Book: Chp 19 The Heart
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Book: Chp 19 The Heart
book notes bio120 heart
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This circuit is known as the blood vessels that carry blood to and form the lungs
What side of the lungs receive rich oxygenated blood?
This circuit has vessels that transport blood to and from all body tissues and back to the heart.
What is the largest organ in the mediastinum?
What region is considered the mediastinum?
the region between the two lungs
Which ribs can u place ur fingers at and feel the heart beat when the apex contacts the thoracic wall?
between 5th and 6th
What is the outermost layer of the pericardium? what is it made of?
strong layer of dense CT
What is the 2 main purposes of the fibrous pericardium?
holds the heart in place and keeps it from overfilling with blood
What 2 layers are between the fibrous percardium and the surface of the heart? Name both layers.
the double-layered serous pericardium:
- The outer layer is the parietal layer
- The inner layer is continous with it called the visceral layer or epicardium.
T or F: The parietal layer of the serous pericardium is considered part of the heart wall.
False: the visceral layer of the serous periardium is considered part of the heart wall
What is the space called between the parietal and visceral layers of the serous pericardium? What was it a division from?
- a division of the embryonic coelom
What are the 3 layers of the heart wall (from superficial to deep)?
What layer of the heart consists of cardiac muscle tissue and is the layer that actually contracts?
Internally, what is the heart divided longitudinally by (between the atria)? as well as between the ventricles?
: interatrial septum
: interventricular septum
This sulcus seperates the ventricles on the back side of the heart
posterior inteventricular sulcus
Which part of the heart first receives poor oxygenated blood?
What 3 parts does the right atrium receive blood from?
1. superior vena cava
2. inferior vena cava
3. coronary sinus
How is the atrium divided? what ridge divides those parts?
and an anterior and posterior parts divided by a horizontal ridge called the pectinate muscles
This landmark in the atrium is important because it locates the sites where veins ente the right atrium. It is a C-shaped ridge
What are the irregular ridges of muscle called in the ventricles of the heart?
What part of the left atrium is the only visible part if viewing the heart anteriorly?
What part of the heart forms the apex and dominates the heart's inferior surface?
the left ventricle
Which valves of the heart are considered "semilunar"
pulmonary and aortic
what are the 4 functions of the cardiac skeleton?
1. anchors the valve cusps
2. prevents overdilation of valve openings
3. it is the point of attachment or the budles of cardiac muscle
4. blocks direct spread of electrical impulses from atria to ventricles
The heart makes a "lubdub" sound. What produces the lub and dub sound?
The lub sound is the closing of the AV valves at the start of ventricular contraction.
The dub is produced by the closing semilunar valves at the end of ventricular contraction
What sinus collects the blood from the heart into the right atrium?
Do the right and left atriums of the heart contract together or seperately?
The term that describes the contraction of a heart chamber is __a__. The time during which a heart chamber is relaxing and filing with blood is termed __b__.
What main 2 things does the myocardium of the heart consist of?
cardiac muscle cells
connective tissues that surround these cells
The average cardiac muscle cell is about __a__ micrometers in diameter and __b__ micrometes in length
What are the branchin networks of cardiac muscles called?
What are the complex junctions that join cardiac muscles called?
This tranverse region of the intercolated discs contains desmosome-like junctions called what?
What is part of the heart that is a series of specialized cardiac muscle cells and carries impulses throughout the heart.
Where does the signal begin for each heartbeat and is considered the heart's pacemaker?
sinoatrial node (SA node)
What is the basic heart rate set by the SA node?
What happens at each number of this electrical pathway?
1. SA node genereates impulse
2. impulse pause (0.1 sec) at the AV node
3. The AV bundle connects the atria to the ventricles
4. The bundle branches conduct the impulses through the interventricular septum
5. the subendocardial conducting network stimulatess the contractile cells of both ventricles.
What is the significance of the brief delay of impulses at the AV node?
Enables the ventricles to fill comletely before they start to contract
What prevents the impulses from the atria to proceed into the ventricle wall?
the fibrous cardiac skeleton between the atria and ventricles are nonconducting
What cells are the nodes and av bundle composed of?
tyical cardiac muscle cells
What nerve decreases heart rate and what is it restricted to?
parasympathetic nerves are restricted to the SA and AV nodes and the coronary arteries.
Which nerve increases heart rate and strength of contractioon?
Where is the autonomic input to the heart controlled?
the cardiac centers in the reticular formation of the medulla in the brain.
In the medulla, the __a__ center influences parasympatheti neurons, whereas the __b__ center influences sympathetic neurons.
Which vessel sends branches into and supplies the interventricular septum and anterior walls of ventricles with nutrients?
anterior interventricular artery (or left anterior descending artery (LAD))
The Right coronary artery branches at the inferior border of the heart into this...
What is the posterior side of the heart where the right coronary artery branches off to? what is the clinical name?
posterior interventricular artery
posterior descending artery (PDA)
What do the RCA and its branches supply nutrients to?
right atrium and much of right ventricle
What is the largest cardiac vein? What 3 large tributaries drain into it?
1. great ardiac vein
2. middle cardiac vein
3. small cardiac vein
Which veins on the anterior surface of the right ventricle empties directly into the right atrium?
anterior cardiac veins
This is an accumulation of fatty deposists in the inner lining of the body's arteries that can block blood flow through these arteries.
When atherosclerosis affects the coronary arteries, what can it lead to? what is a common symptom?
coronary artery disease (CAD)
angina pectoris (thoracic pain caused by inadequate oxygenation of heart muscle cells)
What causes a myocardial infarction? (heart attack)
a blockage of a coronary artery that is more complete or prolonged and the oxygen-starved cardiac muscle cells die.
This condition is when blood flow to the heart is interrupted often, like in angina, but without any pain to provide warning of a sudden, fatal heart attack.
This is a progressive weakenin of the heart as it fails to keep pace with the demands of umping blood and thus cannot meet the body's need for oxygenated blood.
In this condition, the heart enlarges greatly while its pumping efficiency progressively declines.
congestive heart failure
This condition is the enlargement and sometimes failure of the right ventricle resulting from elevatd BP in the pulmonary circuits.
pulmonary arterial hypertension
This is when the ventricles are unable to pump blood into the arteries because rapid, random firing of electrical impulses within ventricular cardiac muscles prevents proper contractions.
This is when multiple waves of impulses circle within the atrial myocardium, randoly stimulating the AV node and signals the ventricles to contract quickly and irregularly.
What is a big possible complication of atrial fibrillation?
a clot acn occur from the lack of blood movement in the heart which can break off and reach the brain, which can cause a stroke.
What do all blood vessels begin as?
condensations of mesodermal mesenchyme called blood islands