Assignment 1 – Functional Anatomy & Physiology Unit UV30378 |
Lou Davidson – March 2012 |
1a – Explain the structures of a human cellMost human cells contain small structures known as organelles (“little organs”), each of which performs a highly specialised task, such as manufacturing protein. Organelles are usually surrounded by a membrane, and they float in a jelly-like substance called cytoplasm. Ninety percent of cytoplasm is water; it also contains enzymes, amino acids, and other molecules needed for cell functions. The structure …show more content…
It is important for the body to have a stable environment for cells to function correctly. There are several things that need to be regulated: 1. The body's temperature. If temperature were allowed to rise out of control, protein and therefore enzyme, structure would be affected, perhaps with disastrous results. 2. The amount of water within the body. The levels of water can affect metabolism and osmosis. Again this can have serious consequences. 3. The amount of glucose in the body. This level can also affect osmosis and obviously the rate of respiration as well. 4. The amount of nitrogenous waste in the body. Nitrogenous waste can become toxic in the body. It is important that this level does not get too high.Negative feedbackTo regulate these things the body needs firstly to detect the level and then to respond in an appropriate way. For temperature, water and glucose there is a level called the 'norm' (e.g., normal body temperature is 36.9°C). If the level gets too high this triggers the body to lower it. If the level gets too low this triggers the body to raise it. This is the principle of negative feedback. (Positive feedback is when a high level of something triggers the body to increase it even further). 1e – Describe the structures and functions of the different types of human tissues Tissues of the human body can be broken down into categories …show more content…
They support and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Bones come in a variety of shapes and have a complex internal and external structure, are lightweight yet strong and hard, and serve multiple functions. One of the types of tissue that makes up bone is the mineralized osseous tissue, also called bone tissue that gives it rigidity and a coral-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum, periosteum, nerves, blood vessels and cartilage.Compact (cortical) boneThe hard outer layer of bones is composed of compact bone tissue, so-called due to its minimal gaps and spaces. Its porosity is 5–30%.[6] This tissue gives bones their smooth, white, and solid appearance, and accounts for 80% of the total bone mass of an adult skeleton. Compact bone may also be referred to as dense bone.Trabecular (cancellous) boneFilling the interior of the bone is the trabecular bone tissue (an open cell porous network also called cancellous or spongy bone), which is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten