Table of ContentsIntroductionDigestive and Urinary SystemsPart Ai) Parts of the Digestive Systemii) Functions of Digestive Systemiii) MacronutrientsIntroductionDigestive and Urinary SystemsPart AThe Digestive System consists of a group of organs that work together to change food into energy along with basic nutrients that feed the whole body.  It breaks down nutrients into parts small enough for the body to absorb them. Waste products are expelled from the body as faeces. Digestion starts at the mouth and the process ends at the anus. The Digestive System co-ordinates the movement of food together with cells that produce hormones and enzymes which aids the breakdown of food.HormonesHormones are chemical messengers secreted by glands directly into the bloodstream and travel to the target organs (the organ that’s requires them). They influence metabolism, reproduction, growth and development.EnzymesEnzymes are proteins which speed up chemical reactions in the body. They breakdown food into small particles so that they can be digested and absorbed by the body.Organs of the Digestive SystemThe organs of the digestive system can be divided into those of the (1.) Gastrointestinal Tract and (2.) Accessory Organs.The Gastrointestinal Tract is also known as the Alimentary Canal. It is made up of hollow organs as follows;MouthPharynxOesophagusStomachSmall IntestineLarge IntestineThe Accessory Organs also play a vital role in helping your body digest food. The accessory organs are as follows;TeethTongueSalivary GlandsGallbladderLiverPancreasFunctions of the Digestive SystemThe main functions of the Digestive System include the following processes:Ingestion – taking food into the Gastrointestinal TractPropulsion – moves the food along the digestive tract through peristalsis and segmentation. Peristalsis is involuntary, it is a wave like movement of muscles contracting and relaxing which moves the food along the tract. Segmentation moves food back and forth transversely within the internal walls where it is mixed with digestive juices. Segmentation is more of a mechanical process other than of propulsion.Digestion is divided into:Mechanical Breakdown – physical action of mastication (chewing) and segmentation (churning food in the stomach).Chemical Breakdown – food is broken down into smaller parts by actions of enzymes in the body. Lipase breaks down Fats. Amylase breaks down Carbohydrates. Pepsin breaks down Proteins.Absorption – this is where the end products of digestion are absorbed into the capillaries in the blood and lymph.Elimination – this is where indigestible deposits of food are excreted as faeces by the bowel.(i)       Parts of the Digestive System(ii)            Functions of Digestive SystemMouth – is a muscular organ and its purpose is to prepare food for further digestion (Stomach and small intestine) it is also responsible for taste. It is the entryway of the Digestive System. When food enters the mouth it is chewed and broken down into smaller pieces. The front teeth cut and tear the food (incisors and canines) the back teeth crush and grind the food (bicuspids and molars). The food is mixed with saliva and moved around by the tongue and forms a pulp. The tongue then passes the pulp (bolus) down the throat into the oesophagus.Oesophagus – is a muscular tube, 25cm long approx., it has a valve at each end called a Sphincter. Its function is to transport food and liquid from the pharynx to the stomach. Food which is now pulp (bolus) is pushed along here by peristaltic action (wavelike contraction of the smooth muscle tissue of the walls). Mucus is secreted by the oesophagus which lubricates the passage of food. No absorption takes place here.Liver – is the largest internal organ and largest gland in the body. It weighs approx. 3.5lbs. It has a soft reddish brown colour and is triangular or wedge shaped. It is located under the diaphragm, above the stomach on the right side of the abdomen. The liver has the capacity to regenerate itself.It has many functions:RemovesHarmful substances and toxins from chemicals, drugs and alcohol.Nitrogen and Amino AcidsStoresGlycogen and IronVitamins A, B12, D, E, KProducesHeparin – an anti-coagulantBileThrombopoietin – Platelet formationHeat – it is the body’s radiatorVitamin A – from Carotene (found in green leafy vegetables and carrots)Vitamin D – the first stage of Vitamin D synthesis within the body takes place in the liver (Healthy Eating, 2018)Plasma ProteinsUric acid and urea from the breakdown of red blood cells and amino acidsConvertsMetabolism of proteinsGlycogen to glucose when energy is neededGlucose