Heart Lab #5

What is the chordae tendineae and where are they found?

**Blood flows from the upper right atrium into the right ventricle through broad openings of fibrous flaps called cusps. The cusps make up the right AV valve (tricuspid valve). These are part of the right AV valve (tricuspid valve---connect the upper right atrium to the right ventricle). Each cusp is attached to a tendinous connective tissue fiber called the chordae tendineae. The chordae tendineae also originate at papillary muscles at the inner surface of the right ventricle. When the right ventricle contracts, this right AV valve (tricuspid valve) closes and prevents the back-flow of blood into the upper right atrium. The chordae tendineae prevents the AV valve cusps from averting into the atrium.

Do arteries carry blood to the heart or away from the heart? Is the blood oxygenated or deoxygenated?

Arteries carry oxygenated blood away from the heart.

What structure delivers deoxygenated blood from the body to the right atrium?

The vena cava delivers deoxygenated blood from the body to the right atrium

Path of Blood Flow in the Heart

1. Blood enters the right atrium from superior and inferior venae cavae. 2. Blood in right atrium flows through right AV valve into right ventricle. 3. Contraction of right ventricle forces the pulmonary valve to open. 4. Blood flows through the pulmonary valve into the pulmonary trunk 5. Blood is distributed by right and left pulmonary arteries (from the pulmonary trunk) to the lungs, where it unloads CO2 and loads O2. 6. Blood returns from lungs via pulmonary arteries to left atrium 7. Blood in left atrium flows through left AV valve into left ventricle. 8. Contraction of left ventricle (simultaneous with step 3) forces aortic valve to open. 9. Blood flows through aortic valve into ascending aorta 10. Blood in ascending aorta is distributed to every organ in the body, where it unloads O2 and loads CO2. 11. Blood returns to the heart via venae cavae.

ECG (or EKG) "Electrocardiogram"

1. Pacemaker generates wave of signals to contract 2. These waves of signals (that the pacemaker generated) are delayed at the AV node. 3. These waves of signals (that the pacemaker generated) and are delayed at the AV node, are then passed to the heart apex ===the wave of signals are passed to the heart apex 4. The wave of signals that just passed through the heart apex now spreads throughout ventricles ===signals pass throughout the ventricles

What is normal blood pressure?

120/75 mmHg

What is the definition of blood pressure? In what artery is blood pressure taken?

Blood pressure is the force blood exerts on a blood vessel wall ---Blood pressure is written as the systolic pressure over diastolic pressure. ---Systolic pressure is the maximum blood pressure during contraction of the ventricles; diastolic pressure is the minimum pressure recorded just prior to the next contraction. ---The Brachial artery is usually used to measure blood pressure.

What is hypertension? What is the blood pressure reading when someone is hypersensitive?

Hypertension is chronic high blood pressure. It happens when the blood's force on the arteries is too strong. 140/90 mmHg

Diastole

Diastole is the relaxation of the heart. This allows for the chambers of the heart to refill with blood. Diastole = filling

What is hypotension? What is the blood pressure reading when someone has hypotension?

Hypotension is chronic low resting blood pressure. a blood pressure reading of 90 millimeters of mercury (mm Hg) or less systolic blood pressure (the top number in a blood pressure reading) or 60 mm Hg or less diastolic blood pressure (the bottom number) is generally considered low blood pressure.

What are the semilunar valves. Where are they located?

Semilunar valves are one-way valves that separate the ventricles from major arteries. The two main semilunar valves are the pulmonary valve and aortic valve. The aortic valve separates the left ventricle from the aorta, while the pulmonary valve separates the right ventricle from the pulmonary artery. As the ventricles contract, ventricular pressure exceeds arterial pressure, the semilunar valves open and blood is pumped into the major arteries. However, when the ventricles relax, arterial pressure exceeds ventricular pressure and the semilunar valves snap shut.

Systole

Systole is the contraction of the heart muscles. This allows for the removal of blood from the heart chambers and eventually into the arteries. Systole = pumping (pumping blood out of the heart and eventually into the arteries). The heart muscles need to contract to pump out the blood.

What is systole and diastole?

Systole is the contraction of the heart. It allows for the removal of blood from the heart chambers and eventually into the arteries. Diastole is the relaxation of the heart. It allows for the chambers in the heart to refill with blood.

What does the bicuspid valve (mitral valve) do? What do they separate?

The bicupsid (mitral valve) closes off the upper left chamber (atrium) collecting the oxygen-rich blood coming from the lungs. Opens to allow blood to flow from the upper left side to the lower left side. (or from the left atrium to the left ventricle). ***The tricuspid is located between the right atrium and right ventricle, and the bicuspid is located between the left atrium and left ventricle.

Is the blood flowing through the pulmonary trunk oxygenated or deoxygenated?

The pulmonary trunk breaks into two pulmonary arteries, which deliver deoxygenated blood to the corresponding lung.

What structures separate the left and right ventricles?

The septum separates the left and right ventricles.

ALL ABOUT BLOOD PRESSURE

The tools used to take a blood pressure are a stethoscope and a sphygmomanometer. ---Make sure you place the round end of the stethoscope 'under' the blood pressure cuff. You inflate the sphygmomanometer (blood pressure cuff) to a little above 180 mm Hg. This collapses the major arteries to the arm (that's why it is uncomfortable). Then you slowly release air by gently turning the air valve, and watch the pressure drop. When you first hear a sound, that will be the Systolic blood pressure. The sound you hear is the blood now flowing in the artery of the arm. This means that the systolic pressure is now greater than the pressure in the blood pressure cuff. As you continue to watch the pressure drop, when you no longer hear any sounds, that will be the Diastolic blood pressure. ---Now let's try it. With the blood pressure cuff deflated and the air valve closed, wrap the cuff around the patient's arm as shown. Pump up the cuff until the pressure reads about 180 mm Hg. ---Then slowly turn the knob on the air valve to release air from the cuff. As the pressure slowly drops, listen for sound with the stethoscope. When you hear the first sound, note the pressure on the dial, that is the Systolic blood pressure. ---When the sound disappears, that pressure will be the Diastolic blood pressure. ---While you're at it, how about measuring the heart-rate. ---Count the number of pulses for 60 seconds, and this will be the heart-rate in beats-per-minute. Or just count the number of pulses for 30 seconds, and multiply that number by 2 for H.R. in bpm.

What does the tricuspid valve do? What do they separate?

The tricuspid valve closes off the upper right atrium (chamber) that holds blood coming in from the body. It opens to allow blood to flow from the top right chamber to the lower right chamber (or from right atrium to right ventricle). The tricuspid valve prevents the back flow of blood from the ventricle to the atrium when blood is pumped out of the ventricle.

Do veins carry blood to the heart or away from the heart? Is the blood oxygenated or deoxygenated?

Veins carry deoxygenated blood to the heart.