Term 4 Science Study Notes PDF

Rocks and minerals Structure of the Earth: Lithosphere The rigid, outermost layer of the Earth. It's made up of the crust and the uppermost part of the mantle. It's divided into several large plates that move slowly over time. The movement of these plates causes...

Rocks and minerals Structure of the Earth: Lithosphere The rigid, outermost layer of the Earth. It's made up of the crust and the uppermost part of the mantle. It's divided into several large plates that move slowly over time. The movement of these plates causes earthquakes and volcanic eruptions. Asthenosphere: A layer of partially molten rock in the upper mantle. It's located below the lithosphere. Mesosphere: The layer of the mantle below the asthenosphere. It's solid rock. Earth's Interior The Earth's interior is made up of four main layers: 1. Crust: The thin, outermost layer of the Earth. It's made up of solid rock and is where we live. 2. Mantle: The thickest layer of the Earth. It's made up of hot, solid rock that can flow slowly over time. 3. Outer Core: A layer of liquid metal, mostly iron and nickel. It's extremely hot and creates the Earth's magnetic field. 4. Inner Core: The innermost layer of the Earth. It's a solid ball of metal, mostly iron and nickel. It's even hotter than the outer core. Strata is levels of rocks Igneous Rocks: Igneous rocks: forms when molten rock cools and becomes solid. (solidifies) Igneous Rocks Form from Magma or Lava.The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. There are two types of Igneous rocks they are Extrusive rocks: Form when magma cools quickly on the Earth's surface, resulting in small crystals. Examples include basalt and obsidian. Intrusive rocks Form when magma cools slowly beneath the Earth's surface, resulting in large crystals the crystal also interlock with each other. Examples include granite and gabbro. A table of some but not all characteristics Minerals A mineral is a naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure. Minerals are the building blocks of rocks. Some common minerals are quartz, feldspar, mica, and calcite.  Weathering Weathering is the process by which rocks and minerals are broken down into smaller pieces. It is a slow process that can take many years to occur. Weathering is caused by a variety of factors, including: Physical weathering: This type of weathering is caused by physical forces, such as wind, water, and ice. For example, wind can wear away at rocks over time, and water can freeze in cracks in rocks and expand, causing the rocks to break apart. Chemical weathering: This type of weathering is caused by chemical reactions, such as acid rain. Acid rain can dissolve rocks, especially limestone and marble. Weathering is an important process that helps to shape the Earth's surface. It helps to create new soil, and it can also change the shape of landscapes. For example, weathering can help to create valleys and canyons. Examples (in more depth) of weathering Type Explanation Phy: Wind Wind can carry sand and dust particles that can wear away at rocks over time. Over time, wind can create interesting rock formations. Phy: Water Water can weather rocks in a number of ways. For example, running Water can wear down material. Water can also dissolve minerals in rocks, which can weaken the rocks and make them more susceptible to weathering. Phy: Ice Ice can weather rocks in a similar way to water. When water freezes in cracks in rocks, it expands and can cause the rocks to break apart. This process is called frost wedging. Ice can also create glaciers, which can grind away at rocks and transport them to new locations. Phy: Plant Plants can also weather rocks. Plant roots can grow into cracks in rocks and break them apart. This process is called root wedging. Che: Gases Air contains oxygen and carbon dioxide, and both can react with certain types of rocks. These gases react with the rock and change to form different chemicals that do not hold together as strong causing the rock to crumble. Che: Acid Carbon dioxide (CO2) combines with water as raindrops fall through the atmosphere. This makes a weak acid, called carbonic acid. Carbonic acid is a very common in nature where it works to dissolve rock. Che: Acid Caused mostly by the burning of fossil fuels, acid rain is a form of precipitation Rain with high levels of sulfuric acid, which can cause erosion in the materials in which it comes in contact. An example of physical weathering is wind blowing across the desert playas.  