Revison WEEK 3- Pharynx

ADHD-FRIENDLY EXTREMELY DETAILED NOTES - PHARYNX ANATOMY VIDEO TRANSCRIPT
KEY: Using exact words from transcript. Adding structure for clarity. Keeping all info.

VIDEO START & INTRO

  • 0:04: Meditay here.

  • Video Topic: Anatomy of the Pharynx.

  • 0:09: Last video was about the Oral Cavity.

  • 0:12: The step after the oral cavity is the Pharynx.

  • What this video will cover:

    1. 0:20: Parts of the Pharynx (detailed structures).

      • Nasopharynx

      • Oropharynx

      • Laryngopharynx

    2. 0:28: Cut the Pharynx to see layers of the pharyngeal wall.

    3. 0:33: Muscles that act on the Pharynx.

PART 1: PARTS OF THE PHARYNX

  • 0:37: Start by holding and pulling out the Pharynx.

  • 0:41: In the anatomy program, it looks like this.

  • Length: 12 to 15 cm long.

  • Consists of THREE parts.

  • 0:51: Anterior view shows what the three parts connect to:

    1. Upper part: Connected to the nasal cavity. Called Nasopharynx (Pars nasalis in Latin).

    2. Middle part: Associated with the oral cavity. Called Oropharynx.

    3. Lower part: Associated with the Larynx. Called Laryngopharynx.

  • 1:13: Switch to lateral view for better overview. Still the three parts.

  • Digestive Pathway: Pharynx continues downward as the Oesophagus.

  • Function: Pharynx is a control point for breathing and swallowing.

    • Oesophagus is usually closed when breathing.

    • When you swallow:

      • Soft palate blocks the Nasopharynx (food doesn't go into nose).

      • Larynx gets blocked by the epiglottis.

      • Tongue pushes food down by going up to the palate.

  • 1:50: That's the overview.

PART 1A: NASOPHARYNX (Expanded Details)

  • 1:54: Expanding on Nasopharynx structures.

  • Level: Corresponds to 1st to 2nd cervical vertebrae.

  • Attachment: Attached to the base of the skull.

  • 2:07: Attachment points are called Fornix Pharyngis (vault of the Pharynx).

    • Where the mucosa (wet surface) is firmly attached to the skull base.

  • 2:25: To see attachment points, look at model.

    • Blue line = attachment points of the Pharynx.

    • Important landmarks for the Vault of Pharynx:

      1. Pharyngeal tubercle of the occipital bone (basal part of occipital bone).

      2. Petro-occipital fissures (where occipital bone & petrous part of temporal bone fuse).

      3. Inferior border of the Petrous part of the temporal bone.

      4. Medial lamina of the pterygoid process.

  • 3:22: Pharynx attaches to these structures = vault of Pharynx.

  • Border with Nasal Cavity:

    • Pharynx and nasal cavity are connected.

    • Strict border between them is the Choanae (internal nose).

    • This is the landmark separating nasal cavity from Pharynx.

  • 3:41: Another structure in Nasopharynx: Auditory Tube (Eustachian tube).

    • 3:46: Tube connects middle ear to the Pharynx.

    • Ear Parts: Outer ear, middle ear, inner ear.

    • In Middle Ear: Ossicles (malleus, incus, stapes) and tympanic membrane.

    • Function 1 - Pressure Equalization:

      • Tympanic membrane vibrates for hearing.

      • Vibration requires stabilized pressure difference.

      • Auditory tube is the only way middle ear can regulate pressure.

      • At rest: Auditory tube is closed.

      • When you swallow, auditory tube opens → slight pressure relief in middle ear.

      • Example: On a plane, driving hills → feel pressure change in ear. Swallowing makes a "pop" → tube opens and equalizes pressure.

    • Function 2 - Drainage:

      • If middle ear infection with pus buildup, auditory tube can drain pus into Pharynx.

      • (Mention: antibiotics like amoxicillin with clavulanic acid can help, but we're doing anatomy).

    • 6:27: Two main functions: 1. Equalizing pressure when swallowing. 2. Draining middle ear.

  • 6:30: Point where auditory tube opens into Pharynx: ostium pharyngeum tubae auditivae (ostium = opening in Latin).

  • Structures around the opening:

    • Torus tubarius: Cartilage protruding above the opening ("cushion of the auditory canal").

    • Pharyngeal recess: Small groove behind the auditory tube.

  • Tonsils in the Nasopharynx:

    • Pharyngeal tonsil (Adenoids): Up here. Can get inflamed/enlarged and block auditory tube.

    • Tubal tonsils: Behind the auditory tube (named for location).

  • 7:17: That's all for Nasopharynx anatomy.

PART 1B: OROPHARYNX

  • Level: Situated at level of 3rd/4th cervical vertebrae.

  • Borders: Bordered by the soft palate (above) and the epiglottis (below).

  • Connection to Oral Cavity: Through the isthmus faucium (oropharyngeal ishmus).

    • This is the opening at the back of the mouth into the throat.

