Grade 10 Science Notes - Hughes Tam - PDF
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Hughes Tam
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These notes cover the functioning of the human body's various systems, like the circulatory, respiratory, and digestive systems. It also describes the organization of cells, tissues, organs, and organ systems. Topics include homeostasis and how different systems contribute to maintaining balance within the body.
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our body is said to be in “homeostasis” when there is a healthy balance in its internal Y conditions and processes (body temperature, blood pressure, heart rate, breathing rate). Explain how the circulatory, respiratory, digestive, and nervous systems contribute to homeostasis. ...
our body is said to be in “homeostasis” when there is a healthy balance in its internal Y conditions and processes (body temperature, blood pressure, heart rate, breathing rate). Explain how the circulatory, respiratory, digestive, and nervous systems contribute to homeostasis. Respiratory System: ○ Brings oxygen into the body. ○ Removes carbon dioxide. Digestive System: ○ Brings nutrients into the body. ○ Excretes waste. Circulatory System: ○ Transports nutrients, oxygen, and carbon dioxide. ○ Maintains blood pressure and heart rate. ○ Regulates body temperature. Nervous System: ○ Controls all other systems in various ways. Direct Control: Breathing, appetite, and heart rate. Indirect Control: Waste removal, body temperature,and water levels. ○ Ensures all parts of the body receive what they need to function effectively. The 4 types of joints 3.1 - The Hierarchy of Structure in Animals 1. Multicellular Organisms Animals are made up of many specialised types of cells, each designed for specific functions. Examples of Specialised Cells S tinging cells(jellyfish): Capture prey. Light-emitting cells(female fireflies): Attract mates. Other specialised cells: ○ Muscle cells ○ Bone cells ○ Blood cells ○ Sensory cells: Detect sights, sounds, and odours. 2. Single-Celled vs. Multicellular Organisms ingle-celled organisms(e.g., bacteria, blue-greenalgae): Function independently and do not rely on S other cells. Multicellular organisms: Specialised cells cannotsurvive on their own. A single bone, hair, or stomach cell will die if separated from surrounding cells. Cells work together as part of a larger group to form the body of the organism. 3. Role of Cells in Complex Organisms The body of large animals may contain trillions of cells. T hese cells work collectively to enable survival and reproduction. Specialised cells perform key tasks such as feeding, breathing, moving, and reproducing. 4. Complexity of Animal Bodies Levels of complexity vary among animals: S imple body structures: Sponges. Moderately complex structures: Slugs and snails. Highly complex structures: Vertebrates (animals withbackbones, such as birds). Conclusion pecialised cells in multicellular organisms depend on one another. Together, they form a highly S organised system that allows animals to perform essential life functions. 1. Hierarchy of Organisation ll animals, despite their differences in appearance, are made up of cells organised into different levels. A These levels form ahierarchy: M ost complexstructures are at the top. Least complexstructures are at the bottom. The hierarchy includes: . 1 ells C 2. Tissues 3. Organs 4. Organ systems 5. Organism 2. Example: White-Tailed Deer To understand the hierarchy, consider thewhite-taileddeer: Level 1: Cells S implest level of organisation. Example: A single heart muscle cell. Heart muscle cells are branched to connect to other cells. Level 2: Tissues G roups of specialised cells working together. Example: Heart muscle tissue. Made up of heart muscle cells. Level 3: Organs M ade oftwo or more types of tissuesworking togetherto perform a function. Example: The heart. ○ Includesmuscle tissue,nerve tissue, andconnective tissue. Level 4: Organ Systems G roups of organs and structures working together to perform a vital body function. Example: The circulatory system. ○ Includes: Heart (pumps blood) Blood vessels (arteries and veins) Blood (transports oxygen and nutrients). Level 5: Organism T he complete living being made up of many organ systems. Example: The white-tailed deer. 3. Importance of the Hierarchy The functioning of the whole organism depends on this hierarchy: O rgan systemsrely on specificorgansto perform theirtasks. Organsare made up of specialisedtissues. Tissuesconsist ofspecialised cellsworking together. Example: Circulatory System in the Deer T hecirculatory systemdelivers oxygen and nutrientsthroughout the deer’s body. The system requires: ○ Theheart(organ) to pump blood. ○ A network ofarteries and veinsto transport blood. The heart itself is made of: ○ Muscle tissue(contracts to pump blood). ○ Nerve tissue(regulates heartbeat). 4. Complexity in Living Organisms L iving organisms are highly complex. Each organ system has its own set of organs and tissues. All systems worktogetherto maintain the survivalof the organism. Key Questions to Explore H ow many organs and organ systems are there? How do organ systems coordinate to keep an organism alive? Organ Systems Basic Functions of All Animals: ○ Obtain oxygen. ○ Obtain nutrients for energy, growth, and repair. ○ Eliminate wastes. ○ Sense and respond to their environment. ○ Grow and repair damage. ○ Reproduce to ensure survival of the species. Role of Organ Systems: ○ Perform these essential life functions. ○ Ensure coordination and functionality of the entire organism. Examples of Human Organ Systems: ○ Respiratory system: Obtains oxygen and removes carbon dioxide. ○ Digestive system: Processes food to extract nutrients and removes solid wastes. ○ Circulatory system: Distributes oxygen and nutrients, and transports waste products. ○ Excretory system: Eliminates liquid waste and maintains internal balance. ○ Nervous system: Detects stimuli and coordinates responses. Key Idea: ○ All organ systems work together to support survival, growth, and reproduction. Organs Definition: O rgans are highly specialised structures that work together within organ systems to perform specific functions. Examples of Organs in the Digestive System: tomach S Small intestine Large intestine Liver Pancreas Organs and Organ Systems: Most organs belong to a single organ system. ○ Example: Thestomachis exclusively part of thedigestivesystem. Some organs function in more than one organ system. ○ Example: Thepancreasis part of both thedigestivesystemand theendocrine system. Key Idea: O rgan systems depend on the specialised roles of their organs to perform the overall functions necessary for the survival of the organism. Tissues F our Major Types of Animal Tissue: ○ Epithelial Tissue: Forms protective coverings and linings of organs and body surfaces. Found in most organ systems. ○ Connective Tissue: Supports, connects, and binds other tissues and organs. Includes blood, bone, and fat. ○ Muscle Tissue: Facilitates movement by contracting and relaxing. Found in organs such as the heart and skeletal muscles. ○ Nerve Tissue: Transmits signals throughout the body. Enables sensing and responding to stimuli. Specialisation: ○ Each tissue type is made up of many specialised cells. ○ These tissues are integral to most organ systems. Key Question: ○ Where do these tissues originate, and how are they organised into complex structures like organs and organ systems? Key Terms ierarchy:an organizational structure, with morecomplex or important things at the top and simpler or H less important things below it Tissue:a collection of similar cells that performa particular, but limited, function Organ:a structure composed of different tissues workingtogether to perform a complex body function rgan system:a system of one or more organs and structuresthat work together to perform a major vital O body function such as digestion or reproduction pithelial tissue (or epithelium):a thin sheet oftightly packed cells that covers body surfaces and lines E internal organs and body cavities onnective tissue:a specialized tissue that providessupport and protection for various parts of the C body uscle tissue:a group of specialized tissues containingproteins that can contract and enable the body M to move Nerve tissue: specialized tissue that conducts electricalsignals from one part of the body to another Formation of Multicellular Organisms: A ll multicellular organisms start as asingle cell,called azygote. Thezygoteundergoes a long process of developmentto become a fully formed plant or animal. Early Stages of Development: 1. Cell Division: ○ The zygote divides repeatedly to form many cells. 2. Embryo Formation: ○ The early-stage organism formed by cell division is known as anembryo. 3. Cell Specialisation: ○ Cells begin to change in shape, contents, and functions. Cellular Differentiation: D efinition: The process by which cells become specialised. Directed by Genetic Information: ○ The specialisation process is controlled byDNAwithinthe cell. ○ DNA contains genetic information passed fromparentto offspringineggsandsperm cells. Key Idea: C ellular differentiation enables the development of a variety of specialised cells necessary for forming tissues, organs, and organ systems in multicellular organisms. Stem Cells Definition: Astem cellis an animal cell capable of differentiatinginto many different cell types. Process of Division: S tem cells divide throughmitosisandcytokinesis,forming twodaughter cells. The fate of the daughter cells depends on which parts of theirDNA are activated. Stem Cell Differentiation: Stem cells form clumps that develop into varioustissuelayers, such as: ○ Epithelial tissue ○ Muscle tissue ○ Nerve tissue Types of Stem Cells: 1. Embryonic Stem Cells: ○ Can differentiate intoany kind of cellin the organism. 2. Tissue Stem Cells (Adult Stem Cells): ○ Found withinspecialised tissues. ○ Can only differentiate intocertain types of cellswithin their tissue. ○ Example: Bone marrow stem cellscan differentiate into: White blood cells Red blood cells Platelets Medical Application: B one marrow transplantsare often used to treat cancersaffecting blood cells due to the ability of tissue stem cells in bone marrow to regenerate various blood components. Cord Blood Cell Banking Umbilical Cord Blood: ○ Rich source ofstem cellsimmediately following birth. ○ These arenot embryonic stem cellsbut are similartotissue stem cells. Properties of Umbilical Cord Stem Cells: ○ Can differentiate into various types ofblood cells. ○ Found in high concentrations in umbilical cord blood. ○ Relativelyeasy to collectat birth. Storage and Use: ○ Collected blood can be“banked”for potential futureuse. ○ Stem cells from cord blood are currently used to treat: Childhood cancers, such asleukaemia. Cord Blood Banking: ○ Offered by some commercial companies as a service. ○ Promoted as a potential treatment resource for the child or siblings. ○ New parents are often given the option to bank their newborn’s cord blood. Key Idea: ○ Umbilical cord blood is a valuable and non-invasive source of tissue stem cells, particularly for blood-related medical treatments. Tissue Stem Cell Transplantation Ease of Isolation: Bothcord blood stem cellsandbone marrow stem cellsare relatively easy to collect. Use in Treating Diseases: Both types of stem cells have been used to treat cancers likeleukaemia. Leukaemia Overview: A cancer of thebone marrow. Stem cells in the bone marrow divide too quickly, creatingnon-functioning blood cells. Leukaemia Treatment Process: 1. Removing Diseased Cells: ○ All diseasedwhite blood cellsandbone marrowmustbe destroyed. ○ This is achieved throughchemotherapy. 2. Obtaining Healthy Stem Cells: ○ Healthy bone marrow or blood stem cells are obtained from amatched donor. 3. Transplantation: ○ The healthy donor stem cells areinjected into thepatient’s bloodstream. 4. Engraftment: ○ The donor stem cells migrate to the patient’s bone marrow. ○ They grow and begin producinghealthy, cancer-freeblood cells. Key Idea: S tem cell transplants are a crucial treatment for leukaemia, allowing the regeneration of functional blood cells from healthy donor stem cells. Regeneration and Tissue Engineering Definition of Regeneration: In complex animals like mammals,regenerationrefers to theability of tissues to repair themselves. Examples of tissues that regenerate: ○ Skin ○ Muscle ○ Bone Some cells, likenerve cells, donot regenerate naturallyor completely. Regeneration in Certain Animals: Some animals can regeneratelimbsorlarge portionsof their bodies: ○ Salamanders ○ Sea stars (starfish) ○ Flatworms Tissue Engineering: A field of research focusing on regeneratinghumanbody tissues and partsthat do not naturally regenerate. Applications: ○ Treatingspinal cord injuries. ○ Tissue graftingto replace damaged or lost tissuesin patients. ○ Drug testingusing biological models created fromengineered tissues. ○ Testingpotentially harmful substancessafely on tissuemodels. Key Idea: T issue engineering holds promise for advancing medical treatments and research, especially in areas where natural regeneration is not possible. cellular differentiation: the process by which a cellbecomes specialized to perform a specifi c function tem cell:an undifferentiated cell that can divideto form s specialized cell 3.3 - Digestive System igestive system:the d organ system that is made up of the mouth, esophagus, stomach, intestines, liver, pancreas, and gall bladder; the system that takes in, breaks up, and digests food and then excretes the waste Purpose of the Digestive System: To supply the body withfood and nutrientsfor survival. ○ ○ Provideschemical energyand essential nutrients tothe cells. Steps of Nutrient Distribution: ○ Food is processed in thedigestive system. ○ Nutrients are transported to cells via thecirculatory system. Functions of the Digestive System: ○ Takes in food. ○ Digests foodto break it down into usable nutrients. ○ Excretes wastethat cannot be digested. Structure of the Digestive System: ○ Digestive Tract: A continuous tube that food passes through. ○ Accessory Organs: Organs that aid in digestion butare not part of the main tract. Key Idea: he digestive system prepares food for absorption and energy conversion, while the circulatory system T ensures the nutrients reach all cells. Digestive Track: Overview T hedigestive tractis a long tube withtwo openings(mouth and anus). Found in most animals, it facilitates the movement, digestion, and excretion of food. Structure in Animals Simple Example: ○ In earthworms, the digestive tube has minimal variation in diameter. Complex Example: ○ In humans, the digestive tract includes: Mouth: Entry point for food. Esophagus: Connects the mouth to the stomach. Stomach: Breaks down food with enzymes and acids. Small Intestine: Absorbs nutrients. Large Intestine: Absorbs water and forms waste. Anus: Excretes waste. Accessory Organs L iver: Produces bile for fat digestion. Gall Bladder: Stores and releases bile. Pancreas: Produces digestive enzymes and regulatesblood sugar. Tissue Composition Epithelial Tissue: ○ Lines the entire digestive tract. ○ Containsgoblet cellsthat secrete mucus. ○ Functions of mucus: 1. Protects the tract from digestive enzymes. 