-
Audio recording started: 5:32 PM Tuesday, April 26, 2011
-
Lecture exam 3: 4/28
Aftenoon lab: exam @ 2:15
-
The cardiovascular system
- � A closed syestem of the heart and blood vessels
- ? The heart pumps blood
- ? The blood vessels provide the path for the blood to travel
-
Function of the cardiovascular system
- � To provide oxygen and nutrients to various parts of the body
- � To remove carbon dioxide and waste products from the cells
-
Circulations of the heart
- � The cardiovascular system has two circulations:
- ? Systemic circulation
- � Delivers oxygenated blood from the heart to the body
- ? Pulmonary circulation
- � Delivers deoxygenated from the heart to the lungs
-
Membrane of the heart
- � The heart is covered y fibrous pericardium made of connective tissue
- � Below it, there is double membrane
- ? Parietal
- ? Visceral
- ? The pericardium cavities forms in between these two members
-
Wall of the heart
- � Three distict leyers:
- ? Outer epicardium
- � Which is the visceral pericardium
- � Reduces friction
- ? Middle myocardium
- � Consists of cardiac muscle tissue
- ? Inner endocardium
- � Consists of epithelium cells and connective tissue
-
� The heart has four valves:
- ? Tricuspid valve
- � Between the right artium and the right ventricle
- ? Bicuspid valve
- � Between the left artium and the left ventricle
- ? Pulmonary valve
- � Between the right ventricle and the pulmonary trunk
- ? Aortic valve
- � Between the left and the aorta
-
Chambers of the heart
- � The heart has four chambers
- ? Right atrium
- ? Right ventricle
- ? Left atrium
- ? Left ventricle
- � The interventricle septum separates the right and left ventricles
-
Blood vessels of the heart
- � Superior vena cava
- ? Returns deoxygenated blood from all structures above diaphragm to the heart
- � Inferior vena cava
- ? Returns deoxygenated blood from all structures below diaphragm to the heart
- � Pulmonary trunk
- ? Takes deoxygenated blood from the right ventricle to the lungs
- � Pulmonarty veins
- ? Brings oxygenated blood from the lungs to left atrium
- � Aorta
- ? Delivers oxygenated blood from left ventricle to the body
-
Pathway of the blood through the heart
- The blood travels to the heart through the superior and inferior vena cavae to the right atrium
- From the right atrium the blood goes through the tricuspid valve
-
Heart cycle
- � When the heart is contracted, it is reffered to as systole
- � When the heart is relaxed, it is referred to as diastole
- � during stole both the aortic and pulmonary volves are open
- � During diastole both the tricuspid and bicuspid valves are open
-
Electral activitiy of the heart
- � The heart is a cardiac muscle tissue that is constantly contracting (heart beat)
- ? Q: how does the heart contract?
- ? A: specialized cells called pacemaker cells that generate their own electrical activities
-
Pacemaker cells
- � Sinoatrial node (SA) locarted in the right atrium
- � Atrioventricular node (AV) locaded on the interatrial septum
- � Bundle of HIS: located on the interventricular septum
- � Purkinje fibers: located on the ventricular walls
-
Electrocardiogram
- � Is a tool to measure the electrical activities of the heart
- � Electrodes are placed on the body to measure the electrical changes that occur during a cardiac cycle
- � P wave: atrial depolartization (contration)
- � QRS complex: ventricular depolarization (contraction)
- � T wave: ventricular repolarization (relaxation)
-
Blood vessels
- � from closed circute tubes that carry blood from the heart cells and back to the heart
- � Five different types of blood vessels:
- ? Arteries
- ? Arterioles
- ? Capilliaries
- ? Venules
- ? veins
-
Arteries
- Strong elatic vessels that carry blood away from the heart
- Branch into smaller aterioles
-
Veins
- Carry blood back to the heart
- Have thinner walls than arteries
- Small branches are called venules
-
Arteries and veins
- Have three layers:
- Tunica external
- Conntective tissue with elastic and collagen fibers
- Tunica media
- Made of smooth muscles
- Mediates vasoconstrition and vasodilation
- Tunica interna
- Made of simple squamous epithelium
- Provides surface for blood to pass through
-
Arterioles
- Large arterioles have similartr composition as arteries
- Small arterioles have endothelial cell and some smooth muscle fibers surround by thin layer of conmnective tissue
-
Capillaries
- Smallest diameter blood vessels
- Made of endothelial layer only
- Have slits
- They are the site of gas exchange with cells
|
|
