Lessons 1 & 2: Transport in Animals and Plants PDF

Lessons 1 and 2: Transport in Animals and Plants General Biology 2 In 1628 William Harvey, an English physician At that time, botanists… …they instead focused their work on the question, “what makes materials move inside plants?”  In 1720 botanists discovered the following: Water travels from...

Lessons 1 and 2: Transport in Animals and Plants General Biology 2 In 1628 William Harvey, an English physician At that time, botanists… …they instead focused their work on the question, “what makes materials move inside plants?”  In 1720 botanists discovered the following: Water travels from the How plants procure gases, roots to the different nutrients, water, and minerals and parts of plants how these are distributed to all parts of the plants Motivation Diagnosis and treatment of diseases Analyzing blood flow patterns can help diagnose cardiovascular issues Understanding drug delivery mechanisms within the body assists in designing better medications Bio-inspired drug delivery systems – nanoparticles designed to mimic the size and targeting mechanisms of red blood cells can deliver drugs selectively to specific tissues, reducing side effects and improving treatment efficacy. In the field of engineering and biomimetics Understanding animal movement and locomotion inspires the development of robots and prosthetics with efficient movement mechanisms Biomimetics or biomimicry is the simulation of the models, systems, and elements of nature for the purpose of solving complex human problems Self-healing coatings: Protect surfaces from scratches and cracks. Self-healing composites: Used in aerospace and automotive applications for increased durability. In the field of engineering and biomimetics (cont.) Knowledge of blood circulation and oxygen transport principles helped develop: Artificial hearts mimic the pumping action of hearts for potential use in medical implants. Pacemakers generate electrical pulses delivered by electrodes to one or more of the chambers of the heart, the upper atria or lower ventricles. Note: Lessons 1 and 2 (next lesson) will show how the transport and gas exchange processes of animals and plants are closely linked in terms of parts and their functions. The Circulatory System of Animals Transport in Animals  1. Identify the main components of the animal circulatory system. 2. Explain the function of each component in blood circulation. Learning 3. Describe the different types of blood cells and their roles. Objectives 4. Differentiate between the pulmonary and systemic circulatory circuits.  One of the most important physiological processes Enables every cell to be nourished and supplied with oxygen Transport Many structural adaptations are evident in certain members of the animal and plant kingdoms (recall our discussion on surface-area-to- volume ratio)  Animals and plants have a lot of differences in terms of the parts involved, however they have a Transport common function of nourishing cells and supplying them with their basic needs.  Other functions include collection and transport of wastes, movement of immune system Transport components, and transport of hormones (endocrine gland secretions in animals) Transport in simple animals Organisms which have a two-cell layer covering, get their supply of gases and excrete wastes via diffusion In simple animals like sponges and cnidarians – gas exchange happens between the water from the environment and the circulating body fluid in the organism In sponges (animals that belong to Phylum Porifera), water passes through porocytes to the spongocoel, the central cavity Transport in simple animals (cont.) In cnidarians such as the hydra, all their cells are in contact with the water, which contains oxygen and nutrients. The key player in transport for cnidarians is their single internal cavity called the gastrovascular cavity. This cavity acts as both a digestive system and a rudimentary circulatory system. Food enters through the mouth, is digested in the cavity, and nutrients are absorbed by the cells lining the cavity. Transport in simple animals (cont.) In roundworms (also known as nematodes) which are pseudocoelomates, body fluid is used for circulation. This is accomplished by the movement of the body against the fluids that are directly in contact with the tissues and organs. No distinct circulatory/transport organs: no organs like hearts, blood vessels, or blood. Pseudocoelom: their body cavity, called the pseudocoelom, is fluid-filled but not enclosed by a separate lining like in true coelomates. Diffusion-based transport: Nutrients, oxygen, and waste products move through the body fluid in the pseudocoelom by diffusion Simple body structure: Due to their small size and simple body organization with only a few thousand cells, diffusion suffices for their needs. Muscular movement: Body wall muscles help mix the fluid in the pseudocoelom, aiding in diffusion and waste removal.  