Cardiovascular System - Downey Unified School District

Cardiovascular System
By: Kayla Sood & Cynthia Amador P.4
What is the
Why is the cardiovascular
system important to us?
• Carries oxygen, nutrients,
hormones, proteins,
electrolytes, gases to cells.
• Transports toxins and carbon
dioxide away from cells.
• Necessary to stay alive,
Heart Chambers and Valves
The heart consists of 4
hallow chambers and 4
valves, that make the
process of blood
circulation throughout the
body possible.
Heart chambers and
Atria- upper chambers
thin walls
Receives blood returning to heart
Ventricle- lower chambers
Forces blood out heart, into arteries
Aorta- carries blood from heart to rest of
body except lungs
Interatrial Septum
• Separates right and left atrium
Interventricular Septum
• Separates right and left ventricles
4 Chambers
Right atrium
• Receives oxygen
• Pumps to right ventricle
Left atrium
• Receives oxygen richblood from lungs
• Pumps to left ventricle
Right ventricle
• Pumps oxygen poorblood to lungs
Left ventricle
• Pumps oxygen rich-blood to
aorta then out to the body
4 Valves
2 Semilunar
1. Mitral Valve (bicuspid valve)
• Located on left side
2. Tricuspid Valve
• Located between upper
atria and lower ventricles
on right side
2 Atrioventricular
1. Aortic Valve
• Located on the left side
2. Pulmonary Valve
• Located in arteries leaving
the heart on right side
Purposes of the 4 major valves
Mitral and tricuspid
• Control blood flow from
atria to ventricle
back flow
of blood in
LA and LV
blood flow
from RA
into RV,
moving in
Aortic and pulmonary
• Control blood flow out of
the ventricles
opens and
allows blood
to leave;
closes and
back flow of
blood in LV
of blood
into RV and
opens as it
Coverings of the Heart
The heart consist of two major layers:
Heart is enclosed in a double-walled
sac: pericardium
The loose fitting superficial part of this
sac: fibrous pericardium.
The fibrous pericardium:
 protects heart
 holds together surrounding structures
 prevents overfilling heart with blood
 Deeper part of fibrous pericardium is
the serous pericardium…
Coverings of the heart (continued…)
 Serous Pericardium: a thin, two-layer membrane that forms a closed sac
around the heart.
 Parietal layer of serous pericardium lines internal surface of the fibrous
 At superior edges of heart, parietal layer attaches to large arteries exiting
the heart.
 Then turns inferiorly and continues over the external heart surface as the
visceral layer, also called the epicardium,
*which is an essential part of the heart wall.
Coverings of the heart
Layers of the Heart Wall
The heart wall is composed of three layers:
• Epicardium
• myocardium
• endocardium
 Epicardium(superficial layer) is the visceral layer
of the serous pericardium.
• Thin layer of CT and fat
 Myocardium(middle layer) composed mainly of
cardiac muscle cells (cardiomyocytes) and forms
the bulk of the heart.
• CT fibers form a dense network called the fibrous
cardiac skeleton that support structure of the
myocardium & cardiac muscle fibers.
 Inner layer: Endocardium made up of endothelial
& consist of thin, smooth membrane, lines inside
chambers of heart, located under myocardium.
Coverings of the heart
Coverings of the heart
 pericardial cavity:
Between the parietal
and visceral layers;
contains a film of serous
 The serous membranes
are lubricated by the
serous fluid
 Allows for gliding past
each other, allowing the
heart to work in a frictionfree environment.
Blood vessels
Arteries: Vessels that transports blood away form the heart &
to capillaries
Capillaries: small blood vessel that connects an arteriole to
a venule; thin and fragile
Veins: vessels that carry blood towards the heart
5 major vessel that go to
and leave the heart:
• Superior vena cava
• Inferior vena cava
• Pulmonary artery
• Pulmonary vein
• aorta
Blood vessels(continued…)
 Vena cava: veins that return deoxygenated blood
from circulation & body and empty into the right
• Superior: transports deoxygenated blood from upper
extremities (head, neck etc.)
• Inferior: transports deoxygenated blood from lower
extremities (thorax, abdomen, etc.)