back to glycogen when insulin is presentStored fats (saturated) into cholesterolStomach – is a C shaped organ, it has layers of muscle fibres that expand and contract. It is lined with a mucus membrane and contains folds called Rugae. It expands when full and contracts when empty.It is a temporary storage area for food. It churns food (chemical digestion) with gastric juices **. The mucus membrane produces mucus to help lubricate food. It absorbs alcohol directly into the bloodstream. It digests protein through the action of enzymes (chemical digestion). It also forms a thick liquid called Chyme. Chyme is squirted from the stomach into the first part of the small intestine (duodenum).Gastric glands secretes gastric juices/enzymes as follows: **Gastric GlandsEnzymesHydrochloric Acid – kills bacteriaPepsin – Breaks down Protein into PolypeptidesSodium Chloride and Potassium Chloride – Assist with the breakdown of ProteinsGallbladder – is a hollow pear shaped sac attached to the liver by cystic and bile ducts. It’s located under the liver in the upper right hand side of the abdomen. It is a storage area for bile, bile is made in the liver, but is stored in a concentrated form in the gallbladder until needed. It delivers bile to the small intestine. Its lining is made up of many folds, the folds flatten out when it expands. The gallbladder is an ____________ Gland, as it secretes directly into the bloodstream and contains Ducts.Pancreas – is a greyish pink long flat gland, is has a fish like shape. It weighs approx. 80g and is 6 inches long. It is located behind the stomach. The head of the pancreas connects to the small intestine (duodenum). It plays a key role in digestion and glucose control. It plays a role in the digestive system and endocrine system. ItIt produces very important hormones – Insulin and Glucagon. It is both an Endocrine and Exocrine Gland.Endocrine – produces hormonesInsulinGlucagonExocrine – produces enzymesLipaseTrypsinAmylasehttp://www.innerbody.com/image/endo03.htmlSmall Intestine – is approx. 20 meters long. It is made up of 3 parts, Duodenum (1ft), Jejunum (3-6ft) and ileum (6-12ft).  90% of the digestive process takes place here. The walls (lumen) of the small intestine have many folds called villi and microvilli these tiny finger like projections increase the surface area of the small intestine. They contract and relax, and sway in order to come into contact with most of the contents of the small intestine. All food is moved through the small intestine by Peristalsis – Involuntary wave like contractions of smooth muscle of hollow organs which move food through the body.Duodenum – C shaped hollow organ located below the stomach and curves around the pancreas.  It is the first part of the small intestine and the shortest. It connects the stomach to the Jejunum.  It continues the process of digestion which began in the stomach. Its primary function is to receive Chyme a combination of partly digested food and stomach acids into the Duodenum.  Mucus is also produced in the folds between the villi in glands called Crypts of Lieberkuhn, the mucus protects the duodenum from the acidic content of chyme. The duodenum also receives bile from the Liver and Pancreatic Juices from the pancreas to aid digestion of food. Bile emulsifies fats and aids in their digestion. Pancreatic juices work as follows: Trypsin breaks down Protein into Amino Acids, Pancreatic Amylase breaks down Carbohydrates into Monosaccharides and Saccharides, Lipase breaks down Fats into Fatty Acids. The spaces in between the villi in the duodenumJejunum – is a continuation of the small intestine from the Duodenum. It is the middle segment found between the duodenum and Ileum. The villi in the jejunum are tall and cylindrical. It is located in the upper left hand side of the body. It has a thick intestinal wall. It has longer straight arteries. It is red in colour. This is where the chemical digestion food is completed.Ileum – is the final part of the small intestine and opens to the large intestine. The villi in the ileum are short and cylindrical. The ileum is located in the lower left hand side of the body. It has a thin intestinal wall. It has shorter straight arteries. It is pink in colour. The main function of the ileum is to absorb nutrients. Bile is also absorbed here, through the blood vessels in the intestinal walls it is returned to the liver. Peyers Patcheshttp://teachmeanatomy.info/abdomen/gi-tract/small-intestine/Large Intestine – it is the last part of the gastrointestinal tract. It is 1.5meters in length. It begins on the right side of the