2. Ensures smooth passage of materials. Muscle Layers: Facilitate the movement of food throughthe tract. Nerve Layers: Help regulate digestive functions. Defence Mechanism T he body detectstoxins(e.g., from spoiled food oralcohol). Response: ○ Vomiting: Expels toxins rapidly from the stomach. ○ Diarrhoea: Clears toxins from the intestines. Key Takeaway he digestive tract is a specialised system that processes food, absorbs nutrients, and expels waste, T while also protecting the body from harmful substances. Mouth: Functions of the Mouth in Digestion Initiates Food Breakdown: ○ Mechanical Digestion: Teeth: Grind and break down food into smaller pieces. Tongue: Helps in moving and positioning food for effectivechewing. ○ Chemical Digestion: Enzymes in saliva begin breaking apart food molecules. Saliva C omposition: A mixture ofwaterandenzymes. Source: Produced byepithelial tissuelining the mouth. Functions: 1. Softens Foodfor easier swallowing. 2. Begins Chemical Breakdownof food molecules. Process . F 1 ood is chewed and mixed with saliva. 2. Softened food is swallowed. 3. Food passes into theesophagusfor further digestion. Key Takeaway he mouth plays a critical role in both mechanical and chemical digestion, preparing food for smooth T movement through the digestive system. Esophagus: Structure and Function Definition: ○ Amuscular tubeconnecting themouthto thestomach. Type of Muscle: ○ Made ofsmooth muscle tissue, which functionsinvoluntarily(without conscious control). Movement: ○ Controlled bynerve tissue. ○ Food is moved along the esophagus by a process calledperistalsis, which involves rhythmic contractions of the smooth muscles. Key Takeaway he esophagus efficiently transports food from the mouth to the stomach using involuntary muscle T contractions controlled by nerves. tomach: Structure S and Function Primary Role: ○ Holds food andchurns it to further the digestion process. Stomach Lining: ○ Contains specialised cellsthat produce: Digestive enzymes(to break down food). Acids(to aid in chemical digestion). Muscle Tissue: ○ Made ofsmooth muscle tissue, which contracts to mixthe stomach's contents effectively. Nerve Supply: ○ T he stomach is richly supplied withnervesthat help regulate digestion and signal when the body has consumed enough food. Key Takeaway he stomach plays a crucial role in digestion by mechanically and chemically breaking down food and T regulating food intake through nerve signalling. Intestine: General Overview he intestine is the part of the digestive tract located between thestomachand theanus. T Containssmooth musclethat contracts and relaxesinvoluntarily. Lined withepithelial tissuethat produces mucus. Interwoven withblood vesselsto facilitate nutrientabsorption. Two Parts of the Intestine 1. Small Intestine: ○ Length: Approximately6 m, narrow in diameter. ○ Function: Primary site of digestion. Goblet cells release mucus. Nutrients diffuse through the intestinal wall into thebloodstream. 2. Large Intestine (Colon): ○ Length: About1.5 m, larger in diameter than the smallintestine. ○ Function: Absorbswaterfrom undigested food. Formssolid waste (faeces), which is excreted throughthe anus. Colitis (Inflammation of the Colon) Causes: ○ Viruses, bacteria, narrowed blood vessels, or immune system failure. Symptoms: ○ Inflamed epithelial tissue lining the colon. Diagnosis: ○ Performed using anendoscopeand microscopic examinationof tissue samples. Key Takeaway he small intestine is vital for nutrient absorption, while the large intestine focuses on water absorption T and waste excretion. Colitis disrupts normal colon function and requires medical diagnosis and treatment. Accessory Organs of the Digestive System 1. Liver: ○ Producesbile, which aids in the breakdown of fats. ○ Supplies digestive enzymes to the digestive tract. 2. Gall Bladder: ○ Stores and releasesbileinto the digestive tract. 3. Pancreas: ○ Producesdigestive enzymes. ○ Producesinsulin, which regulatesblood glucose levels. Role of Insulin Regulates glucose (sugar) concentration in the blood. Diabetes A disease caused by the pancreas producingtoo muchor too little insulin. Effects: ○ Weakness and dizziness fromlow or high blood glucoselevels. Management: ○ Some forms can be controlled throughdiet. Key Takeaway ccessory organs contribute vital enzymes and substances to aid digestion, regulate blood glucose A levels, and support overall digestive health. Disorders like diabetes highlight the importance of insulin in maintaining balanced blood sugar. Section 3.3: The Digestive System our body needs food to survive! Your cells require a constant supply of food (chemical energy) and Y nutrients to function. This process begins with thedigestive system, which takes in food, digests it,and excretes the remaining waste. The Digestive Tract In most animals, the digestive tract is one long tube with openings at either end. In humans, this tract is more complex, consisting of: outh M Esophagus Stomach Small Intestine Large Intestine Anus Additionally, there areaccessory organsthat aiddigestion but are not part of the digestive tract: L iver Gallbladder Pancreas Stages of Digestion . Ingestion: Taking in food/nutrients by mouth. 1 2. Digestion: Breaking down complex organic moleculesinto smaller parts through physical and chemical means. 3. Absorption: Nutrients move into the cells of the digestivetract and are carried to all parts of the body (occurs in the small intestine). 4. Egestion: Removal of waste food materials from thebody. Gastrointestinal Tract umans have a tube system open at both ends. The H digestive tract is lined withepithelial cellsthatsecrete mucus via goblet cells. Mucus: P rotects the tract from damage by digestive enzymes. Helps food pass smoothly through the tract. he tract also contains layers ofmuscle tissueand T nerve tissue. Ingestion and Digestion . T 1 eethbegin the physical breakdown of food. 2. The muscular action of chewing stimulates thesalivaryglandssurrounding the mouth. 3. Salivary glandssecretesaliva(a mixture of mucusand an enzyme called amylase). The Esophagus heesophagusis a musculartube connecting T the mouth to the stomach. It consists of: Smooth muscles: Contract and relax without conscious thought, controlled by nerves. Peristalsis: Contractions that move the bolus (food) along the esophagus. The Stomach Thestomachperforms the following functions: Holds and churns food. Contains circular muscles called sphinctersthat regulate food entry and exit. Composed ofthree muscle layers that contract and relax to mix partially digested food. Thestomach liningsecretes gastric juices: H ydrochloric Acid Enzymes Mucus Smooth muscle contractions mix contents, while nerve cells signal when the stomach is full. Note: Ulcers can result if the mucus barrier is damaged. The Small Intestine Characteristics: M easures up to6min length and has a narrow diameter. Most chemical digestion occurs in the first25 cmportion called theduodenum. Functions: . G 1 oblet cellsrelease mucus. 