Physiology learning objective exam prep

What are the three broad functions of the blood

Transportation, Regulation, and protection

What does transportation do for blood

gases, nutrients, hormones, and wastes

What does the regulation do in the Broad function of the blood

Temperature, pH, and fluid balance

What are the broad function of Protection for blood

immune defense and clotting

What is the composition of the blood and what does it contain and do?

Plasma 55% containing water, ions, nutrients, hormones and proteins which transports medium. The other part is 45% of formed elements containing RBC, WBC and platelets this then transports gas, immunity and clotting.

What are the three most abundant plasma proteins and the function

Albumin that takes care of osmotic pressure and carrier proteins. The other protein is Globulins that is in charge of antibodies and transport. The last protein being Fibrinogen that does clotting precursor

What is the most abundant formed element

RBC of erythrocytes

What is the difference between the Plasma and serum

The plasma is liquid with clotting factors, and the serum is liquid after clotting with no fibrinogen

What are platelets, where do they come from, and what do they do

They are cell fragments that come from the Megakaryocytes in the bone marrow that then starts clotting forming the platelet plug releasing clotting factors.

Why do blood tubes have different cap colors and why is it important

The reason for this is because there are different additives such as preventing clotting EDTA, heparin, and citrate. The other additives are serum tubes that allow clotting. This is important because of the platelets activate differently depending on the additive

What are the Leukocyte formations and their lineages

Myeloid lineage having RBS, platelets, granulocytes, and monocytes. The other main stem cell is lymphoid lineage having B cells, T cells, and NNK cells

Structure of cardiac muscle, what do they contain and why does it matter

Striated, branched cells with intercalated discs containing Gap junction with electrical sync, Desmosomes with mechanical strength, and lots of mitochondria with high ATP demand. This matters because the heart then acts as a functional syncytium contracting as one coordinate pump

How is Excitation–Contraction Coupling ECC in cardiac muscle similar to Skeletal muscle

Action potential leads to Ca²⁺ release making troponin causing cross-bridge cycling

How is Excitation–Contraction Coupling ECC in cardiac muscle different from Skeletal muscle

Ca²⁺induced Ca²⁺ release (CICR) Ca²⁺ then enters through L-type Ca²⁺ channels making Triggers for more Ca²⁺ from SR and there being long plateau phase due to Ca²⁺ influx, preventing tetany meaning the heart can’t cramp

What is the structure of the smooth muscle

The structure has non-striated spindle-shaped cells having dense bodies instead of Z-discs containing a single nucleus with no troponin and calmodulin-based regulation

What makes single unit and multi-unit different from each other in smooth muscles

Single unite has gap junction that contracts like a sheet ex. Gi tract and the multi-unit has independent fibers that have fine control

What’s the difference between smooth vs. striated muscle contraction

Smooth muscles have slow sustained energy efficiency, and the striated muscle contraction is fast and powerful fatiguing faster

What triggers smooth muscle contraction

Autonomic neurotransmitters, hormones, stretch, local factors, pH, O2, and CO2, and lastly electrical activity such as pace makers

What are the steps for molecular mechanism of smooth muscle contraction

Ca²⁺ enters cell or is released from SR causing Ca²⁺ to bind calmodulin where Ca²⁺calmodulin activates MLCK making MLCK phosphorylates myosin leading to myosin binding to actin causing contraction. Relaxation occurs when MLCP removes phosphate

Whats the difference between Phasic and Tonic smooth muscle

Phasic does quick rhythmic contraction of GI peristalsis and tonic does sustained tension with blood vessels and sphincters

What occurs when myosin regulation is on vs. off in smooth muscle

When on the MLCK is activated by Ca2+ calmodulin and the off switch is MLCP that removes phosphate

What is the intracellular pathway for Ca2+ release

Gq pathway that activates PLC making IIP3 where IP3 then triggers CA2+ release from SR

Why can one neurotransmitter cause opposite effects

The different types of expression and different receptors such as alpha contraction and Beta relaxation