 Pulmonary artery: carries deoxygenated blood from
right ventricle into lungs for oxygenation.
 pulmonary vein: carry oxygenated blood from lungs
into left atrium; return to systemic circulation.
 The aorta (largest artery): carries oxygenated blood
from left ventricle of heart into systemic circulation.
*Pulmonary trunk artery: vessel in which blood from RV
exits, then branches to left and right pulmonary arteries;
transports blood to lungs
Blood vessels( continued…)
3 layer of blood vessels
Tunica Intima: inner most layer
• Composed of thin layers of endothelial
• Allows for nutrients and gas
Tunica media: muscular middle layer
• Contains smooth muscle allowing to
constrict and dilate; to adjust volume of
Tunica extrema: outer most layer
• Surrounds tunica media
• Composed of CT
Blood Path
1. Superior
Vena Cava
2. Inferior Vena
3. Right Atrium
4. Tricuspid
8. Pulmonary
7. Pulmonary
6. Pulmonary
5. Right
9. Left Atrium
10. Mitral
11. Left
12. Aorta
Blood Pressure
There are 5 major parts that make up
the process of blood pressure:
• Glomerular filtration:
• Fluid in blood is filtered across
capillaries of the glomerulus and
into the urinary space of Bowman’s
2. Systole vs. Diastole
• Systole: maximum pressure
achieved during ventricle
• Diastole: Lowest pressure that
remains in the arteries before the
next ventricle contraction
*Both numbers make up blood
Blood Pressure
3. Pressure vs. Distance
• Pressure- speed
• Distance- how far blood circulates
throughout body
4. Plasma and protein relation to blood
• Plasma
 extracellular matrix (yellow liquid)
 Make up about 55% of body’s total
blood value
• Proteins
 Transport of lipids, hormones,
vitamins, and metals
Blood Pressure
5. Cardiac Output (aka Q)
Made up of 2 components:
• Heart rate (HR): refers to number
of times heart beats every
minute (BPM)
• Stroke volume (SV): refers to
amount of blood pumped out
of the left ventricle with every
heart beat
• Equation for cardiac output:
HR x SV = Q
Heart Beat and Sounds
• Noises created by beating heart and flow of blood
• Sounds reflect turbulence created when the heart valves
snap shut
• 2 normal heart sounds “lub” & ”dub”
• Lub: caused by closing of AV valves; during ventricular systole
• Dub: cause by closing of pulmonary and AV valves; during
ventricular diastole
• 2 different heart sounds S1& S2, produced by closing of
AV valves and semilunar valves
• S1: caused by AV valves, Mitral and tricuspid
• S2: caused by semilunar valves, aortic and pulmonic
• Other sounds:
• Murmur: when cusps don’t close completely and blood is
leaked back through valve
• Aortic/pulmonic sound, mitral/tricuspid
 Important tissues, cells, fibers, etc. and their
location and function
 Bundle branches: transmits cardiac impulse
from AV bundle to myofibers
 Stimulates ventricles to contract
 Atrioventricular bundle: transmits cardiac
impulses from AV node to bundle of
branches causing contraction
 Regulates heartbeat
 Consists of cardiac muscle
 Purkinje: specialized cardiac muscle fibers
 Conducts electrical impulses through
heart from AV bundle to ventricular
 Located in between lining of serous
Conduction (continued…)
 Cells:
 Non-pacemaker cells
 Fast rate of depolarizing
 Located all throughout heart with the
exception of pacemaker cells
 Pacemaker cells
 Slow rate of depolarizing
 Located in SA and AV nodes
 Smooth muscle cells
 Cardiac muscle cells
 Able to depolarize at own rate because
of unstable membrane resting potential
and leaky ion channels
Conduction (continued…)
 SA Node (Sino atrial) “pacemaker”
 Controls heart rate
 Consists of specialized cardiac
muscle fibers
 Located in RA near superior vena
 AV Node (atrioventriclular)
 Part of electrical control system of
 Between artia and ventricles
 Located beneath endocardium
and on inferior part of septum
Conduction (continued…)
The cardiovascular
system follows a very
precise regulation so
that an appropriate
supply of oxygenated
blood can be provided
to different body tissues.
Conduction (continued…)
Sympathetic nervous system: speeds up
heart rate
Parasympathetic nervous system: slows
down heart rate

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