2. Nutrientsdiffusethrough the intestinal wall andenter the bloodstream. 3. Secretionsfrom the pancreas and liver enter the smallintestine at the duodenum. Accessory Organ Functions: L iver: Produces bile (breaks down fats), stores carbohydrates/vitamins, detoxifies harmful substances. Gallbladder: Stores bile and sends it to the small intestine. Pancreas: ○ Producessodium bicarbonateto neutralise acidic chyme. ○ Producesinsulinto regulate blood sugar levels. ote: Diabetes results from too much or too little N insulin. Enzymes: xamples include lipase, trypsin, maltase, and peptidases. E These enzymes break down proteins, fats, and carbohydrates. Food also provides essential vitamins and minerals. bsorption: Small and Large A Intestines Small Intestine: N utrients like glucose, amino acids, fatty acids, and glycerol move through the intestinal wall. Villiincrease the surface area of the small intestineby 10x. Microvillifurther increase absorption efficiency. Capillarieswithin each villus transport absorbed nutrients. Large Intestine (Colon): M easures about1.5min length but is wider in diameter. Absorbs water from indigestible food. Remaining solid matter is stored in the rectum and excreted as faeces through the anus. ote: Lack of fibre (cellulose) can lead to fewer bowel movements and increasedrisk of N colon cancer. Digestive Disorders Colitis: D efinition: Inflammation of the large intestine lining. Causes: Viruses, bacteria, narrowed vessels, or immunesystem failure. Crohn's Disease: C hronic inflammation of the digestive system. Can cause ulcers anywhere between the mouth and anus. Digestion and Homeostasis Thenervous,endocrine,circulatory, anddigestivesystemsinteract to control digestion: H ormones are released in response to seeing, smelling, or tasting food. Hormones also regulate the speed of digestion. 3.4 - Circulatory System irculatory system: the organ system that is madeup of the heart, the blood, and the blood vessels; the system that c transports oxygen and nutrients throughout the body and carries away wastes Main Components: Blood,Heart, andBlood Vessels Primary Function: Transport substancesaround the body Key Processes: . N 1 utrient Transport:Moves nutrients from the intestineto body cells. 2. Oxygen Transport: ○ Blood flows through thelungs(respiratory system)to absorboxygen. ○ Delivers oxygen toactive cells. 3. Waste Removal: C ○ arbon dioxidetransported to thelungsfor exhalation. ○ Otherwaste substancescarried to thekidneys(urinarysystem) for filtering and excretion. Other Functions: R egulates body temperature. Transports white blood cellsto fight infections (immune response). Parts of the Circulatory System Main Parts: . B 1 lood 2. Heart 3. Blood Vessels Blood Flow Pathway: 1. H eartpumps blood intoarteries (large blood vessels). 2. Arteries branch into smaller vessels and eventually into capillaries(smallest blood vessels). 3. Capillariesexchange substances (e.g., oxygen, nutrients, and wastes) with surrounding tissues. 4. Blood flows from capillaries into larger vessels calledveins. 5. Veinsreturn blood to theheart. Function of Capillaries: S ite of exchange between blood and tissues. Blood Blood: A connective tissuethat circulates throughout the body. Components of Blood: 1. Red Blood Cells (RBCs): Most abundant (almost50% of blood volume). ○ ○ Containhaemoglobin, a protein that transportsoxygen. ○ Haemoglobin gives RBCs theirred colour. 2. White Blood Cells (WBCs): ○ Make upless than 1% of blood volume. ○ Fight infectionsby identifying and destroyingbacteriaandviruses. ○ Theonly blood cells with a nucleus. . Platelets: 3 ○ Tiny cellsthat assist inblood clotting. ○ Make upless than 1% of blood volume. 4. Plasma: ○ Protein-rich liquidthatcarries blood cells. ○ Makes upover 50% of blood volume. Circulatory System: Includes theheart,blood, andblood vessels. Functions: ○ Transports oxygenandnutrients. ○ Removes wastesfrom the body The Heart Tissues in the Heart: ○ Cardiac Muscle Tissue: Foundonly in the heart. Contracts simultaneously topump bloodthroughoutthe body. ○ Nerve Tissue: Regulatesheart rateandcontractions. ○ Connective Tissue: Providessupportandstructureto the heart. Heart Rate: ○ The frequency of beats changes based on: Physical activity Stress levels Temperature Overall health Epithelial Tissue (Protection and Smooth Flow): ○ Outer layer:Reducesfrictionandprotects the heartduring lung movement. ○ Inner layer: Provides asmooth surfaceforblood flow. Preventsdamageand reduces risk of health problemscaused by rough or hardened surfaces. Blood Pressure Three Types of Blood Vessels: 1. Arteries: Function:Carry bloodawayfrom the heart. ○ ○ Pressure:High pressure due to pumping action of theheart. ○ Structure:Thick walls towithstand pressure. ○ Size:Larger near the heart, smaller further away. 2. Veins: ○ Function:Carry bloodtowardthe heart. ○ Pressure:Lower pressure than arteries. ○ Structure:Thinner walls than arteries. ○ Size:Larger near the heart, smaller further away. . Capillaries: 3 ○ Function: Connectarteriesandveins. Allowdiffusionof substances between blood and tissues. ○ Structure: Very thin wallsto enable exchange ofoxygen,nutrients,carbon dioxide, and wastes. ○ Network:Present inall parts of the bodyto ensureblood supply. Key Functions of Blood Vessels: T ransportoxygenandnutrientsto tissues. Removecarbon dioxideandwastesfor disposal. Artery: a thick-walled blood vessel that carries blood away from the heart Vein: a blood vessel that returns blood to the heart apillary: a tiny, thin-walled blood vessel that enables the exchange of gases, nutrients, and wastes between the C blood and the body tissue Diseases and Disorders of the Circulatory System Overview: M any conditions can affect thefunctionof thecirculatorysystem. Over adozen types of heart diseasesimpact peopleof allagesandfitness levels. Common Heart Condition: 1. Coronary Artery Disease (CAD): ○ Cause:Narrowing or blockage of thecoronary arteries(vessels supplying the heart muscle). ○ Effect:Reduces blood flow to the heart, leading tochest pain (angina)orheart attack. ○ Risk Factors: Poor diet,lack of exercise,smoking,high blood pressure,diabetes, and high cholesterol. Serious Outcome: Heart Attack: ○ O ccurs when blood flow to part of theheart muscleis completelyblocked, causing tissue damage. Coronary Artery Disease Overview: Theheartrequires aconstant supplyofoxygenandnutrientsviacoronary arteries. Cause: Plaque buildupin coronary arteries: 1. Plaque consists offat,cholesterol,calcium, andother substances in the blood. Contributing factors: 1. Genetics(inherited risk). 