Chapter 19 - The Heart

92 terms by karscool Plus

Create a new folder

Advertisement Upgrade to remove ads

the heart as a double pump

The right side of the heart pumps blood though the pulmonary circuit The left side of the heart pumps blood to all the body tissues via systemic circuit

pulmonary circuit

the blood vessels that carry blood to and from the lungs

systemic circuit

vessels that transport blood to and from all body tissues

Name the two receiving chambers of the heart.

1. right atrium
2 left atrium
These atriums receive blood returning from the systemic and pulmonary circuits

Name the heart two main pumping chambers.

1. right ventricle
2. left ventricle (hollow belly)
these ventricles pump blood around the two circuits

The heart is a muscular double pump with two functions:

1.right side receives oxygen poor blood from the body tissues and then pumps this blood to the lungs to pick up oxygen and dispel carbon dioxide
2. left side receives the oxygenated blood returning from the lungs and pumps this blood thoughout the body to supply oxygen and nutrients to the body tissues

exterior landmarks of the heart

Start with the 2nd rib lateral to the sternal angle
1.superior right point
-lies where the costal cartilage of the 3rd rib joins the sternum
2.superior left point
- lies at the costal cartilage of the 2nd rib, a finger lateral to the sternum
3.inferior right point
-lies at the costal cartilage of the sixth rib, afinger lateral to the sternum
4. inferior left point (appex point)
-lies in the 5th intercostal space at the midclavicular line, the line extending inferiorly form the midpoint of the left clavicle
*the imaginary lines that connect these points are the size of a normal heart

major heart vessels

...

oracle flap

...

apex and base of heart

its apes points anteriorly and to the left
-its base is its posterior surface

great vessels valves

...

Name the components of the cardiovascular system.

-Blood vessels
-Pulmonary circuit-blood to lungs
-systemic- blood to organs of the body

Blood Flow

1. Blood returning to the heart fills artia
-blood puts pressure against the atrioventricular valves
-atrioventricular valves are forced open
2. As ventricles fill, atrioventricular valve flaps hang limply into ventricles

What vessels lead into each atria?

Right atrium
1.Superior vena cava
2. Inferior vena cava
Left atrium
1. Pulmonary veins

Trabeculae carneae

irregular ridges of muscle in the inside of ventricular wall
-"little beams of flesh",
-This is the name for the structures that are similar to the pectinate muscles of the atria. -
-muscular ridges on the walls of the two ventricles
-most easily seen in the right ventricle
-As is the case with the pectinate muscles, they resemble tree roots.

chordae tendineae

-are tendons linking the papillary muscles to the tricuspid valve in the right ventricle and the mitral valve in the left ventricle.
-As the papillary muscles contract and relax, the chordae tendineae transmit the resulting increase and decrease in tension to the respective valves,
-causing them to open and close.
-string-like in appearance
-referred to as "heart strings."

valves

1. pulmonary valve
2. aortic valve
3. Mitral valve
4. Tricuspid valve
remember note:TAMP

Fossa ovalis

a prominent feature of the interartrial septum is an oval depression called the fossa ovalis, the remnant of the foramen ovale, an opening in the interatrial septum of the fetal heart that normally closes soon after birth.

vena cava

One of two large vessels (superior and inferior) that return deoxygenated blood to the right atrium of the heart.

Two types of vena cava

!. superior vena cava(returns deoxygenated blood from
2. inferior vena cava (return deoxygenated blood from

Valves int the right ventricle

1. Tricuspid valve
2. Pulmonary semilunar vavle

Valves in the left ventricle

1. Aortic semilunar valve
2. Mitral (bicupsid) valve

Visceral pericardium

-membrane that surrounds the heart

Interventricular septum

an internal partition that separates the right and left ventricles of the heart

papillary muscle

- located in right and left ventricles
-project from the walls into the ventricular cavity
-cone shaped muscles that project into the walls of a ventricle
-they are attached to string-like structures called the chordae tendineae.
-The contraction of the papillary muscles closes these valves. When the papillary muscles relax, the valves open.
- the tricuspid valve in the right ventricle and the mitral valve in the left ventricle.

