Circulatory System

Chapter 14, 15, 16

The Heart’s Layers Endocardium –

innermost layer, squamous layer

Myocardium – thick middle layer, cardiac muscle

Pericardium – outermost layer

Heart Anatomy – Blood Flow

Heartbeat Animation

Lub – Dub –

Contraction of Ventricles– systole (highest pressure on artery

Relaxation of ventricles- Diastole (lowest pressure on artery

Lub – ventricles contract, bicuspid/tricuspid valves close

Dub – semi lunar valves close, ventricles relax

Heart Murmur:

Cardiac Conduction System

Impulse begins at the SA node, travels over atria so both contract at the same time

Impulse moves to the AV node to stop atria from contracting and to contract the ventricles

Through AV bundle Purkenje Fibers Contraction – Apex and

up.

                                                

            

Electrocardiogram (ECG) P wave – electrical

activity associated with atrial depolarization

QRS complex – ventricular polarizaton

Twave – ventricular repolarization

Disorders of the heart: Pictures of heart damage Heart Transplant Surgery

Systemic Circulation Circulation from

heart to rest of body and back to heart

Arteries and Arterioles Take blood away

from heart Thick walls Able to expand Arterioles –                                                                        

Capillaries – most important Microscopic tube – one cell layer

thick Capillary Beds -

Capillary with red blood cell

Venules and Veins Take blood to heart Venules – drain blood from

capillaries then to a vein.

Veins and muscle contraction

Valves – allow blood flow back to heart and prevent Back flow of blood (rely on skeletal muscle contraction

Varicose Veins Abnormal and

irregular dialations in superficial veins.

Valves become weak

Hemorrhoids -

Cause of Varicose Veins

Hemorrhoids

Disorders of : Hypertension – high blood pressure

Systolic is greater than 140 mm/Hg Diastolic is greater than 95 mm/Hg Blood being pumped with too much

force Decrease in the diameter of ateriole.

Comparison of Hearts

Chapter 14: Blood 3 main functions: transport,

clotting, infection fighting

Parts of Blood Plasma: straw

yellow fluid Water, nutrients,

salts, wastes, gases Proteins: albumin,

fibrinogin (clotting), globulins (fight infection

Serum – plasma without clotting proteins

Formed Elements of Blood Erythrocytes

(RBC’s) – involved in the transport of oxygen

Hemoglobin – Protein in blood, oxygen attaches to the “Heme”

Iron Deficiency Anemia A diet lacking in

iron.

Sickle-celled anemia Gentic defect in

shape of blood cells.

Tear-dropped shaped

Abnormal shaped hemoglobin

White Blood Cells (formed ele) Leukocytes Have nucleus No hemoglobin Fight infection –

phagocytes

Types of White Blood Cells Classified

according to the granules in cytoplasm

1. Granulocytes- phagocytes

2. Agranulocytes – have the ability to change into a macrophage

Platelets (Thrombocytes) Very small in size Important for

clotting

Blood Clotting - Hemostasis

1. Formation of platelet plug, platelets clump at wound site

2. Platelets activate prothrombin activator – enzyme that converts prothrombin into thrombin

Steps in blood clotting continued

3. Thrombin – solidify fibrinogen in blood plasma.

4. Fibrin forms around platelet plug

5. Blood clot with RBC’s and serum

Blood Types

Antigens An ANTIGEN is a

protein or carbohydrate that acts as a signal, enabling the body to recognize foreign substances in the body.

Rh factor - antigenIf Rh is present then Rh+. If Rh is not present then Rh-