Download Chapter 18 - Las Positas College

PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
18
HUMAN
ANATOMY
PART 1
The Heart
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
The Heart

A muscular double pump
 Pulmonary circuit – takes blood to and from the
lungs
 Systemic circuit – vessels transport blood to and
from body tissues
 Atria – receive blood from the pulmonary and
systemic circuits
 Ventricles – the pumping chambers of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
The Pulmonary and Systemic Circuits
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.1
Location and 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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Four “Corners” of the Heart

Superior right
 At costal cartilage of third rib and sternum

Inferior right
 At costal cartilage of sixth rib lateral to the sternum

Superior left
 At costal cartilage of second rib lateral to the
sternum

Inferior left
 Lies in the fifth intercostal space at the
midclavicular line
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Structure of the Heart – Coverings

Pericardium – two primary layers
 Fibrous pericardium
 Strong layer of dense connective tissue
 Serous pericardium
 Formed from two layers
 Parietal pericardium
 Visceral pericardium
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Coverings
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.3
Structure of the Heart – Layers of the Heart Wall

Epicardium
 Visceral layer of the serous pericardium

Myocardium
 Consists of cardiac muscle
 Muscle arranged in circular and spiral patterns

Endocardium
 Endothelium resting on a layer of connective tissue
 Lines the internal walls of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Layers of the Heart Wall
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.4
Heart Chambers




PLAY
Right and left atria

Superior chambers
Right and left ventricles

Inferior chambers
Internal divisions


Interventricular septa
Interatrial septa
External markings



Coronary sulcus
Anterior interventricular sulcus
posterior interventricular sulcus
Rotatable Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5b
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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Atrium



Makes up heart’s posterior surface
Receives oxygen-rich blood from lungs
Opens into the left ventricle through
 Mitral valve (left atrioventricular valve)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Ventricle


Forms apex of the heart
Internal walls of left ventricle
 Trabeculae carneae
 Papillary muscles
 Chordae tendineae

Pumps blood through systemic circuit via
 Aortic semilunar valve (aortic valve)
PLAY
Rotatable Heart Section
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5e
Inferior View of the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5d
Pathway of Blood Through the Heart

Beginning with oxygen-poor blood in the
superior and inferior venae cavae
 Go through pulmonary and systemic circuits
 A blood drop passes through all structures
sequentially
 Atria contract together
 Ventricles contract together
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Blood Flow Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6
Pathway of Blood Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6b
Heartbeat

70 – 80 beats per minute at rest
 Systole – contraction of a heart chamber
 Diastole – expansion of a heart chamber

Systole and diastole also refer to
 Stage of heartbeat when ventricles contract and
expand
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Walls differ in thickness
 Atria – thin walls
 Ventricles – thick walls
 Systemic circuit
 Longer than pulmonary circuit
 Offers greater resistance to blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Left ventricle – three
times thicker than
right
 Exerts more
pumping force
 Flattens right
ventricle into a
crescent shape
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.7
PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
18
HUMAN
ANATOMY
PART 2
The Heart
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
The Heart

A muscular double pump
 Pulmonary circuit – takes blood to and from the
lungs
 Systemic circuit – vessels transport blood to and
from body tissues
 Atria – receive blood from the pulmonary and
systemic circuits
 Ventricles – the pumping chambers of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
The Pulmonary and Systemic Circuits
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.1
Location and 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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Four “Corners” of the Heart

Superior right
 At costal cartilage of third rib and sternum

Inferior right
 At costal cartilage of sixth rib lateral to the sternum

Superior left
 At costal cartilage of second rib lateral to the
sternum

Inferior left
 Lies in the fifth intercostal space at the
midclavicular line
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Structure of the Heart – Coverings

Pericardium – two primary layers
 Fibrous pericardium
 Strong layer of dense connective tissue
 Serous pericardium
 Formed from two layers
 Parietal pericardium
 Visceral pericardium
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Coverings
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.3
Structure of the Heart – Layers of the Heart Wall

Epicardium
 Visceral layer of the serous pericardium

Myocardium
 Consists of cardiac muscle
 Muscle arranged in circular and spiral patterns

Endocardium
 Endothelium resting on a layer of connective tissue
 Lines the internal walls of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Layers of the Heart Wall
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.4
Heart Chambers




PLAY
Right and left atria

Superior chambers
Right and left ventricles

Inferior chambers
Internal divisions


Interventricular septa
Interatrial septa
External markings



Coronary sulcus
Anterior interventricular sulcus
posterior interventricular sulcus
Rotatable Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5b
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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Atrium