pectinate muscles

-muscular ridges that extend along the inner surface of the right atrium

pulmonary trunk

the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries

atria

-the two upper chambers of the heart- the receiving areas that pool incoming blood.
-Two upper chambers of the heart

Layers of the pericardium

-superficial layer
1.fibrous pericardium
2.parietal layer of the serous pericardium
Deep layer
1. visceral layer of the serous pericardium

-outer layer of this sac fibrous pericardium
-next layer double-layered serous pericardium

Tissue layers of the heart wall

from external to internal
1. epicardium
2. myocardium
3. endocardium

pericardium

-"around the heart"
-triple-layered sac that encloses the heart

Function of right ventricle

to receive blood from the right atrium
- pump it into the pulmonary circuit via the pulmonary trunk

How much does a typical heart weigh?

250-350 grams

Where does the heart lie?

in the thorax posterior to the sternum and costal cartilages
-rests on the superior surface of the diaphragm
-oblique position in the thorax
-with apex lying to the left of the midline and anterior to the rest of the heart

pericardial cavity

is between the superficial and deep layer of the the heart
-it contains lubricating serous fluid
-the epithelial cells of the serous pericardium that line the pericardial cavity secrete a lubricating film of serous fluid
-fluid reduces friction between the beating heart and the outer wall of the pericardinal sac

epicardium

one of the three layers of the heart wall
-"upon the heart"
-the visceral layer of the serous pericardium
-often infiltrated with fat, especially in older people

myocardium

one of the three layers of the heart wall
-"muscle heart"
-forms the bulk of the heart
-consists of cardiac muscle tissue
-the layer that actually contracts

endocardium

one of the three layers of the heart wall
-"inside the heart"
-located deep to the myocardium
-a sheet of simple squamous epitherlium resting on a thin layer of connective tissue
-lines the heart chambers and covers the heart valves

interatrial septum

internally divides heart chambers longitudinally at the wall between the atria

interventricular septum

internally divides heart chambers longitudinally at the wall between the ventricles

external boundaries of the four chambers

-marked by two grooves
1. first groove: coronary sulcus
-forms a crown by encircling the boundary betwn the atria and ventricles
2. second groove:interventricular sulcus
a.anterior interventricular sulcus
b.posterior interventricular sulcus
1)separates the 2 ventricles on the heart's inferior surface

The right atrium receives blood via what three veins?

1. superior vena cava
2. inferior vena cava
3. coronary sinus

fossa ovalis

a depression in the interatrial septum that marks the spot where an opening existed in the fetal heart called the foramen ovale

tricuspid valve

inferior and anteriorly the right atrium opens into the right ventricle through this valve

left atrium

makes up most of the heat's posterior surface or base.

right ventricle

forms most of the anterior surface of the heart

right atrium

forms the entire right border of the human heart

left ventricle

forms the apex of the heart and dominates the heart's inferior surface

crista terminalis

C shaped ridge
-a vertical ridge of smooth myocardium within the right atrium of the heart. It is on the lateral wall of the chamber. It extends between the right side of the orifice of the superior vena cava inferiorly to the right side of the valve of the inferior vena cava.

What is coronary artery disease caused by?

atherosclerotic blockage of cornonary sulcus and intervetricular sulci

Where is the coronary sulcus?

...

Intervetricular sulci

...

arrhythmia

a variation from the normal rhythm of the heartbeast

ventricular fibrillation

the ventricles are unable to pump blood into the arteries due to rapid, random firing of electrical impulses within ventricular muscle prevents coordinated contraction of the ventricle.

atrial fibrillation

multiple waves of impulses circle within the atrial myocardium, randomly stimulating the AV node which signals the ventricles to contract quickly and irregularly

pulmonary arterial hypertension

enlargement and sometimes ultimate failure of the right ventricle resulting from elevated blood pressure in the pulmonary circuit

heart failure

a progressive weakening of the heart as it fails to keep pace with the demands of pumping blood and cannot meet the demands for oxygenated blood.

congestive heart failure

the heart enlarges greatly while its pumping efficiency progressively declines.

