THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

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THE HEART THE HEART Ch 19 Ch 19 Human Anatomy Human Anatomy Sonya Schuh-Huerta, Ph.D. Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart

Transcript of THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Page 1: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

THE HEARTTHE HEARTCh 19Ch 19

Human AnatomyHuman Anatomy

Sonya Schuh-Huerta, Ph.D.Sonya Schuh-Huerta, Ph.D.

Leonardo Da Vinci, Human Heart

Page 2: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Heart: An Amazing Piece ofMachinery

• Although it’s not where

you keep your emotions,

it’s an amazing vital

organ of your body

Page 3: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Heart

• A muscular double pump– Pulmonary circuit takes blood to & from

the lungs– Systemic circuit vessels transport blood

to & from body tissues– Atria receive blood from the pulmonary &

systemic circuits– Ventricles the muscular pumping

chambers of the heart

Page 4: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Pulmonary & Systemic Circuits

Oxygen-rich,CO2-poor blood

Oxygen-poor,CO2-rich blood

Capillary bedsof lungs wheregas exchangeoccurs

Capillary beds of allbody tissues where gas exchange occurs

Pulmonary veinsPulmonaryarteries

PulmonaryCircuit

Systemic Circuit

Aorta and branches

Left atrium

Heart

Left ventricleRight atrium

Right ventricle

Venae cavae

Page 5: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Location & Orientation Within the Thorax

• Heart typically weighs 250–350 grams (~healthy heart)

• Largest organ of the mediastinum– Located between the lungs– Apex lies to the left of the midline – Base is the broad posterior surface

Page 6: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

(c)

Superior vena cava

Left lung

AortaParietal pleura (cut)

Pericardium (cut)

Pulmonary trunk

Diaphragm

Apex of heart

Location of the Heart in the Thorax

Heart

Posterior

Right lung

(b)

Mediastinum

Pericardium(cut)

Fat inepicardium

Rib 5

Left lung

Aorta

Mediastinum

Apex ofheart(d)

Right auricleof right atrium

Superiorvena cava

Right ventricle

Diaphragm

(a)

Rib 2

Midsternal line

Page 7: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Structure of the Heart – Coverings

• Pericardium – 2 primary layers– Fibrous pericardium

• Strong layer of dense connective tissue

– Serous pericardium• Formed from 2 layers

– Parietal layer of the serous pericardium– Visceral layer of the serous pericardium (= epicardium)

Page 8: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Layers of the Pericardium & of the Heart Wall

Fibrous pericardium

Parietal layer of serous pericardium

Pericardial cavity

Epicardium (visceral layer of serous pericardium)

Myocardium

Endocardium

Pulmonarytrunk

Heart chamber

Heart wall

Pericardium

Myocardium

Page 9: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Structure of the Heart – Layers of the Heart Wall

• Epicardium – Visceral layer of the serous pericardium

• Myocardium– Consists of cardiac muscle – all the muscle of the heart– Muscle arranged in circular & spiral patterns

• Endocardium– Endothelium resting on a layer of connective tissue– Lines the internal walls of the heart

Page 10: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Circular & Spiral Arrangements of Cardiac Muscle Bundles

Cardiacmusclebundles

Page 11: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart Chambers

• Right & left atria– Superior chambers

• Right & left ventricles– Inferior chambers

• Internal divisions– Interventricular septa– Interatrial septa

• External markings – Coronary sulcus– Anterior interventricular sulcus– Posterior interventricular sulcus

Page 12: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Gross Anatomy of the HeartLeft common carotidarteryLeft subclavian artery

Aortic arch

Ligamentum arteriosum

Left pulmonary artery

Left pulmonary veins

Auricle ofleft atrium

Circumflex artery

Left coronary artery(in coronary sulcus)

Left ventricle

Great cardiac vein

Anterior interventricularartery (in anteriorinterventricular sulcus)

Apex

Brachiocephalic trunk

Superior vena cava

Right pulmonary artery

Ascending aortaPulmonary trunk

Right pulmonary veins

Right atrium

Right coronary artery(in coronary sulcus)

Anterior cardiac vein

Right ventricle

Right marginal artery

Small cardiac vein

Inferior vena cava

Page 13: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Inferior View of the Heart

(d) Inferior view; surface shown rests on the diaphragm (base of heart).

