1. The Heart and Circulation
Cardiovascular System = Heart, Blood and Vessels
Lymphatic System = Lymph nodes, Organs and Vessels
Medical ppt

2. Functions of Heart and Cardiovascular System
Bulk flow of blood
Exchange with tissue
Heart
Right side receives oxygen-poor blood from body tissues and pumps the blood to the lungs
Left side receives the oxygenated blood from the lungs and pumps the blood throughout the body

3. Location of Heart in Chest
Oblique Position
Apex = Left of Midline (5th ICS), Anterior to rest of heart
Base (posterior surface) sits on vertebral column
Superior Right = 3rd Costal Cartilage, 1” right midsternum
Superior Left = 2nd Costal Cartilage, 1” left midsternum
Inferior Right = 6th Costal Cartilage, 1” right midsternum
Inferior Left = 5th Intercostal Space at Midclavicular line
Pg 155

4. Cardiac Conduction
Intrinsic system initiating and coordinating contraction of heart muscle
Sinoatrial node (where SVC enters RA)
Atrioventricular node (in atrioventricular septum)
AV Bundle (in IV septum then splits)
Purkinje fibers (throughout LV)
Cardiac Plexus (external innervation)
Vagus (parasympathetic)
Sympathetic trunk
pg 178

5. Pericardium Pericardium (3 layers) Pericardial Cavity pg 178
1) Outer-fibrous pericardium
Serous pericardium
2) parietal
3) visceral (epicardium)
Pericardial Cavity
between layers of serous pericardium
serous fluid
lubricate heart while beating

6. External Features of Heart
Interventricular sulcus
Coronal/Coronary sulcus
Auricles of atria
Apex
Base
Coronary vessels
Ligamentum Arteriosum
Pg 158

7. 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
Pg 180

8. Layers of Heart Epicardium (most superficial) – Visceral serosa
Myocardium (middle layer)
Cardiac muscle
Contracts
Endocardium (inner)
Endothelium on CT
Lines the heart
Creates the valves

9. Fibrous Skeleton of Heart
Insertion for cardiac muscle
Anchors valve cusps
Prevents valves from opening too much
Block electrical impulses from atria to ventricles
Contains AV node
Pg 170

10. Heart Chambers 2 receiving chambers: 2 pumping chambers: Right atria
Left atria
2 pumping chambers:
Right ventricle
Left ventricle

11. Right Heart Chambers: Pulmonary Pump
pg 163, 165
Right Atrium (forms most of base of heart)
Receives O2-poor blood from body via IVC, SVC, Coronary sinus
Ventral wall (w/Pectinate muscles) and dorsal wall (no pectinate muscles) separated by crista terminalis
Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale
Right Ventricle
Receives O2-poor blood from right atrium through tricuspid valve
Pumps blood to lungs via Pulmonary Semilunar Valve in pulmonary trunk
Trabeculae Carnae- muscle ridges along ventral surface
Chordae Tendinae-fibrous cords running between AV valve cusps and papilary muscles
Papillary Muscles (3)-cone-shaped muscles within ventricles to which chordae tendinae are anchored
Moderator Band (septomarginal trabeucla)-muscular band connecting anterior papillary muscle to interventricular septum

12. Left Heart Chambers: Systemic Pump
Left Atrium
Receives O2-rich blood from 4 Pulmonary Veins
Pectinate Muscles line only auricle
Left Ventricle (forms apex of heart)
Receives blood from Left Atrium via bicuspid valve
Pumps blood into aorta via Aortic Semilunar Valve to body
Same structures as Rt Ventricle: Trabeculae carnae, Papillary muscles (2), Chordae tendinae
No Moderator band

13. Heart Valves: Lub*-Dub**
*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
They close together
pg 165

14. Semilunar Valves (the dub)
Semilunar valves: prevents backflow in large arteries
Pulmonary Semilunar Valve
Right Ventricle and Pulmonary Trunk
Aortic Semilunar Valve
Left Ventricle and Aorta
Made of 3 Cusps
As blood rushes past the cusps are flattened
As it settles they’re pushed down (valve closed)
pg 165

