The Cardiovascular System

Blood

The Heart

Blood Vessels

Cardiovascular system

Functions:

Transports:

oxygen

carbon dioxide

nutrients

wastes

chemical messengers

Homeostasis of

pH

temperature

clotting

Disease Defense

Systemic Vessels

Blood = Plasma + Formed (Cellular) Elements

Plasma• ~ 55% blood volume• ~ 92% of plasma is water

• High dissolved oxygen content• Dissolved proteins

• Albumins• Globulins• Fibrinogen

Cells• ~ 45% blood volume• RBCs ~ 99% of cells• WBCs ~1% of cells

• Albumins– 60% of plasma proteins– viscosity

The Proteins in Plasma

• Globulins– 35% of plasma proteins

• Immunoglobulins attack foreign invaders

• Fibrinogen– React in clotting reaction– Form fibrin (serum = plasma - fibrinogen)

Cellular Components• RBCs (erythrocytes)~ 99% of all cells.

• ~ 1/2 blood volume.

Lacks mitochondria,

ribosomes, nuclei

Life span = ~120 days

Hematocrit = % of blood occupied by cellular components (~ RBC volume)

Scanning Electron Micrograph (SEM)

of Erythrocytes or Red Blood Cells (RBCs)

on the tip of a hypodermic needle.

Hemoglobin

Erythropoietin

Life and death of an RBC

Anemia• Pernicious anemia

– Low Fe absorption – Vitamin B12 and instrinsic factor

• Hemorrhagic anemia

• Sickle cell anemia

• Hypochromic anemia

• Hemolytic anemia

• polycythemia

Pernicious anemia

Blood Types - ABO

What type?

What type?

Erythroblastosis fetalis

• Neutrophils– 70% circulating leukocytes– Highly active aggressive phagocytes

• Eosinophils (acidophils)– Much less common– Attracted to foreign compounds reacted with

antibodies– Parasitic infections

• Basophils– Relatively rare– allergeries– Release histamines.

Granular Leukocytes (WBCs)

• Monocytes– Migrate into peripheral tissues

and differential into Macrophages

– Highly mobile phagocytic cells– diapedesis

• Lymphocytes – Primary cell of the lymphatic system

• T-cells attack foreign cells directly• B-cells produce antibodies

Agranular Leukocytes

NeverLet Monkeys Eat Bananas

• Platelet cells (Thrombocytes)– Fragments of Megakaryocytes – enclosed packets of cytoplasm for blood

clotting

Pulmonary circuit - from heart

to lungs

back to heart

Systemic circuit- from heart

to body

back to heart

Arteries = vessels that carry blood away from the heart.

Veins = vessels that return blood to the heart.

Capillaries = smallest vessels, found between smallest arteries

and veins. These are the exchange vessels.

• Myocardium

• Chambers

• Valves(one-way-flow)

• Pericardial Sac

The Heart

Location of the Heart in the Thoracic Cavity

Epicardium– Visceral pericardium

Myocardium– Muscular wall of the heart

Endocardium– Epithelium of inner surface

• Most of the heart is Myocardium

- Contractile Myocardiocytes

* Interconnected by intercalated discs

The Heart is Dual Pump

Position and Orientation of the Heart

Sectional Anatomy of the Heart

RA -> ______ valve -> RV -> _____ valve -> pulmonary trunk -> pulmonary ______s -> lungs -> pulmonary _____s -> LA -> ____ valve -> LV -> ___ valve -> ascending aorta -> aortic arch

Receives blood from systemic circuitSuperior vena cavaInferior vena cava

Coronary veinsReturn blood to coronary sinus then on to right ventricle

Foramen ovale open during embryonic developmentFossa ovalis after birth

Blood Flow through Heart

Right Ventricle

Blood comes from right atrium to right ventricle through the atroventricular (AV) valve

- Pulmonary semilunar valve

Blood leaves Rt Ventricle via pulmonary Semilunar valve to pulmonary trunk.

Branches to left and right pulmonary arteries

- Chordae tendineae- Papillary muscles

Right AV valve / Tricuspid valveThree cusps of fibrous tissue

Valves of the Heart

How do papillary muscles work?

Heart Valves and Heart Sounds

• Placement of a stethoscope varies depending on which heart sounds and valves are of interest.

• Closure of the AV valves create the 1st heart sound (‘lub’).

• Closure of the semilunar valves create the 2nd heart sound (‘dupp’).

Coronary Circulation

Normal Functional Heart Anatomy

Congenital Heart Defects

Congenital Heart Defects

Congenital Heart Defects

The Cardiac Cycle

Recording of the electrical activities in the heart

The Electrocardiogram

P wave = Atrial Depolarization

QRS complex

= Ventricular Depolarization

T wave

= Ventricular Repolarization

ECG

The Conducting System of the Heart

Heart cycle