Aorta

Left pulmonary artery

Left pulmonary veins

Auricle of left atrium

Left atrium

Great cardiac vein

Posterior vein of left ventricle

Left ventricle

Apex

Superior vena cava

Right pulmonary artery

Right pulmonary veins

Right atrium

Inferior vena cava

Right coronary artery(in coronary sulcus)

Coronary sinus

Posterior interventricularartery (in posteriorinterventricular sulcus)

Middle cardiac vein

Right ventricle

Page 14: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Right Atrium

• Forms right border of heart

• Receives blood from systemic circuit

• Pectinate muscles – Ridges inside anterior of right atrium

• Crista terminalis– Landmark used to locate veins entering right

atrium

• Fossa ovalis– Depression in interatrial septum

• Remnant of foramen ovale (from embryonic developmt)

Page 15: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Right Ventricle• Receives blood from right atrium through

the tricuspid valve• Pumps blood into pulmonary circuit via

– Pulmonary trunk

• Internal walls of right ventricle– Trabeculae carneae – Papillary muscles– Chordae tendineae

• Pulmonary semilunar valve– Located at opening of right ventricle &

pulmonary trunk

Page 16: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart Chambers

Aorta

Left pulmonary artery

Left atrium

Left pulmonary veins

Mitral (bicuspid) valve

Aortic valve

Pulmonary (semilunar) valve

Left ventricle

Papillary muscleInterventricular septum

Epicardium

Myocardium

Endocardium

(e) Frontal section

Superior vena cava

Right pulmonary artery

Pulmonary trunk

Right atrium

Right pulmonary veins

Fossa ovalis

Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava

Page 17: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Left Atrium

• Makes up heart’s posterior surface

• Receives oxygen-rich blood from lungs through pulmonary veins

• Opens into the left ventricle through:– Mitral valve (= bicuspid; left atrioventricular

valve)

Page 18: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Left Ventricle

• Forms apex of the heart

• Very thick strong muscle

• Internal walls of left ventricle– Trabeculae carneae – Papillary muscles– Chordae tendineae

• Pumps blood to systemic circuit via– Aortic semilunar valve (= aortic valve)

Page 19: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart Valves

• Each valve composed of– Endocardium with connective tissue core

• Atrioventricular (AV) valves– Between atria & ventricles tricuspid & bicuspid

• Aortic & pulmonary valves– At junction of ventricles & great arteries pulmonary

& aortic semilunar

Page 20: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart Chambers & Valves

Aorta

Left pulmonary artery

Left atrium

Left pulmonary veins

Mitral (bicuspid) valve

Aortic (semilunar) valve

Pulmonary (semilunar) valve

Left ventricle

Papillary muscleInterventricular septum

Epicardium

Myocardium

Endocardium

(e) Frontal section

Superior vena cava

Right pulmonary artery

Pulmonary trunkRight atrium

Right pulmonary veinsFossa ovalis

Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava

Page 21: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Fibrous Skeleton

• Surrounds all 4 valves– Composed of dense connective tissue

• Functions:– Anchors valve cusps– Prevents overdilation of valve openings– Main point of insertion for cardiac muscle– Blocks direct spread of electrical impulses

Page 22: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Fibrous Skeleton & Valve StructurePulmonary valve

Aortic valve

Area of cutaway

Mitral valve

Tricuspid valve

Myocardium

Tricuspid(right atrioventricular) valve

Mitral (bicuspid,left atrioventricular)valve

Aorticvalve

Pulmonaryvalve

Fibrousskeleton

Anterior

Page 23: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Beating Heart

Blood returning to the heart fills atria, putting pressure against atrioventricular valves; atrioventricular valves are forced open.

