Sunday, October 27, 2019

Organisation of the Body: An Overview of Cell Types

Organisation of the Body: An Overview of Cell Types 1.1) Light microscopes can magnify an object to be seen 400-1000 times. Microscopes that allow electron can magnify up to two million times. This allows scientists to see things in more detail such as cells, this result has given doctors and scientists more understanding and function. Light microscopes use a visible light that bends and passes through the lens. Electron microscopes use a beam of electrons for light magnification. Electron microscopes allow higher magnification compared to a light microscope, this then allows a vision in internal structure. Electron is the particle having a negative charge and then orbiting the nucleus, the flow of electrons in the conductor of electricity. Resolution is in which a image can be recorded, or produced. This is often expressed in per unit. To calculate the length of an object that has been magnified. You find the length of the object equals the length of the object after it has been magnified then divide by the magnification. Electron mi croscopes can be very expensive. They need a constant supply of voltage, this then needs to be always stable, monitored and maintained throughout. This machine is man made and can make errors. Only skilled people may use it, without these pro cations the reading may not be accurate. 2.1) The cell wall is located in and around the plasma membranes of different types of cells. Cell wall function is to support protect and allow water, carbon dioxide to diffuse in and out of the cell. Plants have cell walls while animal cells do not. Cell walls are made up of carbohydrates, they give shape to the cell. They help plants keep there shape and allow them to stand straight. The cell wall provides protection against pathogens and other substances that maybe harmful to the cell.  Ã‚   The cell membrane is inside the cell wall. In a animal it is in the outer layer and supports and gives protection, also controls movement of materials in and out of the cell. It is also a barrier between the cell and the cells environment but also maintains homeostasis. The nucleus is located in all cells except prokayotes. The shape is large and oval. The nucleus contains one or sometimes more nucleoli and holds DNA. The nucleus controls the activities in the cell and also contains hereditary material located in the cell. The cytoplasm is located in all cells. It is a clear jelly material. The cytoplasm holds organelles in the cell in place. The cytoplasm has three components, the organelles, cytosol and cytoplasmic inclusions. The cytosol is in part of the cytoplasm, it contains cytoskeleton, molecules salt and water. Organelles are small in structure. They perform a variety of functions. Endoplasmic is in all cells except prukaryoles. It connects to the nuclear envelope and cell membrane. It also carries materials through the cell. This also helps to make proteins. Some of the functions of the endoplasmic are mechanical support, the transport and function of the synthesis, this is especially the transport of proteins. The ribosomes is contained in all cells. The ribosomes synthesizes proteins that will be used inside the cell. Ribosomes are found in the reticulum and can be found around in the cytoplasm. Ribosomes are responsible for making and assembling acids and proteins. Ribosomes will be found in the cytoplasm of the cell. The proteins they make will function in the cytosol, they are then moved outside the cell and included in the cells membranes. 3.1) Membrane structure is located in all cells. In plants it is inside the cell wall, in animals it is in the outer layer wall. Most of the cell membrane structure is made up of proteins and phospholipids. The cell membrane structure is not solid. The cell membrane structure gives support and a barrier between the cell and movement. The membrane structure holds everything in but also keeps any harmful things out. 3.2) Diffusion is the spreading of different particles of gas, substance or a solution. The act is the movement of particles, the higher the temperature the faster the particles will move, then the faster the diffusion will take place. Osmosis happens when two solutions are separated this is the movement of water from one area of high to an area of low water across a membrane (semi-permeable). Permeable membranes will let water through but other solution such as sugar cannot flow through freely. The active energy uses energy to move different substances in and out of cells. Active transport is important in the kidneys for keeping a hold of different substances needed by the body. These substances are glucose and ions. 4.1) There are four types of tissues in the human body, epithelial, connective, nervous, and muscle. 4.2) Epithelial tissue protects the human body from moisture loss, bacteria and internal injury. There are two types of epithelial tissue in the human body, one covers all the internal and the other external body surfaces and also the outer layer of your skin, the lymph vessels and digestive tract. Glandular epithelial also produces hormones and other products such as, sweat, saliva, stomach acid and milk. Connective tissue holds structures together, the loose connective tissue holds the outer layer of skin and the under layer of muscle tissue. This tissue is also found in lymph nodes, fat layers and red bone marrow. The nervous tissue forms the nervous system. This is responsible for all the movements of the body though its network of nerves. It can bring on the fight or flight response to the body. This response is a survival technique enabling people to react quickly to