2. Lifestyle choices: High-fat diet,smoking, andlack of exercise. Symptoms: T iredness Dizziness Chest painorburning sensation(may spread to arms). Diagnosis: Angiogram– Aspecial X-ray: ○ Usesfluorescent dyeinjected into the bloodstream. ○ Highlightsblockagesin the coronary arteries. Heart Attack Cause: Complete blockageofcoronary arteriesby: ○ Plaquebuildup. ○ Blood clotformation. Result: ○ Heart muscle cellslose oxygenandnutrients. ○ Heart stops pumping, and tissue begins todie. General Symptoms: hest painorpressure. C Shortness of breath. Nausea. Anxiety. Upper body pain(arms, neck, jaw). Abdominal/stomach pain. Sweating. D izziness. Unusual fatigue. Key Notes: Symptoms canvarybetweenmen and womenandindividuals. Immediate medical attentionis required forsuspectedheart attacks. Diagnosis: . B 1 lood Test:Detectsproteinsreleased whenheart muscledies. 2. Electrocardiogram (ECG):Measureselectrical signalsfrom the heart. ○ Damaged heart tissueproducesabnormal signalscomparedtohealthy tissue. lectrocardiogram (ECG): a diagnostic test that measures the electrical activity pattern of the heart e through its beat cycle Structure of the Circulatory System The circulatory system has 3 main parts: 1. B lood - A type of connective tissue that contains blood cells, nutrients, and gases transported throughout the body. 2. Blood vessels - A system of vessels that transport fluids throughout the body. 3. Heart - A pump that pushes fluid through blood vessels. Functions of the Circulatory System he circulatory system consists of the heart, blood, and blood vessels. As the body's T transport system, it has 4 main functions: . 1 ransport oxygen and carbon dioxide. T 2. Distribute nutrients and transport wastes. 3. Maintain body temperature. 4. Circulate hormones. Blood Composition Blood is composed of: Plasma - Fluid that contains gases, nutrients, wastes, and hormones. Blood Cells: ○ Erythrocytes (Red Blood Cells) - Contain hemoglobin to bind oxygen molecules. ○ Leukocytes (White Blood Cells) - Recognize and destroy invading bacteria and viruses. ○ Platelets - Small fragments of bone marrow cells that function in blood clotting. The Heart Structure: ○ 4 Chambers: Right atrium Left atrium Right ventricle Left ventricle ○ Atria receive blood, ventricles discharge blood. ○ Functions as a double pump, separated by a septum. Tissue Composition: ○ Cardiac muscle tissue, nerve tissue, and connective tissue. ○ Covered with epithelial tissue to reduce friction. Heart Valves: ○ Atrioventricular Valves (AV): Tricuspid and Mitral valves. ○ Semilunar Valves (SV): Pulmonary and Aortic valves. ○ Valves prevent backflow of blood. Blood Vessels 1. Arteries - Carry blood away from the heart. Thick walls withstand high pressure. 2. V eins - Carry blood towards the heart. Thinner walls as blood pressure is lower. 3. Capillaries - Tiny vessels with thin walls that allow diffusion of substances between blood and tissues. Vein Valves: ○ Prevent backflow of blood and help push it toward the heart. Major Blood Vessels S uperior Vena Cava - Large vein bringing deoxygenated blood from the head and arms to the heart. Inferior Vena Cava - Large vein bringing deoxygenated blood from the abdomen and legs to the heart. Aorta - Largest artery transporting oxygenated blood throughout the body. Coronary Vessels C oronary Arteries - Deliver oxygen-rich blood to the heart muscle. Coronary Veins - Return deoxygenated blood to the right atrium. Circulation Two Circuits: 1. Pulmonary Circuit: ○ Deoxygenated blood moves from the right side of the heart to the lungs to pick up oxygen. ○ Oxygenated blood returns to the left side of the heart. 2. Systemic Circuit: ○ Oxygen-rich blood is pumped from the left side of the heart through the aorta to the rest of the body. Flow: Right Atrium → Right Ventricle → Lungs → Left Atrium → Left Ventricle → Body The Heart's Nerves S inoatrial Node (SA): Pacemaker that sets rhythm (~72 bpm). Atrioventricular Node (AV): Passes signals to ventricles for contraction. The Heartbeat Two Phases: ○ Diastole: Ventricles relax; AV valves open, SV valves closed. ○ Systole: Ventricles contract; SV valves open, AV valves closed. Sound: ○ "Lubb": AV valves close during systole. ○ "Dubb": SV valves close during diastole. Blood Pressure D efinition: Pressure of blood in arteries due to heart contractions. Measurement Tool: Sphygmomanometer. 1. Inflate cuff to block blood flow. 2. Slowly release pressure and listen with a stethoscope. 3. Record: Systolic Pressure (~120 mm Hg) - First sound. Diastolic Pressure (~80 mm Hg) - When sound stops. Normal BP: 120/80. Low BP: Reduced capacity to transport blood. High BP: Risk of artery rupture. Heart Diseases 1. Coronary Artery Disease: ○ Cause: Plaque buildup in coronary arteries. ○ Symptoms: Tiredness, dizziness, chest pain. ○ Diagnosis: Angiogram (X-ray with dye). 2. Heart Attack: ○ Cause: Complete blockage of coronary arteries. ○ Symptoms: Chest pain, shortness of breath, nausea, sweating, dizziness. ○ Diagnosis: Blood test (detects proteins) and ECG (measures electrical signals). Fun Facts T he heart pumps about 2000 gallons of blood per day. At rest, it takes 6 seconds for blood to circulate between the heart and lungs. Squid and octopus have 3 hearts! The circulatory system is the transport system of the body and has 4 principal functions; ransport of oxygen and carbon dioxide T Distribution of nutrients and transport of wastes Maintenance of body temperature Circulation of hormones BP is measured with an instrument called a sphygmomanometer he pump cuts off blood flow to major arteries in the arm, allowing you to listen for the sound of blood as T it re-enters the artery he pressure on the gauge where the sound is first heard is called the systolic blood pressure (about T 120mm Hg) hen the sound disappears (because the ventricles fill with blood) we can measure the diastolic blood W pressure - about 80 mm Hg We describe a normal BP rate as 120/80 Low blood pressure means your body has a reduced capacity to transport blood around High blood pressure can weaken an artery, which might result in its rupture In The Beginning… ohn Doe, a 47-year-old male, enters the emergency room at York Central Hospital complaining J of chest pains, shortness of breath, and nausea. Diagnosis and Treatment Initial Suspicion:Heart Attack Hospital Actions: W ithin 10 minutes:A blood sample is taken to testfor proteins made when muscle tissue is damaged. ECG Monitoring:The patient is connected to an electrocardiographmachine to produce an electrocardiogram (ECG) that checks heart rate and rhythm. Electrocardiogram (ECG) A diagnostic tool used to detect abnormalities in the heart's electrical activity. Heart Attack Treatment Step 1: Anti-Clotting Drugs P revents further artery blockage. Low-risk patients are given Aspirin. Oxygen is provided to compensate for any shortage due to low blood flow. Next Steps E CG Analysis:Determines damage location but not severity. Cardiac Catheterisation: ○ A narrow tube (catheter) is threaded into an artery in the groin. ○ Dye visible on X-rays is injected into the catheter to locate blockages. Angioplasty P erformed while the catheter is in place. A second, thinner catheter with a deflated balloon at the tip is threaded through the first catheter. T he balloon inflates to open the blockage, restoring blood flow. Stent Placement:A metallic mesh tube is insertedto keep the artery open and prevent narrowing. Coronary Bypass Surgery If angioplasty is ineffective, bypass surgery is used: A vein graft from another part of the body bypasses the blockage to restore blood flow. Cardiovascular Diseases Types of Circulatory Diseases: 1. Arterial Diseases: ○ Arteriosclerosis (hardening of the arteries). 