Nursing notes for first year, Lecture notes of Nursing

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Overview of the

Respiratory System

 Major function is to exchange oxygen and carbon dioxide between the body and the environment. Respiratory division  Gas exchange process takes place Serves as passageways for air to flow in and out of the lungs:  Nose  Pharynx  Larynx  Trachea  Bronchi and bronchioles  Adding up the conducting division Conducting Division Nasal cavity  Lined with ciliated mucus membrane *sticky mucus traps inhaled particles; cilia drives debris-laden mucus toward the throat to be swallowed Bacteria(inhaled) are destroyed by:  Lysozyme in mucus  Lymphocytes and antibodies (lgA)

• Additional protection against potential pathogens Nasal conchae/ turbinates  Three folds of tissue in nasal cavity wall
• Superior
• Middle
• Inferior  Serve to increase the contact surface with inhaled air, allows nose to rapidly warm, moisten and cleanse it. Olfactory nerve cell  Found in the roof of nasal cavity  Sense of smell *from the nose, inhaled air turns 90 degrees downward as it reaches the pharynx. This is another trap for large dust particles *crash into the posterior wall of the throat, and stick to the mucosa Pharynx (throat)  Nasopharynx  Oropharynx  Laryngopharynx  Houses several tonsils  Also passes food and drink from the mouth to the esophagus Tonsils (lymphoid tissue)  Pharyngeal  Palatine  Lingual  Positioned to respond to inhaled pathogens. Larynx  Guarded by tissue flap called epiglottis *during swallowing, larynx is pulled up and epiglottis flips over Epiglottis  Directing food and drink to the esophagus  Vocal folds also closes to protect the airway *from the larynx, air passes to the trachea Trachea  Windpipe  Has primary bronchi (2) supplying the two lungs
• Secondary bronchi
• Tertiary bronchi
• Bronchioles (bronchial tree) Airways  Have a layer of smooth muscle in their walls that allows them to construct and dilate  Airways dilate during exercise to increase airflow  Airways constrict to minimize the entry of pollutants to the lungs Ciliated columnar epithelium  Larynx, trachea, and bronchial tree  Produces mucus  Functions as mucociliary escalator Terminal bronchioles (last component of conducting division)  Branch into several respiratory bronchioles which marks the beginning of respiratory division Respiratory bronchioles  Ends with microscopic air sacs called alveoli Alveoli  Surrounded by blood capillaries  Composed of:  type 1 thin squamous cells (gas diffusion) *inhaled oxygen moves from alveoli into the blood in the capillaries *carbon dioxide relocates from the blood to the alveoli to be exhaled out  type 2 cuboidal cell (surfactant secretion) *function is to lower the surface-tension and prevent alveolus from collapsing  Where the gas exchange process takes place(respiratory division)

 Houses macrophages - engulfs particles that managed to past previous barriers to the lungs and rides mucociliary escalator up to the throat to be swallowed and digested *oxygen moves from the alveoli into the blood in the capillaries *carbon dioxide relocates from the blood to the alveoli to be exhaled out of the body

Gas Exchange

I.

• after the tissue used oxygen, blood will return to the heart
• blood returning to the blood is deoxygenated blood
• deoxygenated blood leaves tissue through:  Venules  Veneuls  Inferior/ superior vena cava of the heart II. *from the heart, this will pump the deoxygenated blood through pulmonary artery III. *as the deoxygenated blood enters the lungs, the blood will offload the carbon dioxide and the lungs will re-oxygenate the blood forming oxygenated blood IV.
• oxygenated blood will go back to the heart through the pulmonary vein
• the heart will pump the oxygenated blood to tissues through:  Aorta  Artery  Arterioles  Capillaries  Then to tissues V.
• within the tissues, oxygen is being offloaded into the tissue to use it as energy
• carbon dioxide is released back to the blood

Offload of oxygen and carbon

dioxide in Red blood cell and

Tissue

I. two ways oxygen enters tissue from the blood

• some oxygen can be dissolved in plasma and enters the interstitial fluid and onto the tissue
• most oxygen is transported through blood cells; molecule (hemoglobin). This enters the interstitial fluid and onto the tissue II. ways carbon dioxide offload from the tissue to blood
• some carbon dioxide, very little amount, can be transported through plasma
• some of it can react through water through slow process forms bicarbonate and hydrogen ions. Carbon dioxide is transported as bicarbonate
• most of the carbon dioxide will enter the red blood cells and then react with water