15. 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

16. Cardiovascular Flow of Blood
HeartArteries(conducting-distributing) ArteriolesCapillaries of tissues
At Capillaries O2 is delivered and CO2 picked up
CapillariesVenulesVeinsHeart

17. Circuits Pulmonary Circuit Systemic Circuit
Vessels carrying blood to and from lungs
Pulmonary arteries and veins
Systemic Circuit
Vessels carrying blood to and from the rest of the body
All other vessels

18. 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
pg 171

19. Blood Vessels Powered by the heart! Carry blood to and from the heart
3 main types:
Arteries
Carry blood away from heart
arterioles
Capillaries
Veins
Carry blood toward heart
Venules

20. Anatomy of Arteries and Veins
Tunica externa
Outermost layer
CT w/elastin and collagen
Protects, Strengthens, Anchors
Tunica media
Middle layer
Circular Smooth Muscle
Collagen & Elastic Fibers
Vaso-constriction/dilation
Tunica intima
Innermost layer
Endothelium
Minimize friction
Lumen

21. Vessels of Cardiovascular System: Arteries
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

22. Capillaries Smallest BV Usually 1 RBC thick
1 layer endothelial cell thick surrounded by basal lamina
Deliver O2 and nutrients to cells and remove waste
Capillary Beds: networks of capillaries
Regulating amount of blood going to cells throughout tissues
Supply tissues and organs that otherwise have poor capillary circulation
Epithelium, cartilage has no capillaries

23. Vessels of Cardiovascular System: Veins
Carry blood from capillaries INTO the heart
Systemic Circuit: O2 poor blood
Pulmonary Circuit: O2 –rich blood
Pressure in Veins less than that in arteries
Thinner walls than arteries (tunica externa > tunica media, less elastin)
Larger lumen than arteries
Contain valves (made of T. intima)
Normal movement, Muscular contraction push blood through
Venules- smallest veins

24. Cardiovascular Blood Flow
Portal System: Special vascular circulation where blood goes through 2 capillary beds before returning to the heart to achieve 2nd function
(eg) Hepatic Portal System: aids digestion by picking up digestive nutrients from stomach + intestines and delivers to liver for processing/storage
Pick-up occurs at capillaries of stomach and intestine
Via Hepatic Portal Vein goes to capillaries of liver
Via Hepatic Vein blood goes back to heart

25. Vascular Anastomoses Vessels unite and connect Arteriole Anastomoses
Communication between arteries
Joints, Abdominal Organs, Brain, Heart
Venous Anastomoses
Communication between veins
More common
(eg) back of hand
Vaso Vasorum
Tiny arteries, veins, capillaries in tunica externa of vessels to nourish them (outer half)
pg 726

26. Fetal Circulation All major vessels in place by third month
2 main differences:
1. Fetus must supply blood to placenta
2. Lungs do not need much blood because respiratory organ is the placenta

27. 1. Blood to Placenta Umbilical vessels Ductus venosus
Run in umbilical cord
2 umbilical arteries
Carry blood (little oxygen and waste) to placenta
1 umbilical vein
Returns this blood (with oxygen and nutrients) to fetus and to portal vein (to liver)
Ductus venosus
Shunt that puts blood to hepatic veins, IVC, and RA from placenta
Too much blood for liver to handle
Results in highly O2 blood going to heart

28. 2. Bypassing the Lungs: Foramen Ovale
Becomes Fossa Ovalis
Hole in the inter-atrial septum
Allows blood to flow from RA to LA
Bypasses the RV
Would usually bring blood to lungs
pg 163

29. 2. Bypassing the Lungs: Ductus Arteriosus
Becomes Ligamentum arteriosum
Carries blood from pulmonary trunk to aortic arch
Empties distal to coronary arteries
This enables the heart and brain to receive the most highly oxygenated blood
Bypasses the lungs
pg 186

30. First Breath!! Lungs inflate
Ductus arteriosus constricts and closes
Oxygenated blood begins pouring into LA for first time
Raises the pressure within the LA
This pushes the 2 flaps of foramen ovale together and closes it
Medical ppt