Cardiovascular SystemBy: Kayla Sood & Cynthia Amador P.4

What is the Cardiovascular

System?

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, duhhh!

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 valves(continued…)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

Left atrium

•Receives oxygen rich-blood from lungs

•Pumps to left ventricle

Left ventricle

•Pumps oxygen rich-blood to aorta then out to the body

Right atrium

•Receives oxygen

•Pumps to right ventricle

Right ventricle

•Pumps oxygen poor-blood to lungs

4 Valves2 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

Aortic and pulmonary

•Control blood flow out of the ventricles

When ventricles contract, prevents back flow of blood in LA and LV

Allows blood flow from RA into RV, prevents blood moving in wrong direction

As LV contracts, opens and allows blood to leave; closes and prevents back flow of blood in LV

Prevents backflow of blood into RV and opens as it contracts

Coverings of the HeartThe 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 pericardium.

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 (continued…)

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 (continued…)

Coverings of the heart (continued…)

pericardial cavity: Between the parietal and visceral layers; contains a film of serous fluid.

The serous membranes are lubricated by the serous fluid

Allows for gliding past each other, allowing the heart to work in a friction-free 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 atrium• 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 cells

•Allows for nutrients and gas

Tunica media: muscular middle layer

•Contains smooth muscle allowing to constrict and dilate; to adjust volume of blood

Tunica extrema: outer most layer

•Surrounds tunica media

•Composed of CT

Blood Path

3. Right Atrium

4. Tricuspid Valve

5. Right Ventricle

6. Pulmonary Valve

2. Inferior Vena Cava

8. Pulmonary Veins

7. Pulmonary Artery

12. Aorta

1. Superior Vena Cava

9. Left Atrium10. Mitral

Valve11. Left Ventricle

REST OF OUR BODY!

Blood PressureThere are 5 major parts that make up the process of blood pressure:

1.Filtration• Glomerular filtration:• Fluid in blood is filtered across

capillaries of the glomerulus and into the urinary space of Bowman’s Capsule

2. Systole vs. Diastole• Systole: maximum pressure

achieved during ventricle contractions

• Diastole: Lowest pressure that remains in the arteries before the next ventricle contraction

*Both numbers make up blood pressure

Blood Pressure (continued…)

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

• ProteinsTransport of lipids, hormones,

vitamins, and metals

Blood Pressure (continued…)

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

Conduction

Conduction (continued…)

Conduction (continued…)

SA Node (Sino atrial) “pacemaker”Controls heart rateConsists of specialized cardiac

muscle fibersLocated in RA near superior vena

cavaAV Node (atrioventriclular)Part of electrical control system

of heartBetween artia and ventriclesLocated 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…)

Regulation:Sympathetic nervous system: speeds up heart rateParasympathetic nervous system: slows down heart rate

Bibliographyhttps://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/the-cardiovascular-system-18/the-heart-172/heart-great-vessels-866-9331/

http://anatomyandphysiologyi.com/heart-anatomy/

http://www.sharecare.com/health/blood-basics/how-blood-travel-human-body

http://learn.fi.edu/learn/heart/vessels/capillaries.html

http://www.cliffsnotes.com/sciences/anatomy-and-physiology/the-cardiovascular-system/blood-vessels