As ventricles fill, atrioventricular valve flaps hang limply into ventricles.

Atria contract, forcing additional blood into ventricles.

(a) AV valves open; atrial pressure greater than ventricular pressure

Direction ofblood flow

Atrium

Ventricle

Cusp ofatrioventricularvalve (open)

Chordaetendineae

Papillarymuscle

1

2

3

Page 24: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Beating Heart

Ventricles contract, forcing blood against atrioventricular valve cusps.

Atrioventricular valves close.

Papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria.

(b) AV valves closed; atrial pressure less than ventricular pressure

Atrium

Blood inventricle

Cusps ofatrioventricularvalve (closed)

1

2

3

Page 25: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Beating Heart

As ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open.

As ventricles relax and intraventricular pressure falls, blood flows back from arteries, filling the cusps of semilunar valves and forcing them to close.

(a) Semilunar valves open

(b) Semilunar valves closed

Aorta

Pulmonarytrunk

Page 26: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart Sounds

• “Lub-dub” sound of valves closing– First sound “lub”

• The AV valves closing

– Second sound “dub”• The semilunar valves closing

Page 27: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heart SoundsPulmonary valve

Aortic valve

Area of cutaway

Mitral valve

Tricuspid valve Myocardium

Tricuspid(right atrioventricular) valve

Mitral(left atrioventricular)valve

Aorticvalve

Pulmonaryvalve

Fibrousskeleton

Anterior

“Lub”

“dub”

Page 28: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Pathway of Blood Through the Heart

• Beginning with oxygen-poor blood in the superior & inferior venae cavae– Go through pulmonary & systemic circuits– Blood passes through all structures

sequentially• Atria contract together • Ventricles contract together

Page 29: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Blood Flow Through the Heart

Rightatrium

Aorta

To body

To heart

To heart

To lungs

MitralvalveLeftventricle

Leftatrium

Leftatrium

Aorta Leftventricle

Four pulmonary

veins

Rightventricle

Superior vena cava (SVC)Inferior vena cava (IVC)

Coronary sinus

Rightatrium

Pulmonarytrunk

Pulmonaryveins

Pulmonaryarteries

Aorticsemilunarvalve

Tricuspidvalve

Tricuspidvalve

Pulmonarytrunk

Rightventricle

Pulmonarysemilunarvalve

Pulmonarysemilunar valve

IVC

SVC

Two pulmonary arteriescarry the blood to thelungs (pulmonary circuit)to be oxygenated.

Oxygen-rich blood returnsto the heart via the fourpulmonary veins.

Oxygen-poor bloodreturns from the bodytissues back to the heart.

Oxygen-rich blood isdelivered to the bodytissues (systemic circuit).

Oxygen-rich blood

Oxygen-poor blood

Mitralvalve

Aorticsemilunar

valve

Coronarysinus

Page 30: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Heartbeat

• 70–80 beats per minute at rest (adult)– Systole contraction of a heart chamber– Diastole expansion (relaxation) of a heart

chamber

• Systole & diastole also refer to– Stage of heartbeat when ventricles contract &

expand

Page 31: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Structure of Heart Wall

• Walls differ in thickness– Atria thin walls– Ventricles very thick walls (especially left)– Systemic circuit

• Longer than pulmonary circuit• Has greater resistance to blood flow

Page 32: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Structure of Heart Wall

• Left ventricle:3 times thicker than right– Exerts more

pumping force– Flattens right

ventricle into a crescent shape

Rightventricle

Leftventricle

Interventricularseptum

Page 33: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Cardiac Muscle Tissue

• Forms a thick layer called myocardium– Striated like skeletal muscle– Contractions pump blood through the heart &

into blood vessels

Page 34: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Cardiac Muscle Tissue

• Cardiac muscle cells– Short– Branching– Have 1 or 2 nuclei– Not fused muscle cells like skeletal muscle fibers

Page 35: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Cardiac Muscle Tissue

