Transcript Anatomy of the Cardiovascular System

Anatomy of the
Cardiovascular System
TENTATIVE Dates:
Tuesday April 19th – Chapter 18 Quiz
Wednesday April 20th – Heart Anatomy Practical
Friday May 6th – Project Due
Block Days (May 11th or 12th) – Chapter 18/19
Test
Cardiovascular System
• Also circulatory system
• Consists of: the heart, arteries, veins,
capillaries
Heart
• Four chamber muscular organ
• Comparable to the size of a closed fist
• Located in the mediastinum
– Behind sternum
– Between 2nd and 6th ribs
– Between T5-T8
• Apex – base of heart
– Located at the 5th intercostal space
Heart
Coverings of the Heart
• Pericardium – loose fitting sac
surrounding the heart
– Fibrous pericardium – tough, loose-fitting,
inelastic
– Serous pericardium
• Parietal layer: lines the inside of the fibrous
pericardium
• Visceral layer: adheres to outside of the heart
– Pericardial space: between parietal and
visceral layer
• Filled with 10-15mL of pericardial fluid
• Decreases friction
Walls of the Heart
• Epicardium – outer layer
– Epicardium = serous pericardium
• Myocardium – thick, contractile layer composed
of cardiac muscle cells
– Intercalated disks contain many gap junctions
– Allow cardiac muscle cells to function as a single unit
 syncytium
• Endocaridium – interior of cardiac wall
– Endothelial tissue
– Covers projections of myocardial tissue called
trabeculae
Walls of the
Heart
Chambers of the Heart
• Atria – two superior chambers
– “Receiving chambers”
– Blood from veins enters atria
• Ventricles – two inferior chambers
– “pumping chambers”
– Thick muscular walls to increase force of
pumping action
• Left > right
– Separated by interventricular septum
Valves of the Heart
• Permit blood flow in one direction during
circulation
• Atrioventricular valves (AV valves)
– Also cuspid valves
– Between atria and ventricles
• Semilunar (SL valves)
– Between R ventricle and pulmonary arteries
and L ventricle and aorta
Atrioventricular Valves
• Tricuspid valve
– Btwn R atrium and ventricle
– 3 flaps of endocardium
– Connected to ventricular papillary muscle
via chordae tendinae
• Bicuspid valve
– Btwn L atrium and ventricle
– Also called mitral valve
– Two flaps of endocardium
Semilunar Valves
• Pulmonary semilunar valve
– Btwn R ventricle and pulmonary trunk
• Aorta semilunar valve
– Btwn L ventricle and aorta
Chambers & Valves
Trace the blood flow through the heart
Blood Supply to the Heart
• Right and left coronary arteries
– First branches off aorta
– Right coronary artery  right marginal
artery & posterior interventricular artery
– Left coronary artery  circumflex artery
& anterior interventricular artery
– Most of the blood goes to the L ventricle
– In 50% of the population, the R coronary
artery is dominant
Blood Supply to the Heart
• Anastomosis: Connections between blood
vessels that allow for collateral circulation
• Few exist between large branches of coronary
arteries
• In presence of an obstruction in a large
artery ischemia will result to a large area of
tissue
– Myocardial infarction (MI) (aka heart attack)
• Anastomoses do exists between smaller
branches of the R and L coronary arteries
Blood Supply to the Heart
• After traveling through the capillaries
of the heart, blood empties into the R
atrium via the coronary sinus
Conduction System of the Heart
• Four structures composed of modified
cardiac muscle
• Sinoatrial Node (SA Node)
– Pacemaker of the heart
– 100s of cells in the R atrium near the
opening of the superior vena cava
• Atrioventricular Node (AV Node)
– Small mass of cardiac muscle tissue
– Left lower border of R atrium
Conduction System of the Heart
• Atrioventricular Bundle
– Also Bundle of His
– Bundle of specialized cardiac muscle fibers
originating in the AV node
– Branches into R and L branches eventually
becoming Purkinje fibers
– Extend into the walls of the ventricles and
papillary muscles
Warm Up 4/12/11
1. The apex of the heart rests on the:
2. True/False: The epicardium and the fibrous
pericardium are the same structure.
3. What is the correct order of the layers of
the heart from outside to inside?
4. The ____________ connect the cuspid
valves to the papillary muscles.
5. What is an anastomosis?
6. What is also known as the pacemaker of the
heart?