• within red blood cell have this membrane bound enzymes, carbonic anhydrase
  • carbonic anhydrase will fast process converts carbon dioxide and water to form bicarbonate and hydrogen ion
• bicarbonate pumped out by the red blood cell into the actual plasma and bring in to the rbc chloride ion

• another mechanism, where carbon dioxide can enter the red blood cell and attach with hemoglobin to form carbo amino hemoglobin Carbon dioxide transport (shortcut)  Dissolved in plasma  Carboamino hemoglobin  Bicarbonate plasma (slow and fast process)  Carbon dioxide and pH  Increase carbon dioxide, decrease in pH (acidic)  Decrease in carbon dioxide, increase in pH (alkaline)

How carbon dioxide is offloaded

and oxygen is transported in

lungs (within the alveoli)

 Pulmonary artery for coming in  Pulmonary vein for going out I. *some carbon dioxide is transported through plasma, and enters the alveolus

• majority of carbon dioxide is transported is bicarbonate

• bicarbonate can react with hydrogen ions in the blood through slow process and enter the alveolus
• much of these bicarbonate can enter the red blood cell and bring out chloride ion in exchange. Through a fast process, it’s fast because of carbonic anhydrase present, and exit the red blood cell and enters the alveolus

• some of the carbon dioxide is transported I blood bound to hemoglobin as carboamino hemoglobin. This will exit from the red blood cell and enters the alveolus II. *small amount of oxygen will be transported or inhaled in as plasma *most will enter the red blood cell and bind with hemoglobin.

Oxygen transport (shortcut)  Dissolved in plasma  Bound to hemoglobin

Pneumonia

 Infection/ inflammation of lung tissue  Caused by variety of pathogens including bacteria, virus, and fungi

Signs and symptoms

 Cough  Dyspnea rapid breathing  Chest pain  Tachycardia *pneumonia can be categorized into several types *one way to categorized it is how it affects the lungs or where it affects the lungs

Two types

 Lobar pneumonia  Bronchopneumonia What happens in pneumonia?  Buildup of fluid within the lungs which referred to as consolidation

Consolidation

 Water  Blood  Pus  Microbes *filling the lung tissues *alveoli are filled with fluid

Alveoli

 Functional unit of the lungs  Where oxygen and carbon dioxide is exchanged Pneumonia can be categorized on where the person has developed the signs and symptoms of pneumonia:

Community- acquired pneumonia

*causative agents are:  Streptococcus pneumonia  Haemophilus influenza  Moraxella catarrhalis

Hospital- acquired pneumonia

*causative agents are:  Staphylococcus aureus  Pseudomonas species  Enterobacteriae

Examination

 Decreased lung expansion on the affected side  Dullness on percussion on the affected lung or lobe  Crackles or rails on auscultation *X-ray is one of the lines of investigation performed *findings can include the site of consolidation

Risk Factors for Pneumonia

 Smoking  Recent respiratory infection  Recent antibiotic use  Recent travel  Age above 65  Immunosuppressed *patients are hospitalized based on a set of criteria indicates severity *patients are treated with therapy based on history, examination, and comorbidities

Lung volumes and

Capacities

 Volume of our lungs depends on the mechanics of our lung tissue, chest wall, and respiratory muscles

4 different types of lung volume

Tidal volume (TV)  Slow air, quiet breath, type of breathing we do most often  5000 ml or 0.5 L Inspiratory Reserve Volume (IRV)  Forceful inhalation of air  2.5 L Expiratory Reserve Volume (ERV)  Forcefully exhale air  1.5 L Residual Volume (RV)  Air or gas we cannot forcefully exhale  1.5 L IRV 2.5L TV 0.5L ERV 1.5L RV 1.5L  Vital Capacity (VC)- IRV, TV, ERV  Inspiratory Capacity (IC)- IRV, TV  Functional Residual Volume (FRV)- ERV, RV  Total Lung Capacity (TLC)- IRV, TV, ERV, RV

Diseases  Obstructive diseases  Restrictive diseases Restrictive Disease  Is like pulmonary fibrosis, fibrosis is a scar tissue in the lungs  Limits the lungs compliancy, their ability to stretch  Amount of air can breathe in is limited, the same to amount of air you can exhale IRV reduced TV ERV reduced RV reduced *Total capacity of lungs in restrictive disorder is reduced Obstructive Disorder  Emphysema, chronic bronchitis  Obstruction in the airways itself

• Mucus
• Narrowing of airway  When breathes in, everything opens up  Inhaling is not limited  When breathes out, the airway narrows preventing gasses to leave  Gasses remain in lung tissue IRV normal TV ERV dicreases RV Increases *Total capacity of lungs in obstructive disorder is increased