Respiratory System for Nursing PDF

Respiratory system - overview  Consists of: 1- Nose & nasal cavity 2- Air passages: ❖ Pharynx ❖ Trachea ❖ Bronchi ❖ Bronchioles 3- Lungs – Alveoli  Nose  Nose has a nasal cavity that leads to the pharynx.  Nasal cavity is lined with...

Respiratory system - overview  Consists of: 1- Nose & nasal cavity 2- Air passages: ❖ Pharynx ❖ Trachea ❖ Bronchi ❖ Bronchioles 3- Lungs – Alveoli  Nose  Nose has a nasal cavity that leads to the pharynx.  Nasal cavity is lined with cilia and hairs and goblet cells that make mucus (antiseptic and moisten air)– filter the air – dust, pollen and other foreign material sticks to it..  Pharynx – pass air form nose to trachea via larynx.  Trachea: long, straight tube kept open by C-shaped cartilage rings.  Trachea – lined with cilia and goblet cells (mucus production) – traps foreign particles  Trachea: -divides into 2 bronchi (right and left) – consist of C-shaped cartilage rings and lined with cilia goblet cells (mucus).  Bronchi: - branch in lung to form bronchioles – branch further and cartilage rings disappears – lead air to air sacs of lung.  The lungs are the primary organs of the respiratory system in humans  Spongy, elastic pink organ.  Consists of several air sacs called alveoli.  Alveoli are grouped together and form the endings of the bronchioles.  Right lung → (3 lobes - shorter)  left lung → (2 lobes – longer, narrow).  it is a hollow cup-shaped cavity found in the lung parenchyma where gas exchange takes place  it is lined with single layer squamous epithelial cells →Thin easy diffusion of gas.  Alveoli is surrounded by a network of blood capillaries → gasses diffuse into and out of blood.  Alveoli is lined with moist layer→ oxygen dissolves in moisture and diffuses through alveoli wall into blood capillary.  Pulmonary vein Pulmonary (Oxygenated artery blood) (Deoxygenated blood) Turbinate bones Pharynx Alveoli Trachea Bronchus Bronchiole Diaphragm SEM TEM  Pulmonary surfactant pulmonary surfactant →↓↓surface tension at the air–water interface in the alveoli → preventing collapse of these structures at end-expiration. so, surfactant reduces the work associated with breathing Premature lung in premature infants→ Infant respiratory distress syndrome 1- Breathing : Inspiration and expiration. 2- Respiration A- External respiration: Gas exchange between air (in lungs) and blood. Blood then transport Oxygen to the body tissue cells. B- Internal respiration: Gas exchange between blood and tissue fluid. Blood then transports carbon dioxide to the lungs. Gas exhange surface must be: Alveoli filled with air (gas) External Moist respiration Carbon dioxide oxygen Thin Large in relation of size of body Blood – part of circulatory system contain red pigment Process: Diffusion of – hemoglobin, to gasses (oxygen and transport gasses carbon dioxide Internal respination oxygen Carbon dioxide Body cells surrounded by tissue fluid  Is the process whereby an organism uses oxygen and food to produce energy (ATP) and 2 by products e.g. water and carbon dioxide  Glucose + O2 ATP + H2O + CO2 Therefore gaseous exchange is necessary for to get oxygen for cellular respiration.  Breathing Respiratory centers Nervous control of breathing Common bronchial and pulmonary diseases   INSPIRATION  EXPIRATION Air inhaled Air exhaled Rib cage expands Rib cage as rib gets muscles smaller as contract rib muscles relax When pressure in lungs increase – When pressure in air is pushed out INSPIRATION lungs decrease – Diaphragm EXPIRATION Diaphragm contracts relaxes air rush in (moves down) (moves up)  The lungs are not completely emptied during each breathing cycle.  The air entering mixes with used air remaining in the lungs.  This help to conserve water, but decreases gas-exchange efficiency Tidal volume: is the amount of air that moves in or out of the lungs with each respiratory cycle. 500 mL in healthy adult male and 400 mL in a healthy female  A spyrometer can be used to determine how much air enters the lungs.  Your lungs has a volume of +/- 5 liters (Total lung capacity)  During a normal breath, only 0.5 liters of air is exchanged – This air is known as tidal volume.  During forced breathing, as much as 3.5 liters of air can be exchanged, this is known as vital capacity. (The fitter you are, the higher your vital capacity.)  Residual air/volume: +/- 1.5 liters of air always remains in the lungs  Normal breathing rate for adults: 12 – 20 breaths per minute  Respiratory Center in the Medulla Oblongata of the brain controls breathing. The respiratory center send impulses through: Phrenic nerve → diaphragm Intercostal nerve → intercostal muscles (Contract during inspiration and relax during expiration)  Brain Respiratory center automatically regulates breathing Intercostal nerves stimulate the intercostal muscles Intercostal muscles Pheric nerve stimulates the diaphragm Diaphragm  Most oxygen is transported by hemoglobin (red pigment protein in erythrocytes).  Oxygen combines with hemoglobin to form oxyhemoglobin. Hb + O2 = HbO2 Hemoglobin Oxygen Oxyhemoglobin  A small amount of oxygen is transported in solution in the blood plasma.  Consist of 4 polypeptide chains (protein – 2 alpha and 2 beta).  Each chain is associated with a heme group.  Each heme group contains an iron atom.  Iron binds with oxygen. Each red blood cell carries 250 million Hb molecules = 1 Billion Oxygen molecules  Most CO2 is transported as bicarbonate ions (HCO3-) HOW? FIRST CO2 binds with water to form carbonic acid (H2CO3) CO2 + H2O = H2CO3 Then carbonic acid dissosiates to form hydrogen and bicarbonate ions. H2CO3 = H+ + HCO3-  The higher the amount of hydrogen ions in the blood the lower the pH.  Therefore hydrogen ions bond with the globin part of Hb to keep the pH normal in the blood.  A small amount of carbon dioxide is transported by the Hemoglobin molecules in the form of carbaminohemoglobin (HbCO2). CO2 + Hb = HbCO2