Respiration (1) PDF

Respiration Dr Zeinab Hussein Bakr  Introduction Org ns auociated with the respiratory ct: -Mouth - Nose - Larynx -Trachea -Bronchi - Bronchioles -Alveoli -Air Sacs. The alveoli are v...

Respiration Dr Zeinab Hussein Bakr  Introduction Org ns auociated with the respiratory ct: -Mouth - Nose - Larynx -Trachea -Bronchi - Bronchioles -Alveoli -Air Sacs. The alveoli are very thin walled and are surrounded by a network of capillaries; they offer a huge internal surface where exchange of gases takes place. Pleural sac-surrounds the lungs fonned of 2 layers. Pleural cavity - airtight. - - -- -- - -  Definition of Respiration: Respiration is the exchange of gases between an organism and its environment i.e. intake of oxygen and output of carbon dioxide.It is the process by which all living organisms release the energy needed for their living activities.  Respiration consists of external and internal respiration: External Respiration: This is the exchange of gases between the blood in the pulmonary capillaries and the air in the lungs. Internal Respiration: This is the exchange of gases between the blood and the tissue cells. The respiratory cycle: At rest a normal adult about 16 times/minute. Each respiration cycle consists of inspiration, expiration.  Inspiration: The tips of the ribs are pulled upward and outwards by contracting of the intercostals muscles. The dome shaped diaphragm is flattened by contraction of its muscles, the chest cavity is enlarged, the air pressure outside forces air into the lungs through the glottis. Expiration: The tips of the ribs move backwards. The muscles of the diaphragm relax and it bulges into the thorax, partly also the pressure of the abdominal organs.The chest cavity is reduced, the pressure inside is increased, (positive pressure)and the air is driven out of the lungs, decrease in size. Control and regulation of Respiration: ► Respiration is essentially an involuntary act i.e. it is carried out automatically and without thought. ► Respiration is however, partly under our voluntary control e.g. one can cease breathing for a time or vary the rate or the rhythm of respiration as swallowing, coughing, sucking, blowing, swinging etc........ ► Breathing can be suspended voluntarily for more than 45 seconds or so, at the end of the time one is compelled to take a breath.  Factors that help to regulate res pi ration: Neural regulation: Respiratory center located in the medulla oblongata are part of the nervous system that controls breathing. It measures the blood's level of oxygen and carbon dioxide and uses the respiratory muscles to provide the appropriate signals. ✓ Carbon dioxide concentration in the blood. ✓ H+ concentration in the blood. ✓ Stretching of the thoracic and pulmonary walls. ✓ Oxygen saturation in the blood.  Normal respiration: - The normal respiration rate for healthy adults=12- 20 times/minute. - The usual ratio of respiration rate and pulse rate is around 1:4. - If the pulse is increasing, respiration will usually increase correspondingly as well. At birth the rate of respiration =30-40 times/ minute. Old age =14-16 times/minute.  Factors causing variation in res pi ration: - Age: the respiration rate is much greater in the new born than in the adult. - Sex: the females tend to have a slightly greater rate of respiration than in male. - Rate: an increase in respiratory rate causes swallowing of breathing and vice versa. - Exercise and muscular activity: causes a temporary increase in respiratory rate. - During digestion: respiration may be slightly increased in rate during the digestion of food.  - Diseased conditions: the rate of respiration may be increased or decreased by disease,depending upon the disease and its effect on the body. Stimulant drugs as caffeine make the respiration faster and shallower. - Drugs: depressant drugs as morphine or general anesthetics will make respiration slower and deeper. CO2 a respiratory stimulant, is often used with the administration of a general anesthetic to help overcome the depressant action of the drug. - Application of cold: stimulation of nerve endings in the skin makes breathing fuller, deeper and slower. - Application of heat: e.g. hot water bottles increased respiratory rate temporarily and causes swallowing of breathing. - Pain: sever pain tends to increases the rate of respiration. - Toxins: stimulate the respiratory center and cause increased respiration. - Fever: this usually causes an increase in the rate of both pulse and respiration. - Hemorrhage: the decrease blood volume blood will decrease the amount of oxygen supplied to tissue cells its increases respiratory rate. - Change in atmospheric pressure: e.g. high attitudes cause an increase in respiration rate in an attempt to meet the increased demand for oxygen.  Types of respiration: Eupnea: regular, normal respiration. Apnea: a temporary cessation of breathing. Dyspnea: difficulty or painful breathing. Hyperpnoea: increase respiration -both rate and depth may be increased. Orthopnea: inability to breath or difficulty in breathing while lying in a horizontal position.  Cyanosis: blueness or discoloration of the skin and mucous membrane caused by lack of 02 in the blood. Air hunger: a characteristics symptom indicating a lack of sufficient oxygen for the proper functioning of tissue cells. Deep respiration: when the volume of air inspired and expired is more than 500cc with each respiration. Shallow respiration: if the nature of air inspired and expired is less than 500cc with each respiration. Polypnea: is a rapid breathing. Cheyne - Stokes respiration: this consists of periods of hyperpnea followed by period of apnea occurring in a rhythmic cycle, each paroxysm lasting 30-40 seconds. Stretoruo breathing: breathing accompanied by abnormal, abounds resembling snores. Thank You