pain and other life threatening situations. The nervous system is the brain, spinal cord and sensory organs, the se nerves consist with these two parts of the body. Neurons are the structural unit of the nervous system. They communicate within the body by transporting signals. There are three types of neurons, afferent neurons are sensory neurons. They transport sensory signals to the sensory nervous system from other receptors in the human body. Efferent neurons are known as motor neurons and transmit signals from the muscles and glands. Inter neurons form within the central nervous system to relay information received from the afferent neurons and direct the function of the body through effect information, in other words they work together. Muscle tissue forms over the skeleton and is attached to bones and causes movement within the human body. Cardiac muscle is formed and located in the heart. Smooth muscle is located in the walls of the blood vessels, it is also located and found in the digestive and urogenital tracts. 5.1) Cells that join together are not identical but work together to accomplish different functions for the human body. All living things are made up of cells. One cell makes a form of tissue. Nerve cells will form nerve tissue, sweat glands form sweat gland tissue. Skin tissue is made of hair tissue oil and sweat tissue, they all have cells that form from this and are all working together to form the skin. The human body is made of cells, which then form tissue, which then form organs all working together because without this the body would not work. Word count: 1210 Claire Richardson Bibliography: la.a.2.2.1.4.1. (2001-2003). The making of an organ.  Available: www.beaconlearningcentre.com/1966. Last accessed 29 July 2014. BBC teachers. (aqa science). Tissues organs in animals.  Available: gcse bite size. Last accessed 29 July 2014. 1.1) Comparing light and electron microscopes. description usage Light microscope Uses radiation, in the form of light and electron beams. This forms a larger and more detailed image to the human eye. Can be used for looking at specimens. Immediate image. Lower resolution. Can measure living processes taking place, eg cell division. Magnification: x1000 to x 2000 image and quality.. Light microscopes are smaller and lighter and easier to move. Less expensive, wavelength 400-700nm. Wavelength 1nm. The light is via glass lenses. Images can be viewed directly. Eyepiece to use is projector lenses. Source used is light. Electron microscope Uses radiation, in the form of light or electron beams. Uses beams of electrons instead of rays of visible light. Forms highly magnified images of areas materials and biological specimens. Immediate image. Higher resolution in measuring smaller images. Not possible to view and living material due to a vacuum inside the electron microscope. Magnification: x 100,000 sem to tem x 250,000. Two types of electron microscope: transmission electron microscope, and scanning electron microscope. Form larger images used that the human eye would not see. Techniques used staining, mounting, and slicing. Cost is expensive to run. Use electromagnet(magnetic projector). Effective wavelength 1 nm. 2.1) Organelle Function of the organelle chromatin Is a combination of DNA and other proteins that make up the chrmosomes. Found in nuclear envelope of the eukaryotic cells. The chromosomes are made when there is cell division. Chromatin is in the nucleus of the cell. ribosome Located in the cytoplasm. Make proteins that is used in the cell. Others are found in the enoplasmic reticulum. Endoplasmic recticulum (rough) Endoplasmic reticulum is a membrane that is found in animal cells and plant cells but not in prokaryotic cells. Responsible for transporting proteins and carbohydrates to other organelles. The surface of rough endoplasmic reticulum is with the protein making ribosome, which gives the appearance of a rough surface. It is called rough because it is studded with ribosomes.. Endoplasmic recticulum (smooth) The smooth is a production of metaolism of fats, and steroid hormones. It is also connected with some slippery fats Lymosome Contains digestive enzymes, break down material that enters the cell. Break down components, bacteria and other materials. Enzymes are strong and can destrong cell function if released. Remain in the cell within lysosomes membrane to prevent this. Golgi apparatus This sorts out packaging of proteins for secretion, and also involved in the transport of lipids around the cell. Also the creation of lysosomes. Flagella The flagella is the censory of the organelle. Checks chemical balances and temperature outside the cell. Found in prokaryptic and eukaryotic cells. Mitrochondria Organelles that break down nutrients and creates energy for the cell. Creating cell energy, cellular respiration, similar to the digestive system. Mitochondria are small in size organelles. Nucleus The nucleus creates and regulates cell activity, controls enzymes that are in the cell. Nucleus is found in the eukaryotic cells, contains cells genetics, DNA molecules, in proteins to form chromosomes. 