2. Venous Diseases: ○ Inflammation and varicose veins. Heart Diseases: Category Description oronary Artery C lockage of arteries supplying blood to the heart B Disease muscle. Arrhythmias Malfunctions in the heart's electrical system. Valve Disorders Dysfunction of heart valves. Heart Muscle Disease Inflammation or infection of the heart muscle. Causes of Cardiovascular Disease Coronary Artery Disease Causes: Atherosclerosis: ○ Plaque accumulation along artery walls. ○ Fat deposits grow, narrowing blood vessels. ○ Calcium and minerals form plaques that block arteries. Heart Attack (Myocardial Infarction) H eart muscles need oxygen—cutting off the supply leads to tissue death. Plaque rupture triggers blood clot formation, causing blockages. Symptoms: harp chest pain. S Pain in neck and arms. Shortness of breath. Nausea. Risk Factors: moking. S High blood cholesterol. High blood pressure. Obesity. Physical inactivity. Poor eating habits. Diabetes. Heredity. Prevention M aintain a healthy lifestyle. Follow medical advice post-heart attack to reduce recurrence risk. 3.5 - Respiratory System Breathing Rate: A verage breathing rate:15 breaths per minute. Breathing rateincreases automaticallywith physical activity. Air Movement: N ormal breathing moves10,000 L of airin and outof the lungs daily. Functions of the Respiratory System: . P 1 rovides oxygenneeded by the body. 2. Removes carbon dioxideproduced as a byproduct of energy use. Purpose of Energy Use in the Body (use of oxygen?): G rowth Repair Movement Collaboration with the Circulatory System: T herespiratory systemworks closely with the circulatory system. T he circulatory systemtransports substances(oxygen and carbon dioxide) throughout the body. Related Content: R efer toSection 3.4for more information on thecirculatory system. r espiratory system: the organ system that is made up of the nose, mouth, trachea, bronchi, and lungs; the system that provides oxygen for the body and allows carbon dioxide to leave the bo Structural Features 1. Components of the Respiratory System: L ungs– Primary organs for gas exchange. Connecting Organs– Link lungs to the outside environment. 2. Airflow Pathway: . 1 outh and Nose– Air enters the body. M 2. Pharynx (Throat)– Air passes through this region. 3. Trachea (Windpipe)– Carries air to the lungs. 4. Bronchi (Singular: Bronchus)– Branches of the tracheathat deliver air into the lungs. 3. Trachea and Bronchi Features: Lined with Epithelial Cells: ○ Mucus productiontraps dust and foreign particles. ○ Cilia (hairlike projections):Move mucus and filterout debris. Supported by Rings of Cartilage: ○ Function:Keeps the trachea open for free airflow. ○ Structure: Made ofconnective tissue. Containsspecialized cellsin astrong but flexiblematrix. Matrix isnon-living materialformed by the cells. 4. Functions of Components: Mucus and Cilia: ○ Protect the system bytrapping and removing debris. Cartilage: ○ Providessupport and flexibilityto prevent airway collapse. Gas Exchange 1. Main Purpose: G as Exchange– Oxygen enters and carbon dioxide exitsthe bloodstream through diffusionin the lungs. 2. Efficiency Adaptations of the Respiratory System: Bronchi Branching: ○ Bronchi branch repeatedly, ending intiny air sacscalledalveoli(singular: alveolus). Alveoli Structure: ○ Thin walls– Allow efficient gas exchange. ○ Surrounded by capillaries– Provide a close link tothe bloodstream. 3. Gas Exchange Process: Oxygen Movement: ○ Diffuses through thealveolar wallsandcapillarywallsinto thebloodstream. ○ Blood with oxygen is quickly transported tocellsthroughout the body. Carbon Dioxide Movement: ○ Produced by cells during metabolism. ○ Diffuses into thebloodstream, travels to thelungs,and diffuses out into the alveolito beexhaled. 4. Factors Supporting Efficiency: Good Blood Supply (Circulatory System): ○ Ensures continuous transport of gases. Concentration Gradient: ○ Oxygen concentrationis alwayshigherin thealveolithan in the blood—maintaining aconstant diffusion gradient. ○ Carbon dioxide concentrationishigherin thebloodthan in thealveoli, promoting its diffusion out of the body. lveolus (plural: alveoli): tiny sac of air in the lungs that is surrounded by a network of capillaries; where gas A exchange takes place between air and blood Breathing 1. Breathing Definition: The process ofmoving air in and out of the lungs. Involves two phases: ○ Inhalation– Drawing air into the lungs. ○ Exhalation– Pushing air out of the lungs. 2. Muscles Involved in Breathing: Rib Muscles: ○ Move theribs, causing therib cageto expand andcontract. Diaphragm: ○ Large sheet of musclelocated beneath the lungs. ○ Works with rib muscles tochange lung volume. 3. Mechanism of Breathing: Inhalation: ○ Rib muscles contract– Rib cage expands. ○ Diaphragm contracts and moves downward– Lung volumeincreases. ○ Pressure inside lungs decreases– Fresh air flowsin. Exhalation: ○ Rib muscles relax– Rib cage contracts. ○ Diaphragm relaxes and moves upward– Lung volumedecreases. ○ Pressure inside lungs increases– Air flowsout. 4. Importance of Volume and Pressure Changes: C hanges inlung volumecreatepressure differences. Pressure differences causeair to flow into and outof the alveoli, enablinggas exchange. Control of Breathing 1. Involuntary Control: B reathing is mostly involuntary– We do not need tothink about it. Theinvoluntary systemautomatically resumes controlif we: ○ Pause breathing(e.g., while talking or holding breath). ○ Override it temporarily. 2. Role of the Brain: A specific part of the brainmonitorscarbon dioxidelevelsin the blood. Whencarbon dioxide levels increase, the brain: ○ Sends signalsto thediaphragm,rib muscles, andheart. 3. Response to High Carbon Dioxide Levels: B reathing rate increases– Morecarbon dioxideisexpelled. Heart rate increases– Moreoxygenis supplied tothe body. 4. Double Effect of the Response: C arbon dioxide levels decrease. Oxygen availability increases. The Respiratory System in Other Animals 1. Primary Role of the Respiratory System: S upply Oxygen:Deliversoxygento allcellsin thebody. Remove Carbon Dioxide:Eliminateswaste carbon dioxideproduced during metabolism. 2. Diffusion in Gas Exchange: K ey Process:Gas exchange relies ondiffusion. How it Works: ○ Oxygen diffuses in– Moves into the body. ○ Carbon dioxide diffuses out– Moves out as waste. 3. Comparison to Other Organisms: M ammals:Havecomplex respiratory systemswith lungs, alveoli, and capillaries. Other Organisms: ○ Many havesimpler systems(e.g., insects usetrachealtubes, fish usegills). Common Feature:Regardless of complexity,all respiratorysystems rely on diffusionfor gas exchange. The Respiratory System is Fish Gas Exchange Organs in Fish: G ills– Specialised organs forgas exchangein water. Structure: ○ Exposed directly to waterfor efficient exchange. ○ Contain manycapillariesto bringblood close to water. 2. Gas Exchange Process: Oxygen Diffusion: ○ Oxygendiffuses from thewaterinto thebloodin thegills. Carbon Dioxide Diffusion: ○ Carbon dioxidediffuses from thebloodinto thewater. 