Tiêu đề MOD8-1.1-Histology of the Respiratory System (Laboratory).pdf ✅

ANAT ● ANATOMY Histology of the Respiratory System (Laboratory) TRANS #1.1 D MODULE 8 r. N. Calimbahin & Dr. S. Remulla December 19, 2022 LECTURE OUTLINE I Nose, olfactory epithelium II Nasal septum A. Nasal Septum B. Nasal Turbinates C. Nasal Cavity D. Hard Palate III Epiglottis IV Larynx, Vocal cord V Trachea VI Lung A. Lung 1 B. Lung 2 C. Lung 3 D. Lung-Fetus VII Blood-Air Barrier VIII Electron Micrographs IX References X Practice Questions XI Rationale LECTURE OBJECTIVES 1. Identify the essential features of normal anatomy at the cellular, tissue, and organ system level of the respiratory system and electron micrographs. I. NOSE, OLFACTORY EPITHELIUM ● located at the roof of the nasal cavity and the superior turbinate ● contains receptors for the sense of smell ● occupies a small area ( about 5 cm2 ), and it stands out the surrounding pinkish respiratory epithelium ● A pseudostratified columnar epithelium with no goblet cells and an indistinct basement membrane makes up the olfactory epithelium. ○ Taller and more cellular than respiratory epithelia ● Lamina propria ○ Contains Mucosa-associated Lymphoid Tissue (MALT) ○ It is richly supplied with blood and lymphatic vessels ○ Contains olfactory glands (glands of Bowman) Types of cells that compose the olfactory epithelium Figure 1. Olfactory epithelium of the nose, under high magnification a. Sustentacular (supporting) cells b. Olfactory cells c. Basal cells ● Sustentacular cell ○ These are characterized as tall and slender cells that are broad at their apices and narrow at their bases ○ Its apical surface contain numerous long and slender microvilli covered in mucous ○ There are also ovoid shaped nuclei located above the center of the cell ○ The cytoplasm of the cell contains a small Golgi complex, numerous sER lipofuscin granules that are responsible for the yellowish brown color of the olfactory area and provides it with structural support for the olfactory cells ● Olfactory cell ○ These are bipolar spindle neurons that sit between the sustentacular cells. ○ The receptor elements of the olfactory cell are the dendrites. ○ The axons aid in the transmission of olfactory stimuli to the olfactory cortex. ● Basal cell ○ Small, rounded or conical, deeply stained cells found between the bases of the sustentacular and olfactory cells. ○ A dark and ovoid nucleus with branching cytoplasmic processes ○ Basal cells are stem cells that can develop into sustentacular and olfactory cells ● Two types of Epithelium that are both pseudostratified columnar ○ Respiratory Epithelium ○ Olfactory Epithelium Group 8A | Histology of the Respiratory System (Laboratory) 1
Figure 2. Lamina propria of the olfactory epithelium, under high magnification ● Lamina Propria ○ This is the section where the glands of Bowman (olfactory glands) are embedded. ○ Olfactory glands are tubuloalveolar serous glands, the secretions of which moisten the skin and acts as a solvent for epithelial surface odoriferous substances. II. NASAL SEPTUM Figure 3. Nasal Septum under low magnification ● Nasal Septum ○ Divides the nose into its left and right halves ○ Median bony structure that divides the nasal cavity into the nasal fossae. ○ Made up of septal cartilage ● Nasal Cavities ○ These are the spaces found immediately lateral to the nasal septum ● Nasal Turbinates (Conchae) ○ These are the three shelf-like structures that are found hanging on the lateral wall of each nasal cavity. ● Hard Palate ○ This forms the lowermost border of the Nasal Septum A. Nasal Septum Figure 4. Nasal Septum under high magnification ● Composition of the framework ○ Superior: Hyaline Cartilage ○ Inferior: Bone and Hyaline Cartilage ● The epithelium is lined by respiratory epithelium (ciliated pseudostratified epithelium) ● There are six cells that comprise the Respiratory Epithelium ○ Goblet cells ○ Ciliated columnar cells ○ Basal cells ○ Brush cells - these are not seen in the slide ○ Serous cells - these are not seen in the slide ○ Granule cells - these are not seen in the slide Figure 5. Nasal Septum (Respiratory Epithelium) under high magnification ● Lamina propria ○ This portion is made up of loose connective tissues wherein mucous and serous glands, and blood vessels are embedded ○ The Mucosa-associated Lymphoid Tissue (MALT) is comprised of numerous lymphocytes Group 8A | Histology of the Respiratory System (Laboratory) 2
