Anatomy and Physiology for Health and Social Care Essay

Task2: The main tissue types of the body and the role these play in two named organs of the body. P2: Outline the structure of the main tissues of the body There are many different types of cells in the human body. These cells would not be able to function on their own, they are all part of a large organism that is called – you. The two named organs that I have chosen for this assignment are the intestines and the heart. Tissues All cells group together within the body to form tissue, a collection of similar cells group together to perform a specialized function. There are four primary tissue types in the human body – epithelium, connective tissue, nervous and the muscle tissue. Epithelial tissue- This tissue is specialised to cover the whole part of the body lining of all of the internal and external body surfaces, they are packed tightly together to form continuous layers that serve as linings in different parts of the body. Epithelial tissue serves as membranes lining organs and helping to keep the body’s organs separate, in place and protected. Some examples of epithelial tissue are the outer layer of the skin, the inside of the mouth and stomach, and the tissue surrounding the body’s organs. These kinds of tissues can be divided into two groups depending on the number of layers that it has. An Epithelial tissue which is only one cell thick is known as Simple epithelia, if it consists of several layers then it is known as Compound Epithelia. Epithelial tissue In the Intestines- The apical surface of epithelial cells usually have tiny projections called microvilli. These function to increase the surface area. For example, microvilli on intestinal cells increase the surface area open for absorption. Absorption is an important function of epithelial tissue within the intestines. The surface of the small intestine is lined with simple columnar epithelium. This type of epithelium appears as a single layer of tall, column-shaped cells with oblong nuclei. The primary function of this type of epithelium is absorption of nutrients, secretion of digestive juices as well as secretion of mucus by goblet cells. The surface area of the small intestine is increased by outward finger-like extension sand inward indentations, as villi and crypts. Both of these structures are lined with simple columnar epithelium. In the heart- The epithelial tissue protects the heart from becoming damaged from the lobes that are in the heart against the lungs; it provides an extra barrier of protection from injuries. Epithelial tissues line all the ducts and glands within the heart and protect it with an exterior membrane. P2: Outline the structure of the main tissues of the body The Intestine P2: Outline the structure of the main tissues of the body The Heart Connective tissue- There are many types of connective tissue that are widely distributed throughout the body that lie beneath the epithelial tissue. This type of tissue does not contain many cells, as they are separated from each other by an intercellular ground substance, (matrix), they are hidden by the cells. It is made up of either liquid, solid, or connective tissue, within the matrix there are many types of connecting fibres, such as collagen and elastic fibres. The function of the connective tissue is to support, bind, cover, protect and give structure to the body. Most types of connective tissue contain fibrous strands of the protein collagen that add strength to connective tissue. Some examples of connective tissue include the inner layers of skin, tendons, ligaments, cartilage, areolar, adipose bone and fat tissue. In addition to these more recognizable forms of connective tissue, blood is also considered a form of connective tissue. Cartilage tissue is a smooth, firm substance that protects ends of the bones from friction during movement and they can be found at the end of our bones in mobile joints, the front ends of the ribs, also in parts of our nose and ears. Our bone tissues are made of a much harder substance than the cartilage, but they can be worn away by friction. They are tough on the outside, but on the inside they have a sponge-like design that helps to reduce the weight while retaining strength. They are designed to maintain the body’s structure and support the body’s movement and are used to protect weaker tissues, such as the brain,  lungs and heart. P2: Outline the structure of the main tissues of the body Blood is a specialized bodily fluid in human’s that delivers necessary substances such as, nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. Bones have a rigid structure that constitutes part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a dense type of connective tissue. Cartilage is a flexible connective tissue found in many areas in the body including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs. It is not as hard and rigid as bone but is stiffer and less flexible than muscle. Areolar tissue is a common type of connective tissue, also referred to as ‘loose connective tissue’. It is strong enough to bind different tissue types together, yet soft enough to provide flexibility and cushioning. Adipose tissue (fatty tissue) it provides insulation and protection of organs, muscle fibres, nerves, and supports blood vessels. It protects us from excessive heat loss or heat increase and also acts as a shock absorber to protect against injury. In the intestine- The lumen is the cavity where digested food passes through and from where nutrients are absorbed. Both intestines share a general structure with the whole gut, and are composed of several layers. Going from inside the lumen radially outwards, one passes the mucosa (glandular epithelium and muscularis mucosa), submucosa, muscularis externa (made up of inner circular and outer longitudinal), and lastly serosa. Serosa is made up of loose connective tissue and coated in mucus to prevent friction damage from the intestine rubbing against other tissue. Holding all this in place are the mesenteries which suspend the intestine in the abdominal cavity and stop it being disturbed when a person is physically active. In the heart- Connective tissue provides the final