abdomen and is draped around the small intestine. It is shorter than the small intestine but it is thicker in diameter. It is also known as the Colon or Large Bowel. The large intestine is made up of the Caecum, Appendix, Colon, Rectum, Anal Canal and Anus.The functions of the large intestine are:Absorption of nutrients, salt, water and vitamins that remain in digestive waste.Secretion – secretes mucus which helps lubricate the passage of waste.Produces Vitamin – produces Vitamin K, this plays an important role in blood clotting.Breaks down undigested food using bacteria.Formation of Faeces – the undigested residue of food is formed here as Faeces.Storage of Faeces – the rectum is a temporary storage area for Faeces.Appendix – it is located in the lower right hand of the abdomen. It is approx. 4inches long and has a diameter of about ¼inch.  It is a narrow pouch of tissue with a wormlike appearance. It consists of a tissue call Lymphoid Tissue which plays a role in the immune system. It is not a vital organ. Scientists are still debating as to what the exact function of the Appendix are. Appendicitis occurs as a result of inflammation of the appendix.One theory is that it was used in the past by our ancestors to digest cellulose material from plant based products, which we no longer have a need for or use.Another theory is that the appendix is used for or acts as a storage area for bacteria which are beneficial to our bodies during times of illness. These bacteria survive and rebalance our intestines once the illness has left our system.http://www.innerbody.com/image/dige03.htmlRectum – is a short straight section of the gastrointestinal tract. It is approx. 12cm long.  This leads from the Colon to the Anus. It is a temporary storage area for faeces. It is usually empty and only receives the contents of the colon when faeces are ready to be expelled from the body from the Anus. Faeces are waste products from food combined with indigestible residues, dead blood cells, fatty acids, mucus and bacteria that are both living and dead. Faeces gets its colour from the pigment in bile called Bilirubin and from dead blood cells.Anus – it is the final part of the large intestine, it begins at the bottom of the rectum. The anus is separated from the rectum by the anorectal line. It is the external opening where faeces are expelled/excreted from the body. The anus is surrounded by touch tissues called fascia. Fluid is released into the anus to keep the surface moist. The anus is held closed by the internal sphincter which is under involuntary control. The external sphincter is under voluntary control, this is the only part of the bowel that we have conscious control over.(iii)       MacronutrientsProteins, Fats and Carbohydrates are known as macronutrients. They provide energy for the body in bulk amounts. Carbohydrates and protein provide 4 calories per 1 gram while Fat provides 9 calories per 1 gram.ProteinsFatsCarbohydratesCompositionDigestionAbsorptionPART B(i)            Animal CellCellsCells are the smallest living unit in the body, they are also the building blocks of the body. They are eukaryotic cells, this means that they have a true nucleus and have specialised structures called organelles.  Organelles work together to allow the cell to function, they a variety of functions (each with their own function) to perform such as enzyme and hormone production and also providing energy for the cell.Cells relationship to the bodyA group of cells of similar type join to form tissueA group of tissues of related function join to form an organ (heat, lung, stomach)A group of organs of related function join to form a system (respiratory, digestive, vascular)A group of systems join together to form an organism – the human body OrganelleFunctionDiagramCell MembraneThe cell membrane surround the cellIt protects and gives shapeIt is made of 2 layers – Proteins and LipidsIt is Semi Permeable – allows some substances to move in and out of the cell [O2 and Glucose – IN, waste – OUT]CytoplasmCytoplasm fills the cell with a fluid matrix – jelly like substanceIt holds the organelles in placeIt provides water and nutrients to the cellFluid matrix maintains the pressure inside the cell to ensure that the cell does not shrink or burst.NucleusThe nucleus is the brain of the cellIt directs all the activity of the other cellular organellesIt contains DNA and Chromosomes (genetic information)Nuclear MembraneandNucleoporeThe nuclear membrane is a porous membrane that surrounds the nucleusThe nucleopore is the tiny hole, in the nuclear membrane. It allows movement of proteins and