The Main Types of Circulation in Animals Open Circulatory System The circulating fluid or hemolymph does not pass through enclosed tubes (blood vessels); instead, it is pumped by the heart to a network of channels and cavities (hemocoels) It is also through the hemocoels where gas exchange takes place Closed Circulatory System The blood or circulating fluid passes within blood vessels that transport blood away from and back to the heart  Insects and other arthropods are examples of animals with an open circulatory system The heart pumps blood into the small cavities or hemocoels, where gas exchange between tissues and the hemolymph also take place. Earthworms are examples of invertebrates with a closed type circulation They all have a heart and blood vessels through which the blood circulates The Human Circulatory System Heart A muscular organ that pumps blood to all parts of the body One of the organs that develop in an embryo about four weeks after fertilization On average, the heart beats around 2.5 billion times without interruption Heart (cont.) Composed of cardiac muscle, an involuntary striated type of muscle About the size of a fist It has its own cavity, the pericardial cavity, and it is covered by the pericardium A septum divides the heart into two sides The right side receives deoxygenated blood from different parts of the body The left side receives oxygenated blood from the lungs Heart (cont.) Each side of the heart is also divided into the upper and lower chambers The upper chambers are called atria while the lower chambers are called ventricles One-way valves called atrio-ventricular valves are located between the upper and lower chambers Heart (cont.) Flow of blood: Blood enters through the superior and inferior vena cava -> blood fills the right atrium -> tricuspid valve (found between the right atrium and the right ventricle) opens, and blood enters the right ventricle, tricuspid valve closes to prevent regurgitation -> The right ventricle contracts, pumping blood through the pulmonary valve into the pulmonary arteries, and then flows into the capillaries of the air sacs in the lungs (this is where the blood gives off carbon dioxide and take in oxygen) -> the oxygenated blood flows through the pulmonary veins into the left atrium -> with pressure buildup, the mitral valve opens and oxygenated blood is pumped into the left ventricle -> The left ventricle contracts, the strongest chamber, pumping blood through the aortic valve into the aorta FYI: The "lub dub" sound This characteristic sound of a heartbeat comes from the closing of the heart valves: "Lub": The lower-pitched sound occurs when the tricuspid and mitral valves close at the end of ventricular filling (atria contracting). "Dub": The higher-pitched sound occurs when the aortic and pulmonary valves close at the end of ventricular contraction (ventricles pumping). Blood The internal circulating medium of the human body Plays a vital role in our body, performing several crucial functions like transporting oxygen, nutrients, and nitrogenous waste products Consists of 55% plasma, 45% blood cells Blood (cont.) Red blood cells (erythrocytes) transport oxygen and carbon dioxide These disc-shaped cells are packed with hemoglobin, a protein that binds to oxygen. They are produced in the bone marrow and have a lifespan of about 120 days. Blood (cont.) White blood cells (leukocytes) function for defense and immunity Neutrophils: Phagocytize (engulf and destroy) bacteria and other pathogens. Lymphocytes: Produce antibodies to target specific pathogens. Monocytes: Become macrophages that phagocytize pathogens and debris. Eosinophils: Attack parasitic infections and allergic reactions. Basophils: Release chemicals involved in allergic reactions and inflammation. Blood (cont.) Blood platelets (thrombocytes) are essential in blood clotting These small, cell fragments play a crucial role in blood clotting. They clump together at the site of an injury, forming a plug to prevent blood loss. Blood (cont.) Plasma is composed of water (about 90%) and other substances like: Proteins: albumin (regulates fluid balance), globulins (fight infection), clotting factors (for wound healing) Electrolytes: sodium, potassium, calcium, chloride (maintain electrical balance and cell function) Hormones: chemical messengers for various bodily functions Nutrients: sugars, amino acids, lipids (transported to cells) Waste products: urea, uric