ANAPHY FINALS HEART Flashcards
Located within mediastinum of thoracic cavity
Heart
________ surrounds heart, forming ______
Pericardium ; pericardial cavity
is posterior—site where great vessels attach to heart
Base
inferior tip of heart
• Just left of the sternum
• Indention forms cardiac notch of left lung
Apex
superior chambers
Atria
receives deoxygenated blood
from systemic circuit
Right atrium
Via superior, inferior vena cava and coronary sinus
receives oxygenated blood from pulmonary circuit
Left atrium
Via pulmonary veins
inferior chambers
Ventricles
ejects deoxygenated blood
into pulmonary trunk
Right ventricle
▪ Pulmonary trunk divides into pulmonary arteries and sends blood to lungs
ejects oxygenated blood into aorta
Left ventricle
Sends blood to systemic tissues
Circulation through the Heart
• Deoxygenated blood is received by right atrium
• Via superior vena cava, inferior vena cava, and coronary sinus
• Blood enters right ventricle and is ejected into pulmonary trunk
• Pulmonary trunk divides to form pulmonary arteries that deliver blood to lungs
• Pulmonary veins carry oxygenated blood from lungs to left atrium
• Oxygenated blood enters left ventricle and is ejected into aorta and systemic arteries
Two systems of blood vessels in human circulation
Systemic circuit
Pulmonary circuit
Transports oxygenated blood to tissues and returns deoxygenated blood back to heart
Systemic circuit
Transports deoxygenated blood from heart to lungs and returns oxygenated blood back to heart
Pulmonary circuit
Membranous sac that surrounds heart
Pericardium
attaches heart to
diaphragm
Fibrous pericardium
reduces friction as heart beats
Serous pericardium
• Parietal and visceral layers
• Pericardial cavity in between
Serous pericardium begins as a
fluid-filled sac
As heart enlarges, it—
Pushes into the sac
Results in a double-layered sac with a fluid-filled cavity between the heart and the pericardium
pouch-like extensions of each atrium • Allow atria to accept extra amounts of
blood
Auricles
Grooves that contain coronary blood vessels
Cite (3)
Sulci
• Coronary sulcus
• Anterior interventricular sulcus
• Posterior interventricular sulcus
are prominent on anterior surface
Left and right ventricles
protects the heart and blood vessels within sulci
Fat deposits
most superficial
• Same as visceral layer of serous pericardium
• simple squamous epithelium and a thin layer of areolar connective tissue
Epicardium
contains cardiac muscle
• Thickest layer of heart wall
• Contains collagenous framework of heart, blood vessels, and nerves
Myocardium
deepest layer
• Simple squamous epithelium
• Continuous with endothelium of blood vessels
Endocardium
are oriented for effective contraction
Cardiac muscle fibers
Fibers wrap around each
Atrium
forces blood into the ventricles
Contraction of cardiac muscle
Fibers swirled from apex toward
great arteries around ventricles
forces blood into the great vessels
Contraction at apex
Transverse and coronal sections of the heart show
Myocardial thickness
Left ventricle has a _____ compared to the right ventricle.
Hypertrophies early in life
Due to increased resistance of the aorta (to systemic circuit), which must be overcome
Thicker myocardium
located between atria
Interatrial septum
Interatrial septum contains
Fossa ovalis
▪ Oval shaped depression
▪ Remnant of foramen ovale of fetal heart that
allowed blood to bypass pulmonary circuit • Lungs don’t oxygenate blood in fetus
▪ Septum primum closes foramen ovale at birth
Fossa ovalis
located between ventricles
• More muscular than interatrial septum
• Aids in ventricular contraction
Interventricular septum
Separates atria from ventricles
Fibrous Skeleton of Heart
Fibrous Skeleton of Heart has _____ that allow blood to move through the heart
4 openings
between atria and ventricles
Atrioventricular (AV) valves
between ventricles and great vessels (pulmonary trunk and aorta)
Semilunar (SL) valves
prevent blood from moving in the wrong direction
Valves
Atrioventricular (AV) valves (2)
• Tricuspid valve on right
• Bicuspid valve on left
Semilunar (SL) valves (2)
• Pulmonary valve on right • Aortic valve on left
open and close in response to pressure differences
Valves
_________ blood rushes toward atria and AV valves close
When ventricles contract
______ blood attempts to reenter heart and SL valves close
When ventricles relax
wall between ventricles
Interventricular septum
anchors AV valves
Chordae tendineae
large bundles of muscle attached to chordae tendineae
Papillary muscles
large ridges on interior of ventricular walls
Trabeculae carneae
Fills with venous blood during atrial relaxation
• Venous return
Right atrium
The right atrium Contains _____ within auricle and anterior wall of chamber
pectinate muscles
In the right ventricle, Blood initially passes through the __
open tricuspid valve first
Receives deoxygenated blood from the right atrium
Right ventricle
The Walls of ____ contain ridges of muscle called trabeculae carneae
Right ventricle
Pressure increases during
Ventricular contraction
(Right ventricle) Increased pressure closes ? yet opens ?
tricuspid valve ; pulmonary semilunar valve
(Right ventricle) Deoxygenated blood ejected into?
pulmonary trunk
After gas exchange in the lungs, oxygenated blood returns to?
left atrium
Via pulmonary veins
(Left atrium) ? contains pectinate muscles
Auricle
Fills during atrial relaxation
• Ejects blood through open bicuspid (mitral) valve into left ventricle
Left atrium
• Receives oxygenated blood from left atrium
• Contraction closes bicuspid valve and opens aortic semilunar valve
• Ejects oxygenated blood into the aorta and into the systemic circuit
Left ventricle
Failure to function properly leads to—
valvular heart disease
? occurs when valves allow blood to move in wrong direction (e.g., from ventricle into the atrium)
Regurgitation
This occurs when valves become calcified
• Valve may be harder to open causing heart to work harder
Valve stenosis
• Arise from ascending aorta and travel in coronary
sulcus
• Fill during ventricular relaxation
Left and right coronary arteries
This branches to form circumflex artery and anterior interventricular artery
Left coronary artery
This branches to form marginal arteries and posterior interventricular artery
Right coronary artery
Travels in anterior interventricular sulcus
Great cardiac vein
This accompanies the circumflex artery
Posterior cardiac vein
This accompanies right coronary artery
Small cardiac vein
This accompany small cardiac artery
Anterior cardiac veins
Most ____ drain into coronary sulcus
cardiac veins
Leading cause of death worldwide
Coronary Artery Disease
_____ decreases coronary blood flow
• Blockages visible on coronary angiogram
• Begins as fatty streak during childhood and continues throughout life
(Coronary Artery Disease)
Plaque buildup
Coronary Artery Disease can—
Can lead to hypoxia and myocardial ischemia
(Electrocardiogram) Leads on surface of _______ as they move through the body and cardiac muscle
body monitor electrical signals
(Electrocardiogram) An ___ evaluates ionic movement through the body
ECG
(Electrocardiogram) In contrast, a recording _____ evaluates ionic movement across a cellular membrane
microelectrode
Major components of a healthy ECG (3)
• P wave
• QRS complex
• T wave
atrial depolarization
P wave
—ventricular depolarization
▪ Atrial repolarization occurs at the same time
QRS complex
Ventricular repolarization
T wave
____ are regions between waves
ECG segments and intervals
ECG segments and intervals
PR interval
ST segment
_____ from beginning of P wave to beginning of QRS complex
PR interval
▪ Delay usually indicates (PR interval)
heart block
Elevation usually indicates heart attack
ST segment
(Stages of the cardiac cycle)
Contraction
Systole
(Stages of the cardiac cycle)
Relaxation
Diastole
Stages of the cardiac cycle
- Total diastole
- Atrial systole
- Early ventricular systole
- Late ventricular systole
- Early ventricular diastole
Pressure increases with
systole
Pressure increases with
systole
Pressure decreases with
diastole
Ventricles fill to End Diastolic Volume (EDV) of ____
~130mL
Stroke Volume (SV)—amount of blood ejected per beat; _____
~70mL
End Systolic Volume (ESV)—amount of blood remaining in ventricle after systole; ____
~60mL
_____ illustrates the pressures within the atria, ventricles, and aorta during the cardiac cycle
Wiggers diagram
The amount of blood ejected by each ventricle per minute
Cardiac output
At rest CO is approximately the entire blood volume of an adult
~5L/min