nucleic acids both in and out of the cell.NucleolusThe nucleolus is the structure (the dark spot) within the nucleus.It is the location for ribosome formation, helps with the synthesis of ribosomes.MitochondriaThe mitochondria is the power house of the cell, it’s the main energy source of the cellIt produces and releases energy for the cell (cellular respiration)A type of energy called ATP is produced hereIt’s an independent organelle it has its own hereditary materialIt is spherical/rod shaped organelle, it has an inner and outer membraneGolgi ApparatusThe golgi apparatus is the communication centre for the cellIt packages cellular products and secretes energy – sends around cell where neededRibosomesProtein factories of the cell, its function is the synthesise proteinTo produce enzymes and protein compounds – protein is used for growth and repair for cellSince protein synthesis is vital to the cell, ribosomes are found in large numbers  within all cellsThey are located freely suspended within the cytoplasm and they are also attached to the endoplasmic reticulumLysosomesLysosomes are the digestive system of the cellThey contain digestive enzymes that digest cellular waste and worn out parts of a cell plus bacteriaBreaks down food and uses it for energy transfer within the cellSmooth Endoplastic ReticulumSmooth ER are less widespread in the cell – involved in lipid and steroid productionSmooth ER do not have ribosomesRough  Endoplastic ReticulumRough ER is the circulatory system of cell – network of membranesRibosomes present on its surface, transports the protein made by the ribosomes throughout the cellVacuolesVacuoles are bound by a single membrane and small organellesThey are large storage organelles, they store excess water or foodCentriolesThese are paired rod-like organelles that lie at right angles to each otherThey are made of fine tubulesThey play an important role in Mitosis (single cell division), they organise the microtubules assembly during mitosis.CentrosomeCentrosomes are located near the nucleus in the cell They are known as the ‘microtubule organising centre’ of the cellMicrotubules are produced in the centrosomeThe centrosome helps during mitosis by dividing the cell and moving  the chromosomes to each end of the cellIt is the dense area of the cytoplasm that contains the centrioles(ii)            Tissues TissueTissues are groups of cells that are similar in structure and function which act together to form tissues. The study of tissue is known as “Histology”. There are four basic types of tissue in the human body:Epithelial TissueConnective TissueMuscle TissueNerve Tissue Epithelial TissueEpithelia tissue is comprised of epithelial cells. They are widespread in the body. They are closely packed cells, arranged in continuous flat sheets. They have one free surface that is not in contact with other cells. They are avascular – have no blood supply but have an excellent nerve supply – innervated. They cover body surfaces and line hollow organs and the main tissue of glands. They have the ability to regenerate themselves, this means that they can renew themselves. There are 8 types of Epithelial Tissue: 6 of them are identified based on their number of layers and shape, 2 of them are identified by the cell type (squamous) that are found in them. They are usually described with two names, the first name refers to number of layers of cells and the second refers to the cell shape.Functions of Epithelial TissueProtection – from external factors such as toxins, also protects against physical trauma.Absorption – food/substances in the lining of the digestive system.Secretion – of enzymes, mucus, sweat and any other substances that are delivered by ducts. Also secretes hormones into the vascular system.Detection – of sensations such as touch, cold, heat etc.Regulation and Excretion – of chemicals between tissues and body cavities.Epithelial TissueExampleDiagramSimple Squamous EpitheliumStructure: Single layer of flat cells attached to a base membrane.Function: forms a thin, permeable lining to allow diffusion and filtration for the Alveoli of the lungs, the heart, the blood and lymph vessels.Simple Cuboidal EpitheliumStructure: Single layer of cub shaped cells attached to a base membrane.Function:  they form the lining of tubules in the kidney and some glands.Simple Columnar EpitheliumStructure: single layer of tall, rectangular cells attached to a base membrane. They are resilient.Function:  form the lining of very active parts of body, such as the stomach, intestines and urethra. Some cells secrete mucus and enzymes, some absorb mucus