Sedimentary rocks Sedimentary Rocks: What are sedimentary rocks? Rocks formed from pieces of other rocks, minerals, or once-living things. Formed at or near the Earth's surface. How are they formed? Lithification: A process involving: o Compaction: Squeezing sediments together. o Cementation: Minerals fill gaps between sediments, binding them. Types of Sedimentary Rocks 1. Clastic Sedimentary Rocks: o Made of rock fragments (clasts). o Examples: shale, sandstone, conglomerate. 2. Chemical Sedimentary Rocks: o Formed from minerals that precipitate from water. o Examples: limestone, chert, rock salt. 3. Organic Sedimentary Rocks: o Formed from remains of living things. o Examples: coal, limestone (from marine organisms). Why are they important? Fossils: They can contain fossils, giving us clues about past life. Climate Record: They can tell us about past climates.  Metamorphic Rocks Metamorphic Rocks: What are metamorphic rocks? Rocks that have changed form due to heat and pressure. They start as igneous, sedimentary, or even other metamorphic rocks. How are they formed? Heat and Pressure: These forces change the rock's mineral composition and texture. No Melting: The rock doesn't melt, but it does change its form. Types of Metamorphism 1. Contact Metamorphism: o Occurs near igneous intrusions. o Heat from the magma changes the surrounding rock. 2. Regional Metamorphism: o Occurs over large areas due to tectonic forces. o High pressure and temperature change rocks over a wide region. Examples of Metamorphic Rocks Marble: Formed from limestone. Slate: Formed from shale. Gneiss: A banded metamorphic rock. Why are they important? Economic Value: Many metamorphic rocks are used in construction and industry. Geological History: They provide clues about the Earth's past. Rock Cycle The rock cycle is a continuous process that describes how rocks change over time. It involves three main types of rocks: igneous, sedimentary, and metamorphic. Physical and Chemical Change How do you Identify physical change? Physical changes are changes that don't change the substance itself, just its appearance or state. Here are some ways to identify physical changes: Change in state: This is the most common type of physical change. It includes melting, freezing, boiling, and evaporation. Change in shape: Cutting, tearing, bending, and crushing are all examples of physical changes that change the shape of a substance. Change in size: Crushing a rock or tearing paper are examples of physical changes that change the size of a substance. Example of Change in state: Dissolving: When a solid (solute) is dissolved in a liquid (solvent), they form a solution. A solution is a mixture. The smallest particles of the solute mix and spread evenly throughout the smallest particles of the solvent—just like a mixture of balls but invisible to the naked eye. Liquids and gases can also be dissolved. For example, Figure 7.1.5 shows liquid food colouring dissolving in water. In a solution, the solute seems to disappear. In reality, the solute is broken down into such small particles that they are invisible. If the solvent is removed by boiling or evaporation, then the solute particles can join together again to form crystals. This process is known as crystallisation. Chemical Change Chemical changes are changes that create new substances with different properties than the original substances. Here are some ways to identify chemical changes: Change in colour: This is a common sign of a chemical change. For example, when iron rusts, it changes colour from silver to brown. Formation of a gas: When a chemical change occurs, a gas may be produced. This can be seen as bubbles forming in a liquid or as a gas being released into the air. For example, when baking soda and vinegar are mixed, carbon dioxide gas is produced.  Formation of a precipitate: A precipitate is a solid that forms when two liquids are mixed. For example, when silver nitrate and sodium chloride are mixed, a white precipitate of silver chloride forms. Change in temperature: A chemical change can either release or absorb heat. If heat is released, the temperature of the mixture will increase. If heat is absorbed, the temperature of the mixture will decrease. For example, when baking soda and vinegar are mixed, the temperature of the mixture increases. Change in odor: A chemical change can produce a new odor. For example, when milk goes bad, it produces a sour odor. Understanding Physical Change The particle model is a way of thinking about how matter is made up of tiny particles. These particles are always moving, and the way they move and are arranged determines the state of matter (solid, liquid, or gas). Key points of the particle model: All matter is made up of tiny