3. Breathing Mechanism in Fish: Fish do notbreathe airlike humans. Instead, theymove water over their gillsto extractoxygen. 4. Methods to Maintain Water Flow: Mouth Movement: ○ Fish open and close theirmouthsto create aflowof waterover their gills. Constant Swimming: ○ Some fish need toswim continuouslyto keep a supplyofoxygenated water moving over their gills. Diseases of the Respiratory System Tubercolosis Overview of Tuberculosis (TB): T ype:Infectious disease, easily passed between people. Cause:Bacteria that enter the body throughbreathing. Primary Site of Infection:Lungs, though it can spreadto other parts of the body (e.g., nervous system,bones). 2. Symptoms of TB: General Symptoms: ○ Fever ○ Cough ○ Weight loss ○ Tiredness ○ Chest pain Untreated TB:Can befatalif not addressed. 3. Diagnosis of TB: Chest X-ray: ○ Used to detect abnormalities in the lungs. ○ Similar results can be found with other conditions likepneumonia. Confirmatory Tests: ○ Examination ofstomach or lung secretionsfor thepresence of bacteria. 4. Dormancy and Reactivation: T B bacteria can remaindormantin the body fordecadesafter initial contact. Reactivationmay occur under certain conditions, leadingto active disease. 5. Treatment and Recovery: M edicine:TB can betreated successfullywith medication. Hospitalisation:A few weeks ofhospital caremaybe required for effective treatment. Cancers 1. Threat to Respiratory Health: T obacco Smoke– A serious threat to the health ofthe respiratory system. Affects bothfirst-handandsecond-hand smokeexposure. 2. Carcinogens in Tobacco Smoke: C ontainsmany known carcinogens(cancer-causing chemicals). These chemicals contribute tocancersin various partsof the body, including: ○ Lungs ○ Mouth ○ Esophagus ○ Larynx ○ Pancreas ○ Bladder 3. Impact of Smoking: F irst-hand smoke– Direct inhalation by the smoker. Second-hand smoke– Inhalation of smoke by non-smokersexposed to it. Both forms significantly increase the risk of developingrespiratory diseasesand cancer. SARS Overview of SARS: ame:Severe Acute Respiratory Syndrome. N Emergence:Early2003. Origin:Spread fromChinato37 countriesglobally. Impact in Canada: ○ 438 cases identified. ○ 44 deaths reported. Global Concern:Threatened to become aglobal epidemic. 2. Symptoms of SARS: Flu-like symptoms: ○ High fever ○ Shortness of breath ○ Dry cough ○ Sore throat ○ Headache ○ Muscle pain ○ Exhaustion 3. Diagnosis of SARS: S ymptom Evaluation:Based on flu-like symptoms. Chest X-ray: ○ Looks forevidence of pneumonia. Laboratory Tests: ○ Examination ofcell samplesto confirm infection. 4. Key Takeaways: H ighly contagious respiratory illness. Requiredstrict public health measuresto containits spread. Highlighted the importance ofglobal disease surveillanceandresponse systems 1. Overview of the Respiratory System Humans can only survive a few minutes without oxygen. ll animals must exchange gases with their surroundings. A Respiration: Process of taking in oxygen (O2) andreleasing carbon dioxide (CO2). Oxygen is needed to produce energy in mitochondria. Carbon dioxide is a waste product of energy production. 2. Gas Exchange and Circulatory System T he circulatory system transports O2 and CO2 to and from cells. Gas exchange occurs bydiffusion: ○ Aquatic animals: Occurs overgills. ○ Land animals: Occurs inlungs. 3. Major Components of the Respiratory System ose N Mouth Trachea Bronchi Lungs Air Processing . W 1 armed: By warm blood in the nose. 2. Moistened: By mucus in nasal passages. 3. Cleaned: Dust and particles trapped by cilia and mucus. 4. Pathway of Air A ir enters through nostrils or mouth. Passes through thepharynx(throat). Moves down thetrachea(windpipe). ○ Supported bycartilage ringsto stay open. ○ Epiglottisprevents choking by covering the tracheawhen swallowing. 5. Gas Exchange Process ir moves through thebronchiinto smaller tubes calledbronchioles. A Goblet cellsin bronchioles produce mucus to trapparticles. Coughing expels trapped particles. Ends inalveoli(tiny air sacs). Alveoli Features: E ach lung has150 million alveoli. Total surface area:40x skin surface area. Surrounded bycapillariesfor gas exchange: ○ Oxygen diffusesinto blood. ○ Carbon dioxide diffusesout of blood. 6. Breathing Process Two Stages: . Inspiration: Breathing in (inhaling). 1 2. Expiration: Breathing out (exhaling). Air moves fromhigh pressuretolow pressure: ○ Pressure in lungs < outside = air movesin. ○ Pressure in lungs > outside = air movesout. Mechanics of Breathing: D iaphragm(muscle under lungs) andrib musclesexpand/contractthe lungs. Lungs are surrounded bypleura (pleural membrane): ○ Contains liquid to reduce friction. ○ Prevents lung collapse by maintaining an airtight seal. 7. Breathing Control C ontrolled by theautonomic nervous system(involuntary). Brain monitorsCO2 levels(not O2). Increased CO2 →faster breathingto remove CO2. 8. Respiratory System in Fish Gas exchange occurs ingills: ○ Capillaries bring blood close to water. ○ Oxygen diffuses from water into blood. ○ Carbon dioxide diffuses out into water. Some fish swim constantly for water flow over gills; others control flow by mouth movements. 9. Diseases of the Respiratory System Tuberculosis (TB): Infectious diseasecaused by bacteria. Bacteria enter lungs via inhalation and can spread to other parts (e.g., nervous system, bones). Symptoms: ○ Fever, cough, weight loss, tiredness, chest pain. Diagnosis: ○ Chest X-rays and analysis of lung secretions. Issue:Bacteria can remaindormant for decades. Treatment:Antibiotics and hospitalisation. Severe Acute Respiratory Syndrome (SARS): O utbreak:Began inChina (2002)and spread globally. Impact:8,098 cases and 744 deaths worldwide. Symptoms: ○ High fever, shortness of breath, dry cough, sore throat, headache, muscle pain, exhaustion. Diagnosis:Symptoms, chest X-ray, lab tests. COVID-19 (SARS-CoV-2): D eclared aglobal pandemicby WHO onMarch 11, 2020. Rapid spread worldwide with respiratory complications. 3.7 - Organ Transplantation Tissue and Organ Transplants Historical Overview: ○ Tissue transplants date back to theearly 1800swithblood transfusions. ○ Thefirst successful organ transplant(a kidney) occurredin1954between identical twins. Advances in Science and Technology: ○ Modern technology has significantly improved transplant procedures. ○ Replacement tracheascan now be created using a cartilage scaffoldcombined with a patient's owncells. Organs That Can Be Transplanted: ○ Heart ○ Liver ○ Lung ○ Pancreas ○ Intestines Transplantable Tissues: ○ Cornea ○ Skin ○ Bone ○ Bone marrow ○ Tendons ○ Blood vessels Donors: ○ Some transplants can be taken fromliving donors(e.g.,kidneys, bone marrow). ○ Others require tissue or organs fromdeceased donors. Benefits and Risks Benefits: For Recipients: ○ Enables recipients to live ahealthy, normal life. For Donors (or Donors' Families): ○ Providessatisfactionknowing the donation saved alife. For Society and Medicine: ○ Advancesmedical knowledgeabout the human body. ○ Improvestreatment optionsthrough ongoing research. Risks: Rejection: ○ The recipient’simmune systemmay attack the transplantedorgan, recognizing it asforeign material. Minimising Rejection: ○ Usegenetically similar tissuesto reduce the risk. ○ Patients often requireimmunosuppressive drugstoprevent rejection. Side Effects of Drugs: ○ Suppressed immune systems reduce the body’s ability tofight infections, increasing susceptibility toillnesses. Living Organ Donations Advantages of Living Donors: Genetic Match: ○ Often relatives, reducing the risk ofrejection. Shorter Waiting Time: ○ Eliminates long waiting periods fordeceased donororgans. Risks to Donors: Loss of Backup Organs: ○ Donors sacrifice theirbackup system, especially inkidney transplants. Surgical Risks: ○ Like all major surgeries, there are risks ofcomplicationsduring and after the procedure. Deceased Donor Organs Source of Organs: M ajority of transplant organscome from deceased donors. Consent for Donation: Pre-death Decision: ○ Individuals cansign a donor card while alive to authorise donation after death. Family Consent: ○ If no donor card is signed,family memberscan giveconsentfor organ donation afterdeath. Steps in the Donation Process: 1. Evaluation of Organs: ○ Organs are checked to ensure they arehealthyandundamaged. 