acid, carbon dioxide (carried to organs for removal) Blood Vessels Serve as highways through which blood is circulated in the body There are three types: arteries, veins, and capillaries Arteries are thick-walled vessels which carry oxygenated blood except the…? Thick walls counteract the pressure exerted by the contraction of the heart Aorta is the largest artery Blood Vessels (cont.) Veins are thinner vessels compared to arteries and they carry deoxygenated blood toward the heart, except for the…? There are two large veins in the body, the superior and inferior venae cavae (singular, vena cava) Blood Vessels (cont.) Capillaries are the abundant microscopic blood vessels that carry blood throughout the tissues and organs, connecting the small arteries and veins Very thin, made up of only one layer of cells Serve as sites through which materials between the blood and cells are exchanged Because they are very thin, diffusion of materials across their walls readily take place Arteries Commonly Associated With Health Conditions Aorta: The largest artery in the body, originating from the left ventricle of the heart and branching out to deliver oxygenated blood throughout the body. Carotid arteries: Located on either side of the neck, carrying blood to the brain and face. Brachial artery: Located in the upper arm, supplying blood to the forearm and hand. Femoral artery: Located in the groin, supplying blood to the leg and foot. Coronary arteries: Branching from the aorta, supplying blood to the heart muscle itself. Blockages in these arteries can lead to heart attacks. Renal arteries: Supplying blood to the kidneys for filtering and waste removal. Veins Commonly Associated With Health Conditions Vena cava: Two large veins (superior and inferior) that return deoxygenated blood from the body to the right atrium of the heart. Jugular veins: Located on either side of the neck, draining blood from the head and brain. Subclavian veins: Located in the chest, draining blood from the arms and head. Femoral vein: Located in the groin, mirroring the femoral artery and draining blood from the leg and foot. Portal vein: Carries blood rich in nutrients absorbed from the digestive system to the liver for processing. Valves (tricuspid, pulmonary, mitral or bicuspid, and aortic) These are flaps of tissues that prevent the backward flow or regurgitation of blood Located between the atrium and ventricle, and at the base of arteries attached to the heart The closure of valves create the sounds heard during auscultation, a medical term for the act of listening to internal sounds of the body that usually uses a stethoscope Patterns of Circulation The Two Main Circulations Pulmonary circulation is the movement of blood from the heart to the lungs, and back to the heart. Its primary function is to transport deoxygenated blood from the body to the lungs for oxygenation and then return oxygenated blood back to the heart. Systemic circulation follows pulmonary circulation. It is responsible for distributing oxygenated blood from the heart to all the tissues and organs of the body, delivering oxygen and nutrients, and collecting carbon dioxide for return to the heart. Pulmonary Circulation Pathway 1. Deoxygenated blood from the body flows into the right atrium of the heart through the superior and inferior vena cava. 2. The right atrium contracts, sending blood into the right ventricle. 3. The right ventricle pumps the deoxygenated blood into the pulmonary arteries. 4. The pulmonary arteries carry the blood to the lungs. 5. In the lungs, carbon dioxide is exchanged for oxygen in the alveoli through the process of respiration. 6. Oxygenated blood returns to the heart via the pulmonary veins. 7. The pulmonary veins deliver oxygenated blood to the left atrium. Systemic Circulation Pathway 1. Oxygenated blood from the left atrium enters the left ventricle. 2. The left ventricle contracts, pumping the oxygenated blood into the aorta. 3. The aorta carries the oxygenated blood to various arteries that branch out to supply oxygen and nutrients to the body's tissues and organs. 4. Capillaries facilitate the exchange of oxygen, nutrients, and waste products between the blood and the body's cells. 5. Deoxygenated blood returns to the heart via the systemic veins, specifically the superior and inferior vena cava, entering the right atrium. The Vascular System of Plants Transport in Plants  1. Appreciate the importance of transport in plants. 2. Describe how water and minerals are moved from the soil to the different parts of a plant. 