pathway for diffusion of nutrients, oxygen, waste and metabolites to and from the cells of the body. All blood vessels are embedded in connective tissue. The only cells which receive their sustenance directly from the blood are the endothelial cells lining the vessels themselves. All of the other cells are supplied via diffusion through intermediary connective tissue. The transport functions of blood and connective tissue cannot be separated. The heart and circulatory system simply facilitate the movement of this travelling tissue. The valves in the heart are also made from connective tissues, they control the amount of blood that is passed through the heart and into the blood stream, and it also helps to reduce the flow back to the heart. Nervous tissue- The nervous tissue includes the brain, spinal cord and the nerves throughout the organism, it contains two types of cell they are the neurons and glial cells. Nerve tissue has the ability to generate and conduct electrical signals in the body. These electrical messages are managed by nerve tissue in the brain and transmitted down the spinal cord to the body. The nervous tissue, main function is to carry messages throughout the body, gathering and feeding back information via electronic impulses along specialised cells called neurons. It is like an information speedway, it directs the drive force of the nervous system by sending messages, to ensure that all of the systems are able to work together within the body, this is to maintain that the internal conditions are needed to enable the body to respond to motivation. In the heart- The nervous tissue in the heart controls the heart’s main functions. It is controlled by specialised nerves called nodes. A node is a specialised type of tissue that behaves as both muscle and nervous tissue. When nodal tissue contracts (like muscle tissue) it generates nerve impulses (like nervous tissue) that travel throughout the heart wall. The heart has two nodes that are instrumental in cardiac conduction, which is the electrical system that powers the cardiac cycle. These two nodes are the sinoatrial (SA) node and the atrio-ventricular (AV) node. The sinoatrial node, is also referred to as the pacemaker of the heart, it coordinates the heart contractions. It is located in the upper wall of the right atrium, it generates nerve impulses that travel throughout the heart wall causing both of the atria to contract. The atrio-ventricular node lies on the right side of the partition that divides the atria, near the bottom of the right atrium. When the impulses generated by the SA node reach the AV node, they are delayed for about a tenth of a second. This delay allows the atria to contract, thereby emptying blood into the ventricles. The AV node then sends the impulses down the atrio-ventricular bundle. This bundle of fibres branches off into two bundles and the impulses are carried down the centre of the heart to the left and right ventricles. Btec Level: 3 in Health and Social Care Nervous Tissue In the intestine In order to propel the food into the small intestine, a small electrical impulse is passed down the nerve into the lower part of the stomach to grind the food and it is expelled little by little. Then in order for digested food to pass through the intestine and the electrical impulses tract messages to the brain pass through the spinal cord to the nervous tissue within the intestines which then stimulates the muscle to contract causing the digested food to be passed down through to the rectum to the be excreted. Muscle tissue- Muscle tissue is a specialized tissue that is able to conduct electrical impulses and to contract. Muscle tissue contains the specialized proteins actin and myosin that slide past one another to allow movement. Examples of muscle tissue are contained in the muscles throughout your body. There are three types of muscles, they are known as: Striated (also called voluntary or skeletal muscle), produces movement and maintains posture, contract and relax, applies force to joints and bones, is under voluntary control. Non-striated (also called involuntary, plain or smooth), it protects, controls movement of substance along tubes, not under voluntary control, found in stomach, intestines, bladder, uterus and the eyes. The cardiac muscle (also called involuntary, has four chambers), can only be found in the heart, shares similarities to skeletal muscle, and cannot be controlled. Cardiac muscles are only found in theheart. They are self-contracting, autonomically regulated and continue to contract in rhythmic fashion for the whole life of the organism. Some of the cardiac muscle cells contract without any nervous stimulation. P2: Outline the structure of the main tissues of the body Muscle Tissue P2: Outline the structure of the main tissues of the body In the heart- The cardiac muscle has several different unique features. The muscle’s that are present in the cardiac are intercalated discs, which are connected between two adjacent cardiac cells. Intercalated discs help multiple cardiac muscle cells to contract rapidly as a unit. This is important for the heart to function properly. The cardiac muscle can also contract more powerfully when it is stretched slightly. When the ventricles are filled, they are stretched beyond their normal resting capacity. The result is a more powerful contraction, ensuring that the maximum amount of blood can be forced from the ventricles and into the arteries with each stroke. This is most noticeable during exercise, when the heart beats rapidly. This pumps blood around to all the cells in the body, to help to retrieve it and re-oxygenate it and pump it back around. In the intestine- The smooth muscle is found in the walls of hollow organs like your intestines and stomach. The muscular walls of the intestines contract to push food through your body and help to break it up, this is an involuntary function. Resources Books Stretch B.and Whitehouse M., (2014), Health & Social Care, level 3, 1st edition. Edinburgh Gate, Harlow and Essex. College notes and hand-outs Ms Mansell,, Guernsey College FE, unpublished. Websites www.en.wikipedia.org www.technion.ac.il www.kentsimmons.uwinnipeg.ca www.uoguelph.ca