Physiology of Pulmonary and Autonomic Systems

<p>In the aortic arch and carotid arteries (D)</p> Signup and view all the answers

<p>Discontinuous capillaries (B)</p> Signup and view all the answers

<p>Sensory input (B)</p> Signup and view all the answers

<p>Monitor blood volume (A)</p> Signup and view all the answers

<p>Through protein channels called aquaporins (D)</p> Signup and view all the answers

<p>Pulmonary vasoconstriction leading to pulmonary hypertension (A)</p> Signup and view all the answers

<p>Relaxation of smooth muscle and vasodilation (A)</p> Signup and view all the answers

<p>Increased heart rate and increased breathing rate (C)</p> Signup and view all the answers

<p>To regulate skin blood flow for thermoregulation (B)</p> Signup and view all the answers

<p>Fingers and toes (B)</p> Signup and view all the answers

<p>By regulating heart rate and respiratory neurons (B)</p> Signup and view all the answers

<p>Dilation of arterio-venous anastomoses to increase skin blood flow (C)</p> Signup and view all the answers

<p>Fluid produced in capillaries exceeds fluid removed (A)</p> Signup and view all the answers

<p>Capillary hydrostatic pressure and osmotic pressure (B), Colloid osmotic pressure of plasma and interstitial pressure (C)</p> Signup and view all the answers

<p>Rate of diffusion is proportional to the concentration gradient (D)</p> Signup and view all the answers

<p>It increases due to alternating muscle contractions (B)</p> Signup and view all the answers

<p>Venous blood pools in the legs (A)</p> Signup and view all the answers

<p>Circadian rhythms and activity changes (A)</p> Signup and view all the answers

<p>Muscle compression leads to peripheral vasoconstriction and impaired blood flow (D)</p> Signup and view all the answers

<p>To drain excess fluid back to the venous system (D)</p> Signup and view all the answers

<p>Increase in pressure difference (A)</p> Signup and view all the answers

<p>Increase in vessel compliance (A)</p> Signup and view all the answers

<p>Vessel radius decreases (A)</p> Signup and view all the answers

<p>Degree of stretch in response to pressure (D)</p> Signup and view all the answers

<p>Metabolite-induced vasodilation (A)</p> Signup and view all the answers

<p>Increases in blood flow velocity follow relaxation of muscle (A)</p> Signup and view all the answers

<p>They activate voltage-gated channels regulating vessel contraction (A)</p> Signup and view all the answers

<p>Intrinsic is local; extrinsic involves neurohormonal systems (C)</p> Signup and view all the answers

<p>Influx of Ca2+ ions (A)</p> Signup and view all the answers

<p>Phase II (C)</p> Signup and view all the answers

<p>Ventricular depolarization (D)</p> Signup and view all the answers

<p>Transmits electrical impulses to the atria (D)</p> Signup and view all the answers

<p>Resting membrane potential is reached (C)</p> Signup and view all the answers

<p>Isovolumetric relaxation phase (C)</p> Signup and view all the answers

<p>Prevents continuous contraction or tetanus (A)</p> Signup and view all the answers

<p>Delay at the AV node during atrial depolarization (B)</p> Signup and view all the answers

<p>Isovolumetric relaxation (A)</p> Signup and view all the answers

<p>Thick walls with lots of elastin (D)</p> Signup and view all the answers

<p>Increases preload, enhancing contraction energy (A)</p> Signup and view all the answers

<p>Capillaries (D)</p> Signup and view all the answers

<p>The aortic valve opens (A)</p> Signup and view all the answers

<p>To act as a physiological pacemaker (D)</p> Signup and view all the answers

<p>CO = SV × HR (D)</p> Signup and view all the answers

<p>The heart relaxes to allow ventricular filling (B)</p> Signup and view all the answers

<p>The largest volume of blood in the ventricles (D)</p> Signup and view all the answers

<p>It increases heart rate (A)</p> Signup and view all the answers

Low oxygen levels in the lungs, causing vasoconstriction of pulmonary blood vessels.

Balancing air flow (ventilation) with blood flow (perfusion) in the lungs.

Noradrenaline (released by the sympathetic nervous system) causes vasoconstriction by binding to alpha-adrenoreceptors on smooth muscle cells, leading to contraction.