B. Nasal Turbinates Figure 6. Nasal Turbinates under high magnification ● Bony spicules ○ These are integral structures that forms part of the framework ○ There is also the presence of adipose tissues which come in the form of (yellow marrow) in between ● The epithelium is lined by respiratory epithelium (ciliated pseudostratified epithelium) ● Lamina propria ○ The Lamina propria is made up of loose connective tissue where the mucous and serous glands, and the blood vessels are embedded ○ The Mucosa-associated Lymphoid Tissue (MALT) is comprised of numerous lymphocytes ○ Veins form extensive venous plexuses that serve to warm inhaled air C. Nasal Cavity Figure 7. Lateral walls of the nasal cavity under high magnification ● Framework consists of bone ● Lined by respiratory epithelium ● Its mucosa is richly supplied with mucous, serous glands, blood vessels, and MALT. C. Hard Palate Figure 8. Hard Palate under high magnification ● This portion’s interior surface is lined by keratinized stratified squamous epithelium ● Its Lamina Propria is located deep in the epithelium and rich in blood vessels, nerves, MALT and adipocytes but no glands ● The superior surface is lined by nasal mucosa and underlying lamina propria III. EPIGLOTTIS ● The epiglottis, like a leaf, extends dorsally from the hyoid bone and the back of the tongue. ● Composed on a framework of elastic cartilage and lining of epithelium and lamina propria, the mucosa protects and lines the inside of the body. ● The glottis, the passageway between the lungs and the vocal cords, is shielded by this. ● The epiglottis retracts during swallowing, blocking the opening to the larynx, to keep food and fluids from entering the airway. ● As soon as it finishes swallowing, it returns to its upright position. 6 epiglottis elastic cartilage: ● UNPAIRED CARTILAGE ○ Thyroid hyaline cartilage ○ Cricoid hyaline cartilage ○ Epiglottic elastic cartilage ● PAIRED CARTILAGE ○ Cornicate elastic cartilage ○ Cuneiform elastic cartilage ○ Arytenoid hyaline cartilage There are 2 types of epithelium lines or covers the epiglottis: ● OLFACTORY EPITHELIUM ○ Lines the roof of the nasal cavity and its adjacent areas ● RESPIRATORY EPITHELIUM ○ Except for the area where the vestibule meets the rest of the nasal cavity, which is lined by non-ciliated cuboidal/columnar epithelium, the nasal mucosa is lined with ciliated epithelium. Group 8A | Histology of the Respiratory System (Laboratory) 3
Figure 9. Epiglottis Figure 10. Epiglottis Cartilage Figure 11. Orange arrow: Serous; Green arrow: Mucous glands IV. LARYNX, VOCAL CORD LARYNX (VOICE BOX) Figure 12. Larynx, Vocal Cord ● Laryngeal Ventricle ○ space that separates the true and false vocal cords ○ has narrow pouch-like invaginations called ventricular recesses, not well delineated in this slide. ○ The epithelium lining the ventricular recesses is respiratory (ciliated stratified columnar), however the epithelium on this slide is not intact. ● The laryngeal cartilages are held together by ligaments and membranes. ○ They serve as attachments for 2 groups – extrinsic and intrinsic – of named skeletal muscles. ○ The extrinsic muscles connect the larynx to the surrounding structures. (During deglutition, they raise the larynx) ● Epithelium and lamina propria form the mucous membrane lining the False vocal cord and True vocal cord, respectively. ○ The linings of both are MALT- and blood vessel-supplied nonkeratinized stratified squamous epithelium. ● As can be observed on the right side of the picture, the false vocal cord is packed with glands of various types (serous, mucous, and mixed). ● The true vocal cord consists of a lamina propria that includes the vocalis ligament and a group of skeletal muscles known as the vocalis muscle. Figure 13. Vocalis Muscle & Vocalis Ligament Figure 14. False & True Vocal Cords Group 8A | Histology of the Respiratory System (Laboratory) 4
V. TRACHEA Figure 15. Trachea under low magnification ● Trachea ○ A permanently patent tube that transports air to and from the larynx and main bronchi. ○ has a large ovoid space called a lumen that occupies the specimen's center ● Esophagus ○ tubular structure on the lower portion of the micrograph (Fig 15) ● Thyroid Gland ○ consists of cystic structures that contain a highly eosinophilic material on either side of the trachea Histologic Layers of the Trachea Figure 16. High magnification micrograph of the mucosal layer of the trachea ● Mucosa ○ This layer is made up of respiratory epithelium and a lamina that is abundantly supplied with MALT ○ The basement membrane of the epithelium is thick, it distinguishes itself from the underlying lamina propria Figure 17. High magnification micrograph of the submucosal layer of the trachea ● Submucosa ○ Contains the Tracheal Glands that are classified as Mixed Tubuloalveolar glands Figure 18. High magnification micrograph showing the hyaline cartilage ● Cartilage and Muscle Layer ○ The trachea's most visible layer consists of C-shaped hyaline cartilages with open ends ○ Muscle tissue connects the posterior ends. Figure 19. High magnification micrograph showing the trachealis muscle ● Smooth muscle fibers run the length of the open posterior end of the C-shaped cartilage that makes up the trachealis muscle Group 8A | Histology of the Respiratory System (Laboratory) 5