Animal Respiration

• Breathing involves inhaling oxygen and exhaling carbon dioxide.
• Cellular respiration is the process of using oxygen to break down sugar and release carbon dioxide.

Respiration in Different Animals

• Animals use various structures, known as respiratory surfaces, for gas exchange.
• Earthworms: Oxygen enters through capillaries in their skin.
• Gills: Outfoldings extending from the body, immersed in water.
• Lungs: Internal sacs, heavily subdivided, found in land vertebrates.

Human Respiratory System

• Lungs are located in the thoracic cavity, protected by the rib cage.
• The muscular diaphragm below the lungs aids in ventilation.
• Air travels through the nasal cavity, pharynx, larynx, trachea, two bronchi, bronchioles, and alveoli.
• Oxygen diffuses from air in the alveoli into the thin epithelium lining the air sac, then to blood capillaries.
• Carbon dioxide diffuses from blood capillaries into the alveoli's epithelium to be exhaled.
• Hemoglobin, a respiratory pigment, changes color when carrying oxygen.

Circulatory Systems

• Circulatory systems transport nutrients, gases, and waste materials.
• Components include a muscular pump (heart), circulatory fluid, and interconnecting tubes (vessels).
• Open-circulatory system: Fluid is not restricted to vessels; no separate circulatory and interstitial fluid.
• The heart pumps hemolymph to distribute body fluids.
• Closed-circulatory system: Blood is restricted inside vessels, separate from interstitial fluid.
• Arteries: Carry blood away from the heart.
• Veins: Carry blood back to the heart.
• Capillaries: Connect arteries and veins to tissues.

Human Circulatory System

• The network of blood vessels and the heart moves blood throughout the body.
• The human heart has four chambers: two atria (receive blood) and two ventricles (pump blood).
• Valves include atrioventricular valves and semilunar valves, which prevent backflow of blood.
• Oxygen-poor blood returns to the heart, is pumped to the lungs for gas exchange, and oxygen-rich blood is then distributed to the body.
• Oxygen-poor blood is pumped from the right ventricle to both sides of the lungs via pulmonary arteries.
• After gas exchange, blood becomes oxygenated in the capillaries.
• Oxygenated blood returns to the left atrium through pulmonary veins.
• The left atrium pumps oxygenated blood to the left ventricle, which pumps it to the rest of the body through the aorta.
• Blood reaches capillaries in different parts of the body.
• Oxygen-poor blood from the body's upper and lower parts returns to the heart via the superior and inferior vena cava to the right atrium and ventricle, repeating the cycle.

Blood Vessels

• Blood vessels transport materials to different parts of the body.
• Blood carries oxygen and nutrients to tissue cells, transports carbon dioxide to the lungs, and transports other metabolic wastes to the kidneys.
• Material exchange occurs only in the capillaries whose single-layered epithelial cells allows molecules to pass through.
• Arteries, arterioles, veins, and venules have thicker walls made of three cell layers, preventing diffusion
• Arteries have thicker walls than veins
• Connective tissue is made of 55% plasma liquid, 45% blood cells and other cells dissolved in the fluid.
• Plasma is 90% water with ions, salts and proteins to help immunity
• Cellular components found in plasma:
• Red blood cells- transport oxygen
• White blood cells- immunity
• Platelets- blood clotting

Heart Conditions

• The cardiac cycle consists of rhythmic contraction (systole) and relaxation (diastole).
• Contraction pumps blood and relaxation receives blood
• One cycle lasts 0.8 seconds, a normal beat is 72
• Blood pressure is measured using a sphygmomanometer.
• Normal healthy blood pressure is 120/70 (systolic/diastolic).
• Blood pressure higher than normal indicates cardiovascular disease such as hypertension.
• Cardiovascular disease occurs when fat deposits (plaque) accumulate in the heart and blood vessels.

Plant Transport

• Plants produce sugar through photosynthesis using carbon dioxide, oxygen, and hydrogen.
• Carbon dioxide from the air produces oxygen and carbon, and hydrogen is made from water.
• Sugar products are the source of raw materials for synthesizing other organic molecules, like carbohydrates.
• Plants undergo cellular respiration, breaking down sugar for energy production.

Water and Solute Transport

• Water and solutes enter root hairs from the soil and travel through different routes.
• One route (apoplast) goes through cell walls and extracellular spaces.
• Another route (symplast) goes through plasmodesma, cell wall openings from one cell to another, until reaching the endodermis, innermost layer in the cortex.
• The Casparian strip, a waxy belt, stops harmful substances from reaching the vascular tissue.
• Xylem consists of tube-like cells that die at maturity, which forms a continuous tube where water and minerals pass through
• Water and dissolved minerals are called xylem sap.
• At the root level, organic ions stored in the endodermis may help push water
• Transpiration is the evaporation of water molecules from the surface of leaves.
• Cohesion is the bonding together of similar molecules.
• Adhesion is when unlike molecules attach to each other
• This process is known as the transpiration-cohesion-tension mechanism or transpirational pull.
• Stomata are openings on the leaf surface controlled by guard cells.

Sugar Transport

• Phloem tissue transports photosynthetic products and is made up of living cells connected to each other.
• The cells have sieve plates on the end that allows phloem sap to move continuously.
• Phloem sap travels from a sugar source (produces sugar) to a sugar sink (breaks down or stores sugar).
• Pressure flow is responsible for the movement from sugar source to sugar sink.