Makes up heart’s posterior surface
Receives oxygen-rich blood from lungs
Opens into the left ventricle through
 Mitral valve (left atrioventricular valve)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Ventricle


Forms apex of the heart
Internal walls of left ventricle
 Trabeculae carneae
 Papillary muscles
 Chordae tendineae

Pumps blood through systemic circuit via
 Aortic semilunar valve (aortic valve)
PLAY
Rotatable Heart Section
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5e
Inferior View of the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5d
Pathway of Blood Through the Heart

Beginning with oxygen-poor blood in the
superior and inferior venae cavae
 Go through pulmonary and systemic circuits
 A blood drop passes through all structures
sequentially
 Atria contract together
 Ventricles contract together
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Blood Flow Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6
Pathway of Blood Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6b
Heartbeat

70 – 80 beats per minute at rest
 Systole – contraction of a heart chamber
 Diastole – expansion of a heart chamber

Systole and diastole also refer to
 Stage of heartbeat when ventricles contract and
expand
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Walls differ in thickness
 Atria – thin walls
 Ventricles – thick walls
 Systemic circuit
 Longer than pulmonary circuit
 Offers greater resistance to blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Left ventricle – three
times thicker than
right
 Exerts more
pumping force
 Flattens right
ventricle into a
crescent shape
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.7
PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
18
HUMAN
ANATOMY
PART 3
The Heart
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
Heart Valves – Valve Structure

Each valve composed of
 Endocardium with connective tissue core

Atrioventricular (AV) valves
 Between atria and ventricles

Aortic and pulmonary valves
 At junction of ventricles and great arteries
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Fibrous Skeleton

Surrounds all four 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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Valves – Valve Structure
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.8a
Function of the Atrioventricular Valves
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.9a
Function of the Atrioventricular Valves
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.9b
Function of the Semilunar Valves
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.10a, b
Heart Sounds

“Lub-dup” – sound of valves closing
 First sound “lub”
 The AV valves closing
 Second sound “dup”
 The semilunar valves closing
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Sounds
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.8a
Heart Sounds

Each valve sound – best heard near a different
heart corner
 Pulmonary valve – superior left corner
 Aortic valve – superior right corner
 Mitral (bicuspid) valve– at the apex
 Tricuspid valve – inferior right corner
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Sounds
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.11
Cardiac Muscle Tissue

Forms a thick layer called myocardium
 Striated like skeletal muscle
 Contractions pump blood through the heart and
into blood vessels
 Contracts by sliding filament mechanism
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Cardiac Muscle Tissue

Cardiac muscle cells
 Short
 Branching
 Have one or two nuclei
 Not fused colonies like skeletal muscle
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
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 and nerves
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Cardiac Muscle Tissue

Intercalated discs – complex junctions
 Adjacent sarcolemmas interlock
 Possess three types of cell junctions
 Desmosomes
 Fasciae adherans – long desmosome-like junctions
 Gap junctions
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Microscopic Anatomy of Cardiac Muscle
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.12a, b
Cardiac Muscle Tissue
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.12c, d
Cardiac Muscle Tissue

Triggered to contract by Ca2+ entering the
sarcoplasm
 Signals sarcoplasmic reticulum to release Ca2+ ions
 Ions diffuse into sarcomeres
 Trigger sliding filament mechanism
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Cardiac Muscle Tissue

Not all cardiac cells are innervated
 Will contract in rhythmic manner without
innervation
 Inherent rhythmicity
 Is the basis for rhythmic heartbeat
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Conducting System

Cardiac muscle tissue has intrinsic ability to
 Generate and conduct impulses
 Signal these cells to contract rhythmically

Conducting system
 A series of specialized cardiac muscle cells
 Sinoatrial (SA) node sets the inherent rate of
contraction
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Conducting System
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.14
Innervation


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 and upper
thoracic chain ganglia
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.15
PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
18
HUMAN
ANATOMY
PART 4
The Heart
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
Blood Supply to the Heart

Functional blood supply
 Coronary arteries

Arise from the aorta
 Located in the coronary sulcus
 Main branches
 Left and right coronary arteries
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Blood Supply to the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.16
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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Disorders of the Heart

Heart failure
 Progressive weakening of the heart
 Cannot meet the body’s demands for oxygenated
blood

Congestive heart failure (CHF)

Cor pulmonale
 Heart enlarges
 Pumping efficiency declines
 Enlargement and potential failure of right ventricle
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings