-
– muscular organ that pumps
blood throughout the body.
Heart
-
Cardiovascular System Consist of:
heart, blood vessels, and blood.
-
Healthy heart (adult), at rest, pumps
approximately ___ L of blood per MMinute
5 Liters
-
space around the heart
Pericardial cavity
-
double-layered sacs that
anchors and protects heart
Pericardium
-
outer layer
composed of tough, fibrous
connective tissue.
Fibrous pericardium
-
inner layer
composed of flat epithelial cells with
thin layer of connective tissue;
produces pericardial fluid
Serous pericardium
-
lines fibrous pericardium; membrane
around heart’s cavity
Parietal pericardium
-
aka epicardium, covers heart surface
Visceral pericardium
-
located at the base of the heart
Atria
-
extend from the base of the
heart towards the apex
Ventricles
-
extends around the
heart, separating the atria from the
ventricles.
Coronary sulcus
-
valves
between atria and ventricles
Atrioventricular heart valves
-
cone-shaped muscular
pillars in each ventricle
Papillary muscles
-
connective tissue
strings attached to papillary muscles in free
margins of cusps of atrioventricular valves.
Chordae tendineae
-
When ventricles relax, pressure in aorta and pulmonary trunk are ___ than in
ventricles
higher
-
consists of fibrous rings that surround
atrioventricular and semilunar valves;
Cardiac skeleton (fibrous skeleton)
-
Supply blood to heart wall
Coronary Arteries
-
Supply blood to anterior heart
wall and left ventricle
Left coronary artery
-
Path of Blood flow Deoxygenated to Oxygenated
IVC/SVC-RA-TV-RV-PSV-PA/PT-LUNGS-PV- LA-BV-LV-ASV-A
-
Where can the heart receive blood supply?
Coronary Arteries
-
Supply blood to anterior heart
wall and left ventricle
Left coronary artery
-
Originates on right side of aorta
▪ Supply blood to right ventricle
Right coronary artery
-
Drain blood from cardiac muscles
Cardiac veins
-
3 Layers of Heart Wall
- -Epicardium – surface of heart
- (outside)
- -Myocardium – thick, middle layer;
- composed of cardiac muscle
- -Endocardium – smooth, inner
- surface
-
ridges and
columns of cardiac muscle in surface
of interior walls of ventricles
▪ Trabeculae carneae
-
cell-to-cell contacts adjacent to cardiac muscle cells; highly folded
Intercalated disks
-
specialized cell membrane structures in intercalated disks; allows cytoplasm to flow freely between cells.
Gap junctions
-
What happens during Depolarization phase?
- Na2+ channels open (increase
- permeability of cell membrane to
- Na2+)
- ▪ Ca2+ channels open
- ▪ Sodium ions diffuse to cell, causing
- depolarization
-
What Happens during Plateu phase
- ▪ Na2+ channels close
- ▪ Some K+ channels open
-
specialized cardiac muscle cells in heart wall responsible for coordinating
contraction of atria and ventricles.
Conduction system
-
Where action potential originates
Sinoatrial node (SA node)
-
Action potentials from SA node sent to
this node
Atrioventricular node (AV node)
-
Pass to the apex of heart and then
extend to the cardiac muscle of
ventricle walls
Purkinje fibers
-
Sequence for conduction of action
potential:
- SA node, AV node, AV bundle,
- bundle branches, Purkinje fibers
-
▪ record of electrical events in heart
▪ diagnose cardiac abnormalities
ELECTROCARDIOGRAM
-
depolarization of atria
▪ P wave
-
depolarization of
ventricles; contains Q, R, S waves
QRS complex
-
repolarization of ventricles
T wave
-
__ – primers for pumps; ____
– actual pumps
Atria, Ventricles
-
contraction of atria
Atrial systole
-
contraction of
ventricles
Ventricular systole
-
relaxation of atria
Atrial diastole
-
relaxation of
ventricles
Ventricular diastole
-
First heart sound (‘lubb’ sound) is due to?
- due to closure of atrioventricular
- valves
-
Second heart sound (‘dupp’
sound) is due to?
- due to closure of semilunar
- valves.
-
abnormal heart sounds
that are a result of faulty valves
Murmurs
-
volume of
blood pumped by ventricles of heart
per minute; 5 L/min
Cardiac Output (CO)
-
volume of
blood pumped per ventricle per
contraction; 70 mL/beat
Stroke Volume (SV)
-
number of times
the heart contracts per minute; 72
beats/min
Heart Rate (HR)
-
amount of blood
that returns to the heart
Venous return
-
If venous return increases,
resulting in a greater preload, ___ output increases
cardiac
-
mechanism of
NS that plays an important role in
regulating heart function
Baroreceptor reflex
-
monitor blood pressure in aorta and carotid arteries;
Baroreceptors
-
involves
chemical regulation of heart
Chemoreceptor reflex
-
due to decrease in blood supply to the heart; coronary arteries are narrowed
Coronary Heart Disease
-
– due to closure of one or
more coronary arteries; areas of
cardiac muscle lacking adequate
blood supply die, and scars
- Myocardial Infarction (Heart
- Attack)
-
procedure opens blocked blood vessels
Angioplasty
-
structures inserted to keep
vessels open
Stent
-
procedure reroutes blood
away from blocked arteries
Bypass
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