Lecture 1: Cardiovascular and Pulmonary A&P Flashcards
The heart lies in what sac in what space?
Lies in the pericardium sack in the mediastinum
What ribs lie infront of the mediastinum
3-5
Mediastinum is inferiorly bordere by the diaphragm, posterior by the ribs and vertebral column, latearlly by the pleural cavity, and anteriorly by the sternum and ribs 3-5
where is the apex of the heart (from the outside)
5th intercostal space
KNOW: The mid clavicular line is a vertical lien that runs from the mid clavicle up and down
Why does the left side of the heart of so much muscle mass?
Because the left side has to pump the blood out systemically to the body while the right side only has to pump it to the left side of the heart
Which side of the heart is a high pressure system and why?
Left side is a high pressure system and the right side is a low pressure system because the left side needs to push blood out systemically while the right side just has to push to the contraltateral side
What is the white part called and the muscle that attaches to it?
Corda Tendina
Papillary muscle
What are the 4 layers of cardiac tissue, starting from deepest to superfical
Endocardium, myocardium, Epicardium, Pericardium
Which layer of the heart is synthesized of connective tissue and forms the valves?
Endocardium
What does the middle layer of heart tissue do?
The myocardium consists of muscle tissue and moves blood
KNOW: The epicardium is the outer layer of the heart and inner visceral layer of serous pericardium; secretes, absorbs, protects
Which layer of heart tissue is a thick outer layer of the fibrous sac around the heart?
Pericardium
What is the name of the blood supply to the heart?
Coronary blood supply
What are the 3 main coronary arteries?
1) Right coronary artery
2) Circumflex
3) Left Anterior Descending
What two coronary arteries subdivide from the left main coronary artery?
Circumflex
Left Anterior Descending
Where do coronary arteries arise from?
Left and right cusps of the aortic valve (she just said they come from the aorta)
KNOW: If aortic BF drops, than theres going to be decreased BF to the myocardium –> because decreased BF to the cornary arteries = decreased ability to contract myocardium = decreased/no BF to the body
What portion of the heart recieves blood supply from the right coronary artery?
Right side
What portion of the heart recieves blood supply from the left anterior descending (LAD) cornary artery?
Mainly the front (has anterior in the name)
Which cornary artery is considered the widow maker and why?
Left Anterior descending cornary artery
Because, it supplys the left/anterior portion of the heart. If gets blocked the myocardium in the L ventricle is no longer supplied, meaning blood cannot be pumped systemically
What portion of heart is recieves blood from the circum flex cornary artery?
It wraps around to the back side
Why is dilinating between the cornary arteries helpful in clinical practice?
Different arteries being blocked can cause different symptoms to arise
What are the names of the 3 layers of the coronary arteries?
Outer layer (adventitia)
Middle layer (tunica media)
Inner layer (Tunica intima)
Which later of the coronary arteries has collagen, making it flexible?
Adventitia (outer layer)
* Know: this provides structure
Because they have collagen fibers they do repairs
Which layer of cornary artery consists of smooth muscle cells?
Tunica media (middle layer)
Which layer of cornary artery makes adjustments to luminal diameter through vasomotor tone?
Tunica Media (because its made up of smooth muscle so can adjust the arterial diameter)
Vasomotor tone: What works to either keep the blood vessel open to increase BF or constrict it
* Its the amount of tension/contraction in the smooth muscle cells within the tunica media
* Medications can affect this and your body regulates it
Where does plaque (athrosclerosis) happen within the cornary arteries?
Tunica intima (inner layer)
Which layer of cornary artery is an endotheilial layer ontop of basement membrane?
Tunica intima
What 4 functions does the tunica inntima have?
1) Protecting the arterial wall
2) Exchange of gasses and nutrients from the blood
3) Assisting in the regulation of coaagulation
4) Signaling of any needed inflammatory responses
Which part of the cornary artery signals for any needed inflammatory response?
tunica Intima
KNOW: When there is plaque buildup it typically creates a tear in the tunica intima, which starts the inflammatory response (because it does inflammation), and this inflammatory response is what leads to all the problems.
The tunica intima is selectively permable to macromolecules the size of?
Low density lipoprotein
Myocardial perfusion = the amount of perfusion the heart is going to get
* Your heart needs BF, and it can get ischemia (area that doesnt get enough BF)
Perfusion = the flow of blood/flood to tissue/organs
What is the primary driving force moving blood into myocardial tissue?
Diastolic blood pressure
* Because when its in diastole its being filled w/ blood
Systolic = Beat
Diastolic = rest
KNOW: Heart lets BF in at rest.
What do we expect to increase during EX, diastolic BP or systolic BP? Why?
Systolic - because the heart wants to beat harder to get more blood out
Diastolic stays down because we don’t want as much pressure when the heart is filling
What changes the amount of blood flow to the heart?
