*11.1 Cardiovascular System Notes Honors

Ch 11.1 Cardiovascular System

Thoracic cavity

Obliquely in the mediastinum

above the diaphragm

between the lungs

Location

Average 8-12 oz or 200-350 grams

Women

8-10 oz

Men

10-12 oz

​Size (fist size)

Heart

• pericardial cavity

  • the space the heart occupies

• Parietal pericardium

  • membrane that surrounds the pericardial cavity

• Visceral pericardium

  • membrane that covers or surrounds the heart

Heart Membranes

• Endocardium- inner layer

• Myocardium - thick muscular layer

  • involuntary muscle

  • cardiomyocytes ​

  • repeating sections of sarcomeres ​

• Epicardium - uppermost layer

Layers of the Heart

Cardiomyocytes make up 30% of muscle mass

functional cardiac muscle tissue

Cardiomyocytes

​(remember shake the patients hand)

• right atrium

• right ventricle

• left atrium

• left ventricle​

​Structures that divide the chambers

• ​Interatrial septum- divides the atriums

• Interventricular septum- divides the ventricles

Chambers of the Heart

​(remember shake the patients hand)

• right atrium

• right ventricle

• left atrium

• left ventricle​

4 Chambers

Chambers of the Heart

​Structures that divide the chambers

• ​Interatrial septum- divides the atriums

• Interventricular septum- divides the ventricles

Heart Septum

• atrioventricular (AV) valves

  • tricuspid

  • bicuspid (mitral)

• semilunar valves​

  • pulmonary semilunar valves

  • aortic semilunar valves

• Vena cava valve

  • Vena cava is the eustachian

Close to prevent backflow of blood during contraction

Heart Valves

• Chordae tendineae

  • (heart strings) fibrous connective tissue that maintain the tension and position of the valves

• ​Papillary muscles

  • ​are extensions of the cardiac muscles that help hold the cups of the valves together preventing backflow

Accessory Structures

Heart Valves

• Delivers deoxygenated blood to the heart​

  • superior (head and neck)

  • inferior (lower extremities)​

• Valve

  • Eustachian ​

    • prevents backflow of blood

Vena Cava​

These transport blood between the heart and lungs

• Pulmonary artery

  • ​transport deoxygenated blood from the heart to the lungs

• Pulmonary Vein

  • transport oxygenated blood from the lungs to the heart

​Pulmonary Vessels

​The largest artery​ and transports oxygenated blood to the other blood vessels to the body

• ​aortic valve

Aorta

The arterial supply to the heart is the left and right coronary arteries​

Arterial

Blood Vessel of the Heart

The venous heart vessels are the great and small cardiac veins ​

​Venous

Blood lacking O₂ and carrying CO₂

• Veins primarily carry DO blood

  • not blue (dark red)

Deoxygenated Blood

Blood Terms

1. Vena Cava (VC)

   1. Eustachian valve opens

2. Right atrium (RA) (during contraction)

   1. eustachian valve closes

   2. tricuspid valve opens

3. Right Ventricle (RV) (during contraction)

   1. tricuspid closed

   2. pulmonary semilunar valve opens

4. Pulmonary artery (PA)

   1. DO blood to the lungs

From the body to the lungs

Blood Flow

1. Pulmonary Vein (PV)

   1. Oxygenated blood fills the left atrium

2. Left atrium (LA) (during contraction)

   1. bicuspid/mitral valve opens

3. Left ventricle (during contraction)

   1. Bicuspid/mitral valve closes

   2. aortic semilunar valve opens

4. Aorta

   1. carries O₂ rich blood to the smaller arteries

From the lungs to the Body

Blood Flow

Multiple Choice

Deoxygenated blood enters the heart at the:

• Right Ventricle

• Left Ventricle

• Right Atrium

• Left Atrium

Ventricular diastole

​ventricle relax, atria contract

Ventricular systole

ventricles contract, atria relax​

​

Mean Arterial Pressure (map)

overall pressure within cardiovascular system

​

MAP = 2/3 (Diastole) + 1/3 systole.

Cardiac cycle

Amount of blood pumped by heart in 1 minute measured in liters/minute

stroke volume

amount of blood pumped in 1 beat

heart rate

number of beats per minute

​

SV (ml/beat) x HR (beats/min) = Q (Cardiac Volume)

Ex. 72 beats/min x 70 mL/beat = 5,040 L/min

Cardiac Output

• Intrinsic (ANS)

  • PNS and SNS​

• Extrinsic

  • ​Endocrine and Baroreceptors

​Conduction System

Regulation of the Heart

Sympathetic

Increases rate and forces contractions

Parasympathetic (branches of Vagus n.)

Slows the heart rate

ANS (Autonomic Nervous System

RAAS (Renin Angiotensin Aldosterone System)

• Negative feedback loop

• regulates blood pressure and blood volume

  • fluid retention

  • vasoconstriction

Endocrine (extrinsic) RAAS

​Dysfunction leads to Chronic Hypertension (high blood pressure)

• heart disease

• renal failure

• heart failure