The Nasopharynx

• The nasal part of the pharynx has a respiratory function.
• It lies superior to the soft palate and is a posterior extension of the nasal cavity.
• The nose opens into the nasopharynx via to large posterior apertures called choanae.

• The roof and posterior wall of the nasopharynx form a continuous surface that lies inferior to the body of the sphenoid bone and the basilar part of the occipital bone.
• In the mucous membrane of the roof of the posterior wall of the nasopharynx is a collection of lymphoid tissue, known as the pharyngeal tonsil (commonly known as the adenoids).

• The pharyngeal orifice of the auditory tube is on the lateral wall of the nasopharynx, 1 to 1.5 cm posterior to the inferior concha, and level with the superior border of the palate.
• The orifice is directed inferiorly and has a hood-like tubal elevation over it called the torus of the auditory tube or the torus tubarius (L. torus, swelling).

• Extending inferiorly from the torus is a vertical fold of mucous membrane, known as the salpingopharyngeal fold.

• The collection of lymphoid tissue in the submucosa of the pharynx, posterior to the orifice of the auditory tube, is known as the tubal tonsil.

• Posterior to the torus and the salpingopharyngeal fold, there is a slit-like lateral projection of the pharynx called the pharyngeal recess.
• It extends laterally and posteriorly.

• Long bones (e.g.. femur and humerus)
• Short bones (e.g.. wrist and ankle bones)
• Flat bones (e.g.. ribs)
• Irregular bones (e.g.. vertebrae)

Connective Tissue

Functions of Connective tissue:

→ joins together other tissues

→ supporting framework for the body (bone)

→ fat stores energy

→ blood transports substances

Connective tissue is usually characterized by large amounts of extracellular materials that separate cells from each other, whereas epithelial tissue is mostly cells with very little extracellular material. The extracellular substance of connective tissue consists of protein fibers which are embedded in ground substance containing tissue fluid.

Fibers in connective tissue can be divided into three types:

→ Collagen fibers are the most abundant protein fibers in the body.

→ Elastic fibers are made of elastin and have the ability to recoil to original shape.

→ Reticular fibers are very fine collagen fibers that join connective tissues to other tissues.

Connective tissue cells are named according to their functions:

 → Blast cells produce the matrix of connective tissues

→ Cyte cells maintains the matrix of connective tissues

→ Clast cells breaks down the matrix for remodeling (found in bone)

Superior Constrictor Muscle

• Origin: Hamulus, pterygo-mandibular raphe, and mylohyoid line of the mandible.
• Insertion: Median raphe of the pharynx.
• Nerve Supply: Vagus nerve via the pharyngeal plexus.
• Arterial Supply: Ascending pharyngeal artery, ascending palatine artery, tonsillar branch of the facial artery, and dorsal branch of the lingual artery.
• Action: Constricts the wall of the pharynx during swallowing.