particles. These particles can be atoms, molecules, or ions. The particles are always moving. They are constantly vibrating, rotating, and colliding with each other. The amount of space between the particles depends on the state of matter. In solids, the particles are packed tightly together. In liquids, the particles are close together but can move around each other. In gases, the particles are far apart and move freely. The temperature of a substance is related to the average kinetic energy of its particles. The higher the temperature, the faster the particles are moving. And the farther the distance. The particle model can be used to explain many different phenomena, such as why solids, liquids, and gases have different properties, why substances expand when heated, and why diffusion occurs. Expansion and Contraction Solids: Particles vibrate in fixed positions. As temperature increases, vibrations increase, causing expansion. As temperature decreases, vibrations decrease, causing contraction. Liquids: Particles vibrate and are free to move. As temperature increases, vibrations and movement increase, causing expansion. As temperature decreases, vibrations and movement decrease, causing contraction. Liquids expand and contract more than solids. Gases: Particles move freely. As temperature increases, particles move faster and hit the container walls more frequently and with more force, causing expansion. As temperature decreases, particles move slower and hit the container walls less frequently and with less force, causing contraction. Gases always fill their container, so they expand or contract to fill the container. Changes of State and the Particle Model The particle model explains changes of state by looking at the relationship between the movement of particles and the forces of attraction between them. Melting Particles in a solid vibrate in fixed positions. As temperature increases, vibrations increase. If the vibrations become strong enough to overcome the forces of attraction, the particles become unstuck. This transition from solid to liquid is called melting. Freezing The reverse of melting. As temperature decreases, particles in a liquid slow down. If the particles slow down enough, the forces of attraction can hold them in fixed positions. This transition from liquid to solid is called freezing. Evaporation Particles in a liquid are weakly held together. As temperature increases, particles move faster. Some particles may gain enough energy to escape from the surface, forming a gas. This process is called evaporation. At the boiling point, all particles have enough energy to escape, forming bubbles. Condensation The reverse of evaporation. As temperature decreases, gas particles slow down. If the particles slow down enough, the forces of attraction can bring them together to form a liquid. This process is called condensation. Mixtures and the Particle Model Mixtures are formed when two or more pure substances are mixed together. Solutions are a type of mixture where one substance (the solute) dissolves in another substance (the solvent). When a solute dissolves, its particles spread evenly throughout the solvent. The particles are so small that they cannot be seen with a microscope. Diffusion and the Particle Model Diffusion is the process by which particles of two gases or two liquids mix evenly. During diffusion, gas particles travel in a zig-zag fashion. Eventually, the particles will be distributed evenly throughout the space. Increasing the temperature speeds up diffusion because the particles will travel faster.  Chemical reaction Chemical vs Physical Change: The key difference between a physical and chemical change is that new substances are produced during chemical change. You can determine that a new substance has been produced by observing the following: A permanent colour change A gas is given off A solid precipitate out of a solution A change in temperature happens or light is produced. Why are substances different? The unique set of characteristics of each substance is known as its properties. The properties of a substance are determined by the type of atom it contains and how those atoms are arranged. Chemical reactions During a chemical reaction, old substances disappear and new substances form. The only way this can occur is if the atoms in the old substances rearrange to form the new substances during change. IN chemical reactions, the old substances are known as the reactants. IN chemical reactions, the new substances that form are referred to as the products. Combustion Combustion is the term given to any chemical reaction that involves