Types of Blood Vessels
• Artery – carries oxygenated blood away
from the heart
– “distributors”
– Arteriole: small artery
– Precapillary sphincters: regulate the blood
flow into capillaries
Types of Blood Vessels
• Vein – carries unoxygenated blood
towards the heart
– Great ability to stretch (capacitance)
– Function as reservoirs: blood pools in the
valves then is pushed forward from the
pumping pressure
– Venules: small vein
Types of Blood Vessels
Types of Blood Vessels
• Capillaries – arterial system switches to
venous system
– “primary exchange vessels”
– Transport materials to and from the cells
– Speed of blood flow decreases to increase
contact time
– Microcirculation: blood flow between
arterioles, capillaries and venules
Types of Blood Vessels
Structure of Blood Vessels
• Tunica adventitia - outermost layer
– Fibrous connective tissue
– Holds vessels open; prevents tearing of
vessels walls during body movements
– Larger in veins than arteries
• Tunica media – middle layer
– Smooth muscle and elastic CT
– Helps vessels constrict and dilate
– Larger in arteries
Structure of Blood Vessels
• Tunica intima – innermost layer
– Composed of endothelium
– Semilunar valves present in veins
– One cell thick in capillaries
Circulatory Routes
• Systemic Circulation – blood flow from
the L ventricle to the body & back to
the R atrium
• Pulmonary Circulation – blood flow from
the R ventricle to the lungs and back to
the L atrium
Circulatory Routes
Aorta
Systemic Arteries
•
•
•
•
•
•
•
•
Arch of aorta
Subclavian (L and R)
Brachiocephalic
common carotid (L
and R)
Axillary (L and R)
Brachial (L and R)
Radial
Ulnar
•
•
•
•
•
•
•
•
Abdominal aorta
Common iliac
External iliac
Femoral
Popliteal
Posterior tibial
Anterior tibial
Dorsal pedis
Systemic Veins
•
•
•
•
•
Superior vena cava
Inferior vena cava
External jugular
Internal jugular
Brachiocephalic (L
and R)
• Subclavian (L and R)
• Cephalic
• axillary
•
•
•
•
•
•
•
•
•
Basilic
Median basilic
Median cubital
Common iliac
External iliac
Femoral
Popliteal
Great saphenous
Small saphenous
Fetal Circulation
• Two umbilical arteries carry blood to the
placenta
• The placenta allows for exchange of oxygen
and nutrients from the mother. Maternal and
fetal blood do NOT mix.
• Umbilical vein returns oxygenated blood and
enters fetus via the umbilicus
• Foramen ovale – hole btwn the R and L atria
– Allows for blood to bypass the R ventricle and
pulmonary circulation
Fetal Circulation
• Ductus arteriosus – small vessel
connecting the pulmonary artery and
the aorta
– Allows for another bypass route from the
lungs
**Most of fetal blood is a mixture of
oxygenated and deoxygenated blood**
Fetal
Circulation
Changes After Birth
• Umbilical vein become round ligament
• Umbilical arteries become umbilical
ligaments
• Foramen ovale closes after first few
breaths
– Full closure may take up to 9 months
• Ductus arteriosus contracts as soon as
respirations begin
– Become fibrous cord
Changes After Birth
Warm Up 4/13-14/11
1. What is the function of the precapillary
sphincters?
2. List the layers of arteries and veins from
superficial to deep. How do the layers
differ in arteries vs veins?
3. What type of tissue are capillaries composed
of?
4. What blood vessel has valves?
5. Differentiate between pulmonary and
systemic circulation.
Warm Up 4/15
Announcements:
•
Warm ups due today
•
Chapter 18 quiz next Tuesday – will finish notes on
Monday
•
Heart and Blood Vessel Practical next Wednesday
Warm Up:
1. Name the arteries that branch off the aorta.
2. What are the 4 divisions of the aorta?
3. True/False: During fetal circulation fetal and maternal
blood mix.
4. Explain the function of the umbilical cord during fetal
circulation.
5. Describe the foramen ovale and the ductus arteriosus.
Warm Up 4/18/11
Announcements:
1. Chapter 18 Quiz tomorrow
2. Practical Wednesday (sheep heart and blood
vessels)
Warm Up:
1. Respectively, the right and left atrioventricular
(AV) valves are also referred to as:
2. From the L ventricle, blood flows into the:
3. The pulmonary veins carry blood to the:
4. The most abundant blood supply goes to the:
5. What type of blood vessel has valves? What type
of valves are they?