depending on their position in the body.Pseudostratified Columnar EpitheliumStructure: Falsely stratified single layer of cells attached to a base membrane. The cells appear stratified as they differ in height. All the cells rest on the base membrane however, all of them do not reach the apical surface or surface of the lumen. The nuclei are staggered giving the appearance of stratification.Function:  secretes and move mucus, can be subdivided as follows;Ciliated Pseudostratified Columnar Epithelium – lines the respiratory tract (upper).Non ciliated Pseudostratified Columnar Epithelium – lines the epididymis (curved tube at the back of the testicles) male reproductive system.Stratified Squamous EpitheliumStructure: has two or more layers. This tissue is constantly renewing itself. The bottom layer of cells divide and the new identical daughter cells move towards the surface there they mature and then rejuvenate.This tissue can be subdivided as follows:Keratinised – surface layer which has been dried out by keratin (fibrous protein). This creates a waterproof layer. Forms a dead layer in the skin, hair and nails.Non Keratinised – wet surface cells, kept moist to prevent them from drying out, found in the oesophagus. Provides lubrication by using bodily secretions. Function: the main function of this tissue is for protection, the higher the number of layers it has the more protection it gives. It is also very good at tolerating abrasion.Stratified Cuboidal EpitheliumStructure: made up of two or more layers. Usually no more than four layers. Round, square or hexagonal in shape. Have equal dimensions on every side. There is a round nucleus in each cell. The bottom row of cells sit on a base membrane. The upper row of cells are freely exposed to a body cavity.Function: Protection – can withstand chemical and physical assault. Areas that are exposed to higher potential of being damaged such as the oesophagus, vagina, anal canal and most ducts.Stratified Columnar EpitheliumStructure: column shaped cells arranged in multiple layers. They are rare in the body.  It mainly occurs in embryonic tissue and not in adults. Can be found in certain glands and ducts but are uncommon in the bodyFunction: Secretion and protection. Found in the urethra, uterus, vas deferens, eye (conjunctiva), pharynx, salivary glands, anus and lobar ducts.Transitional EpitheliumStructure: It is only found in the Urinary System – ureters and bladder. It is so called as it gradually changes shape as the bladder fills up with urine. When empty the bladder’s epithelium is convoluted with a convex umbrella shaped surface. When it fills the convolutions are lost and the cells change from cuboidal to squamous. When the bladder is empty the epithelium appears thicker and multi layered. When the bladder is full it is less stratified and more stretched out.Function: Allows urinary organs to expand and contract.https://www.google.ie/search?q=Simple+Squamous+Epithelium&tbm=isch&tbs=rimg:CcaUbC1Lcj2TIjiZbTcetEUHzK8aKYay33UDb0MptwmfGjFMqJ8RItUMTg-mGUCfAHacN4lHv_1F81sZmkANwf0-eUSoSCZltNx60RQfMEbIn0ByBu4PbKhIJrxophrLfdQMRZlPpdUw6S1MqEglvQym3CZ8aMRFFovCb_1dTSLSoSCUyonxEi1QxOEWZT6XVMOktTKhIJD6YZQJ8AdpwRVpmsIBdbk5wqEgk3iUe_18XzWxhFWmawgF1uTnCoSCWaQA3B_1T55REY-EHYvfKen4&tbo=u&sa=X&ved=2ahUKEwjlzZjfjM7ZAhXqLMAKHZLnAjoQ9C96BAgAEBk&biw=1366&bih=637&dpr=1#imgrc=xpRsLUtyPZPdWM:      Connective TissueAs the name suggests, connective tissue connects all other tissue in the body. It is widely distributed and the most abundant in the body. It varies in blood supply. Cartilage lacks blood vessels – avascular, dense connective tissue has a poor blood supply. Bone has a rich supply of blood vessels.It is comprised of three main components: fibres, cells and ground substance. Ground substance is a colourless, clear, gelatinous fluid that fills the space between cells and fibres. The fibres combined with the ground substance make up extracellular matrix. The extracellular matrix provides support to the cells, it also provides biochemical support – regulates the cells dynamic behaviour. Connective tissue is classified into two subcategories: soft and specialised connective tissue.There are three types of fibres found in connective tissue:Collagen – fibrous proteins that provide high malleable strengthElastin – long, thin fibres that allow the tissue to stretch and recoilReticular – short, fine collagenous fibres which branch into tiny delicate networksTypes of Connective TissueConnective tissue is divided into main categories as follows:Solid ? BoneSemi Solid ? Fat/CartilageLiquid ? BloodThe Functions of Connective TissueProtection – against impact, friction and contaminants.Insulation – thermal insulation (fat)Support – structural support (tendons, ligaments, cartilage)Storage – stores fuel reserve.Transportation – of substances within the body: water and oxygen, vitamins and minerals, energy.Connective TissueExampleDiagramLoose Connective Tissue:AreolarStructure: loose random fibres of loos connective tissue. Wide variety of cell types. Semi Permeable allowing substances to pass through.  