KIN 3304 1nd Edition Exam 4 Study Guide Lectures 22 33 Lecture 22 October 19 The Respiratory System is divided into the upper respiratory system and the lower respiratory system The Upper Respiratory Tract o Nose nasal cavity paranasal sinuses pharynx o Warms and moistens the air You always humidify air o Protects the delicate LRS Well developed lymphoid barrier Superficial mucus barrier The Lower Respiratory Tract o Larynx trachea bronchi and lungs o Gas exchange occurs here o Larynx Closed during swallowing o Lumen of trachea Held open by incomplete C shaped cartilaginous rings Helps to keep airway open o Trachea bifurcates splits into main bronchi Then forms the bronchial tree Airway Generations The number of airway generations to reach the respiratory zone Airways get smaller but double in number Possible TQ s CO2 is just as important in the breathing process Passive Breathing uses just the diaphragm which is the major respiratory muscle Active Breathing uses more muscles Be familiar with muscles of inspiration and expiration You don t have lung muscles you have respiratory muscles Be familiar with the Respiratory Mechanics Picture Physiology of Respiration All processes involve the uptake of O2 and the release of CO2 3 Basic Processes o Mechanics of lung and thorax o Gas Exchange atmosphere to alveoli o Transport of gases in the blood Structure of Thorax Thorax provides structure and protection for lungs Allows for lung volume changes o The larger the individual usually the larger the lungs o Due to articulation of the ribs and diaphragm motion Lots of muscles Pleural Space Lungs are covered by thin visceral pleura and it normally contains a few mL of lubricating fluid Inspiratory force of chest wall diaphragm is transmitted to the lung by negative pressure Penetration rupture of the lung surface can happen here o Pneumothorax An abnormal collection of air or gas in the pleural space Common in tall slender men o Air can enter the thoracic cavity Gas Exchange Occurs in the alveoli when fresh inspired air comes in contact with capillary blood o Alveoli is what expands and contracts and they fill up with air Must pass through conductive airways o Some air remains in the CA means there is no exchange o CA are termed anatomical dead space because its using air to push air Respiratory bronchioles alveolar ducts sacs and alveoli Occurs where basal laminae of alveolar epithelium and capillaries have fused Rapid diffusion due to o Size o Gases are lipid soluble Alveolar Cells can be either Type 1 or Type 2 Type 1 o Creates air sacs Type 2 o Secretes surfactant that s a combination of a phospholipid o Absorbs Na H2O o Lowers surface tension o Keeps alveoli from collapsing o Has a structural interdependence Local distortion opposed by surrounding tissue If a small zone of alveoli collapses surrounding tissue stretches pulls zone back open Termed structural interdependence Along with surfactant collateral air pathways help prevent collapse of alveoli called atelectasis o Scattered among squamous cells Also have alveolar macrophages phagocytosis Lecture 23 October 31 Pulmonary Physiology in Pregnancy Tidal Volume increases o b c she s breathing for two Residual Volume decreases o b c the uterus is pressing up on the diaphragm Total Lung Capacity decreases o b c the uterus is pressing up on the diaphragm Expiratory Reserve Volume decrease o b c the uterus is pressing up on the diaphragm Partial Pressure Sea level PP ambient air 760 mmHg Usually measured dry o Water vapor is removed when comparing o Allows for universal comparisons 760 ambient air 47 water vapor in trachea 713 mmHg O2 Transport Hemoglobin Hb o One mole carries 4 moles of O2 Decrease in pH increase in PCO2 and temperature o Helps to unload O2 at the tissues o Ex exercise Normal Arterial O2 Content Fick s Equation VO2 Q x a VO2 difference o VO2 O2 consumption o Q cardiac output o CaO2 CvO2 difference between alveolar and mixed venous O2 content o CaO2 arterial O2 content o CvO2 mixed venous O2 content o PVO2 mixed venous PP of O2 Lecture 24 November 3 Gas Diffusion Simply from high to low concentration o In lungs between alveolar gas and capillary blood We call this the diffusion capacity DL o Total DL of lung made up of Diffusion process through alveolar membrane Resistance of RBC chemical combination with Hb RBC s spread every 75 seconds in alveolar capillaries o This is called the capillary transit time With normal DL o 25 seconds enough O2 crosses the membrane to bring Hb to equilibrium with alveolar PO2 With severely limited DL 25 o There will be diffusion abnormality o Low O2 saturation at rest disease Lecture 25 November 5 Things to know As soon as you go unconscious breathing resets Left lung is where the cardiac notch Hb will drop O2 to pick up CO Known what a collapsed lung looks like Incubator is similar in relation to the lower respiratory tract because a lot of stuff can grow there Iron lung Functions of the Respiratory System We will only be focusing on 2 o Gas Exchange o Move air to from Lung Surface Primary Bronchi The trachea branches into the right and left primary main bronchi o Extrapulmonary bronchi are located outside the lungs The main bronchi then travel to a groove hilum along the lung o This provides cross for pulmonary vessels and nerves o Anchored with dense CT the rest of the lung Bronchioles Tertiary bronchus branches many times ANS regulates activity and controls diameter Epithelium causes bronchodilation Parasympathetic stimulation causes bronchoconstriction Respiratory Bronchioles Each terminal bronchiole delivers air to a single pulmonary lobule Within a lobule terminal bronchiole branches into respiratory bronchioles o These deliver air to lung surface exchange o No mucus cells glands here Alveolar Ducts and Alveoli Respiratory bronchioles are connected to independent and multiple alveoli along alveolar ducts o They end at alveolar sacs o Why the lung is spongy in appearance There is a huge capillary network association with each alveolus o Surrounded by Elastic Fiber expansion Elastic Fibers are well developed Found at every level of respiratory system When lungs expand elastic recoil returns lungs to unexpanded volume Alveolus and Respiratory Membrane Alveolar epithelium consists primarily of simple epithelium Squamous epithelium cells type 1 or type 2 alveolar cells are thin delicate Blood Supply to Lungs Respiratory exchange surfaces receive blood from arteries of the pulmonary