burning with oxygen to release light and heat. Photosynthesis and Respiration Photosynthesis is a series of chemical reactions that use sunlight to convert water and carbon dioxide into oxygen gas and a form of sugar called glucose C6H12O6 The word equation for photosynthesis can be summarized as: Carbon dioxide+water------------>Oxygen gas+glucose The process of obtaining energy from food is called respiration Word equation is glucose+oxygen→carbon dioxide+water vapour Chemical weathering A chemical process that involves all three non-living spheres is chemical weathering. Chemical weathering is the gradual breaking down of rocks due to reactions with chemicals in rainwater, hail, sleet, and snow.  Body systems The need for body system In the body there are different levels of organisms. Cells will come in many types such as: Skin cells Muscle cells Cells of the same type that carry out the same Job in the body are grouped together to form tissues, such as muscles and nerves. At the next level of organisation, tissues are grouped to form organs, such as the stomach or brain. An organ: Is a structure that contain at least two different types of tissues that work together to complete a task. Organ systems: Organs that’s arranged into organ systems have two or more different organs that work together. The systems of the body Respiratory system: Takes in oxygen Digestive system: makes food available in a form the body can use The circulatory system: carries food and oxygen to the cells where it’s needed The Excretory system: Get’s rid of waste The skeletal system: Supports the body and enables it to move The digestive system: Digestion is the process of breaking down food into a usable form and making the nutrients available. The digestion takes place in your digestive system. Your digestive system consists of: A digestion tract, the path way that the food takes through a series of organs. The first part of the digestive tract is the mouth. Organs off to the side of the digestive tract is that produce chemicals to assist with digestion. Type of digestion In digestion there are two types of digestion: Mechanical digestion Chemical digestion Mechanical digestion is then the food is broken down into smaller pieces. Mechanical digestion is a physical change because no new substances are made. Chemical digestion: the large complex substance in the food is broken down into simpler chemicals. This then will produce smaller chemicals that the body can absorb. Chemical digestion is a chemical change because new substances are produced. The mouth Teeth The process of digestion starts with your teeth. There are 4 types of teeth The incisors are the four pairs of teeth at the front. Their job is to bite off pieces small enough to chew. The tongue then pushes the food back to the premolars and molars. The premolars and molars grind the food into smaller and smaller pieces as you chew. Canine teeth has no significant function to humans however in animals that catch live prey the canines old onto the food as they chew. Saliva The saliva contains a chemical that starts to change any starch (complex sugar) into glucose (A simple and easily absorbed sugar). Saliva also moist the food making it: slimy, slippery and easy to swallow. The tongue rolls the food into a ball (called bolus) which is pushed down into the net part of the system. The oesophagus. Swallowing and oesophagus The oesophagus is a long muscular tube that has the mouth on one end and the stomach at it other. The muscles of the oesophagus push the ball of food down the tube by contracting behind the ball. The muscle swill then relax (called Peristalsis) A flap of skin called the epiglottis close the end of the windpipe as you swallow to make sure that the food goes to the stomach and not to your lungs. You choke if food get’s to your windpipe. You then cough enough force to force the food back up A circle of muscle called a sphincter separates the oesophagus from the stomach. The sphincter opens and the food passes into the stomach. It will close to stop food or stomach juices from flowing back up A second sphincter separates the stomach from the small intestine.  (Peristalsis) (sphincter) Stomach The stomach is shaped like a bag The food is stored in the stomach for 1-6 hours. The muscular walls of the stomach contract and relax, churning up the food. This further digest the food mechanically as well as mix it with Gastric Juice The churning of food as the muscles contract and relax the creates the gurgling noises in your stomach Gastric juice Gastric juice is produces by special cells in the stomach wall. Gastric juice contains: Hydrochloric acid- A strong acid that kills many bacteria that may enter the body with the food. Mucus- creates a layer on the lining of the stomach and prevent the stomach from digesting itself. Small intestine: The small intestine is a very long, narrow tube. It’s the longest part of your digestive tract (up to 6m) however it’s only 3 meters in diameter. The duodenum Is the first part of the small intestine. Two tubes entering the duodenum carry chemicals important for digestion. These tubes come from the pancreas and the liver. The duodenum are muscular, and they continue to squeeze and chum food, breaking it down and making sure that the digested chemicals change the remaining food into forms that the body can use, The Pancreas is no part of the digestive tract rather an organ that’s connected to it and produces pancreatic juice. That contains chemicals that help digesting carbs, fats, and protein. The liver is the body’s largest internal organ and preforms over 500 different chemical processes. The liver is important for digestion as it’s the production of bile. Bile is a greenish liquid responsible for mechanical digestion of fats The Bile causes large pieces of fats to be broken down into tiny pieces so that it can be digested easier. The ileum absorb digested food into the body. On the inner lining of the ileum are villi. These Microsoft fingers greatly increase the surface area of the intestine wall are tiny blood vessels called capillaries. The walls of the villi and walls of the capillaries are only one cell think meaning nutrients can only travel a very very tiny distance as they mover from the digestive system. The nutrients that pass from the small intestines are: Fatty acids and glycerol produced from the digestion of fats. Amino acids from the digestion of proteins Glucose from the digestion of carbs The body used glucose as it’s main source of energy Large Intestine The Large intestine is the final section of the digestive system at 1.5 m long but at 6-7cm in diameter. The large intestine, water is reabsorbed into the body from what’s left of the food, along with any remaining nutrients into the body from what's left of the food, along with any remaining nutrients. The waste forms umps of faeces (known as stools) are later expelled from the body through the anus The Anus is a sphincter muscle at the other end of the digestive tract. 1/3 of the solid material in faeces is bacteria from the intestine. Most of these help you body digest the food by they are passes out and contribute to the smell of faeces. Digestive disorders Vomiting Vomiting is the forceful ejection of the contents of your stomach and upper digestive system through your mouth. It's also known as throwing up or being sick. Vomiting is a reflex that helps your body get rid of substances that may be harmful Diarrhoea Diarrhoea is the passage of 3 or more loose or liquid stools per day, or more frequently than is normal for the individual. Heartburn Heartburn occurs when stomach acid backs up into the tube that carries food from your mouth to your stomach (esophagus). Appendicitis Appendicitis occurs when the appendix becomes inflamed and filled with pus. Appendicitis is an inflammation of the appendix. The appendix is a finger-shaped pouch that sticks out from the colon on the lower right side of the belly, also called the abdomen. Appendicitis causes pain in the lower right part of the belly The Respiratory System: Key Organs and Their Roles: Lungs: o Spongy organs primarily responsible for gas exchange. o Divided into lobes: right lung (3 lobes), left lung (2 lobes). o Alveoli: Tiny air sacs within the lungs where oxygen and carbon dioxide are exchanged. Nose and Mouth: o Entry points for air. o Nose filters, warms, and moistens the air. o Mouth is a secondary entry point, often used during physical exertion. Trachea (Windpipe): o Carries air to the lungs. o Lined with cilia and mucus to trap dust and germs. Bronchi: o Two main branches of the trachea, one leading to each lung. Bronchioles: o Smaller branches of the bronchi that lead to the alveoli. Diaphragm: o Dome-shaped muscle that aids in breathing. o Contracts during inhalation, pulling air into the lungs. o Relaxes during exhalation, pushing air out of the lungs. The Process of Respiration: 1. Inhalation: o Diaphragm contracts, pulling air into the lungs. o Air travels through the nose or mouth, trachea, bronchi, and bronchioles. o Oxygen-rich air reaches the alveoli. 2. Gas Exchange: o Oxygen Diffusion: Oxygen molecules in the alveoli diffuse into the bloodstream, where they bind to hemoglobin in red blood cells. o Carbon Dioxide Diffusion: Carbon dioxide molecules in the bloodstream diffuse into the alveoli.  