destructive positive feedback loop

a weakened heart causes the sympathetic nervous system to stimulate the heart to pump harder. This demand further weakens the heart----which causes it to stimulate the hear to pump harder

atherosclerosis

an accumulation of fatty deposits in the inner lining of the body's arteries that can block blood flow through these arteries

coronary artery disease CAD

arteries supplying the heart wall are narrowed or blocked
-symptom angina pectoris

angina pectoris

"choked chest"
-thoracic pain caused by inadequate oxygen of heart muscle cells, which weaken but do not die

When do angina attacks mostly occur?

during exercise when the heart is vigorously contracting and there is a higher demand for oxygen

myocardial infarction

- heart attack
-when the blockage of a coronary artery is more complete or prolonged and oxygen starved cardiac muscle cell die

symptoms of myocardial infraction

-sharp pain strikes with lighting speed through the chest and sometimes the left arm and left side of the neck and does not subside.

silent ischemia

a condition in which blood flow to the heart is interrupted often like in angina but without pain to provide warning

coronary sinus

largest of the cardiac veins
-

What arteries delivery blood supply to the tissues of the heart?

right and left coronary arteries
-start at the base of the aorta and run in the coronary sulcus

branches of the left coronary artery

anterior interventricular
circumflex arteries

branches of the right coronary artery

marginal artery
posterior interventricular artery

What type blood vessel carries deoxygenated blood from the heart wall?

coronary sinus which occupies the posterior part of the coronary sulcus and returns almost all venous blood from the hear to the right atrium

Name the three veins that drain into the coronary sinus.

great cardiac vein
middle cardiac vein
small cardiac vein

vagus nerve

parasympathetic, decreased heart rate

conducting system

of the heart is a series of specialized cardiac muscle cells that carry impulses throughout the heart musculature signaling the heart chambers to contract in proper sequence
-sets basic heart rate

sinoatrial (SA) node

the impulse that signals each heartbeat begins here
-sets basic heart rate by generating 70-80 electrical impulses per minute
-heart's pacemaker

how does the signal of the SA node spread?

throughout the myocardium through the gap junctions in the intercalated discs

Intrinsic conduction system of the heart

1. The sinoatrial (SA) node (pacemaker) generates impulses
2. The impulses pause (0.1 sec) at the atrioventricular (AV) node
3. The atrioventicular (AV) bundle connects the atria to the ventricles
4. The bundle branches conduct the impulses through the interventricular septum
5. The Purkinje fibers stimulate the contractile cells of both ventricles

purkinje myocytes

long row of special, large-diameter, barrel-shapped cells
-these muscle cells contain few myofilaments because they are for conduction
-located in the deepest part of the venticular endocardium

where are purkinje myocytes found

between the endocardium and myocardium layers

sympathetic cardiac nerves

increase heart rate and force of contraction
-travel to the heart from the cervical and upper thoracic chain ganglia

What sets the heart's inherent rate of contraction?

SA node

visceral sensory fibers

nerves to the heart

name two types of visceral sensory fibers

parasympathetic fibers
sympathetic fibers

parasympathetic fibers

slow heart rate
-arise as branches of the vagnus nerve in the neck and thorax

What controls the autonomic input to the heart

cardiac centers (2 types) in the reticular formation of the medulla of the brain

Name the 2 types of cardiac centers and influence

cardioinhibitory center influences the parasympathetic neurons
-cardioacceleratory center influences the sympathetic neurons

heartbeat

a single sequence of atrial contraction followed by ventricular contraction

How many times does the average person heart beat per minute

70-80 times per minute

systole

the contraction of a heart chamber
-both atria and ventricles experience this

diastole

the time during which a hear chamber is relaxing and filling with blood
-both atria and ventricles experience this

Oxygen poor blood enters the heart through what valves of the heart?

Superior vena cava
Inferior vena cava
Coronary sinus

What is the the path of blood once it enters the right atrium?

tricupsid valve
right ventricle
pulmonary semilunar vavle
pulmonary trunk
to lungs
pulmonary arteries
to heart
pulmonary veins
left atrium
mitral vavlc\ve
left ventricle
aortic semilunar valve
aorta
to body through systemic circuit

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set