Heat and Neck Vessels systems Flashcards
Precordium
Mediastinum
What are the positions of the heart
-what produces the apical pulse
Precordium- the area on the anterior chest OVER the heart and great vessels
Mediastinum- area in the chest that contains the heart
Heart Position:
- The top (wider) area of the heart is the base
- The bottom (pointed) area is referred to as the apex
The apex beats against the chest wall– producing the apical pulse
Landmarks: The heart
Where is the heart located
What is the apex location
Heart Location:
Top to bottom:
-2nd– 5th intercostal space (ICS)
Left to Right:
-Right border of the sternum to the LEFT mid-clavicular line
Apex Location:
- 5th intercostal space
- Between mid-sternal and mid-clavicular lines
What are the three layers of the heart and what fluid is there
Pericardium
- Tough, fibrous, sac that surrounds and protects the heart
- Between the layers is pericardial fluid (this ensures a smooth, FRICTION FREE movement of the heart muscle)
Myocardium
-Muscular wall of the heart. Responsible for the pumping action of the heart.
Endocardium
-Thin layer of endothelial tissue that lines the heart chambers and valves
Heart Valves
What is a valve
what is its purpose
how do they open
what are the four valves
Valves- separate the chambers
-Act as swinging doors (unidirectional or one-way only)
Purpose: prevent backflow of blood
They open PASSIVELY based on changes in the pressure gradient in the heart
4 valves in the heart:
- Right Atrioventricular (Tricuspid)
- Left Atrioventricular (Bicuspid/Mitral)
- Right Semilunar (Pulmonic)
- Left Semilunar (Aortic)
AV valves
What do they separate
What are their names
When do they open
When do they close
What are Chordae tendineae and what do they do
What happens when the ventricles are relaxed 3
what happens when the ventricles contract 3
Two AV valves (atrioventricular) separate the atrium and ventricles:
- The RIGHT AV valve is the tricuspid valve
- The LEFT AV valve is the BICUSPID or mitral valve
- The AV valves OPEN during the heart’s filling phase so the blood from the atria can fill the ventricles
- The AV valve CLOSE after filling to prevent a back flow into the atria.
Chordae tendineae are collagen fibres that anchor the AV valves to papillary muscles which are embedded in the ventricle floor
When the ventricles are relaxed
- Chordae tendineae are slack
- Valves are open
- Blood fills the ventricles
When the ventricles contract
- Blood in the ventricles push the valves closed
- The papillary muscles contract & tighten the chordae tendineae (prevents the valve leaflets from flipping back up into the atria)
- Blood is ejected from the ventricles
Semilunar Valves
What do they separate
what are their names
When do they open
Where does the right and left side of your heart send blood
Two semilunar (SL) valves separate the ventricles and the greater vessels:
The RIGHT semilunar valve is the pulmonic valve
-Between right ventricle & pulmonary artery
The LEFT semilunar valve is the aortic valve
-Between left ventricle & aorta
They open when the heart pumps to allow blood to be ejected from the heart (either to the lungs or to the body)
Right side of your heart is sending blood to our lungs
Left side of your heart is sending blood to the aorta and then out systemically to the rest of the body
What are the great vessels, where are they located
What does each do and what kind of blood
When is the only time an artery carries de-oxygenated blood and when does a vein carry oxygenated blood
What is the largest artery in the body
what are the 4 divisions of the 4rth
- Superior & Inferior Venae Cavae- returns deoxygenated blood to the RIGHT Atrium
- Superior- from above
- Inferior- from below - Pulmonary Artery- takes deoxygenated blood to the lungs from the RIGHT ventricle
- Leaves right ventricle and bifurcates (divides into 2)
- Carries deoxygenated blood to the lungs, where it then gets oxygen
- *This is the ONLY time that an artery will carry de-oxygenated blood - Pulmonary Veins- take oxygenated blood to the LEFT atrium from the lungs
- *This is the ONLY time that a vein will carry oxygenated blood - Aorta- takes oxygenated blood to the body from the LEFT ventricle
- Largest artery in the body
4 divisions: Ascending- coronary arteries Arch- head and arms Thoracic- lungs and mediastinum Abdominal- abdomen and lower limbs
Circulation of blood
What makes up the CV system
CV system is a double pump with 2 divisions
Division #1 – pulmonary circulation
RIGHT SIDE OF HEART → circulates to the lungs
Division #2 – systemic circulation
LEFT SIDE OF HEART → circulates to the body
Pulmonary Circulation
What side does it work on
Where does it take blood
and what does it do
Division #1 – Pulmonary circulation
RIGHT SIDE OF HEART → circulates to the lungs
Pulmonary artery carries DEOXYGENATED blood to the lungs, where the blood picks up O2 and releases CO2 in CAPILLIARIES
Systemic Circulation
What side does it work on
Where does it take blood
Division #2 – Systemic circulation
