Heart

Heart

• Approximately size of fist

• Hollow cone-shaped

• Weights approximately (0.6lbs)

Blood vessels

Arteries: carry blood away from heart

Veins: carry blood toward heart

Capillaries: only vessels to contact tissue cells; directly serve cellular needs

Heart (two ventricles)

Is a biological pump (two ventricles)- works with blood vessels

Right side: Receives OXYGEN-POOR BLOOD from body + tissues. Pumps to lungs to pick up oxygen & end carbon dixoide

Left side: Receives OXYGENATED BLOOD from lungs & pumps this blood throughout body to supply oxygen + nutrients to body tissues

Circulations

Systemic circuit: Blood vessels that transport blood to & from all body tissues

Pulmonary circuit: Blood vessels that carry blood to & from the lungs

Systemic & Pulmonary circuits in (Arteries, Veins, & Capillaries)

Arteries:

Systemic- carry oxygenated blood

Pulmonary- carry oxygen low blood

Veins:

Systemic: Carry oxygen poor blood

Pulmonary: Carry oxygenated blood

Capillaries:

Systemic: N/A

Pulmonary: N/A

Receiving Chambers of Heart

Right atrium- receives blood returning from systemic circuit

Left atrium- receives blood returning from pulmonary circuit

Pumping Chambers of the heart

Right ventricle: pumps blood through pulmonary circuit

Left ventricle: pumps blood through systemic circuit

Blue Blood vs Red blood

Blue- OXYGEN POOR/ CO2 RICH BLOOD

Red- OXYGEN RICH/ CO2 POOR BLOOD

Heart via blood transports…

O2, nutrients, waste, & other substances into blood vessels that support cellular functon

Coverings of the Heart: Pericardium

Heart surrounded by double-walled sac (pericardium)

Fibrous pericardium: loose fitting superfical part of the sac

• tough dense connective tissue

• 3 functions: protects, anchors to surrounding structures & prevents overfilling of heart with blood

Inside fibrous pericardium is… Serous pericardium

• Thin slippery 2 layer serous membrane that forms a sac around the heart

• 2 layers: Parietal vs visceral layer

• Parietal layer lines the internal surface of the fibrous pericardium

• Visceral layer lines the external surface of the heart aka epicardium

• Between the parietal and the visceral is the pericardial cavity (contains serous fluid)

Pericarditis

• Inflammation of pericardium

• Roughens membrane surfaces —> pericardial friction rub (creaking sound) heard with stethescope

• Deep pain to sternum

• May led to visceral & pareital pericardia sticking to one each other

• Abonrmal amounts of excess fluid in the sac that surrounds theheart (aka pericardial effusion)—> limited pumping ability

Layers of the Heart Wall

Highly vascualr ( contains channels, vessels, & tissues that carry fluids through body)

Composed of three layers of heart wall:

• Epicardium

• Myocardium

• Endocardium

Epicardium

visceral layer of serous pericardium

Myocardium

made of spiral bundles of contractile cardiac muscle cells

• layer that contracts

• Branching muscles are connected & arranged in circular bundles

Cardiac skeleton: Cricrossing, interlacing layer of connective tissue

• Anchors cardiac muscle fibers of the myocardium

• Makes rings around + provides support for great vessels & valves preventing stretching

• Limits spread of action potentials to specific paths

Endocardium (inside the heart)

• Made up of squamous epithelium on a layer of connective tissue

• Lines heart chambers; covers fibrous layer of valves

• Continous with the endothelial lining of the blood vessels coming from & leaving the heart

Endocarditis

Inflammation of the inner layer of the heart. Usually involving the heart valves

• occurs when bacteria & germs from another part of your body (ex: mouth), spread through bloodstream & attach to damaged areas in your heart

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• Left untreated: can damage or destory heart valves

• Can be treated: With antibotics