Contains – yellow and white fibres, fibrocytes, masts cells which produce histamine (protection) and heparin (anti-coagulant, prevents clotting).Function: Supports and binds other tissues.  Defends against infection – when a region of the body is inflamed this tissue soaks up all the excess fluid in the area, this condition is called Edema.Location: Found under the skin, between muscles and in the outer coverings of blood vessels, nerves, oesophagus etc.Loose Connective Tissue:AdiposeStructure: loose connective tissue, also known as fatty tissue. Consists of fat calls containing fat globules. There are two types (1) white adipose tissue (2) brown adipose tissue: found in specific locations these areas are referred to as adipose depots.Function:  main function is to store energy. Protects and insulates the body. Retains heat as it is a poor conductor of heat.Location: Found under the skin, around the heart, kidneys, eyes, breast and abdominal membranes.Loose Connective Tissue:ReticularStructure: is a loose connective tissue. It is mesh like. The reticular cells form reticular fibres they form a network in which other cells attach. If forms the scaffolding/framework for soft organs.Location: Found in the spleen, liver and lymphatic tissue.Dense Connective Tissue:Dense RegularDense IrregularElastic CTDense connective tissue contains more collagen fibres than loose connective tissue. As a result it has greater resistance to stretching. Dense connective tissue can be classified as follows:Dense Regular Connective Tissue – has closely packed bundles of collagen fibres that all run in the same direction. These fibres can stretch a little, they are wavy.Function: they enhance tensile strength.Found in ligament and tendons. Also found in the fibrous membranes of blood vessels, nerves and wrapped around muscles.Dense Irregular Tissue – structurally the same as dense regular tissue, however the bundles of collagen fibres are arranged irregularly and are much thicker.Function: gives tissue greater strength in all directions and then less strength in one particular direction.Found in the dermis of the skin. Dense irregular elastic tissue in the lungs and arteries give them the ability to regain their shape after stretching.Elastic Connective Tissue – is a modified dense connective tissue, it consists of interwoven elastic fibres in addition to collagen fibres.Function: it allows tissue to recoil, return to its original length after being stretched.Found in walls of bronchial tubes and arterial blood vessels. BoneStructure:  hardest structure in the body. Also called Osseous tissue.There are two types (1) compact (2) cancellous. Compact is dense bone, it has minimal gaps and spaces. Its porosity is 5–30%. It accounts for 80% of the skeleton. Cancellous is spongy and composed of 25% water, 30% organic material, 45% inorganic salt.Function: Support and protect the body and all the organs. Formation of red blood cells in the bone marrow. Stores and releases phosphorus and calcium.Location: Found in the skeleton.BloodStructure: this is a specialised form of connective tissue. It is atypical of this tissue as it does not connect, bind or network with any body cells.  It is made up of blood cells – 45% cells and 55% plasma.Function: transports nutrients, oxygen, hormones, gases and metabolic waste products.Location: Found in Cardiovascular System.Cartilage TissueHyalineElasticFibro-cartilageCartilage Tissue: firm, solid, tough, flexible connective tissue. Composed of specialised calls, called Chondrocytes. Cartilage does not contain blood vessels.Cartilages is classified into three types:Hyaline – structure: blueish white, smooth and resilient. Most abundant in the body.  