• Cells join at intercalated discs– Complex junctions– Form cellular networks

• Cells are separated by delicate endomysium– Binds adjacent cardiac fibers– Contains blood vessels & nerves

Page 36: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Intercalated Discs

• Intercalated discs complex junctions– Adjacent sarcolemmas interlock– Possess 3 types of cell junctions

• Desmosomes• Fasciae adherens long desmosome-like junctions• Gap junctions

Page 37: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Fasciae adherensGap junctions

Microscopic Anatomy of Cardiac MuscleNucleus Intercalated discs Cardiac muscle cell

(a)

Nucleus

Nucleus

I bandA band

Cardiac muscle cell

Sarcolemma

Z disc

Mitochondrion

Mitochondrion

T tubuleSarcoplasmicreticulum

I band

Intercalated disc

(b)

Page 38: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Cardiac Muscle Tissue

• Triggered to contract by Ca2+ entering the sarcoplasm– Signals sarcoplasmic reticulum (SR) to release Ca2+ ions– Ions diffuse to sarcomeres

• What does this trigger?

sliding filament mechanism – remember this?

Page 39: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Cardiac Muscle Tissue

• Not all cardiac cells are innervated– Will contract in rhythmic manner without

innervation– Inherent rhythmicity

• Is the basis of the rhythmic heartbeat – heart can beat on its own!

Page 40: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Conducting System

• Cardiac muscle has intrinsic ability to:– Generate & conduct impulses– Signal cells to contract rhythmically

• Conducting system: – A series of specialized cardiac muscle cells– Sinoatrial (SA) node (= pacemaker) sets the

inherent rate of contraction generates the electrical impulses

Page 41: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Conducting System of the Heart

The Sinoatrial (SA) node (pacemaker)generates impulses.

Internodal pathway

Superior vena cava Right atrium

Left atrium

Purkinje fibers

Inter-ventricularseptum

The impulsespause (0.1 sec) at the Atrioventricular(AV) node.

The atrioventricular(AV) bundle of His connects the atria to the ventricles.

The bundle branches conduct the impulses through the interventricular septum.

The Purkinje fibersstimulate the contractilecells of both ventricles.

1

2

3

4

5

Page 42: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Thoracic spinal cord

The vagus nerve(parasympathetic)decreases heart rate. Cardioinhibitory

centerCardio-acceleratorycenter

Sympathetic cardiacnerves increase heart rateand force of contraction.

Medulla oblongata

Sympathetictrunkganglion

Dorsal motor nucleusof vagus

Sympathetic trunk

AV node

SA node

Parasympathetic fibers

Sympathetic fibers

Interneurons

Innervation of the Heart

• Heart rate is altered by external controls

• Nerves to the heart include– Visceral sensory fibers

– Parasympathetic branches of the vagus nerve

– Sympathetic fibers from cervical &

upper thoracic chain ganglia

Page 43: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Blood Supply to the Heart

• Functional blood supply– Coronary arteries

• Arise from the aorta– Located in the coronary sulcus– Main branches

• Left & right coronary arteries

Page 44: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Blood Supply to the Heart

Rightventricle

Rightcoronaryartery

Rightatrium

Rightmarginalartery

Posteriorinterventricularartery

Anteriorinterventricularartery

Circumflexartery

Leftcoronaryartery

Aorta

Anastomosis(junction ofvessels)

Leftventricle

Superiorvena cava

(a) The major coronary arteries

Left atrium

Pulmonarytrunk

Superiorvena cava

Anteriorcardiacveins

Smallcardiac vein

Middle cardiac vein

Greatcardiacvein

Coronarysinus

(b) The major cardiac veins

Page 45: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Disorders of the Heart

• Coronary artery disease– Atherosclerosis fatty deposits– Angina pectoris chest pain– Myocardial infarction blocked coronary

artery• Heart attack!

