CVR Physiology

Calcium moves in and out of the cytosol during each action potential, influencing the cell's electrical activity.

Gradual depolarization of the cell, leading to an action potential.

Rapid depolarization caused by the influx of calcium into the cell.

Calcium entering the cell triggers more calcium release from the sarcoplasmic reticulum.

A graphical recording of the electrical activity of the heart.

ECG wave representing atrial muscle depolarization.

Direction of electrical impulse during an action potential.

The maximum rate your body can take in, transport, and use oxygen during intense exercise. It reflects your overall fitness level.

A unit for measuring how much energy your body uses during an activity compared to resting.

Categorizations of exercise intensity based on how hard your body is working. They include moderate, heavy, severe, and extreme.

Specialized cells in your blood vessels that detect changes in oxygen, carbon dioxide, and pH levels, influencing your heart rate and breathing.

Sensory receptors in your muscles and joints that sense position, movement, and force, providing feedback to your brain for coordination.

A mechanism where the signals from the cardiovascular and respiratory centers in your brain regulate heart rate and breathing.

The amount of air you breathe in or out with each normal breath.

The number of breaths you take in one minute.

Exercise intensity domains are categorized as moderate, heavy, severe, and extreme. These categories reflect the level of effort your body exerts during exercise.

When exercise begins, the parasympathetic nervous system reduces activity while the sympathetic system increases. This signals the need for more oxygen in the muscles. Signals are sent to increase heart rate and ventilation, delivering more oxygen to working muscles.

A hormonal mechanism that helps regulate blood pressure. It involves the production and release of renin (from kidneys), which triggers a cascade of events leading to the formation of angiotensin II (a powerful vasoconstrictor) and aldosterone (a hormone that promotes sodium retention).

Small blood vessels that regulate blood flow to different tissues. They are essential for controlling blood pressure and distribution of blood.

When arterioles constrict (narrow), they increase resistance to blood flow, leading to decreased blood flow. When they dilate (widen), they decrease resistance, allowing for increased blood flow.

Arterial pressure is determined by the product of cardiac output (amount of blood pumped by the heart per minute) and peripheral resistance (阻力) (resistance to blood flow in the blood vessels).

Blood pressure tends to increase with age due to several factors including: increased arterial stiffness, decreased baroreceptor sensitivity, increased responsiveness to the sympathetic nervous system (SNS), and alterations in the renin-angiotensin-aldosterone (RAA) system.

High blood pressure caused by an underlying medical condition, rather than genetic or lifestyle factors. Examples include kidney disease, anatomical issues like coarction of the aorta (narrowing of the aorta), or chronic changes in blood vessel structure.

High blood pressure can lead to several health issues, including stroke, damage to eye capillaries, edema (swelling), renal (kidney) failure, injury to artery walls, and heart failure.

A condition where fatty deposits (plaque) build up inside the arteries, narrowing them and restricting blood flow. It's a major contributor to heart disease.

Atherosclerosis starts with injury to the artery epithelium. In response, leukocytes (white blood cells) create an inflammatory response, leading to retention and oxidation of lipoproteins. Monocytes (type of white blood cell) turn into macrophages that engulf low-density lipoproteins (LDL), contributing to plaque buildup.

The phenomenon where a decrease in blood pH (increased acidity) reduces hemoglobin's affinity for oxygen, leading to increased oxygen release to tissues.

High CO2 levels in the blood decrease hemoglobin's affinity for oxygen, promoting oxygen release. Low CO2 levels increase affinity, favoring oxygen uptake.

Elevated temperatures lower hemoglobin's affinity for oxygen, meaning more oxygen is released to tissues. Lower temperatures increase affinity.

2,3 Bisphosphoglycerate (2,3 BPG) is a molecule within red blood cells that binds to hemoglobin, reducing its affinity for oxygen and promoting oxygen delivery to tissues.

CO2 is transported in the blood mainly as bicarbonate ions (HCO3-) formed by the reaction of CO2 with water inside red blood cells. This process also generates hydrogen ions (H+), contributing to the Bohr effect.

The total volume of air inhaled and exhaled per minute. Calculated by multiplying tidal volume (air inhaled per breath) by breathing frequency (breaths per minute).

The amount of blood pumped out of the heart with each beat. It increases during exercise, plateauing at around 40-60% of VO2max (maximum oxygen uptake).

Systolic blood pressure increases during exercise, while diastolic blood pressure remains relatively unchanged.

A test that assesses the function of the cardiopulmonary system, including the heart, lungs, and muscles responsible for breathing, by measuring gas exchange, breathing rate, blood pressure, heart rate, and ECG.

Hemoglobin is an allosteric protein, meaning its shape changes in response to the presence of oxygen. This allows it to bind oxygen efficiently.

Hemoglobin consists of two alpha and two beta chains, each containing a heme-iron complex. This iron complex binds to oxygen.

Fetal hemoglobin is different from adult hemoglobin, allowing it to bind oxygen more effectively in the womb's low oxygen environment.

Hemoglobin's ability to bind oxygen depends on the partial pressure of oxygen. In the lungs, high oxygen levels make hemoglobin almost fully saturated. In veins, lower oxygen levels cause hemoglobin to release some oxygen.

Oxyhemoglobin is the form of hemoglobin bound to oxygen. Deoxyhemoglobin is the form without oxygen. Both have different structures.

Hemoglobin acts like a transport vehicle for oxygen. It picks up oxygen in the lungs and delivers it to the body's cells where oxygen levels are low.