survey of anatomy and physiology chap 12 part one

The Cardiovascular System: Transport and

SupplyPart One

12

Cardiovascular Cardiovascular SystemSystem

Cardiovascular system transports nutrients and oxygen to cells in body while carbon dioxide and waste products of cells' metabolism are removed


Pump that circulates the

transport medium

(blood) is the heart

System OverviewSystem Overview

The circulatory system uses the

heart as a pump and transports

through blood vessels to

organs and the smallest

tissues and cell

The circulatory system uses the

heart as a pump and transports

through blood vessels to

organs and the smallest

tissues and cell

Veins differ from arteries

because they carry blood toward heart, have valves, and have thinner walls; they are more numerous and have larger capacity


Figure 12-1Figure 12-1Four Functions of the Four Functions of the

Cardiovascular system.Cardiovascular system.

FOUR FUNCTIONS

How the Heart WorksHow the Heart Works

https://www.youtube.com/watch?v=oZ1_TAwCUWw

The HeartThe Heart

The size of your fist and located slightly

left of center of chest.

Base is proximal to your head

while apex is distal

The HeartThe Heart

Pericardium includes the parietal and

visceral layers with potential cavity

The HeartThe Heart

3 layers to heart:•Outer: Epicardium

•Middle: Myocardium•Inner endocardium

The HeartThe Heart

Although heart is one single organ, it is easier

to understand if you think of it as two pumps working

together.

The HeartThe Heart

Right side collects blood from body and sends it to lungs; left side collects blood

from lungs and sends it to rest of body

.

Chambers of the Chambers of the HeartHeart

Four chambers in heart

Two chambers on left side are separated from two chambers

on right side by wall called septum

Septums of the HeartSeptums of the Heart

Wall between upper, smaller

chambers (atria) is interatrial

septumWall between two larger chambers

(ventricles) is interventricular

septum

Figure 12-2The anatomy of the heart

Two large veins that

return blood from the body to right atrium are superior (SVC) and inferior (IVC)

vena cava

Flow of blood through Flow of blood through the Heartthe Heart

Right atrium (RAtr)

(locations are based on patient’s perspective) is collecting chamber where blood is returned to heart after trip around the body


FIRST

Blood travels from

right atrium, through one-way atrioventricular

valve called tricuspid valve (TCVa) , and into right ventricle

(RVe)


When right ventricle

is full of blood, heart contracts; tricuspid

valve prevents backflow and so

blood flows through pulmonary valve

(PVa) to pulmonary arteries (PA)


Second

Right pulmonary artery

(PA)* goes to right lung, left pulmonary artery (PA) goes to left lung

*Remember: Arteries go AWAY from the heart


THIRD


Vessels then get smaller and

smaller, eventually ending in capillaries

around each air sac (alveolus);

Blood then returns to heart via left (LPV) and right pulmonary (RPV)

veins*

*Remember: Veins go TOWARD the heart


Pulmonary veins return blood to left atrium

(LAtr).Blood flows through

atrioventricular valve, called mitral valve (MiVa) , and into left

ventricle (LVe)


Fourth

Ventricular pressure

increases as it fills, and heart contracts forcing

mitral valve closed, blood is ejected

through aortic valve (Ava) to aorta, and then

out to rest of body


Fifth

Figure 12-3The functioning of heart valves

and blood flow.

Blood is ejected during systole, or contraction (of ventricles) phase

Flow of Blood through Flow of Blood through the Heartthe Heart

Both atria fill at same time, both ventricles fill at same time, and both ventricles eject blood at same time when heart contracts


After blood is ejected

from ventricles, heart enters resting period

called diastoleDuring diastole,

ventricles fill with blood


Contraction begins at apex and

travels upward


Valve located at exit to each chamber because

the circulatory system is a pressurized system and valves prevent any ejected blood from flowing backwards


Heart rate is measured

by counting rhythmic expansion and

contraction of arteries due to opening & closing of the aortic semilunar

valves

Measuring Heart RateMeasuring Heart Rate

Measuring Heart RateMeasuring Heart Rate

Atrial walls are thinner than

ventricular wallsHigher

pressures are generated in ventricles to move blood

throughout entire body

The HeartThe Heart

THICK WALL

THIN WALL

Portion of newly oxygen-enriched

blood leaving heart is diverted

from aorta by right and left

coronary arteries

Coronary ArteriesCoronary Arteries

Figure 12-4Figure 12-4Coronary circulation.Coronary circulation.

Regular aerobic exercise improves the ability of the heart to increase the density (number of vessels in

one area) of blood vessels that branch

from the main coronary arteries.

By increasing the density of blood

vessels that branch off the main arteries, there

will be alternate routes for blood to

travel in case of a blockage and decrease

risk of myocardial infarction

Coronary CirculationCoronary Circulation

Figure 12-6Atherosclerosis.

Fatty deposits called plaque develop on the inside of the blood vessels and restrict

flow Mainly the aorta, coronary

arteries and cerebral arteries are effected

Why do you think this is?

