, lips, external ear; mucous
membrane of nose & alimentary canal.
Specialized arteriovenous => skin of digital pads & nail
beds. Small unit is Glomera.
Preferential 'thoroughfare channels' => Forms
microcirculatory unit of 1-2 to 20-30 cap.
This Photo by Unknown author is licensed under CC BY.

32. End Arteries
• Arteries which do not form
anastomoses.
• Absolute end artery - central artery
of retina & labyrinthine artery of
ear.
• Anatomical end artery - central
branch of cerebral arteries & vasa
recta of mesenteric artery.
• Functional end artery -
Coronary artery, arteries of spleen,
kidney, lungs, metaphysis of long
bones.

33. Clinical
Anatomy

34. Batch B : Group 5