3. Exhalation: o Diaphragm relaxes, pushing air out of the lungs. o Carbon dioxide-rich air is expelled through the bronchioles, bronchi, trachea, and nose or mouth. The Role of the Nose: Filtering: The nasal cavity is lined with hairs and mucus, which trap dust, pollen, and other particles. Warming and Moistening: The nasal passages warm and moisten the air, protecting the delicate lung tissue. Trapping Germs: Mucus in the nose traps bacteria and viruses, preventing them from entering the lungs. Oxygen and Cellular Respiration: Cellular Respiration: The process by which cells convert glucose (sugar) from food into energy. Oxygen's Role: Oxygen is essential for cellular respiration. It combines with glucose to release energy. Carbon Dioxide as a Waste Product: Carbon dioxide is a waste product of cellular respiration and is exhaled from the lungs. (Gas exchange) Composition of air when breathed in and out. The Circulatory System A network of organs and vessels that transports blood throughout your body. Blood carries essential substances like oxygen and nutrients to your cells, and removes waste products like carbon dioxide. Key Components: Heart: The heart is a muscular organ that pumps blood throughout the body. o Heartbeat: The rhythmic contraction and relaxation of the heart that pushes blood through the circulatory system. o Heart Disease: A condition that affects o Arteries: Carry oxygen-rich blood away from the heart to the body's tissues. o Capillaries: Tiny blood vessels that connect arteries and veins. They allow for the exchange of oxygen, nutrients, and waste products between the blood and tissues. o Veins: Carry oxygen-depleted blood back to the heart. Blood: A fluid connective tissue that transports essential substances and removes waste products. o Red Blood Cells: Contain haemoglobin, which carries oxygen to the body's cells. o White Blood Cells: Help fight infection and disease. o Platelets: Help blood to clot this is both an essential and a harmful thing. o Plasma: The liquid part of blood that carries blood cells, nutrients, and waste products. How it Works: 1. Oxygen-rich blood is pumped from the heart to the body's tissues through arteries. 2. In the capillaries, oxygen is released to the tissues, and carbon dioxide is picked up. 3. Oxygen-depleted blood returns to the heart through veins. 4. The heart pumps the oxygen-depleted blood to the lungs, where it picks up oxygen and releases carbon dioxide. 5. The oxygen-rich blood returns to the heart, and the cycle repeats. Remember! Veins are in blue (pulling to lung and arteries red (pulling away from lung) The Excretory System: A Deeper Dive The excretory system is a vital part of our body, responsible for removing waste products and maintaining a healthy internal environment. It's like a complex filtration system that keeps our bodies functioning optimally. Defecation The process of getting rid of solid waste (faces) from your body. Faeces is undigested material that’s passed through your digestive tract. Key Organs and Their Roles: Kidneys: o Filtration: Blood is filtered in the nephrons, tiny structures within the kidneys can filter almost 50L per hour. o Reabsorption: Useful substances like water, glucose, and amino acids are reabsorbed back into the bloodstream. o Secretion: Waste products, such as urea, uric acid, and excess ions, are secreted into the tubules to form urine. Urine: A liquid waste product containing water, urea, and other waste substances. Ureter: Tubes that carry urine from the kidneys to the bladder. Bladder: A muscular sac that stores urine (holds up to 1L of urine) 300ml of urine is enough to trigger the urge to urinate. Urethra: A tube that carries urine out of the body (20cm long) Sphincter Muscles: Control the release of urine. Liver: o Processes nutrients from food mainly protein through amino acids. o Produces bile, which aids in digestion. o Filters blood, removing toxins and drugs. o Converts harmful substances into less toxic forms this is called urea. Lungs: o Exhale carbon dioxide, a waste product of cellular respiration meaning lungs is in both cellular and respiration system. o Help regulate blood pH by removing excess carbon dioxide. Skin: o Excretes sweat, which contains water, salts, and urea. o Helps regulate body temperature through sweat evaporation. Common Excretory System Disorders: Kidney Disease: Can be caused by various factors, including high blood pressure, diabetes, and infections. The Skeleton The skeleton is a rigid framework of bones that supports the body, protects the