DAT STUDY SET (Structure and Functions of Systems) Exam Questions With Accurate Answers.

DAT STUDY SET (Structure and Functions of Systems) Exam Questions With Accurate Answers. What are tissues? - answerGroups of cells that are similar in structure and function What is negative feedback? - answerBringing conditions back to their normal or homeostatic function What is positive feedback? - answerFeedback that increases the output of a process. What is respiration? - answerMovement of gases in and out; can also mean cellular respiration in which ATP is produced in the mitochondria What is thermoregulation? - answerControl of exchange of heat with the environment a. Ectotherms/poikilotherms/cold-blooded - obtained their body heat from the environment b. endotherms/homeotherms/warmblooded - generate their own body heat and have higher basal metabolic rate than ectotherms. What is the difference between external respiration and internal respiration? - answerExternal respiration is basically breathing. Internal respiration is cell respiration A breakdown of Invertebrate Respiration - answera. Cnidaria (Protozoa and Hydra) - simple diffusion of gases from the environment into the body (sufficient for small animals only) b. Annelids - they secrete mucus that provides a moist surface for gaseous exchange to take place (diffusion). The circulatory system brings oxygen to cells c. Anthropods - Grasshoppers ( have series of chitin-lined respiratory tubules called trachea that open to the surface via openings called spiracles). Spiders (Book lungs) d. Fish - Gills Countercurrent exchange in fish - answerThe exchange between opposing movements of water and underlying blood that maximizes diffusion of oxygen into the blood and carbon dioxide into water. ( The water has a higher concentration of oxygen while the blood has a lower concentration of oxygen. Oxygen will flow from the water into the blood). Describe the lungs - answerThese are invaginated structures made of two sub-portions (left lung and the right lung). The left lung is smaller and consist of 2 lobes, the right lung is made up of 3 lobes. The left lung is smaller in order to accommodate the heart. What is the name given to the membranous cover of the lung? - answerPleurae. There are two layers of pleurae; visceral and parietal pleura. The space between these layers is the intra pleural space . What is the function of the visceral pleura ? - answercovers the lungs What is the function of the parietal pleura? - answercovers the diaphragm Sequence of events during exhaling - answerDiaphragm rises - volume in lungs decreases - pressure inside the lungs increase relative to the atmosphere - air rushes out. How is CO2 transported in the blood? - answer- Bicarbonate (primary) - Dissolved in the plasma - Bound to hemoglobin The enzyme responsible for catalyzing the conversion of CO2 to HCO3- is carbonic anhydrase. Structures and functions of parts of the lung - answerAlveoli- where gas exchange between the circulatory system and lungs occur. There are two types of epithelial cells in human alveoli ( type 1 (structural support) and type 2 (produce surfactant)). Nose- Filters and moistens in coming air Pharynx - throat, passageway for food and air Larynx - voice box, if non gas enter here it results in coughing trachea - epiglottis covers the trachea during swallowing ; contains C shaped ringed cartilage covered by ciliated mucus cells bronchi - two bronchi enters the lungs and branch into narrower bronchioles Alveoli - Each bronchioles branches ends in these small sacs What are some detailed sequences of gas exchange? - answerDiffusion between alveolar chambers and blood ( O2 diffuses into the blood) bulk flow of O2 - O2 is transported through the body within hemoglobin containing red blood cells Diffusion of O2 from the blood into cells Bulk flow of CO2 - it is mainly transported through plasma as bicarbonate. Bohr effect - answerhemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide. If there is more CO2 in the blood, there will be more H+ ions that reduce hemoglobin causing the release of bound oxygen and vice versa. What are factors that promote the release of oxygen from hemoglobin or prevents the binding of oxygen to hemoglobin? - answerUse the mnemonic "CADET, face right" increase levels of CO2 increased acidity in the blood increased concentration of 2,3-DPG Exercise High temperature (Note when tissues are high in CO2, there will equally be an increase in acidity (decreased pH). Haldane effect - answerExplains how [O2] affects CO2 binding and release What structure is responsible for the control of respiration? - answerthe medulla oblongata . The medulla oblongata receiving a signal on the increased partial pressure of CO2, tells the diaphragm to contract this way inflating the lungs and bring O2 into the body. Interesting fact - CO2 is more soluble in blood than O2. Additionally, the medulla oblongata has central chemoreceptors and the heart has peripheral chemoreceptors that monitor the body. What is the function of central chemoreceptors? - answerdetect the concentration of CO2 and pH in the cerebrospinal fluid What is the function of peripheral chemoreceptors? - answermonitors the atrial concentrations of CO2, O2 and ph via H+ List of diseases relating to respiratory cells - answera. Ciliated pseudostratified columnar epithelial cells - These are found in trachea and upper respiratory system. May contain goblet cells for mucus production. b. emphysema - a pathology marked by destruction of the alveoli c. Effects of smoking - smoking can damage the cilia of the respiratory cells and allow toxins to remain in the lung What is the difference between respiratory acidosis and alkalosis? - answerrespiratory acidosis is as a result of inadequate ventilation (CO2 building up in the body as well as H+ lowering ph). respiratory alkalosis is as a result of breathing rapidly ( in order for the body to compensate for the rapid loss of CO2, it combines HCO3- and H+ to form more CO2, increasing the pH). Facts about myoglobin and fetal hemoglobin curves - answerMyoglobin of the muscles has a hyperbolic curve. Myoglobin also saturates quickly and releases in situations of very low oxygen " emergency situations".