Components of cardiovascular system

1. Blood

2. Heart

3. Blood vessels - arteries, veins, capillaries

Components of the cardiovascular system

• transport - oxgyen, carbon dioxide, glucose, urea, hormones, proteins

• Protection - inflammation, phagocytosis, antibodies

• Regulation - fluid balance, pH, body temp and pressure

Functions of the cardiovascular system

• function - pumps and routes blood, one way flow and regulates blood supply

• Protection - ribcage, membranes and fluid

• 72-75 beat/minute

Heart

• thoracic cavity of mediastium

• Medial to lungs, superior to diaphragm,, posterior to the sternum

• Broad end - base

• Rounded end - apex

Heart location

• tough fibrous outer layer, prevents heart from overfilling, acts as anchor

Fibrous pericardium

• anterior and posterior side

• Sulcus - coronary sulcus, anterior and posterior intrventricular sacs

• Pericardial fat - between visceral and parietal pericardium

• Epicardial fat - between outer layer myocardium and epicardium

Heart morphology

• atria

• Collecting blood

• From to body to heart

Superior chambers

• ventricles

• Discharge

• Blood from heart to blood vessels

Inferior chambers

• Simple squamous epithelium over areolar tissue

• Smooth outer surface

Epicardium

• middle layer

• Thickest

• Cardiac muscle - contractable

Myocardium

• smooth inner layer

• Simple squamous epithelium over alveolar tissue

• Covers valve surface and continuous with endothelium

Endocardium

• separation between two ventricles

Inter ventricular septum

• wall between atria

Inter atrial septum

• a remnant of the feral opening

Fossa ovalias

• muscular ridges in auricles and atrial walls

Pectinate muscles

• muscular ridges and columns on inside walls of ventricles

Trabeculae carnae

• posterior side

• Flaps (auricles) increase volume

• Receives deoxygenated blood returning from body

• Superior and inferior vena cava and coronary sinus

Right atrium

• pumping chamber - anterior side

• Received deoxygenated blood from atrium

• Opens to pulmonary trunk

• Contains trabeculae carnae

Right ventricle

• receives oxygenated blood

• Posterior side

• Auricles - increase volume

• Pectinate muscles - large force of contraction

• Four pulmonary veins

Left atrium

• pumping chamber, form apex and posterior inferior aspect

• Thickest wall

• Receives oxgygenated blood

• Open to aorta

• Contains trabeculae carnae

Left ventricle

• Right atrium - superior and inferior vena cava from systemic circulation and coronary sinus from coronary circulation

• Left atrium - left and right pulmonary veins from pulmonary circulations

Blood into heart

• out of right ventricle - pulmonary trunk to pulmonary circulation

• Left ventricle - aorta to systemic circulation

Blood out of the heart

• between atria and ventricle

• Leaf-life cusps

• Attached to papillary musculoskeletal by tendons - chordate tendineae

• Open valves have atrioventricular canal

• Left - 2 cusps

• Right - 3 cusps

• Closed valve blood exits ventricle

• Open A TO V

Atrioventricular valves

• base of large vessels

• Cup shaped

• Cup filled - valves closes - prevent backflow

• Cups are empty, valves open, blood exists

Semi lunar valves

• base of pulmonary trunk

Pulmonary SL valve

• Base of aorta

Aortic SL valve

• strings connecting valve cusps to papillary muscles, prevents AV valves from bulging into atria

Chordae tendinae

• pillar-like muscles in ventricle prevents prolapse of AV valves

Papillary muscles

• deoxygenated blood is transported to lungs for oxygenation and then returned to heart

Pulmonary circulation

• oxygenated blood is transported to body tissues and then returned to heart

Systemic circulation

• part of systemic circulation that supplies only heart

Coronary circulation

• moves from high to low pressure

Contraction of heart produces the pressure

• systole (contraction)

• Disaster (relaxation of heart chambers

• Cardiac output = heart rate x stroke volume

Cardiac cycle

• maintains blood pressure

• Re-routes blood flow away from skin and viscera towards brain and cardiac muscle

Nervous system

• controls release of hormones

• Adrenaline

Hormonal control

• internal pacemaker and nerve like pathway through myocardium

Cardiac conduction system

• spread through the conducting system of the heart to all cardiac muscle cells - as a result the cardiac muscle cells contract

• Heart can generate

Action potential

• repetitive contractions, caused by autorythmic contractile cells

• Pacemaker - sinotrial node - generate action potential

• Atrioventricular node

• Atrioventricular bundle

• Right/left bundle branches

• Pukinje fibers

Auto-rhythimicity

• proteins

• Water

• Other solutes

Plasma in blood

• platelets

• White blood cells

• RBCs

Formed elements

• no nucleus - increase SA

• Biconcave

• Hameoglobin

• Oxgyen and carbon dioxide

Erythrocyte

• complete

• Nucleus

• Organelles

• Protection/immunity

Leucycotes

• take blood away

• High pressure

• Elastic,muscular and arterioles

• Round lumen

• Deep in muscle

Arteries

• site of exchange with tissue

• Thin walled

• Endothelial cells

• Simple squamous epithelium

Capillaries

• take blood to heart

• No pressure

• Thinner walls

• Venules,small, medium, large

• Flat lumen

• Close to surface

Veins

• endothelium basement membrane, lamina propria, elastic tissue

Tunica intima

• smooth muscle cells and elastin arranged circularly

Tunica media

• connective tissue, transitions from dense to lose it merges with surrounding tissue

Tunica externa

• no gaps

• Less permeable to large molecules

• Closely packed cells

Continuous capillaries

• pores in endothelial cells

• Highly permeable

Fenestated capillaries

• large diameter

• Irreugular incomplete wall

• Less basement membrane

Sinusodial capillaries

• fluid which remains in the tissues is picked up by the lymphatic capillaries

• Mains blood volume, pressure and fluid balance

• Valves

Cardiovascular-lymphatic

• swelling caused by excess fluid accumulation in body tissues

Edema