PA/Instructor Asks:

The material that deposits in the arteries is made up mainly

of:

A. GlucoseB. CalciumC. CholesterolD. Protein

Cardiac muscle is auto rhythmic, meaning it can

contract without nerve impulses or hormones

Electrical System of Electrical System of the Heartthe Heart

There are

specialized cardiac cells that create and distribute electrical current that causes

controlled and directed

contraction of heart


Nodal cells, or

pacemaker cells, are specialized cells

that not only create electrical

impulse, but create impulses at regular interval


Electrical System Electrical System of the Heartof the Heart

Sino atrial node sends impulse to atrio ventricular node before AV node can send

signal

The Electric PathwayThe Electric Pathway

However, atrio

ventricular node acts as backup if

sinoatrial node fails to fire, resulting in

slower heartbeat due to reduced firing

rate

The Electric PathwayThe Electric Pathway

Figure 12-9Conduction system of the

heart.• SA node

causes atria to contract

• Stimulus arrives at AV node

• Follows AV bundle and travels through apex branches

• Purkinjie fibers stimulate ventricles to contract

• SA node causes atria to contract

• Stimulus arrives at AV node

• Follows AV bundle and travels through apex branches

• Purkinjie fibers stimulate ventricles to contract

Factors Affecting Factors Affecting Heart RateHeart Rate

Factors Affecting Factors Affecting Heart RateHeart Rate

Low potassium can lead to

weak heartbeat, while high

calcium can prolong heart

muscle contractions to

point where heart can

stop beating

Factors that Affect Factors that Affect Heart RateHeart Rate

EKG & Electrical ActivityEKG & Electrical Activity

Normal EKG represents•P wave-impulse generated by SA node, atria contract•QRS wave-Depolarization of ventricles right before ventricles contract•T wave-repolarization of ventricles when they are at rest before next beat

Figure 12-10Typical ECG tracing.

Take A BreakTake A Break

Problems with the PumpProblems with the Pump

Problems with the Problems with the PumpPump

Figure 12-20The multisystem effects of heart

failure.

• Neurologic• Respiratory• Cardiovascular• Gastrointestinal• Genitourinary• Musculoskeletal• Metabolic Processes

Page 336Page 336

Heart Attack & CPRHeart Attack & CPR

CPR consists of artificial blood circulation &

artificial respirations. It’s purpose is to maintain a

flow of oxygenated blood to the brain and heart

Watch video on “Myocardial Infarction”

Ventricular Assist Device-Ventricular Assist Device-a bridge to transplanta bridge to transplant

http://abcnews.go.com/Health/HeartFailureTreatment/cheney-heart-pump-high-demand/story?id=16003183

Blood VesselsBlood Vessels

Blood leaves heart through aorta,

which branches into large vessels called

arteriesArteries divide into smaller and smaller vessels, smallest of

which are called arterioles


Arterioles feed into capillaries that

form capillary beds in body's tissues, allowing oxygen and nutrients to infuse into cells

and picking up carbon dioxide

and waste products for

removal


Diameter of only 0.008 mm (slightly

larger than diameter of single

red blood cell) Allow easy movement of oxygen and

nutrients through wall, while carbon

dioxide and wastes can move

into blood


Blood then makes its return trip to the heart by draining into tiny venules, which combine into

veins which eventually become great veins (SVC

and IVC) that return to heart

Figure 12-15 B. Locations of major arteries. C. Locations of the major veins.

Blood Vessel Blood Vessel Structure & FunctionStructure & Function

Figure 12-16Blood pressure measurement.

Done with a stethoscope and

sphygmomanometer an inflatable cuff

placed around the arm, so that when it is

inflated, it squeezes brachial artery shut


Stethoscope placed over artery near elbow and cuff inflated until 30 mm Hg past the point that pulse no

longer heard.Open release valve

slightly


Listen for sound of blood coming through artery,

which is the peak systolic pressure (top

number)Cuff pressure

decreases until sound is not heard. The last sound

is diastolic pressure (lower number)

Elevated Blood PressureElevated Blood Pressure

Prehypertension is:•Systolic-from 120 to 139•Diastolic- from 80- 89

Hypertension is:•Systolic over 140•Diastolic over 90

Desirable blood pressure is:•Systolic - from 90 to 119•Diastolic - from 60 to 79

Plugging the “Leaks” of Plugging the “Leaks” of Blood VesselsBlood Vessels

CV system is closed and pressurized

systemIf break or leak in

system couldn't be stopped, you would

lose large amount of blood

Several substances in blood plug leaks

Fibrin traps blood cells and platelets to form blood clot


When inner wall of vessel is damaged,

underlying collagen fiber becomes

exposedPlatelets floating in

blood begin to attach to that rough damaged site


Attached platelets release several

chemicals that draw more platelets,

creating platelet plug

Platelets secrete

serotonin, which causes

blood vessels to spasm, decreasing

blood flow to that area

Clotting ProcessClotting Process


Fibrin forms netlike patch at site of injury, snagging more blood cells

and platelets; within 3 to 6

minutes a clot is created

Fibrin traps blood cells and platelets to form blood clot


Once clot is formed, it begins to retract and pulls edges of

damaged tissue together allowing

edges to regenerate necessary

epithelial cells to make permanent repair over time

Figure 12-18The clotting process.

WEAR YOUR ASSIGNED WEAR YOUR ASSIGNED COLORCOLOR

Meet here at Room 108 on Thursday and we’ll go to room

over in AAR building for exercise

Complete Handout “Heart Activity” as you will need to

hand that in at the end of Thursday’s class for credit

““The Heart Activity”The Heart Activity”

Work on the handout “The Heart Activity” Read through the first

two pages on the Blood Flow

Sequence. The third page shows structure

of the heart. Complete the 15 questions on back

page

survey of anatomy and physiology chap 12 part one

Health & Medicine

heart blood travels

flow of blood

heart vessels

heart wall

heart contraction

heart rate heart rate

heart pericardium

ejected blood