Adrenaline (released by the sympathetic nervous system) causes vasodilation by binding to beta-adrenoreceptors on smooth muscle cells, leading to relaxation.

A feedback mechanism that regulates blood pressure. Baroreceptors detect changes in blood pressure and send signals to the medulla to adjust heart rate.

Located in veins, they monitor blood volume and pressure.

Sensors in arteries responsible for detecting changes in blood oxygen, carbon dioxide, and pH.

The most common type of capillary, with a continuous wall of endothelial cells with no gaps, allowing the passage of small molecules but not blood cells.

Capillaries with pores in the endothelial cells, allowing for the filtration of blood and other fluids like urine.

Capillaries with large gaps between endothelial cells, allowing the passage of both fluids and large molecules, including blood cells.

The idea that the brain anticipates exercise and sends signals to increase heart rate and breathing rate before physical activity begins.

The autonomic nervous system, controlled by the brain, influences the heart and respiratory system to prepare for exercise.

Skin on the fingers, toes, palms, and soles, involved in thermoregulation and heat loss.

Special blood vessels in acral skin that dilate to increase blood flow and promote heat loss.

Acral skin, due to its arterio-venous anastomoses, plays a crucial role in regulating body temperature by increasing blood flow to the surface to promote heat loss.

Describes how substances move across membranes based on concentration differences, surface area, and membrane thickness.

The rate at which substances move across a capillary wall.

Pressure differences that drive fluid movement across capillary walls.

Capillary pressure and interstitial pressure.

Colloid osmotic pressure of plasma.

Excess fluid in the interstitium, causing swelling.

How the body reacts to postural changes.

The mechanism that keeps blood pressure stable during exercise.

Describes the relationship between pressure difference, vessel radius, length, and fluid viscosity, determining the flow rate of blood.

An increase in the diameter of a blood vessel, leading to increased blood flow.

A decrease in the diameter of a blood vessel, reducing blood flow.

Blood vessels automatically constrict in response to increased pressure, helping to regulate blood flow.

A blood vessel's ability to stretch in response to pressure change.

The ability of a blood vessel, especially veins, to hold a large volume of blood.

Increased blood flow to active tissues, driven by local metabolites.

Sustained blood flow increase to muscles after exercise, due to lingering metabolites.

The sinoatrial node (SA node) is the pacemaker of the heart. It initiates the electrical impulses that trigger heart contractions.

The atrioventricular node (AV node) delays the electrical impulse briefly, allowing the atria to contract before the ventricles.

The bundle of His transmits the electrical impulse from the AV node to the ventricles.

Phase 0 is the rapid depolarization phase. This occurs when voltage-gated sodium channels open, allowing sodium ions to rush into the cell, causing a sudden increase in membrane potential.

The plateau phase (Phase 2) is characterized by a prolonged period where the membrane potential remains relatively stable. This is due to the slow influx of calcium ions and a decreased potassium permeability.

The plateau phase is essential for cardiac muscle contraction. It allows for a prolonged influx of calcium ions, which triggers the release of more calcium from the sarcoplasmic reticulum, initiating contraction.

The P wave represents atrial depolarization, the electrical activity that spreads through the atria before contraction.

The QRS complex represents ventricular depolarization, the electrical activity that triggers the ventricles to contract.

This marks the end of the ejection phase and the beginning of isovolumetric relaxation. Ventricular pressure becomes lower than aortic pressure.

Ventricular pressure drops below atrial pressure, allowing blood to passively flow into the ventricle during diastole.

The force of contraction of a cardiac muscle fiber is proportional to the initial resting length. Greater preload leads to greater energy of contraction.

Arterioles are described as resistance vessels because they have a high resistance to blood flow due to their small diameter and thick smooth muscle layer.

Veins are capacitance vessels because they can hold a large volume of blood, acting as a reservoir before returning blood to the heart.

The amount of blood pumped by the heart per minute. It's calculated by multiplying stroke volume (SV) by heart rate (HR).

The relaxation phase of the heart cycle, when the ventricles fill with blood.

The contraction phase of the heart cycle, when the ventricles pump blood out.

End Systolic Volume. The minimum volume of blood remaining in the ventricle after contraction (systole).