internal organs, and enables movement. It is made up of two main parts: the axial skeleton and the appendicular skeleton. The skeleton is made up of 206 bone. Axial Skeleton The axial skeleton includes the bones of the head, neck, and trunk. It is responsible for protecting the brain, spinal cord, and heart. - Skull: The skull is a bony box that protects the brain. It is made up of 22 bones, including the cranium and the facial bones. - Vertebral Column: The vertebral column is a flexible column of bones that supports the head and trunk. It is made up of 33 vertebrae, which are divided into five regions: cervical, thoracic, lumbar, sacral, and coccygeal. - Ribcage: The ribcage is a cage of bones that protects the heart and lungs. It is made up of 24 ribs, which are attached to the sternum and the vertebral column. The Axial skeleton is made out of 80 total bones. Appendicular Skeleton The appendicular skeleton includes the bones of the arms, legs, and pelvis. It is responsible for movement and locomotion. - Upper Extremities: The upper extremities include the bones of the shoulder, arm, forearm, and hand. The shoulder girdle is made up of the clavicle and the scapula. The arm is made up of the humerus. The forearm is made up of the radius and the ulna. The hand is made up of eight carpal bones, five metacarpal bones, and fourteen phalanges. - Lower Extremities: The lower extremities include the bones of the hip, thigh, leg, and foot. The pelvis is a large, bony structure that supports the lower body and protects the reproductive organs. The thigh is made up of the femur. The leg is made up of the tibia and the fibula. The foot is made up of seven tarsal bones, five metatarsal bones, and fourteen phalanges. The appendicular skeleton is made up of 126 bones. Bones Bones are hard, rigid structures that make up the skeleton. They are made up of a mineralized matrix of calcium and phosphate, which gives them their strength and rigidity. Bones also contain a network of collagen fibers, which gives them their flexibility. Spongy and Compact Bone Spongy bone is a porous type of bone that is found in the epiphyses of long bones and in the interior of other bones. It is lighter and weaker than compact bone, but it is more flexible and porous. Compact bone is a dense type of bone that is found in the diaphysis of long bones and in the outer layer of other bones. It is stronger and denser than spongy bone, but it is less flexible and porous. Bone Marrow Bone marrow is a soft tissue that is found in the medullary cavity of bones. It is responsible for producing blood cells, including red blood cells, white blood cells, and platelets. Joints Joints are the places where two or more bones meet. They allow the bones to move and provide flexibility to the skeleton. There are many different types of joints, each with its own unique structure and function. Cartilage Cartilage is a smooth, elastic tissue that cushions the ends of bones and reduces friction between them. It is also found in other parts of the body, such as the nose, ears, and trachea. Synovial Fluid Synovial fluid is a thick, slippery fluid that lubricates the joints and helps them to move smoothly. It is produced by the synovial membrane, which lines the inside of the joint capsule. Types of Joints - Hinge joint: A hinge joint allows movement in one direction only, such as the elbow joint. - Ball-and-socket joint: A ball-and-socket joint allows movement in all directions, such as the shoulder joint. - Saddle joint: A saddle joint allows movement in two directions, such as the thumb joint. -pivot joint: A pivot joint allows movement by moving a ring shape around another finger ling bone shape. Ligaments Ligaments are strong bands of connective tissue that connect bones to each other. They help to stabilize the joints and prevent them from moving too far. Muscles Muscles are attached to the bones by tendons. They contract to produce movement. There are three types of muscles: skeletal muscle, cardiac muscle, and smooth muscle. Tendons Tendons are strong bands of connective tissue that connect muscles to bones. They allow muscles to pull on the bones, which produces movement. Antagonistic Pair An antagonistic pair is two muscles that work together to produce movement. One muscle contracts to produce movement, while the other muscle relaxes. For example, the biceps and triceps muscles work together to produce movement at the elbow joint. (skeleton axial and appendicular) (The human skeleton)  (bone marrow) Types of joint (disregard the plane and condyloid) ligaments in foot All muscles in the body Muscles working antagonistic pair.