Explain the dual system for human blood circulation

The pulmonary circulation is when the right part of the heart goes to the lungs that then becomes oxygenated. The systemic circulation is the left part of the heart goes to the body tissues that then delivers oxygen. The separation lets there be a higher pressure of systemic flow and a lower pressure of pulmonary flow with efficient oxygen exchange.

what is the only tissue in the body where the arterial blood has a
lower oxygen tension than the venous blood

The lungs that is part of the pulmonary circulation that specifically pulmonary arteries vs. pulmonary veins because the pulmonary arteries carry deoxygenated blood from the right ventricle

how does cardiac muscle receive oxygen and energy

through the coronary arteries leading to a blockage cause a myocardial infarction by loss of contractile tissues, arrhythmias, and pump failure

why the ventricular muscle on the right side of the heart is less thick than the left
ventricular muscle

The reason for this is because the Right ventricle is thinner because its pumping blood to the lungs and the left ventricle is thicker because it is pumping blood to the entire body

Name and identify the positions of the four valves of the heart

The right atrium receives blood then passes through the tricuspid to the right ventricle from the right ventricle it goes through the pulmonary to the lungs and then pours the blood into the Left atrium then through the bicuspid to the left ventricle from the left ventricle through the aorta to the body.

Describe where blood comes from to the left and right atria; likewise, describe where blood goes from the left and right ventricles and the blood vessels they pump to

The blood enters from the Vena cava to the right atrium through the tricuspid to the right ventricle from the right ventricle travelling through the pulmonary arteries to the pulmonary veins leading to the left atrium passing through the tricuspid to the left ventricle going up to the aorta to the body

Using the structure of cardiac muscle, explain how electrical impulses and mechanical synchrony can be achieved to mediate the pumping function of the heart

By the intercalated discs with gap junctions that have electrical coupling. desmosomes, leaving mechanical stability. The functional syncytium helps coordinate contractions

Explain why a heart can beat in the absence of direct nervous system input

by the presence of autorhythmic pacemaker cells, making spontaneous depolarization due to funny Na6 channels and calcium influx, where the autonomic nervous system modulates rates only.

Describe the conduction system of the heart, including its major components

Sinoatrial node to atrioventricular node to Bundle of His to Right/Left bundle branches to Purkinje fibers.The Purkinje fibers cause rapid conduction, and the atrioventricular node delays

Describe the pacemaker [action] potential (impulse curves) of myocardial conducting cells;

Begins at phase 4 with a pacemaker potential having a spontaneous depolarization beginning around -60mV driven by opening funny Na channels (If) that slows Na influx then reducing potassium efflux letting Ca2+enter T type of channels with the membrane slowly depolarizing to threshold of-40mV setting the heart rate at a gradual rise. Then there is phase 0 of depolarization meeting the threshold at mV having a voltage gated Ca2+ rushing into the cell causing an upstroke of action potential. Ultimately leading to phase 3 of repolarization where the Ca channels close and the potassium channels open with the potassium exiting the membrane potential returning back to -60mV

include what channels are responsible for which areas of the curves for pacemaker action potential

The channels involved with phase 4 pacemaker potential having spontaneous depolarization is funny (mixed Na) Na channels HCN channels slow the sodium influx, and the Transient type of calcium channels are transient calcium influx the late phase making the potassium channels close reducing the potassium efflux. The phase 0 depolarization having channels of L-type (long lasting) Ca channels are voltage gated with Ca influx making rapid Ca entry for upstroke no fast Na channel involved. Phase 3 has channels delayed rectified K channels (K efflux) having L-type Ca channels clot making the K leave and the membrane potential to become negative again.

Describe the action potential of cardiac contractile cells; include what channels are responsible for which areas of the curves

When phase 0 is occurring in the bottom there is rapid depolarization with Na going in having the channels be responsible for fast Na. going to phase 1 with inital repolarization moving K out having a channel of Ito transient outward potassium then phase 2 plateau where Ca ions are moving in and the potassium is moving out. The channels are L type Ca and IKr/IKS. Having phase 3 of repolarization with K moving out with key channels of IKR IKS and IK1. The final phase being resting potential having K leak out with a channel of IK1

Compare a cardiac muscle twitch to a skeletal muscle twitch; how and why are their profiles different?