LEFT SIDE OF HEART → circulates to the body
OXYGENATED blood travels FROM THE LUNGS in the PULMONARY veins to the LEFT atrium
This oxygenated blood travels FROM the LEFT ventricle to the AORTA and out to the body
What is the direction of blood flow 5
- DEOXYGENATED travels from superior & inferior vena cava into the RA
- RA through the Tricuspid valve into the RV then through the Pulmonic valve into the Pulmonary artery and to the lungs
- Oxygenated blood from the lungs travels through the Pulmonary veins back to the LA
- From the LA through the Mitral Valve into the LV
- LV through the aortic valve and into the aorta and to the abdomen and lower extremities
What is the cardiac cycle
What are the 2 phases
Why does blood flow occur
Why does the valves open
Cardiac Cycle- the rhythmic movement of blood through the heart
2 phases:
Diastole- Ventricular relaxation
Systole- Ventricular contraction
*Note: blood flow occurs due to pressure changes
When a chamber contracts the valves open
Cardiac Cycle Diastole
What is diastole
what are the 2 stages
When does atrial systole occur
What initiates the cycle
(Rapid filling [protodiastolic] - slow filling -presystole)
Diastole- Ventricles relax and fill with blood
-The AV valves are OPEN → blood rushes into ventricles
- Passive filling- Pressure in the atria is HIGHER than in the ventricles
(a. k.a. early or protodiastolic filling) - Active filling- Atria contract to eject the remaining blood into ventricles
(a. k.a. atrial systole, presystole or atrial kick)
Note: ATRIAL systole occurs during VENTRICULAR diastole
Alternating pressure
Cardiac Cycle: Systole
What is systole
What are the 8 stages
Systole- Ventricles contract and pump blood out
1.Pressure builds in ventricles (due to blood entering from the atria)
2.AV valves CLOSE (to prevent backflow of blood)= S1 occurs
BEGINNING OF SYSTOLE
- All 4 valves are closed for a brief time
- Ventricular CONTRACTION occurs
- Pressure in ventricles exceeds the pressure in the aorta
- Semilunar valves OPEN (blood ejected)
- Ventricle begins to RELAX
- Blood flows backwards towards the ventricle & fills the semilunar cusps - Semilunar valves CLOSE= S2 occurs
- END OF SYSTOLE
Cardiac Cycle Concepts
What is isometric relaxation
when does is occur
What is isometric contraction
When does it occur
Why do we have off sounds in the heart
What is blood pressure
Isometric Relaxation
- Occurs in Diastole
- All FOUR valves are closed and atria are filling once again
Isometric Contraction
- Occurs in Systole
- All FOUR valves are closed. Occurs just before ventricular contraction
Right side of the heart needs less pressure to go to lungs (timing slightly later)
Left side needs to send to rest of the body
That’s why we have the off sounds
BP= systolic pressure OVER diastolic pressure:
-Maximum pressure on the artery during systole
OVER Resting pressure during diastole
What is the S1 sound and where is it the loudest, which av valves close first
What is the s2 sound and where is it the loudest, which SL valve closes first
S1- closure of AV valves
- Mitral then Tricuspid
- Signals beginning of systole
- Loudest at the APEX
S2- closure of SL valves
- Aortic then Pulmonic
- Signals end of systole
- Loudest at the BASE
What is a split s2 sound
When is it normal
moRe to the Right
Less to the Left
Involves actions on both RIGHT and LEFT sides of the heart, causing a splitting of S2
RIGHT:
- Inhalation- chest cavity gets larger= lower intrathoracic pressure (pushing more blood into the vena cava)
- more blood to RIGHT side of the heart= higher RIGHT VENTRICULAR stroke volume
- high RIGHT VENTRICULAR stroke volume= prolonged RIGHT VENTRICULAR systole
- Pulmonic valve closes a bit LATER
LEFT:
- Inhalation- more blood is kept in the lungs during inspiration
- less blood returned to the LEFT side of the heart= less LEFT VENTRICULAR stroke volume & left ventricular systole
- Aortic valve closes a bit EARLIER
What is an S3 and S4 sound and when are they heard, what are they a sign of and when can they be normal
S3 & S4: Not from the valves
S3 – Right after S2
- Occurs with ventricular resistance to filling during the early rapid filling of diastole
- Creates a vibration that can be heard over the chest
- Can be benign in: youth, trained athletes, and pregnancy
S4 - Just before S1
- Occurs with ventricular resistance during atrial contraction, when blood is pushed into a noncompliant ventricle
- Creates a vibration
- Sign of a failing or enlarged left ventricle
What is a heart murmur
What are the three conditions that one can occur
Murmur- audible vibration caused by turbulent blood flow
-Gentle blowing, swooshing sound
Conditions that result in Murmurs:
1.Increased blood velocity– blood is flowing faster than normal
Examples: exercise, sometimes hyperthyroidism,
2.Decreased blood viscosity– blood is thinner than normal (anemia)
3.Structural defects
Examples: narrowed valves, born defects
What are the four heart sound characteristics
Pitch (frequency)- high-pitched or low-pitched?
