Anatomy - Histology of the Respiratory System (Lab)

Respiratory System

Facilitates external respiration, involving gas exchange between inhaled air and blood in the lungs.

Respiratory System

Composed of the nose, pharynx, larynx, trachea, main bronchi, and lungs.

Nose

Contains olfactory organ for smell sensation.

Larynx

Responsible for speech production.

Pharynx, Trachea, Bronchi

Air passageways to and from the lungs.

Nasal Septum

Common cartilaginous wall forming the medial wall of each nasal cavity. Divides the nose

Left and Right Nasal Cavities

Two irregularly shaped spaces divided by the nasal septum. Bounded by orifices (nostrils): anterior nares and posterior nares

Three nasal turbinates

Shelf-like structures forming the lateral wall of each nasal cavity (1) superior, (2) middle, and (3) inferior nasal turbinates or conchae

Hard palate

Makes up the roof of the oral cavity proper along with the soft palate. At the section’s lowermost border

Nasal Septum

Partly hyaline cartilage superiorly while bone and cartilage inferiorly

Respiratory Epithelium

The nasal septum’s luminal surfaces lined with ciliated pseudostratified, otherwise called

Lamina propria of Nasal Septum

Loose connective tissue with mucous and serous glands, blood vessels, and numerous lymphocytes comprising part of the MALT in the nasal cavity.

Left and Right Nasal Cavities

Lateral wells of nasal cavities:

○ Framework: bone

○ Lining: respiratory epithelium

○ Mucosa: supplied by mucous, serous glands, blood vessels, and MALT

Bony Spicules

Framework of turbinates which has adipose tissue (yellow marrow) in between. Lining: luminal surfaces lined by respiratory epithelium

Lamina propria of Nasal Turbinates

Composition: serous, mucous glands, blood vessels, and MALT. Veins form extensive venous plexuses to warm inhaled air.

Lateral wall of nasal cavity

• Framework: bone

• Lining: respiratory epithelium

• Mucosa: rich in mucous, serous glands, blood vessels, and MALT

Paransal Sinus

Large cavity or space on the rightmost part of the slide. Lining: respiratory epithelium. Lamina propria: consists of mucous and serous glands

Hard Palate

Interior surface’s lining: keratinized stratified squamous epithelium. Deep: dense connective tissue making up the lamina propria

Lamina Propria of Hard Palate

Composition: richly supplied with blood vessels, nerves, MALT, and adipocytes. There are no glands

Nasal Mucosa

Lining of the hard palate on its superior surface consisting of respiratory epithelium and underlying lamina propria

Bone

Framework of the hard palate

Adipose Tissue

Yellow marrow occupying the spaces between bone spicules

Respiratory Epithelium

Has an unusually large number of goblet cells

Olfactory Epithelium

Taller. More cellular. No goblet cells

● 3 cell types:

1. sustentacular or supporting cells

2. olfactory cells

3. basal cells

Glands of Bowman

Compound tubuloalveolar serous glands where secretion moistens the epithelial surface and serves as a solvent for odiferous substances

Sustentacular Cell

Similar as neuroglial cells (supportive cells in neuron). Spindle shaped bipolar neuron, ciliated projections in apical domain

Brush Cell

Designed for transduction for general sensation not related to olfactory senses. Not connected to olfactory nerve. Connected to branches of the trigeminal nerve

Epiglottis

A leaf-like structure that projects upward behind the tongue and the hyoid bone. It protects the glottis, the opening between the vocal cords.

Epiglottic Cartilage

A type of elastic cartilage. Makes up the epiglottis. Enveloped by mucous membrane

Mucosa of Epiglottis

Encases epiglottic cartilage. Made up of epithelium and an underlying lamina propria

Nonkeratinized Stratified Squamous Epithelium

Lines epiglottis’ anterior surface and upper half of posterior surface (aryepiglottic folds). These are the areas that get in contact with swallowed food

Respiratory Epithelium

Lines the rest of the epiglottis

False Vocal Cord

Structure with glands in its lamina propria

Laryngeal Ventricle

A space that separates true and false vocal cords. Has narrow pouch-like invaginations called ventricular recesses

Vocalis Muscle

Deep to lamina propria in the true vocal cord. Inserts into the vocalis ligament. The contraction of these muscles allows for the production of different sounds.

Thyroid gland

Easily identified because they consist of cystic structures that contain a highly eosinophilic material. On both sides of the trachea

Respiratory Bronchioles

Directly connected to alveolar ducts. The end/terminal is connected to alveolar ducts

Terminal Bronchioles

A part of the segment of the bronchiole that gives rise to respiratory bronchioles. Last segment of bronchioles/bronchial tree that is conducting in nature (carry air). Will end terminally to form respiratory bronchioles which are bronchioles directly giving rise to alveolar ducts (AD)

Alveolar Ducts

The part of airway/lungs (lined with simple squamous epithelium) but the wall is usually composed of the opening of the alveolar sacs/alveoli. It is a tiny tube that give rise to alveolar sacs and alveoli

Alveolar Sacs

Collection of several alveoli (if singular - alveolus/alveoli, but if it combined with other openings it forms the alveolar sac)

Clara Cells

Similar to pulmonary surfactant that produces pneumocyte type 2. Only found in the bronchioles (not seen in alveoli)