Pericardium Disorders
• Pericarditis – inflammation of the heart
– Causes: trauma, viral or bacteria infection, tumor
– Edema causes visceral and parietal layers to rub
together = chest pain
– Pus or blood build up in pericardial space
– S/S
• Pain with respirations or coughing, dyspnea, restlessness
– Complications: Pericardial Effusion, Cardiac
Tamponade
– Treatment:
• Antibiotics, pain meds, antiinflammatory meds,
pericardiocentesis (Cardiac Tamponade)
Cardiac Tamponade
Heart Valve Disorders
• General Principles:
– Congenital defect: decreased pumping
efficiency
– Incompetent valve leak: allows backflow
into previous chamber
– Stenosed valves: narrowed valve; slowing
blood from out of chamber
Heart Valve Disorders
• Mitral Valve Prolapse (MVP)
– Flaps of mitral valve extend back into L
atrium causes leaking
– Mostly genetic basis
– 1 in 20 people
– S/S: most asymptomatic; chest pain,
fatigue
– Treatment: valvuloplasty
Mitral Valve Prolapse
Heart Valve Disorders
• Aortic Regurgitation
– Blood leaks back into L ventricle during
ejection into the aorta
– Volume overload in L ventricle,
hypertrophy, dilation of L ventricle
– Complications: myocaridal ischemia
– Treatment: valvuloplasty
Myocardium Disorders
• Atherosclerosis
– Type of arteriosclerosis
– Lipids build up on the inside of vessel walls
 calcify  vessels hard & brittle
– Risk factors: cigarette smoking, high
fat/cholesterol diet, hypertension
Atherosclerosis
Myocardium Disorders
• Myocardial Infarction
–
–
–
–
“Heart Attack”
Coronary thrombosis: clot
Coronary embolism: mobilized clot
Occlude coronary artery  heart tissue
deprived of oxygen  cell death
– S/S:
• Angina pectoris – severe chest pain resulting
from inadequate oxygen to myocardium
– Treatment: Coronary Bypass Surgery
• Veins are harvested from other areas of the
body and used to bypass obstructions
Myocardium Disorders
• Congestive Heart Failure (CHF)
– “Left-sided Heart Failure”
– Inability of the L ventricle to pump blood
efficiently
– Causes: myocardial infarction
– S/S: decreased pumping pressure in
systemic circulation; retained fluids
• Can lead to congestion in pulmonary circulation 
pulmonary edema  right-sided heart failure
– Treatment: heart transplant
Congestive Heart Failure
Myocardium Disorders
• Coronary Artery Disease (CAD)
– Leading cause of death in US
– General term to describe decreased blood
flow to myocardium & associated side
effects
Disorders of the Arteries
• Arteriosclerosis
– Arteries become occluded, weak and
hardened
– Complications: ischemia, necrosis, gangrene
– Risk factors: age, diabetes, high
fat/cholesterol diet, hypertension, smoking
– Treatment: vasodilators, angioplasty, stent
placement, bypass surgery
– Complications: aneurysm
Angioplasty
Warm Up 4/25/11
Announcements:
1. Practical grades online
2. Practical & Quiz make ups today after school
3. Use next blank box on warm up sheet
Warm Up:
1. What two vessels return blood to the heart after
systemic circulation?
2. A ___________ is a small artery.
3. What procedure can open a blocked artery and
restore blood to the heart? If this doesn’t work,
what is a more invasive procedure?
4. What does MONA stand for? When is this treatment
used?
5. A cardiac tamponade is the result of too much fluid in
the:
Changes to Schedule
• Project due Friday May 13th
– Computer lab days:
• 4/28 (2nd Period)
• 4/29 (5th, 6th)
• Block day (5/4, 5/5)
• Chapter 19 Quiz 5/11 or 5/12 (block
day)
• Chapter 18/19 Test – Tuesday 5/17
Disorders of Veins
• Varicose Veins
– Enlarged veins caused by pooling
– Results in varicosities or varices (“spider
veins”)
– Risk factors: standing for long periods
• Semilunar valves widen  more pooling
– Treatment: compression stockings, surgical
removal
Varicose Veins
Disorders of Veins
• Phlebitis – vein inflammation
– Causes: irritation by IV catheter
• Thrombophlebitis
– Deep vein thrombosis (DVT)
– Phlebitis caused by a clot
– S/S
• Pain, redness, swelling
– Complications
• Pulmonary embolism
DVT
Pulmonary Embolism
Venous Stasis Ulcers
• Result of chronic
vein insufficiency
• Lack of oxygen
to peripheral
tissues
• Elevate leg &
apply pressure
• Irregular edges
• “Aching” pain
Heart Defect Project
• Description of the anatomical defect(s)
• Etiology (causes/origin)
• Resulting circulatory problem(s)
–
–
–
–
Normal vs abnormal circulation
Perfusion
Oxygenation
Fluid balance
• Associated signs/symptoms
• Prevalence (Statistics)
• Treatment
– Medications
– Surgery
– Life Expectancy (with or without treatment)
Patent Ductus Arteriosus (PDA)
Atrial Septal Defect (ASD)
Ventricular Septal Defect (VSD)
Atrioventricular Septal Defect
(AVSD)
Tetralogy of Fallot (TOF)
Transposition of the Great Vessels
(TGV)
Coarcatation of the Aorta (CoA)
Ebstein’s Anomaly
Pulmonary Atresia
Truncus Arteriosus
Hypoplastic Left Heart
Syndrome