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Chest Surface and Pleura Cavity Advanced Anatomy & Physiology Tony Serino, Ph.D. Biology Department Misericordia Univ. Thoracic Vertebrae Vertebrae and Ribs Rib Types and Sternum Rib Anomalies Cervical ribs Bicipital rib (rib fusion) Bifid rib (two heads) 1st rib 2nd rib Crest of head Head Neck Tubercle 11th rib 12th rib Ribs Clavicle Scapula Scapular Fossa Superficial Muscles Deltopectoral triangle (contains Cephalic vein) Thoracic Apertures Superior Inferior Breast Male nipple at T4 Dermatome Female Breast Retromammary space Suspensory ligaments Tail of breast Glandular tissue and stroma Female Breast Retromammary space Blood supply to the Breast Lateral thoracic (from axillary a.) Internal thoracic a. (from subclavian) Anterior intercostals Post. Intercostals (from thoracic aorta) (Venous drainage mostly to axillary v. and internal thoracic v.) Lymphatic Drainage of Breast Axillary nodes Parasternal nodes Pectoral nodes Subareolar plexus Inferior phrenic nodes Untreated Breast Cancer Muscles of Thorax Primary muscles of respiration Only used during rapid breathing. Chest Plate Pressures affecting Breathing Inspiration Expiration Pressure changes around lung Lung Volumes Normal Lung Volumes Nerves of thoracic wall Intercostal arteries and nerves Pleura Cardiac notch Costomediastinal recess Costodiaphragmatic recess Surface to Deep Structure Alignment Bare Pericardium Respiration • External Respiration – The exchange of gas between the blood and external environment (usually includes ventilation) • Internal Respiration – The exchange of gas between the blood and the tissues • Cellular Respiration – Burning of fuel to produce energy within cells • Ventilation (Breathing) – Movement of air in and out of the lungs Respiratory Organs – Divided into: • Upper Respiratory Tract – Includes: nostrils (nares), nasal cavity, and nasopharynx • Lower Respiratory Tract – Includes: larynx, trachea, bronchi, and lungs – Conducting Air passages include: nares to terminal bronchioles • Move air to respiratory membrane • Condition the air – Moisten, Warm, Clean Trachea Trachea (x.s.) Mucous Membrane (pseudostratified columnar epithelium) Bronchi • Primary bronchi lead to to each lung (left and right) • Secondary (lobar) bronchi lead to each lung lobe (3 on right and 2 on left) Cadaver Lungs Lobes of Right Lung Lobes of Left Lung Bronchi Branches Tertiary Bronchi Primary Bronchi Secondary Bronchi Tertiary (segmental) bronchi lead to each lung bronchopulmonary segment Bronchi continue to divide at least 20 more times. Broncho-pulmonary Segments Lung Blood Supply PA PV Note: blood supply to respiratory surface; airway blood supplied by bronchial a. (branch of aorta) Blood pathways Bronchi PA PV Bronchioles • Air passages less than 1 mm in diameter are bronchioles. • The terminal bronchioles are the last of the purely conducting air passages. Alveoli highly specialized for Gas Exchange •Lots of Surface Area •Highly vascular •Thin walls Lung Tissue Alveolus P = pressure to collapse T = surface tension r = radius Role of surfactant is to decrease surface tension in alveoli. Partial Pressure Favors Resp. Gas Movement Time to Complete O2 Saturation in Pulmonary Capillaries Oxygen Content of Blood Plasma Whole Blood PO2 = 100 mmHg Oxyhemoglobin O2 PO2 = 100 mmHg Oxygen Total Volume of Oxygen = 0.3ml Plasma + 20 ml whole blood Hemoglobin Oxyhemoglobin Dissociation Curve Hemoglobin Affinity for Oxygen: Effect of Temperature Affinity decreases with increasing Temperature Hemoglobin Affinity for Oxygen: Effect of pH Affinity decreases with increasing acidity (i pH) Gas Exchange in Lungs Gas Exchange in Tissues 10% 70% 20% Neural Control of Breathing Neural Control Voluntary control located in cerebral cortex and acts through the corticospinal tract. of Breathing Involuntary located in pons and medulla acting through the spinal cord in the roots of the phrenic nerve (C3-C5) and thoracic cord roots of the external (inspriation(I)) and internal (expiration(E)) intercostal nerves PRG –pontine resp. group (formerly the apneustic and pneumotaxic centers) –play role in smoothing between insp. and exp., especially during sleep, vocalization and exercise. VRG and DRG – ventral and dorsal resp. group of the medulla. DRG primarily responsible for inspiration; VRG mixture of I and E neurons contains Pre-Botzinger complex which may be pacemaker cells for respiration Neural control of Breathing • Red is inhibitory • Black is excitatory PRG DRG Hering-Breuer I neurons Reflex Ext. Intercostals & diaphragm Lung Stretch Chemoreceptors VRG E neurons Int. Intercostals Factors Effecting Respiratory Centers CO2 Drive