Human Heart: Values

Values open & close to control blood flow through heart
- Atriventicular values
  - Tricuspid……. Right
  - Bicuspid………Left
- Semilunar Values
  - Pulmonary
  - Aortic
Blood returning to heart from systemic circuit
- Enters right atrium
- Right atrium pumps through tricuspid value to right ventricle
- Right ventricle pump blood through pulmonary value to the pulmonary circuit
Blood returning to heart from pulmonary circuit
- Enters left atrium
- Left atrium pumps though mitral value to left ventricle
- Left ventricle pumps blood through aortic value to the systemic circuit
Oxygen poor blood never mixes with oxygen rich blood in humans

Heartbeat

After blood moves into the pulmonary artery & aorta the ventricles relax

Stages in the Cardiac Cycle

SA Nodes (Sinoatrial Nodes): keeps the heartbeat regular

AV Nodes (Artioventricular node): signals ventricles to contract- Purkinje Fibers

ECG (Electrocardiogram) : A recording of electrical changes that occurring in myocardium during cardiac cycle

Branches of Ventricular Bundle:

Parking Fibers:

Ventricular Fibrillation:

Rhymetic Contraction due to cardiac conduction system

When SA node triggers an impulse the atrial fibers produce an electrical charge (p Wave)

Human Cardiovascular System includes two major circular pathways:

The beat of the heart supplies pressure that keeps blood moving in the arteries

Systolic Pressure: result from blood forces into the arteries during ventricular systole
Diastolic Pressure: is the pressure in the arties during ventricular diastole

Skeletal muscle contraction pushes blood in the vein toward the heart

Blood Pressure

Transprt substances to and from capillaries for exchange with tissue fluid

Red Blood Cells

Small, Biconcave disk
Lack a nucleus & contains hemoglobin
- Hemoglobin contains
  - 4 globin protein chains
  - Each associated with an iron containing heme
Manufactured continuously in bone marrow of skull, ribs, vertebrae & end of long bone
Carry oxygen, nutrients, and waste

White Blood Cells

Most types larger than red blood cells
Contain nucleus and lack hemoglobin
Lymphocytes protect cells from infection

WBC: Leukocytes

RBC: Erythrocytes)

Platelets

Blood Clots consists of :

Capillaries very narrow- Tiny RBC’s must go through single file

Wall of capillaries are very thin to facilitate diffusion of nutrients, gases & waste

Determined by the presence or absence of surface antigens (agglutinogens)

Antibodies in the plasma

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Dr. Williams Biology 109 The Lecture Notes Feb. 9th, 2015