2. Recipient Search: ○ Medical professionals identify themost suitable recipientbased on: Blood and tissue types Age and locationof donor and recipient Waiting timeof the recipient Ensuring Fair Allocation: M atching ensures organs go to themost appropriatepersonbased on medical need and compatibility. Xenotransplantation Definition: X enotransplantationis the transplantation ofbodypartsfromone species to another. Examples: Pig Heart Valves: ○ Used toreplace damaged human heart valves. ○ Chemically treatedtokill cells, making themnon-livingtissue. Challenges: Rejection of Living Tissue: ○ Therecipient’s immune systemmay attack and rejecttheforeign tissue. ○ Overcomingrejectionremains amajor hurdlein xenotransplantationresearch. enotransplantation: the process of transplanting an organ or tissue from one species to X another 3.9 - The Musculoskeletal System usculoskeletal system: the organ system that is made up of bones and skeletal muscle; the system that supports m the body, protects delicate organs, and makes movement possible Importance of Bones: ones providestructure and supportto the body. B Without bones, the body would collapse into asoft,immobile mass. rotects vital organs (e.g., thebrain) frominjury. P Enablesmovementthrough interaction with muscles. Definition of the Musculoskeletal System: Comprised of: ○ Bones– Providestructure,protection, and support. ○ Muscles– Enablemovementby pulling on bones. Key Functions: . S 1 upport:Keeps the body upright and maintains shape. 2. Protection:Shields organs from damage (e.g., skullprotects the brain). 3. Movement:Works with muscles formobility. 4. Storage:Storesmineralslike calcium and phosphorus. 5. Production:Producesblood cellsin bone marrow. Structural Fractures . Components of the Skeleton: Connective Tissues: 1. Bones: Hard and densetissue made of: Bone cellswithin amatrixofminerals(calcium andphosphorus) andcollagen fibres. Canalsinside bones containnervesandblood vessels. Only asmall percentageof bone tissue isliving cells. 2. Ligaments: Tough and elasticconnective tissue. Made mostly oflong collagen fibres. Function:Holdbones togetheratjoints. 3. Cartilage: Dense connective tissuefound in: Ear, nose, esophagus, disks between vertebrae, andjoints. Made ofspecial cellsin acollagen matrix. Functions: Providesstrong,flexible, andlow-friction supportfor bones and other tissues. 2. Muscles and Movement: Muscle Tissue: 1. Made ofbundles of long cellscalledmuscle fibres. 2. Containspecial proteinsthat contract whensignalledby nerves. 3. Contraction:Muscles becomeshorterandthickertoenable movement. Types of Muscle Tissue: 1. Skeletal Muscle (Voluntary): Attached tobones by tendons. Allowsmovement of body parts. 2. Smooth Muscle (Involuntary): Located inintestinesand other organs. 3. Cardiac Muscle (Involuntary): Found only in theheart. Support, Protection, and Movement Main Functions of the Skeleton: tructure & Support: Provides framework for the body. S Anchoring Muscles: Acts as attachment points for muscles. Protection: Protects internal organs (e.g. heart,lungs) and brain. Mineral Storage: Stores calcium and other minerals. Blood Cell Production: Bone marrow produces red andwhite blood cells. Cartilage: rovides a smooth surface at joints. P Prevents damage to bone ends where they meet at joints. Skeletal Muscle: Used for voluntary movements of the body, e.g. walking. How Muscles make Bones Move Tendons: onnect skeletal muscles to bones. C Less elastic than ligaments. Muscle Contraction: uscles contract in response to signals from the nervous system. M The contraction exerts a force on the bones to which the muscle is attached, moving one or both bones. Muscle Movement: uscles can only pull, not push. M Skeletal muscles work in opposing pairs or groups to create movement. Problems with the Musculoskeletal System Osteoporosis: escription: A disease involving loss of bone tissue,making D bones brittle and weak. Prevalence: More common among older women, but can affect people of all ages. Symptoms: No pain; only detectable through a bonedensity test. Causes: Linked to a loss of calcium in the bones. Prevention: Encourage calcium and vitamin D intakethrough food or supplements. Physical exercise helps increase bone mass and reduce risks. Musculoskeletal System & Injuries: hysical Impacts: The system can suffer from physical P stresses and impacts, such as: ○ Torn ligaments, tendons, and muscle tissues. ○ Bone fractures from severe impacts. Diagnosis: X-rays are used to determine fracturesand guide treatment after serious injuries. The Skeletal System in Other Animals Vertebrates: ll vertebrates (animals with backbones) have musculoskeletal systems similar to humans. A Muscles are attached to bones inside the skin. Invertebrates: o Rigid Frame: Some, like worms and jellyfish, lacka rigid skeletal structure. N Exoskeleton: Insects and arthropods have an externalskeleton called an exoskeleton. ○ The exoskeleton provides structure and protection. ○ Muscles attached inside the exoskeleton enable movement (e.g. walking, flying, eating). Musculoskeletal System Overview Movement & Locomotion: ○ The ability to move from one place to another using the skeletal and muscular systems, collectively known as the musculoskeletal system. The Human Skeletal System Number of Bones: ○ 270 bones at birth, decreasing to 206 by adulthood. Functions of the Skeletal System: ○ Protection of Organs: Bones protect vital internalorgans. ○ Blood-Cell Production: Bone marrow produces red andwhite blood cells. ○ Mineral Storage: Bones store calcium and phosphorus,essential for strength and rigidity. Mineral Storage Calcium & Phosphorus: ○ Bones store large amounts of these minerals, which provide strength and rigidity. ○ Weakened Bones: If the diet lacks calcium, the body will dissolve minerals from the bones, weakening them. Bones and Cartilage Bone Composition: ○ Periosteum: Tough membrane covering the bone. ○ Compact Bone: Living bone cells called osteocytes. ○ Collagen: Connective protein fibres in the bone matrix. ○ S pongy Bone: Soft, spongy tissue beneath compact bone. ○ Bone Marrow: Soft, spongy material in the centre of long bones, containing stem cells. ○ Cartilage: Semi-solid, flexible tissue made of chondrocytes. Ossification: ○ Babies' skeletons are made of cartilage,