Appears glassy or transparent under the microscope.Function: provides cartilage pads for shock absorption, provides support.Found in rib cage, trachea, larynx and nose.Elastic – Structure: yellow elastic fibres. They contain cells called Chondrocytes and Fibrocytes which lie between fibres.Function:  to maintain shape of a structure while still allowing flexibility.Found in the epiglottis and the outer ear – the visible part pinna/auricle.Fibrocartilage – Structure: white closely packed fibres in dense masses. Contains cells called Chrondrocytes. Slightly flexible and extremely tough.Function: acts as a shock absorber.Found in joints between bones, found in knee, hip and shoulder sockets. Forms intervertebral discs.https://courses.lumenlearning.com/nemcc-ap/chapter/connective-tissue-supports-and-protects/Muscle TissueStructure: All muscle cells are made up of 75% water, 20% protein, 5% mineral salts, glycogen, glucose and fat. They are long and fibrous. They are arranged in bundles and parallel lines which makes them very strong. They are likened to a pile of rubber bands that are lines up next to each other, if you attempt to stretch them you will get the idea of what their nature is. They are striated and non-striated. Striated means a striped appearance. Muscle tissue has a striped appearance due to the alternating bands of dark and light protein fibres, Myosin (dark) and Actin (light).Functions of Muscle TissueThe main physiology of muscle tissue is movement.Muscle TypeStructure and FunctionExampleSkeletalUnder voluntary control.Striated.Multiple nuclei located on the periphery of the cell.Help support and move the body.Pulls to allow movement.Attached to the Skeleton. Found in Biceps and Triceps.SmoothUnder involuntary control.Non-striated.Has one or two nuclei located centrally in the cell.Moves food and substances through the body, this is referred to as Peristalsis.Found in tissue systems – digestive system and respiratory system. Also found in the walls of hollow organs. Located in oesophagus, stomach, airway, bladder, uterus, blood vessels.CardiacInvoluntary control.Striated.Pumps the heart to circulate blood around the body.Has a single nucleus which is centrally located in the cell.Differentiated from skeletal muscle tissue by the presence of intercalated discs, these discs synchronise the contraction of cardiac tissue and maintain circulation.Never rests, known for its endurance and consistency.Found in the heart only.Nerve TissueNerve tissue is found in the Brain, Spinal Cord and Nerves. Nerve tissue is composed of nerve cells called neurons. These are specialised unique cells. They are supported by cells called neuroglia, there are six types of neuroglia. Four types of neuroglia are located in the central nervous system and the remaining two are found in the peripheral nervous system.Neurons are found in the Central Nervous System and Peripheral Nervous System. The function of neurons is to send and receive nerve impulses in the body.Sensory Neurons – send impulses from the body and environment to the brain via the spinal cord.Motor Neurons – send impulses from the brain to the body via the spinal cord.Typical neurons (motor neuron) have cell bodies, dendrites and axons.https://www.google.ie/search?q=nerve+tissue&tbm=isch&tbs=rimg:CSNho-0omirVIjjI78Q4LNpaMge0Tqz4WrG9rxTjf1Lik0zWw5t1n5RdQD2iRtkvq_1AtuFh0c9jwhQc6R_1MRftEZnCoSCcjvxDgs2loyERDPiQXesXIWKhIJB7ROrPhasb0RhhM6JPNj2dQqEgmvFON_1UuKTTBGqMiPsyGM71CoSCdbDm3WflF1AEX7OB2Ni51aJKhIJPaJG2S-r8C0ROJKKI3d7Xb8qEgm4WHRz2PCFBxE_1nF4nvQdhlSoSCTpH8xF-0RmcERi2xs3eWlrI&tbo=u&sa=X&ved=2ahUKEwj7v4icpM7ZAhVEFMAKHRqTAxIQ9C96BAgAEBw&biw=1366&bih=637&dpr=1#imgdii=OkfzEX7RGZyvGM:&imgrc=yO_EOCzaWjJ7PM:(iii)            TumoursTumoursThroughout the course of our lives, healthy cells in our bodies, multiply, divide and renew themselves in a controlled way. A tumour also called a Neoplasm occurs when cells escape from the normal process of cell division, they multiply at an abnormal rate forming a mass or a lump. Tumours may be Benign or Malignant. The two most important differences between Benign and Malignant are invasion and spread.Benign TumourA Benign Tumour is an abnormal growth that serves no purpose. It is non-cancerous. It can cause pressure or pain in the area affected. It is enclosed in a capsule. It does not invade or spread and usually does not re-occur.Causes of Benign TumoursThe cause is often unknown, but may be linked toGeneticsDietStressInflammation or infectionLocalised trauma or injuryEnvironmental toxins or exposure to radiationTypes of Benign TumoursAdenomas – they start in the epithelial tissue of glands, also may be found in pituitary, thyroid and adrenal gland, and may be found in the liver. Can be removed with surgery.Fibromas – fibrous tissue or connective tissue tumours. They can form in an organ, most common in uterus. They are symptom causing (vaginal bleeding, pelvic pain and bladder issues) and need to be removed surgically.Hemangiomas – this is an accumulation of blood vessel cells in the