cardiovascular/circulatory system. consists of…. blood vessels blood heart
Post on 02-Jan-2016
228 Views
Preview:
TRANSCRIPT
Cardiovascular/Circulatory System
Consists of….
•Blood vessels
•Blood
•Heart
Blood Vessels
• Two pathways:
–Pulmonary Circulation•Carries blood to lungs and back
–Systemic Circulation•Carries blood to body and back
Capillaries of head and arms
Capillaries of abdominal organs and legs
Inferior vena cava
Pulmonary vein
Capillaries of right lung
Superior vena cava
AortaPulmonary artery
Capillaries of left lung
Pathway of Circulation-3 Types of Vessels
– Arteries- carries blood Away from heart
• Large• Thick-walled,
Muscular• Elastic• Oxygenated blood
– Capillaries• Smallest vessel• Microscopic• Walls one cell thick• Nutrients and gases
diffuse here
– Veins• Carries blood
that contains waste and CO2
• Blood not under much pressure
• Carries deoxygenated blood
BLOOD!
• Body contains 4-6 L (Depending on size)• Consists of
– Water– Red Blood Cells– Plasma– White blood cells and platelets
• It is a tissue
What’s in Blood?Liquid Portion Carries
• Blood cells
–Erythrocytes (RBC - red blood cells)
–Leucocytes (WBC - white blood cells)
• Platelets (non cellular particles)
More About What's In Blood
• Proteins
–Enzymes
–Hormones – Endocrine System
• Nutrients - Digestive System
• Gases - Respiratory System
RBCs
• Transporters of– Oxygen– Carbon Dioxide
• RBC– Lack a nucleus– Contain hemoglobin– Disk-shaped
RBCs
• RBC are produced in red bone marrow of ribs, humerus, femur, sternum
• Lives for 120 days• Old RBC are destroyed in liver and spleen
WBCs
• Fight infection
• Larger size
• Less in number
• Most live for a few days, but can live for months
• Several types
• All contain nuclei
Infection
Platelets
• PLATELETS are for CLOTTING blood
• Cell fragments
• Produced in bone marrow
• Short life span (1 week)
Blood Clotting
Break in Capillary Wall
Blood vessels injured.
Clumping of Platelets
Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin..
Clot Forms
Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..
The Heart
• At REST, the heart pumps about 5 QUARTS of blood a minute.
• During EXTREME EXERTION (exercise) it can pump 40 quarts a minute.
• Composed of – Cardiac muscle– Mitochondria – Enclosed in a sac (Pericardium)
Heart Structure
• Four chambers – Two upper (Atria)
• Walls thinner• Less muscular
– Two lower (Ventricles)• Walls thicker• More muscular• Do more work
Path Through The Heart
• Both Atria fill at same time– Right atrium receives oxygen POOR blood
from body from vena cava– Left atrium receives oxygen RICH blood from
lungs through four pulmonary veins
• After filled with blood atria contract, pushing blood into ventricle
More on the Path
• Right ventricle contracts and pushes oxygen-poor blood toward lungs
• against gravity, through pulmonary arteries
• Left Ventricle contracts and forces oxygen rich blood
• out of heart through aorta (largest vessel)
Heart Wall• Epicardium – visceral layer of the serous
pericardium• Myocardium – cardiac muscle layer forming
the bulk of the heart• Fibrous skeleton of the heart –
crisscrossing, interlacing layer of connective tissue
• Endocardium – endothelial layer of the inner myocardial surface
The Structures of the Heart
Right Ventricle
Right Atrium
Left Atrium
Inferior Vena Cava
Tricuspid Valve
Pulmonary Valve
Pulmonary Veins
Superior Vena CavaAorta
Pulmonary Arteries
Aortic Valve
Mitral Valve
Left Ventricle
Septum
Physiology of the Heart
• Pulmonary Valve: Keeps blood from flowing back into the right ventricle
• Bicuspid Valve: Prevents blood from flowing back into the left atrium, A.K.A. Mitral valve
• Left Atrium: Receives oxygen rich blood from the pulmonary veins
• Pulmonary Trunk: Transfers blood through the pulmonary arteries to the lungs
More Physiology • Tricuspid Valve: Prevents backflow of blood
to the right atrium
• Aorta: Blood flows from the aorta throughout the entire body
• Left Ventricle: Pumping chamber which forces blood through the aortic valve, more muscular than the right ventricle
• Right Atrium: Collecting chamber, Receives blood from the superior and inferior vena cava
More Physiology
• Inferior Vena Cava: Vein that brings oxygen-poor blood from the lower part of the body to the right atrium
• Aortic Valve: Prevents blood from going back into the left ventricle
• Interventricular Septum: Separates the pumping chambers of the heart
• Right Ventricle: Receives blood from the right atria
Heart Valves• Heart valves insure unidirectional blood flow
through the heart• Atrioventricular (AV) valves lie between the atria
and the ventricles• AV valves prevent backflow into the atria when
ventricles contract• Chordae tendineae anchor AV valves to papillary
muscles
Heart Valves
Figure 19.9
Heart Valves
• Aortic semilunar valve lies between the left ventricle and the aorta
• Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk
• Semilunar valves prevent backflow of blood into the ventricles
Heart Valves
Figure 19.10
Blood Pressure
Blood against the blood vessel’s walls (Systole – contraction of heart muscle, Diastole – relaxation of heart muscle)–The systolic pressure refers to
• the pressure recorded while the ventricles pump the blood.
–The diastolic pressure refers to • the pressure recorded as the ventricles fill with
blood.
• A normal blood pressure is 120/80
Disorders
• Atherosclerosis• Hypertension• Heart Attack• Stroke• Endocarditis • Pericarditis • Deep Venous Thrombosis (DVT)• Varicose Veins
top related