Intensity– loud or soft?
Duration– short or long?
Timing– do they occur in systole or diastole?
Normals = low-pitched, soft, long
What is automaticity
Explain conduction 4
Automaticity– able to generate its own impulses that are independent from the body (heart contracts on its own)
Conduction
- Generation and travel of electrical impulses through the heart
- Rate of firing determines ventricular contraction and pulse rate
- Electrical events occur slightly BEFORE mechanical events
- Impulse begins in the Sinoatrial Node (SA) node and moves through the electrical wiring of the heart in an orderly sequence
What is the route of Electrical Impulses 4
1.SA Node- generates impulse- causing atrial muscle cells to contract (rate of firing from the SA node determines Pulse Rate)
Pacing rate of 80-100 bpm
2.AV Node- Electrical Impulse travels to the AV node and pauses briefly
Pacing rate of 40-60 bpm
3.Bundle of His- The impulse travels through the pathway in the Bundle of His fibres in the RV and LV
Pacing rate of 20-35 bpm
- Purkinje fibres- finally it moves to the Purkinje fibres causing ventricular muscles to contract
What is an ECG
What is the P wave
What is the PR interval
What is the QRS complex
What is the T wave
ElectroCardioGram (ECG)- measures and records electrical activity of the heart
P wave: ATRIAL depolarization–which causes atrial contraction
P-R interval: from beginning of P wave to beginning of the QRS complex
(time from beginning of Atrial depolarization to beginning of Ventricular depolarization)
QRS complex: VENTRICULAR depolarization- which causes ventricular contraction
T wave: VENTRICULAR repolarization- ventricles relax and cells repolarize (resting state)
What is cardiac output
What is the equation
what is heart rate
what is stroke volume
what factors affect it 3
Cardiac output- the amount of blood ejected from a ventricle each minute (normally 4–6 L/minute at rest)
Cardiac Output = Heart Rate x Stroke Volume
(CO = HR x SV)
Heart Rate= beats per minute
Stroke Volume= volume of blood ejected by each ventricle with each beat
Factors affecting cardiac output:
Preload– the degree of stretch at the end of diastole (volume prior to contraction)
Contractility– the forcefulness of contraction of the heart muscle
Afterload– the pressure necessary to overcome before ejection of blood can occur
What are the Carotid arteries
where does it come from
what are the two branches
The timing of the carotid artery matches what
what are the characteristics SRG
Carotid arteries - supply the head/neck/brain with oxygenated blood
- The carotid arteries come off the arch of the aorta
- Run on both sides of the neck then divide at the jaw into branches:
Internal carotid- serves the brain
External carotid- serves the external skull
The timing of the carotid artery pulse closely coincides with ventricular systole
Characteristics:
- smooth rapid upstroke
- rounded summit
- gradual downstroke with a dicrotic notch (caused by aortic valve closure)
What are the jugular veins
where do they drain
and what are the two divisions
when do they expose
Jugular veins - drain deoxygenated blood from the head/neck/brain
-drain into the superior vena cava
Internal jugular- drains deeper structures
External jugular- drains more superficial structures
Jugular veins expose when the RIGHT side of the heart fails to pump effectively (distension)
