Respiratory System Lecture Notes PDF

PHYSIOLOGY  Physiology is the science of body functions—how the body parts work  Physiology is the scientific study of functions and mechanisms in a living system.  As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, c...

PHYSIOLOGY  Physiology is the science of body functions—how the body parts work  Physiology is the scientific study of functions and mechanisms in a living system.  As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and physical functions in a living system. RESPIRATORY SYSTEM LEC 1 Dr Hina Abrar Assistant Professor Dow college of Pharmacy RESPIRATORY SYSTEM OBJECTIVES  At the end of lecture student will be able to define respiratory system Anatomy of the system Functions of respiration Mechanics of respiration Types of respiration Respiratory Physiology RESPIRATORY SYSTEM The respiratory system contributes to homeostasis by providing for the exchange of gases— oxygen and carbon dioxide—between the atmospheric air, blood, and tissue cells. It also helps adjust the pH of body fluid DEFINATION  Process by which O2 is taken in CO2 is given out by lungs or  Exchange of O2 and CO2 atmosphere and body cells. or  The transport of oxygen from the out side air to the cells within tissues and transport of CO2 in the opposite direction. ANATOMY OF RESPIRATORY SYSTEM  INTRODUCTION  Goals of respiration To provide O2 to the tissue To remove CO2 from the tissue It helps in air conditioning Warmed/cooled Moistened Cleaned RESPIRATORY SYSTEM Functionally divided into Conducting zone Respiratory zone  Conducting zone The conducting zone consists of a series of interconnecting cavities and tubes both outside and within the lungs. These include the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles; Function filter, warm, and moisten air and conduct it into the lungs.  RESPIRATORY ZONE Consists of tubes and tissues within the lungs where gas exchange occurs. These include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli Function main sites of gas exchange between air and blood. STRUCTURALLY,  The respiratory system consists of two parts: (1) The upper respiratory system includes the nose, nasal cavity, pharynx, and associated structures; (2) The lower respiratory system includes the larynx, trachea, bronchi, and lungs.  DIVISIONS OF THE RESPIRATORY SYSTEM  Upper respiratory tract (outside thorax)  Nose  Nasal Cavity  Sinuses  Pharynx Larynx  DIVISIONS OF THE RESPIRATORY SYSTEM  Lower respiratory tract (within thorax)  Trachea  Bronchial Tree  Lungs  STRUCTURES OF THE UPPER RESPIRATORY TRACT  Nose - warms and moistens air  Palantine bone separates nasal cavity from mouth.  Cleft palate - Palantine bone does not form correctly, difficulty in swallowing and speaking.  Septum - separates right and left nostrils  rich blood supply = nose bleeds.  Sinuses - 4 air containing spaces – open or drain into nose - (lowers weight of skull).  STRUCTURES OF THE UPPER RESPIRATORY TRACT  Pharynx - (throat)  Base of skull to esophagus  3 divisions Nasopharynx - behind nose to soft palate.  Adenoids swell and block. Oropharynx - behind mouth, soft palate to hyoid bone.  tonsils Laryngopharynx - hyoid bone to esophagus.  STRUCTURES OF THE LOWER RESPIRATORY TRACT  Larynx - voice box Root of tongue to upper end of trachea. Made of cartilage 2 pairs of folds  Vestibular - false vocal cords  True vocal cords  STRUCTURES OF THE LOWER RESPIRATORY TRACT LARYNX  Thyroid cartilage - adam’s apple - larger in males due to testosterone.  Epiglottis - flap of skin (hatch) on trachea, moves when swallowing and speaking. closes off trachea when swallowing food  STRUCTURES OF THE LOWER RESPIRATORY TRACT  Trachea (windpipe) Larynx to bronchi Consists of smooth cartilage and C shaped rings of cartilage.  STRUCTURES OF THE LOWER RESPIRATORY TRACT  Bronchi Tubes that branch off trachea and enter into lungs Ciliated Branches: Primary bronchi—secondary bronchi—tertiary bronchi—bronchioles Bronchioles branch into microscopic alveolar ducts. Terminate into alveolar sacs Gas exchange with blood occurs in sacs. STRUCTURES OF THE LOWER RESPIRATORY TRACT  STRUCTURES OF THE LOWER RESPIRATORY TRACT  Lungs Extend from diaphragm to clavicles Divided into lobes by fissures. Visceral pleura adheres to the lungs. (Plural – bronchi) Bronchioles  RESPIRATORY PHYSIOLOGY  Pulmonary Ventilation = breathing Mechanism  Movement of gases through a pressure gradient - high to low.  When atmospheric pressure (760 mmHg) is greater than lung pressure -- -- air flows in = inspiration.  When lung pressure is greater than atmospheric pressure ---- air flows out = expiration.  RESPIRATORY PHYSIOLOGY  Pressure gradients are established by changes in thoracic cavity. increase size in thorax = a decrease in pressure --- air moves in. Decrease size in thorax = increase in pressure --- air moves out. http://people.eku.edu/ritchisong/301notes6.htm TYPES OF RESPIRATION  Two types External respiration  Between lungs and blood Internal respiration  Between blood and tissues PHASES OF RESPIRATION  Inspiration  Expiration FUNCTIONS OF RESPIRATION  Provides for gas exchange: intake of O2 for delivery to body cells and removal of CO2 produced by body cells. Helps regulate blood pH. Contains receptors for sense of smell Filters inspired air Produces vocal sounds (phonation) Excretes small amounts of water and heat.