Gas Exchange and Respiratory Systems

• Gas exchange is vital for all living organisms to obtain oxygen and remove carbon dioxide.
• Organisms can respire through their skin, this allows for gas exchange.
• The avian respiratory system demonstrates efficiency through unidirectional airflow, air sacs connected to the lungs, and crosscurrent gas exchange.
• The human respiratory system includes the nose, pharynx, larynx, trachea, bronchi, and lungs, each with specific roles in respiration.
• Millions of tiny alveoli increase the surface area for gas exchange in the lungs.
• Oxygen is transported around the body by hemoglobin in red blood cells.
• Supplemental oxygen is necessary at high altitudes like Mt. Everest due to the lower partial pressure of oxygen.
• Training and living at high altitudes leads to adaptations like increased red blood cell production, which enhances oxygen delivery.
• The diaphragm and intercostal muscles are critical, and they are key muscles involved in inhalation and exhalation.

Lung Volumes and Capacities

• Vital capacity is the maximum amount of air exhaled after a maximal inhalation.
• Expiratory reserve volume is the extra volume of air that can be exhaled after a normal exhalation.
• Residual volume is the air remaining in the lungs after maximal exhalation.
• Tidal volume is the volume of air moved into or out of the lungs during normal breathing.
• Conditions like bronchitis narrow air passages, which can cause difficulty breathing and reduced oxygen levels.
• Lung transplants and other technologies are available to treat severe respiratory conditions.

Blood Components and Function

• Blood comprises plasma, red blood cells, white blood cells, and platelets.
• Plasma transports nutrients, hormones, and waste.
• Red blood cells carry oxygen, white blood cells fight infection, and platelets assist in blood clotting.
• Hemoglobin, a protein in red blood cells, binds to and transports oxygen.
• Arteries have three layers of tissue: the tunica intima, tunica media, and tunica adventitia, each serving structural and functional roles.
• Veins have a similar structure to arteries but with thinner walls, and their purpose is to return blood to the heart.
• Vasoconstriction is the narrowing of blood vessels.
• Vasodilation is the widening of blood vessels.

Circulatory Circuits

• Systemic circuit carries blood between the heart and the body.
• Cardiac circuit supplies blood to the heart muscle.
• Pulmonary circuit carries blood between the heart and the lungs.
• The hepatic artery supplies the liver with oxygenated blood.
• The renal artery supplies the kidney, and the gastric artery supplies the stomach.
• The human heart has four chambers: two atria and two ventricles.
• Heart valves prevent backflow of blood, ensuring unidirectional flow.
• The pulmonary artery brings blood to the lungs to pick up oxygen.
• Vasodilation of capillaries increases blood flow to tissues.

Blood Flow

• When someone falls into icy waters, blood flow is redirected to vital organs.
• The purpose of this is to conserve heat and maintain core body temperature.
• Valves within veins prevent backflow of blood, especially in the limbs.
• The jugular vein returns blood from the head to the heart.
• An ECG records the electrical activity of the heart over time.
• A normal ECG waveform includes P waves, QRS complexes, and T waves, each corresponding to specific electrical events in the heart.
• ECGs are used in medicine to diagnose heart conditions and monitor heart function.
• A hole in the wall separating the left and right ventricles can cause blood to mix, leading to reduced oxygen delivery to the body.

Cardiac Adaptations

• Endurance athletes have larger and thicker left ventricles to pump more blood efficiently.
• Open circulatory systems have blood that circulates partially within vessels and partially in body cavities.
• Closed circulatory systems have blood that circulates entirely within vessels.
• Fish hearts have two chambers, amphibian hearts have three chambers, and mammalian hearts have four chambers.
• Coronary artery blockage is caused by plaque buildup.
• Blockages happen via atherosclerosis, leading to reduced blood flow to the heart muscle.
• A coronary bypass is a surgical procedure to reroute blood flow around blocked coronary arteries.
• A red blood cell travels from the inferior vena cava to the right atrium, through the tricuspid valve to right ventricle, through the pulmonic valve into the pulmonary artery to the lungs, back through the pulmonary vein into the left atrium, through the mitral valve to the left ventricle, through the aortic valve into the aorta and into the hand.
• Blood pressure measurement involves inflating a cuff and listening for Korotkoff sounds.
• Systolic pressure is the pressure when the heart contracts.
• Diastolic pressure is the pressure when the heart relaxes.
• Normal blood pressure is considered to be around 120/80 mmHg.
• The 'lub' sound in a heartbeat is caused by the closing of the atrioventricular valves.
• The 'dub' sound is caused by the closing of the semilunar valves.
• Atherosclerosis is the buildup of plaque in arteries, leading to reduced blood flow and increased risk of heart attack and stroke.
• Macromolecules include carbohydrates, proteins, and lipids.

Macromolecules

• Monosaccharides are the monomers of carbohydrates.
• Disaccharides are two monosaccharides joined together.
• Polysaccharides are large chains of monosaccharides.
• Examples of foods containing carbohydrates are bread and pasta.
• Amino acids are the monomers of proteins, and examples of foods containing protein are meat and beans.
• Lipids are made of glycerol and fatty acids, and examples of foods containing lipids are oils and butter.
• Carbohydrates provide energy.
• Proteins are for tissue repair.
• Lipids provide energy storage and insulation.
• The digestive tract includes the mouth, esophagus, stomach, small intestine, and large intestine, each with specific functions.
• Villi are small, finger-like projections in the small intestine that increase surface area for absorption.
• Microvilli are even smaller projections on the villi that further increase surface area.
• Peristalsis is the wave-like muscle contractions that move food through the digestive tract.

Accessory Digestive Organs

• The pancreas secretes enzymes and hormones.
• The liver produces bile to aid in fat digestion.
• The gall bladder stores bile.
• Acid reflux is the backflow of stomach acid into the esophagus.
• Stomach ulcers are sores in the stomach lining, often caused by bacterial infection or prolonged use of anti-inflammatory drugs.
• Digestion and respiratory system diagrams show the structures and functions of each system.