3. Explain how food is distributed in plants. Learning 4. Understand the concepts of diffusion, Objectives transpiration, and translocation and their importance in transporting substances within plant cells. Pathways Pathways for Water and Minerals in Plants Land plants (embryophytes) are classified as either nonvascular plants (bryophytes) or vascular plants (tracheophytes) The vascular system has 2 types of tissues Xylem are tissues that help transport water and minerals Phloem are tissues that help transport the products of photosynthesis EXAMPLES OF BRYOPHYTES Pathways for Water and Minerals in Plants (cont.) Nonvascular plants (organisms that belong to Phylum Bryophyta) cannot grow high above the ground since they do not have xylem and phloem tissues 3 to 6 cm tall Pathways for Water and Minerals in Plants (cont.) There are 3 pathways through which water & minerals pass to reach the xylem tissues along the central part of the roots Apoplast pathway: movement through the cell walls and the spaces between cells Symplast pathway: movement through a continuum of cytoplasm between cells called plasmodesma (plural, plasmodesmata) Transmembrane pathway: transport between cells across the membranes of vacuoles within cells  Our previous topic on cellular transport, specifically passive transport, will help you understand Note: this topic better Also, try to recall your Chemistry/Earth Science lesson on cohesion and adhesion Xylem Transport Transpiration (also called evapotranspiration) or the release of water vapor through openings in the leaves causes a pressure that pulls the water up Transpiration happens partly because of the cohesive forces between water molecules and the adhesive forces between water molecules and the walls of xylem vessels Xylem Transport (cont.) Osmosis and diffusion are also passive forces that help molecules move from one cell to another How about the main factor that regulates the transport process in plants? The answer is water potential Xylem Transport (cont.) Water potential represents free energy or the potential to do work Water moves from a cell or solution with higher water potential to a cell or solution with lower water potential Recall our discussion on osmosis, a type of passive transport Xylem Transport (cont.) What happens when the rate of transpiration slows down (such as during nighttime)? Mineral ions accumulate in the roots -> water enters the roots via osmosis -> root pressure increases -> the increase in root pressure could sometimes be so strong that it can force water to move up to the leaves and out the hydathodes (specialized pores found at the tip of leaf margins) The process mentioned above is called guttation Phloem Transport The process that transport food in plants is called translocation The pressure-flow model/hypothesis demonstrates the relevance of turgor pressure on phloem transport by showing how the pressure gradients generated by osmosis- driven water movement into the phloem tubes create positive pressure (turgor pressure), which propels the flow of sap containing sugars and other nutrients from source to sink regions in the plant. So how does the vascular system work? (1) The roots absorb the water and minerals from the soil. -> (2) Water and minerals travel to the stem through the xylem tissues. -> (3) After going through the stem, water enters the leaves and other parts that need water for photosynthesis. -> (4) The sugar (made from photosynthesis) goes to different parts of the plant through phloem tissues. Note: amino acids, hormones, and signaling molecules are also transported through the phloem tissues. These substances are made by other cellular processes (for example, lipid/protein synthesis via the endomembrane system within specialized cells makes hormones). Check Your Understanding 1. What are the differences between transpiration and translocation? 2. What is the relevance of cohesion, adhesion, and water potential on xylem transport? 3. How does the pressure-flow theory demonstrate the relevance of turgor pressure on phloem transport in plants? 4. What are radial rays and in what specific plants are they found? 5. Show the differences between apoplast, symplast, and transmembrane pathways in a drawing. Label your drawing. Science Fact! If the RBCs from one person were to be stacked toward the sky, they would reach 31,000 miles. Lab Activity Reminders Your teacher will roam around the room while the experiments are ongoing. For every mistake committed while doing the experiments, 5 points will be deducted from your total score so make sure you read and understood the procedures. Cut the stems of both flowers so that they will have the same length and make sure the petals will not get wet before, during, and after the lab activity 1 experiment. Remove the leaves before the start of experiment #1. End