Cardiac twitch has a long refractory period due to plateau preventing tetany and skeletal twitch has a short refractory period that can summate and tetanize.

What are the different types of ECG components

The P wave was atrial depolarization then the QRS complex is where ventricular depolarization. The T wave then starts to ventricular repolarization., and the PR interval for AV nodal delay and the ST segment is the plateau phase

What is the Cardiac cycle

This is one full heartbeat cycle

What is systole

this is contraction

What diastole

This is relaxation of the cycle in the heart

What is EDV

This is end of diastolic which means volume before contraction

What is ESV

This is the end of systolic volume which means its volume after contraction

Be able to map atrial and ventricular systole and diastole to events on an ECG tracing

The atrial systole is the entire P wave to the end of the P wave. then to the Ventricular systole starts at the beginning of QRS once it ends at the beginning of T wave is where the ventricular diastole starts

Define isovolumic contraction

This is when ventricles contract with all valves closed and pressure rises without volume change

What are the different heart sounds

Lub comes from the atrioventricular node and the dub heart of the sound comes from the semilunar valves closing

How us heart rate related to cardiac output

This is CO increasing with heart rate until filling time becomes limiting

How do you calculate stroke volume and cardiac output

SV=EDV-ESV and CO=HR x SV

Describe exercise effects on heart rate

This increases the sympathetic tone and increase venous return then increasing the venous return.

Identify the cardiovascular centers and reflexes

They are all located in the medulla oblongata the centers involved are the cardioaccelerator center, cardioinhibitory center, and vasomotor center having reflexes of baroreceptor, chemoreceptor and Bainbridge

Explain autonomic regulation of resting Heart Rate

The resting Heart rate is dominated by parasympathetic (vagal) tone and the Sinoatrial node with an intrinsic rate of 100bpm and the vagus slowing to 60-80

Describe the autonomic nervous system and its effects on heart rate

Sympathetic increases heart rate if channels are increasing conduction and the parasympathetic decreases heart rate opening potassium channels

Distinguish positive vs negative inotropic factors

The positive factors is sympathetic stimulation, epinephrine and increased Ca and the negatives are acidosis, hypoxia, and beta blockers

Define contractility

Force at a given preload

Define preload

Ventricular stretch end of diastolic volume

Define afterload

This is resistance to ejection such as arterial pressure

Summarize factors affecting Stroke Volume & CO

Stroke volume is influenced by preload, afterload and contractility the CO is influenced by heart rate and stroke volume

Describe cardiac responses to changes in blood flow & pressure

the baroreceptor reflex is then put into work after being sensed by the carotid sinus and aortic arch responding to blood pressure changes because of the stretched arterial walls. If pressure drops fire less, medulla increases sympathetic output increasing everything but if blood pressure rises baroreceptors fires more, medulla increases parasympathetic output decreasing everything. Leading to Bainbridge reflex having the same sensors if blood returning to the heart increases the atria stretches more and increases heart rate to prevent back up in veins but if venous decreases heart rate slows. Lastly leasing to the Frank starling mechanism if preload EDV increases ventricular fiber stretch more, contract by force more and stroke volume increased making the heart pump out what it receives if EDV decreases less stretch weaker contraction and lower stroke volume. Activating the Chemoreceptor Reflex being sensed by carotid bodies and aortic bodies if blood flow is low oxygen drops and CO2 rises the chemoreceptors stimulate sympathetic output increasing heart rate, contractility and vasoconstriction

Bainbridge Reflex — Responds to

Blood Volume Changes FAST

What does the Frank–Starling Mechanism — Respond to

Ventricular filling that’s intrinsic

What does the Chemoreceptor reflex respond too

Blood flow and oxygen levels

What are the long-term responses to changes in blood flow & pressure

If blood pressure stays low for hours or days Kidneys activate RAAS, Increased Blood volume, Increased Venous return, increased Stroke volume, increased Blood pressure