Vasomotor tone
* going to increase diameter if more BF is needed and decrease if less BF is needed
What is resistance flow of the heart and what causes it to be higher?
The resistance to blood flow to the heart
Typically increases with athersclerosis (harder to pump blood in)
* if the resistance is high your myocardium is not going to get enough blood
What is Left ventricular end-diastolic pressure?
The pressure within the left ventricle at the end of diastole
Myocardial Oxygen Consumption is the product of what 2 things?
HR and stress on ventricle
* more stress = more oxygen needed
* Increase HR = more BF
What is afterload?
The amount of resistance that the L ventricle has to work against
* if it increases than it will increase the stress on the L ventricle (because its trying to pump into higher pressure area, creating more stress)
Rate Pressure Product is the indrect index of oxygen demand
* What is it a product of?
RPP = HR X Systolic BP
KNOW: If you’re healthy you can reach higher RPP levels (can utilize more O2?)
Where does the heart originally get blood from?
inferior/Superior vena cava
list the blood flow through the heart
Heart BF
What is the Preload?
Whats going into the heart
Essentially the stretch on the heart right before it contracts
* the stretch that the BF caused
Inspire O2–> air into lungs –> into capillaries of the aveoli where gas exchange happens –> flows into the heart –> then into the systemic vessels –> muscle –> mitochondria
Mitrocondria uses O2 and makes waste CO2 –> systmic blood vessels –> diffuses back into lungs and is expires
How oxygen is transported
What is the pacemaker of the heart?
Sinoatrial (SA) node
Diastole = relaxiation
Systole = contraction
KNOW: Blood flows into the R/L atrium and R/L ventricles during diastole
KNOW: SA node is the P wave (probs not on test)
Depolirzation = contraction of what
atrium and is the last event in diastole
SA node fires and depolizes then travels where?
AV node –> bundle of HIS –> bundle branches –> Purkinje fibers
What two valves close during systole and why?
Mitral valve and tricuspid valve close
To prevent backflow
Were increasing the pressure (squeezing the balloon to let the blood out)
If these valves werent working we wouldnt be able to pump the amount of blood needed back into the body because it would back flow into the heart
What event marks the end of systole?
Ventricular contraction
What event is the last one in diastole?
Atrial contraction? kind of conflicting here
cardiac cycle
KNOW: Autonomic NS is made up of sympathic and parasynpathic portions
What two parts of the brain control the autonomic NS?
Vasomotor center in the medulla
Lower Pons
What nerve to the heart gives it parasympathetic innervation?
Vagus Nerve
Chronotropic defenition?
Affecting the rate or timing of a physiological process, especially the HR
Essentially the timing of the HR
Inotrophic definition?
Another word for contractility (amount of ability for something to contract)
Which nerve causes negative chronotropic effects and negative inotrophic effects?
Vagus nerve
Decreases HR and Control ability
During a sympathetic NS response do we get positive or negative chronotropic/inotrophic effects?
Positive
You’re going to contract stronger and quicker (makese senese if you’re going into fight or flight)
What autonomic nerve system causes systemic vasoconstriction?
sympathic NS
* not to the heart/lungs
* This is done so blood can be diverted to heart/lungs
Not really covered this lecture
Increases contraction strength
Decreases contraction strength
Systemic circulation order
Arteries –> Arterioles –> Capillaries –> Capillaries –> Venules –> Veins
What has valves, arteries or veins?
Veins
* Prevents pooling and backflow of blood
Of the systemic ciruclation what regulates blood flow to tissue?
Arterioles
Where is diffusion of gasses?
Capillaries
KNOW: Artial blood flow must be enough to push out and get all the way to the mitochondria within the tissue
* Can’t be to high that it destorys things
What is pulse pressure?
Difference between systolic BP and diastolic BP
What is mean arterial pressure?
What is the lowest it can be for tissue perfusion?
Average BP during a cycle
Need 60 for tissue perfusion
Essentially saying for the O2 to get into the cells you need a MAP of 60
* You really don’t want to exercise someone under this map
good for acute settings
Mean arterial pressure equation?
MAP = DP + 1/3 (SP-DP)
MAP = DP(2/3) + SP(1/3)
What is preload?
* What 2 things cause it to increase?
What you’re adding onto the heart (basically everything at end diastolic volume)
Also known as resting tension (because its not beating here)
* Exercise = increase (more blood pumped back to heart = increased EDV)
* Poor heart function = increase (note this leads to fluid retention, which is dumped in the circulatory system and back onto the heart)
What is afterload?
What the heart works against
There is an increase in afterload. What decreases?
Stroke volume
This is because if the heart is pumping up against more resistance not as much is going to get out, thereby decreasing SV
Stroke volume =
Amount of blood pumped out of LV
Increased or reduced ventricular compliance leads to a higher end diastolic volume?
Increased ventricular compliance leads to a higher end diastolic volume. This is because the ventrical can fill more easily
What is ejection fraction?
