Lectures of Dr. Noura El-Tahawy for Faculty of Nursing

1. Cardiovascular System
By
Dr. Noura El Tahawy

2. Angiology

3. • External/Outermost layer
– CT with elastin and
collagen
– Protects, Strengthens,
Anchors
• Middle layer
– Circular Smooth
Muscle
– Collagen & Elastic
Fibers
– Vaso-
constriction/dilation
• Internal/ Innermost layer
– Endothelium
– Minimize friction
• Lumen
Blood vessel wallBlood vessel wall
Anatomy of Arteries and Veins

4. • Carry blood AWAY from heart
• Systemic Circuit: carry O2
blood
• Pulmonary Circuit: carry de-O2
blood
• Walls thicker than Veins
– Tunica media > Tunica
externa
• 3 Types
– Conducting (elastic)
• large, elastin, high
pressure
– Distributing (muscular)
• medium size, to
organs
– Arterioles
• smallest
Vessels of Cardiovascular System:
Arteries

5. ArteriesArteries
• Carry blood away from the
heart to distribute to tissues
• In Systemic Circulation: carry
Oxygenated (O2) blood from
heart to different tissues
• In Pulmonary Circulation:
carry De-oxygenated (de-O2)
blood from heart to lungs
• Walls thicker than Veins
(middle layer thicker with more
smooth muscle in arteries)
• Heart >>>Arteries >>>>
arteriols >>> capillaries >>
Venuls >> veins >>> heart

6. Capillaries
• Smallest blood vessels
• Single layer of endothelium surrounded by basal lamina
• Deliver O2 and nutrients to cells and tissues and remove
waste
• Capillary Beds: networks of caps.
• Regulating amount of blood going to cells throughout
tissues
• Tendons, Ligaments poorly vascularized
• Epithelium, cartilage has no capillaries

7. • Carry blood from capillaries INTO the heart
• In Systemic Circulation: carry O2 poor blood from tissues to
the heart
• In Pulmonary Circulation: carry O2 –rich blood from lungs to
the heart
• Thinner walls than arteries
– External layer is thicker than middle layer, Less elastin
• Larger lumen than arteries
• Contain valves
• Normal movement, Muscular contraction push blood through
Venules (smallest veins) to veins
Veins

8. Movement through Veins

9. Differences between arteries and veins
Artery Vein
Thickness Thick Thin
Wall Elastic Collapsed
Valves no valves has valves
Union of branches form anastomosis plexus
Lumen empty, reddish Full of blood,
bluish

10. Heart Arteries (conducting-distributing)
Arterioles Capillaries of tissues
At Capillaries O2 is delivered and CO2 picked up
Capillaries Venules Veins Heart
Vaso Vasorum
Tiny arteries, veins, capillaries in tunica externa of
vessels to nourish them (outer half)
Systemic circulationSystemic circulation

11. • Vessels unite and connect
through:
• Arterial Anastomosis
– Communication
between arteries. Fig. A
• Capillary Anastomosis
– Arteries connected to
veins through capillaries.
Fig. B
• Arterio-venous
anastomosis
• Blood Sinusiods
• Venous Anastomosis
Vascular Anastomosis

12. • Anatomic end arteries are
vessels whose terminal
branches do not anastomose
with branches of arteries
supplying adjacent areas.
• Functional end arteries are
vessels whose terminal
branches do anastomose
with those of adjacent
arteries, but the caliber of
the anastomosis is
insufficient to keep the tissue
alive if one of the arteries
become blocked.
End Arteries
Examples of end arteries:Examples of end arteries:
Cerebral As., coronary As., spinalCerebral As., coronary As., spinal
As., central artery of the retinaAs., central artery of the retina

13. Tortuous Arteries
They are found when there are highly movable organ

14. Location of Heart in Thorax

17. The Great Vessels and major branches
Aorta (from Left Ventricle)
• Ascending
– Coronary arteries
• Aortic Arch
– Brachiocephalic trunk
– Left Common Carotid
– Left Subclavian
• Descending
(Thoracic/Abdominal)
– Many small branches to
organs
Pulmonary Trunk (from Rt
Ventricle)
- -2 Pulmonary Arteries into
lungs
Inferior/Superior Vena Cava
- Coronary sinus

19. Heart Valves:
• *Tricuspid Valve: Right AV valve
– 3 Cusps (flaps) made of endocardium and CT
– Cusps anchored in Rt. Ventricle by Chordae Tendinae
– Chordae Tendinae prevent inversion of cusps into atrium
– Flow of blood pushes cusps open
– When ventricle is in diastole (relaxed), cusps hang limp in ventricle
– Ventricular contraction increases pressure and forces cusps closed
• *Bicuspid (Mitral) Valve: Left AV valve
– 2 cusps anchored in Left Ventricle by chordae tendinae
– Functions same as Rt. AV valve
• **Semilunar valves: prevents backflow in large arteries
– Pulmonary Semilunar Valve: Right Ventricle and Pulmonary Trunk
– Aortic Semilunar Valve: Left Ventricle and Aorta
– 3 cusps: blood rushes past they’re flattened, as it settles they’re pushed
down (valve closed)

20. • Pulmonary
Circulation
– Vessels carrying
blood to and from
lungs
– Pulmonary
arteries and veins
• Systemic Circulation
– Vessels carrying
blood to and from
the rest of the body
– All other vessels

21. Flow of Blood
• O2-poor blood (S+I VC, Coronary Sinus) enters Rt Atrium
• Travels through Tricuspid Valve into Rt Ventricle
• Pumped out through Pulmonary Semilunar Valve into Pulmonary trunk
(branches into Pulmonary Arteries) and to lungs
• After circulating through lungs, O2-rich blood returns to the heart
through 4 Pulmonary veins
• The O2-rich blood enters the Left Atrium
• Travels through Bicuspid/Mitral Valve into Left Ventricle
• Pumped out through Aortic Semilunar Valve into Aorta to be
distributed to rest of body by descending aorta and branches of aortic
arch

22. Blood Flow to Supply the Heart Muscle
• Heart wall too thick for
diffusion of nutrients
• Rt and Lft Coronary Arteries
– Branch from Ascending
Aorta
– Have multiple branches
along heart
– Sit in Coronary Sulcus
– Coronary Heart Disease
• Cardiac Veins
– Coronary Sinus (largest)
– Many branches feed into
sinus
– Sits in Coronary Sulcus

23. Transverse section through the thorax at the level of the intervertebral disc between
the sixth and seventh thoracic vertebrae. Inferior aspect. Compare Fig. 2.69.

24. Sagittal section through the trunk. This section lies to the left of the median sagittal
plane.

25. Thank you