bp + heart + muscular

What is blood pressure?

Force of blood against artery walls.

What is systolic pressure?

Pressure when the ventricles contract.

What is diastolic pressure?

Pressure when the ventricles relax and fill.

Which BP number is systolic?

The top number.

Which BP number is diastolic?

The bottom number.

What is pulse pressure?

Difference between systolic and diastolic pressure.

What is the formula for pulse pressure?

$$PP = SP - DP$$

What is mean arterial pressure (MAP)?

Average pressure driving blood to tissues.

What is the MAP formula?

$$MAP = DP + \frac{PP}{3}$$

What is another MAP formula?

$$MAP = \frac{SP + 2 \times DP}{3}$$

What is the main blood pressure equation?

$$BP = CO \times PR$$

What is cardiac output?

Amount of blood pumped by the heart per minute.

What is the cardiac output equation?

$$CO = HR \times SV$$

What is heart rate?

Number of heartbeats per minute.

What is stroke volume?

Amount of blood pumped per beat.

What is the stroke volume equation?

$$SV = EDV - ESV$$

What is EDV?

Blood in the ventricle after filling.

What is ESV?

Blood left in the ventricle after contraction.

What is peripheral resistance?

Resistance of blood vessels to blood flow.

What usually happens to BP when peripheral resistance increases?

Blood pressure increases.

What is preload?

Ventricular filling before contraction.

What usually increases preload?

Increased venous return.

What is afterload?

Resistance the ventricle pumps against.

What happens to afterload during vasodilation?

It decreases.

What happens when blood pressure suddenly drops?

Sympathetic activity increases.

What happens to heart rate when BP drops?

Heart rate increases.

What happens to contractility when BP drops?

Contractility increases.

What happens to arterioles when BP drops?

They constrict.

Where are the main arterial baroreceptors?

Carotid sinus and aortic arch.

What does RAAS help regulate?

Blood pressure and blood volume.

What starts RAAS?

Reduced blood flow to the kidneys.

What does the kidney release to begin RAAS?

Renin.

What does angiotensin II cause?

Vasoconstriction and aldosterone release.

What does aldosterone increase?

Sodium and water retention.

What does the right side of the heart handle?

Oxygen-poor blood going to the lungs.

What does the left side of the heart handle?

Oxygen-rich blood going to the body.

What does the right atrium do?

Receives blood from the body.

What does the right ventricle do?

Pumps blood to the lungs.

What does the left atrium do?

Receives blood from the lungs.

What does the left ventricle do?

Pumps blood to the body.

What does the septum do?

Separates the right and left sides of the heart.

Which vessels bring blood from the body to the heart?

Superior and inferior vena cava.

Which valve is between the RA and RV?

Tricuspid valve.

Which valve is between the LA and LV?

Mitral or bicuspid valve.

Which valve leads from the RV to the lungs?

Pulmonary valve.

Which valve leads from the LV to the aorta?

Aortic valve.

What do pulmonary arteries carry?

Oxygen-poor blood to the lungs.

What do pulmonary veins carry?

Oxygen-rich blood to the heart.

What is the full blood flow pathway?

$$\text{Body} \rightarrow \text{RA} \rightarrow \text{RV} \rightarrow \text{lungs} \rightarrow \text{LA} \rightarrow \text{LV} \rightarrow \text{body}$$

What is the heart's normal pacemaker?

SA node.

What is the electrical conduction pathway?

$$\text{SA node} \rightarrow \text{AV node} \rightarrow \text{His} \rightarrow \text{branches} \rightarrow \text{Purkinje fibers}$$

What does the SA node do?

Starts the heartbeat.

What does the AV node do?

Delays the signal so ventricles can fill.

What does the bundle of His do?

Carries the signal down the septum.

What do Purkinje fibers do?

Spread the signal through the ventricles.

Which ion causes SA node depolarization?

Calcium entering the cell.

Which ion causes ventricular rapid depolarization?

Sodium entering the cell.

Which ion mainly causes repolarization?

Potassium leaving the cell.

Why do ventricular cells have a calcium plateau?

To prolong contraction and the refractory period.

Why is the long cardiac refractory period important?

It prevents tetanus.

What does an ECG measure?

Electrical activity of the heart.

What does the P wave represent?

Atrial depolarization.

What does the PR interval represent?

Atrial depolarization through start of ventricular depolarization.

What does the QRS complex represent?

Ventricular depolarization.

What does the ST segment represent?

Ventricles remaining depolarized.

What does the T wave represent?

Ventricular repolarization.

What does the QT interval represent?

Ventricular depolarization through repolarization.

Why is atrial repolarization usually not seen?

It is hidden by the QRS complex.

What is systole?

Contraction.

What is diastole?

Relaxation and filling.

Which valves are open during ventricular filling?

AV valves.

Which valves are open during atrial systole?

AV valves.

Which valves are open during isovolumetric contraction?

None.

Which valves are open during ventricular ejection?

Semilunar valves.

Which valves are open during isovolumetric relaxation?

None.

What does isovolumetric mean?

Ventricular volume stays the same.

What causes S1 or "lub"?

AV valves closing.

Which valves make S1?

Mitral and tricuspid valves.

What causes S2 or "dub"?

Semilunar valves closing.

Which valves make S2?

Aortic and pulmonary valves.

What is the Frank-Starling law?

More filling causes a stronger contraction.

What happens to SV when EDV increases?

SV generally increases.

What is the Frank-Starling sequence?

More return $\rightarrow$ more EDV $\rightarrow$ more stretch $\rightarrow$ more SV.

What is the muscle structure order from largest to smallest?

$$\text{Muscle} \rightarrow \text{muscle fiber} \rightarrow \text{myofibril} \rightarrow \text{sarcomere} \rightarrow \text{myofilaments}$$

What is the sarcolemma?

Muscle cell membrane.

What do T-tubules do?

Carry the action potential deep into the muscle.

What does the sarcoplasmic reticulum store?

Calcium.

What is a sarcomere?

Contracting unit from Z disc to Z disc.

What is the thin filament mainly made of?

Actin.

What proteins are also on the thin filament?

Troponin and tropomyosin.

What is the thick filament made of?

Myosin.

What do myosin heads do?

Pull on actin.

What happens to the I band during contraction?

It shortens.

What happens to the A band during contraction?

It stays the same length.

What happens to the H zone during contraction?

It shortens.

What happens to Z discs during contraction?

They move closer together.

Do actin and myosin filaments get shorter?

No, they slide past each other.

What is the neuromuscular junction?

Junction between a motor neuron and muscle fiber.

What neurotransmitter is released at the NMJ?

Acetylcholine (ACh).

What causes ACh release from the neuron?

Calcium entering the neuron terminal.