– Silent ischemia no pain or warning; lack of blood & O2 to certain area of heart

Page 46: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Disorders of the Heart

• Heart failure– Progressive weakening of the heart– Cannot meet the body’s demands for

oxygenated blood

• Congestive heart failure (CHF)– Heart enlarges– Pumping efficiency declines

• Pulmonary arterial hypertension – Enlargement & potential failure of right ventricle

Page 47: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Disorders of the Conduction System

• Arrhythmias variation from normal heart rhythm (irregular); often valve problems– Ventricular fibrillation

• Rapid, random firing of electrical impulses in the ventricles

• Results from crippled conduction system• Common cause of cardiac arrest• Ventricles cannot beat together in synchrony

Page 48: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Disorders of the Conduction System

• Arrhythmias– Atrial fibrillation

• Impulses circle within atrial myocardium, stimulating AV node

• Can promote formation of clots– Leads to strokes

• Occur in episodes characterized by:– Anxiety, fatigue, shortness of breath, palpitations

Page 49: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Disorders of the Heart•Congestive heart failure (CHF)

Page 50: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Development of the Heart• Heart folds into thorax region ~Day 20–21• Heart starts pumping on ~Day 22!• Earliest heart chambers are unpaired• Heart in near-final form by Day 35• Blood travels different route than in adult – blood doesn’t

pick up O2 from lungs, but from placenta/mom!

Atrium

Aorta

Superiorvena cava

Inferiorvena cava

Ventricle

Tubularheart Ventricle

Ventricle

4a4

3

2

1

Foramen ovale

Ductus arteriosis

Pulm trunk

Page 51: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Congenital Heart Defects

• Can be traced to month 2 of development– Most common defect is ventricular septal defect

• 2 basic categories of defect– Inadequately oxygenated blood reaches body

tissues– Ventricles labor under increased workload

Page 52: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Congenital Heart Defects

Occurs in~1 in every500 births

Occurs in~1 in every1500 births

Narrowedaorta

Occurs in~1 in every2000 births

(a) Ventricular septal defect.The superior part of the inter-ventricular septum fails to form;thus, blood mixes between thetwo ventricles. More blood isshunted from left to right becausethe left ventricle is stronger.

(b) Coarctation of the aorta.A part of the aorta is narrowed,increasing the workload ofthe left ventricle.

(c) Tetralogy of Fallot. Multiple defects (tetra = four): (1) Pulmonary trunk too narrowand pulmonary valve stenosed, resulting in (2) hypertrophied right ventricle; (3) ventricular septal defect; (4) aorta opens from both ventricles.

Page 53: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Heart in Old Age

Some age-related changes 1. Hardening & thickening of heart valve cusps

2. Decline in cardiac reserve* (= extra pumping ability)

3. Fibrosis of cardiac muscle excess fibrous connective tissue; less elastic & contractile

*Cardiac reserve = the difference between the rate at which the heart pumps blood at a particular time & its maximum capacity for pumping blood

Page 54: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

The Heart in Old Age

• Heart usually functions well throughout life

• But in America, heart disease has become the #1 cause of death!

• Regular aerobic exercise increases the strength & efficiency of the heart

• Decreases bad cholesterol levels (LDL) & lowers blood pressure

So, again exercise is key!

Page 55: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

What You Can Do…

• Exercise 150 minutes+/week (of moderate exercise)

• Or exercise 75 minutes+/week (of vigorous exercise)

• Helps clear fatty deposits in coronary arteries & maintains good cardiovascular health throughout life

• Also increases life expectancy!

(Recommendations by AHA)

Page 56: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Some Hot Current Research

• Stem cells to study human heart cells (their development, growth, & function)

• Future promise for regenerative medicine

Cardiomyocytes derived from human stem cells (all in the dish!)

Page 57: THE HEART Ch 19 Human Anatomy Sonya Schuh-Huerta, Ph.D. Leonardo Da Vinci, Human Heart.

Questions…?

What’s Next?Lab: Sheep Heart Dissection! & Start Blood VesselsWed Lecture: Blood Vessels Wed Lab: Blood Vessels & Respiratory Sys