4.2) Red blood cells are found in bone marrow. All blood cells come from bone marrow and form stem cells. Stem cells are found to be imortal, which means they will never die. Not until the human body does. Erythrocytes are also called red blood cells. There function is to help move and transport oxygen in the blood. They are round in shape but are more like disks. Erythrocytes are flexible and have a membrane, this then allows them to move through capillaries. Erythrocytes contain hemoglobin to carry oxygen, they then loose nucleus and organelles, then develop in bone marrow. Ciliated epithelial are hairs that sit on top of tissue. They move back and forth and help move things such as mucleus. They are found in the lining of the respitory, where the lungs is. They are also found in the fallopian tubes in women. This tissue contains mucous to help your body act against and move bacteria such as a cold out of the body. Cililated epithelium has cells called goblet cells without this harmful bacteria would stay in the body and cause you to be very sick. A sperm cell looks like a tadpole. The tadpole has a head, tail and neck. The head provides information in the nucleus and the tail makes peopulsion. The head is flat and measures five micrometers long and three micrometres wide. The neck has two features nuceus and the actrosome. The head contains a mebrane that acts in penetrating the female egg. The sperm penetrates the female egg, and produces material that is genetic and reaches the ovum. The neck measures one micrometer in length and contains spermatozoon and also two of centrioles which are needed in cell division. 3.1) Composition is the ingredients in what is made up in the cell as a whole. The cell membrane or lipid bi-layer is the outer layer of a cell, all cells have a membrane and this separates a cell from the environment around them. The cell membrane acts as a guard to inspect what it allows in the cell and what leaves the cell. The cell internal structure is made up of proteins and lipids, depending where in the body the location of the cell is. Lipids help the cell in its flexibility and shape, proteins help in the cells transfer of molecules across the membrane. Receptor proteins in the cell help communicate with other things outside of the cell, this happens through neurotransmitters and hormones. 3.2) Diffusion is water molecules moving from one area of high water to areas of very low water. Osmosis is the movement of molecules through a membrane of high water to a low water of concentration. Active transport is the movement of molecules across the membrane into the high concentration, this is done by and assisted by enzymes and requires energy to do this Diffusion Osmosis Active transport Passive transport Water molecules moving from one area of high water to low water concentration. Moves molecules through a membrane of high water to a low water concentration. Moves molecules across the membrane into high concentration using enzymes and energy. The movement of chemicals across a cell membrane. Irons to a higher concentration to a lower concentration. Does not require energy to move molecules from one point to another point. Does not require energy to move molecules from one point to another point. Requires energy to move molecules from one point to another point. Does not require energy to move molecules from one point to another point. 4.1) The nervous tissue have two main cells neuroglia and neurons. The neuroglia have functions that support the nerve cells but they do not transmit pulses. Neurons are nerve cells and are very sensitive to heat and cold, dark and light. They transmit electric nerves and information around the body. Muscle tissue have three types of tissue, cardiac skeletal and smooth muscles. Muscle helps with posture, and support. Smooth muscle tissue controls movement in the human body and contracts with other tissue in the intestines and stomach. Skeletal tissue help in the movement of bones such as hips and wrists, this is enclosed in connective tissue(epimysium). The epithelial tissue covers the whole of the body. It is made of cells with one or more layers. It covers all external and internal layers. Types of tissue Structure and function of tissue Nerve tissue Have two cells neurolia and neurons. Have functions that support nerve cells but do not transmit pulses. Neurons sensitive to heat, and cold. Dark and light.transmit signals and information around the body. Muscle tissue Three types of tissue cardiac, skeletal and smooth. Helps with posture and support, controls movement, contracts with other tissues. Connective tissue Provides movement in bones that is present in connective tissue. Epithelial tissue Covers all the body, made up of cells that have one or more layers. Covers all internal and external layers. 5.1) The human body consists of the head and skull which also contains the brain. The pharynx is in the throat, the larynx is at the back of the mouth, the lympth nodes are in the neck, the heart is in the middle of the chest wall. The lungs are behind the ribs, there is arteries in the arms and there is muscle near the skeleton. The spleen is above the stomach, each organ is linked to another organ and they all work together for the human body to work. The brain sends signals to different parts of the body for them to work. Without these signals you could not function. If the brain is dead the rest of the body does not work. The human hand provide the body with support to move objects in many ways. Each hand has twenty seven different bones and ligaments. The hand join on to the wrist and provide flexible movement and wrist action. The hand is also coverd with skin. The nerves are extended into the palm. There are eight carpal bones in the wrist that are bound. The hand is used for movement and picture up abjects. The hand provides the body with a lot of support. Claire Richardson Word count: 2765 Bibliography: nner body. (1999-2013). Hand and wrist.  Available: page 1. Last accessed 30 july 2014. nner body. (1999-2013).  Hand and wrist.  Available: page 1. Last accessed 30 july 2014. microscope resolution. (2001-2003).human biology.Available: compound microscopes. Last accessed 29 july 2014.

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