Percentage of how much volume of blood the L ventrical pumps out with each contraction
EF = SV/EDV
KNOW: this also determines that amount of EX / medical percedures they can do. Doctor might think they won’t do well under anastegia
They get this on an ultrasound to see how much fluid is running through heart. If its in the 20’s or lower they won’t do surgery.
Think of arterioles as an off ramp on the highway. They split off arteries and slowly come to a stop, dead ending in the capillaries
KNOW: arteries respond to sympathic/parasympathic stimulation (because they have smooth muscle)
What hormones affect arterioles (4)
Epinephrine
Vasopressin
Atrial natriuretic peptide
Angiotensin II
All of these control BP in one way or another (she said we’d dive into it later, so probs don’t memorize)
cardiac output defienition
Amount of blood pumped out of heart per minute
Cardiac output equation
HR*SV
SV equation
EDV-ESV
Heart rate is inversly porportional to… why?
Heart rate is inversely proportional to SV
CO = HR*SV
CO stays constant, so as one increases the other must decrease (HR goes up SV goes down to maintain a constant CO)
Normal CO?
4-6L
* Wants to maintain this amount always
review this more
Bradycardia?
HR less than 60 BPM
Tachycardia?
HR more than 100 BPM
Which of the following functions does the myocardium layer of the heart serve?
A) Facilitates the pumping action of the heart
B) Forms a continuous lining with the tissue of the valves
C) Minimizes friction during cardiac contraction
D) Provides a tough fibrous layer of dense irregular connective tissue
A)
Primary function of the upper respiratory tract?
Humidification (also helps filter the air)
Main structure for humidification?
Nasal cavity
What do Goblet cells produce and where are they?
Produce mucus in the trachea
This mucus traps pathogens and keeps them from going into the body
What kind of cells line the trachea?
Cilia cells (little hairs)
* Move things along
* Goblet cells produce mucus here and the cilia cells move them along
Functional units of the lungs that do gas exchange
* What makes them up
Acini
Alveoli + Alveolar sacs and ducts, and respiratory bronchioles
Gas exchange occurs in the alveolar sacs
What is the manubrium? What does it articulate w/?
Thickest top part of the sternum
Articulates w/ the clavicles and first and second ribs
Which ribs does the body of the sternum articulate w/?
Ribs 3-7
What is at the most caudal aspect of the sternum?
Xiphoid process
Which point marks level of bifurcation of trachea into right and left main stem bronchi?
Sternal angle (angle of louis)
* Joint between the sternum and manubrium
Which ribs are your true ribs?
ribs 1 to 7 (vertebrosternal) attach via their costal cartilages to the sternum
Which ribs are your false ribs?
Ribs 8-10 (vertebrochondral) attach to the tib above by their costal cartilages; ribs 11 to 12 (vertebral) end freely
What are the primary muscles of inspiration? (3)
1) Diaphragm
2) External intercostal
3) Parasternal intercostals
NOTE: Accessory muscles recruited during deep or labored breathing
Is experiation passive or active?
Passive at rest - however, forces expiration uses abdominal and internal intercostals muscles
Which lung has only 2 lobes and why?
L lung because of the heart
What is the Carina?
Split between right an left broncus
What is the respiratory contorl center? (2)
* What do these control centers respond to?
Medulla / Pons (same as the heart)
respond to CO2 levels
Sympathetic NS does what in the lungs?
Bronchodilation and SLIGHT vasoconstriction
Parasympathetic system does what in the lungs?
Bronchoconstriction
What do baroreceptors respond to?
Changes in pressure
* think stretch in arteries
What do chemoreceptors respond to and where are they? (2)
hypoxemia (decrease in oxygenation to vital organs)
Located in carotid and aorta
KNOW: Mucociliary transport
* Cila grab the mucus produced in the trachea by the goblet cells that has captured pathogens and moving it up and away
What does surfactant production do?
Lubricates the alveoli, reducing the tension in the alveioli (note the alveoli are where gas exchange happens so they cant be stuck together, reducing the surface area)
Note, Premature babies can be missing this
Alveoli = little bubbles
What do alveolar macrophages do?
eat virusus
When do mast cells come?
When theres inflammation they come out and alert everything else (lay the cones down in a car wreck)
What two things cause lung inflammation?
Smoking / asthma
For insipration to work we need
* partial pressure difference (high pressure outside –> low pressure inside)
* Alveolar-capillary interface available (gas exchange takes place here)
* Membrane thickness (needs perfect thickness to provide gas exchange)
* Diffusion coefficient (has to be an optimal concentration for diffiusion to occur)
What closes during expiration?
Glottis –> so you don’t get air into belly
NOTE: this is a passive process
Is intrathoracic pressure increased or decreased w/ expiration?
Increased
Pressure inside is more than outside –> so air travels out
