Day 1

1
Cardiovascular System

• Day 1 Chapter 15

2
Overview

• Vascular System
• blood circulates inside closed transport systems

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Anatomy of the Heart

• General
• Size approximately the size of a persons fist
• Location in the mediastinum - the cavity in the
  center of the chest
• Coverings Pericardium
• Double layered sac
• Contains roughly half an ounce of pericardial
  fluid to reduce the friction of the beating heart
• Parietal layer fibrous membrane outer layer
• Visceral layer serous membrane also called the
  epicardium attached to myocardium

4
Heart Wall

• Myocardium heart muscle thicker on left side of
  the heart
• Endocardium lining of heart chambers
  endothelial tissue continuous with the lining of
  the blood vessels

5
Chambers of the Heart

• Atria
• 2 upper chambers of heart thin walls, smooth
  inner surface
• Responsible for receiving blood
• Right atrium receives deoxygenated (oxygen poor)
  blood from the body through the superior and
  inferior vena cava
• Left atrium receives oxygenated (oxygen rich)
  blood from the lungs through the pulmonary veins
• Ventricles
• 2 lower chambers of the heart thicker walls,
  irregular inner surface
• Contain papillary muscles and chordae tendineae
  (prevent heart valves from turning inside out
  when ventricles contract)
• Left wall 3x as thick as right wall forms apex
  of heart
• Responsible for pumping blood away from the heart
• Right ventricle sends deoxygenated blood to the
  lungs via the pulmonary arteries
• Left ventricle sends oxygenated blood to all
  parts of the body via the aorta

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Chambers of the Heart (ctd.)

• Accessory Structures
• Septum muscular wall dividing the heart into
  right and left halves
• Heart valves prevents the backflow of blood
• Papillary muscles
• Chordae tendineae

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Great Vessels

• Superior and inferior vena cava receive
  deoxygenated blood from all parts of the body
• Coronary sinus returns deoxygenated blood from
  the myocardium to the right atrium
• Pulmonary arteries carry deoxygenated blood to
  the lungs from the right ventricle
• Pulmonary veins carry oxygenated blood to the
  left atrium from the lungs
• Aorta carries oxygenated blood to distribute to
  all parts of the body

8
Blood Vessels

• Types of Blood Vessels
• Arteries
• Arterioles
• Capillary beds
• Venules
• Veins

9
Anatomy of Blood Vessels

• Three coats (tunics)
• Tunica intima endothelium lines the interior of
  vessels decreases friction as blood flows
• Tunica media smooth muscle elastic tissue
  (dilates constricts vessels)
• Tunica externa fibrous connective tissue on
  outside supports and protects vessels

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Arteries

• Carry blood AWAY from the heart
• All BUT pulmonary arteries carry oxygenated blood
• Aorta largest artery 1 inch in diameter
• Arterioles smallest arteries
• Coronary arteries most important supply blood
  to the heart muscle
• Left and right main coronary artery
• Left coronary artery - left anterior
  descending, left circumflex branch
• Right coronary artery - right atrium and right
  ventricle

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Veins

• Carry blood TOWARD the heart
• All BUT pulmonary veins carry deoxygenated blood
• Layers much thinner, less elastic
• Series of internal valves that work against the
  flow of gravity to prevent reflux
• Superior and inferior vena cava largest veins
• Venules smallest veins

13
Vericose Veins

• People stand for long periods of time ?
  inactivity or pressure on veins
• Blood pools in feet and legs
• Valves weaken ? veins become twisted dilated
• Treatment compression stockings, exercise, laser
  treatment, surgery

14
Capillaries

• Tiny, microscopic vessels
• Walls one cell layer thick
• Function to transport and diffuse essential
  materials to and from the bodys cells and the
  blood

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Arteries
Capillaries
Veins

• Blood away from heart
• Thicker walls
• Withstand high pressure

• Walls 1-cell thick
• Exchange gases between blood and tissue cells

• Blood back to heart
• Thinner walls
• Low pressure
• Large lumen
• Valves prevent blood backflow
• Skeletal muscles enhance venous return

17
Vital Signs

• Pulse expansion recoil of an artery with each
  beat of left ventricle
• Pressure points (eg. carotid artery, radial
  artery)
• Normal resting 70-76 beats/min

18
Cardiovascular System

• Day 2

19
Vital Signs

• Blood pressure pressure of blood on inner walls
  of blood vessels
• Systolic presure peak of ventricular contraction
• Diastolic pressure ventricles relaxed
• Written Systolic/Diastolic
• Normal (120 mm Hg)/(70 mm Hg) or 120/70

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Measuring Blood Pressure
21
Using a sphygmomanometer

• Wrap cuff around upper arm
• Place stethoscope on brachial artery
• Inflate cuff to 180 mm Hg
• Slowly release air ? listen for whooshing sounds
  in brachial artery (Korotkoff sounds)
• Systolic when sounds begin to appear
• Diastolic when sounds disappear

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Homeostatic Imbalances

• Hypertension high blood pressure (gt140/90)
• Circulatory shock acute hypotension
• Blood loss
• Atherosclerosis artery walls thicken due to
  fatty deposits (plaques)

23
Stent vs. Bypass Surgery
24
Congestive Heart Failure

• Progressive weakening of heart
• Low heart efficiency ? circulation inadequate to
  meet tissue needs
• Caused by
• Coronary atherosclerosis
• Persistent high blood pressure
• Multiple heart attacks scar tissue