tailieunhanh - Histology colour atlas - Textbook (Fifth edition): Part 2

(BQ) Continued part 1, part 2 of the document Histology colour atlas - Textbook (Fifth edition) has contents: Respiratory system, digestive system - oesophagus and stomach, small and large intestines, urinary system, male reproductive system, female reproductive system, endocrine glands,. and other contents. Invite you to refer. | 11 Respiratory System Pattern of right and left bronchial tree are mirror images but the heart on left side gives less room The respiratory system provides for the intake of oxygen and elimination of carbon dioxide which are transported to and from the tissues of the body by the circulatory system. Organs of respiration are nose comprising external nares nasal cavity posterior nares including the paranasal air sinuses. Nasopharynx Larynx Trachea Pleura lungs including the bronchial tree. Functionally the respiratory system is divided into i. Conducting part which comprises nose nasopharynx larynx trachea and bronchial tree till the level of terminal bronchioles. These are always patent for respiration. ii. Respiratory part comprising of respiratory bronchioles alveolar duct atria alveolar sac and alveoli. These are present in the spongy part of lung for exchange of gases. HISTOLOGY OF NOSE NASOPHARYNX AND LARYNX Filtering warming and moistening the inspired air NOSE Comprises two nasal cavities separated by a nasal septum. Its functions are i. ii. Conducting air to and from the lungs iii. As an organ for smell. The receptors for smell are placed in the upper one-third of nasal cavity and is lined by olfactory mucosa with special olfactory neurons. It is described in Chapter 19. The lower two-thirds of nasal cavity is lined by respiratory mucosa which is pseudostratified ciliated columnar epithelium with goblet cells. The lamina propria contans mucous and serous secreting glands lymphocytes plasma cells and large venous plexus. Functions The cilia of the columnar cells carry foreign particles towards oropharynx to be swallowed. Goblet cells produce mucus to trap foreign particles. The cells in lamina propria provide necessary immunity. Clinical Features The nose nasopharynx get attacked by various bacteria pollutants and allergans causing sinusitis and tonsillitis. The venous plexus may rupture due to picking heat leading to epistaxis bleeding from nose . .