THE RESPIRATORY SYSTEM Dr. Mah Jabeen Muneera Associate professor Department of Anatomy KEMU

Subdivisions CONDUCTING PART Nasal cavities Nasopharynx Larynx Trachea Bronchi Bronchioles Terminal bronchioles

RESPIRATORY PART Respiratory bronchioles Alveolar ducts Alveolar sacs Alveoli

FUNCTIONS OF CONDUCTING PART Conduction Conditioning Cleaning Moistening Warming Slowing the current

RESPIRATORY EPITHELIUM PSEUDOSTRATIFIED COLUMNAR CILIATED WITH GOBLET CELLS Cell types: Columnar ciliated cells Immotile cillia syndrome Goblet cells Brush cells Microvilli Receptor Small granule cells Diffuse neuro endocrine cells; Kulchitsky’s granules Basal cells Metaplasia dysplasia

Nose Provides airway Moistens and warms air Filters air Resonating chamber for speech Olfactory receptors

Vestibule NASAL CAVITIES lined by skin (stratified squamous keratinized) Vibrissae, sebaceous & sweat glands Transition to respiratory epithelium (stratified Squamous Non Keratinized)

Nasal Fossae Nasal septum Chonchae Lamina propria Superior –olfactory epithelium Middle – respiratory epithelium Inferior – respiratory epithelium Lamina propria Venous plexus – swell/cavernous bodies Engorged with blood periodically Plexus of large blood vessels next to periosteum & perichondrium Blood flow from rear to front – warms inspired air Mucous & serous glands (bactericides, lysozyme) Nasal Blockade in allergic reactions

Nasal Cavity

Olfactory Mucosa Olfactory epithelium Location Color (pseudostratified columnar) Olfactory cells Bipolar neuron Olfactory vesicle Olfactory cillia Proximal segment Trailing segment Immotile Odorant binding protein Sustentacular cells Shape Microvilli Nuclei; location Adhering junctions Yellow pigment Glial cells functionally

Lamina propria Basal cells Bowman’s/ olfactory gland - serous Shape Location Nuclei Function Lamina propria Bowman’s/ olfactory gland - serous Capillary plexus Anosmia Hyposmia Regeneration

Paranasal sinuses Frontal, sphenoid, ethmoid and maxillary bones Open into nasal cavity Lined by same mucosa (shorter, fewer goblet cells, lymphoid tissue) as nasal cavity and perform same functions Lamina propria; thinner, no swell bodies Periosteum Also lighten the skull Can get infected: sinusitis

Pharynx Parts Mucosa Respiratory epithelium Stratified squamous epithelium Lamina propria – loose-dense irregular CT Elastic issue Vascularized Seromucous gland, mucous in stratified area Lymphoid tissue – posterior: pharyngeal tonsil

Submucosa : Muscularis: Fibrosa Loose connective tissue Only in superolateral part Muscularis: Skeletal muscle Fibrosa Outermost thin layer of fibrous connective tissue

Larynx – voice box Additional function: Phonation Prevent food/drinks – respiratory system Tube : cartilage (hyaline, elastic) – ligaments – skeletal muscles (intrinsic-extrinsic) Mucosa Epihelium Stratified squamous non keratinized epithelium Pseudostratified (respiratory epithelium) Lamina propria: Connective tissue, lymphatic nodules, seromucous glands Vestibular fold – false vocal cord (superior) Vocal fold - true vocal cord (inferior) - stratified squamous Vocalis muscle vocal ligament – regular dense elastic CT

Epiglottis Leaf shaped Elastic cartilage Mucosa on both sides Lingual surface, upper laryngeal; stratified squamous epithelium Lower half respiratory Lamina propria; seromucous glands, more on laryngeal surface reside in Pock marks Taste buds