  • 7:41: "Aaand, that is the Oropharynx; not much to talk about this one."

PART 1C: LARYNGOPHARYNX

  • Level: At level of 5th to 6th cervical vertebrae.

  • Continuation: Continues into the Larynx.

  • Swallowing: Epiglottis closes the Laryngopharynx so food enters Esophagus (to stomach) not lungs.

  • Two Openings:

    1. Laryngeal inlet.

    2. Opening of the Oesophagus.

  • Posterior View: Nasopharynx (up), Oropharynx (middle), Laryngopharynx (down).

  • Anatomical Landmark: Piriform fossa.

    • Located on either side of the Laryngopharynx.

    • It is a depression on either side.

  • 8:34: "So that was all the parts of the Larynx." (Note: Transcript says "Larynx" but context is Laryngopharynx/Pharynx)

PART 2: LAYERS OF PHARYNGEAL WALL

  • 8:36: Cut the Pharynx and look from inside.

  • FOUR Layers:

    1. Tunica Mucosa: Inner lining layer.

      • Lined by epithelial tissue.

      • Nasopharynx: Lined by respiratory epithelium (pseudostratified epithelium with cilia + goblet cells).

      • Rest of Pharynx: Lined by stratified squamous non-keratinized epithelia (for protection against food pressure).

    2. Tela Submucosa: Contains connective tissue, blood vessels, lymph vessels, and glands.

    3. Tunica Muscularis: Muscle layer.

      • Two types of muscle fibers:

        • Inner fibers: Arranged circularly.

        • Outer fibers: Arranged longitudinally.

      • Function: Aids pharyngeal peristalsis (controlled synchronized contraction to move content in/out).

    4. Tunica Adventitia: Outer layer. Tough layer of collagen fibers covering Pharynx from outside.

  • 10:16: That was the pharyngeal wall.

PART 3: MUSCLES OF THE PHARYNX

  • 10:18: External muscles of the Pharynx.

  • Two Groups:

    • A. Pharyngeal Constrictors (3 muscles).

    • B. Pharyngeal Elevators (3 muscles).

  • Constrictors = constrict. Elevators = elevate. (You can guess function from name).

A. PHARYNGEAL CONSTRICTOR MUSCLES

  • All three insert at the Pharyngeal Raphe (the white line).

  • All three function: Constrict the Pharynx when you swallow to aid peristalsis (move content downwards).

    1. Superior Pharyngeal Constrictor:

      • Originates from: Pterygoid process, pterygomandibular raphe, mylohyoid line of mandible.

      • Inserts at: Pharyngeal raphe.

    2. Medial Pharyngeal Constrictor:

      • Originates from: Hyoid bone.

      • Inserts at: Raphe pharyngis (pharyngeal raphe).

    3. Inferior Pharyngeal Constrictor:

      • "Pretty interesting" one.

      • Originates from: Thyroid cartilage & cricoid cartilage (cartilages of the Larynx/voicebox).

      • Inserts at: Pharyngeal raphe.

B. PHARYNGEAL ELEVATOR MUSCLES

  • Function: Elevate the Pharynx when you swallow.

    1. Stylopharyngeus Muscle:

      • Originates from: Styloid process.

      • Inserts at: Lateral wall of the Pharynx.

      • Action: Contraction pulls Pharynx up (elevates).

    2. Palatopharyngeus Muscle:

      • Originates from: Aponeurosis of the soft palate.

      • Inserts at: Lateral wall of the Pharynx.

    3. Salpingopharyngeus Muscle:

      • Originates from: Walls of the auditory tube.

      • Inserts at: Palatopharyngeus muscle fibers.

      • Function: When you swallow, helps open the auditory tube (because tube is normally closed, opens when you swallow).

VIDEO END

  • 13:10: "So that was the anatomy of the Pharynx."

  • Next Video: Is going to be about the Esophagus.

PHARYNX - 20% ESSENTIAL KNOWLEDGE

1. IT'S ONE TUBE WITH 3 SECTIONS:

  • Nasopharynx: Behind nose → air only (connects to ear via eustachian tube)

  • Oropharynx: Behind mouth → food & air

  • Laryngopharynx: Behind voice box → food & air

2. KEY SWALLOWING MECHANISM:

  • Soft palate blocks nasopharynx (keeps food out of nose)

  • Epiglottis blocks larynx (keeps food out of lungs)

  • Tongue pushes food back → into esophagus

3. MUST-KNOW STRUCTURES:

  • Eustachian tube: Equalizes ear pressure (pops when swallowing)

  • Choanae: Opening between nose and nasopharynx

  • Piriform fossa: Pockets on sides of laryngopharynx (where food can get stuck)

4. WALL LAYERS (INSIDE → OUT):

  1. Mucosa (inner lining)

  2. Submucosa (vessels/glands)

  3. Muscularis (muscle layer for squeezing food down)

  4. Adventitia (outer tough coat)

5. MUSCLE GROUPS (2 FUNCTIONS):

  • Constrictors (3): Squeeze tube to push food down

  • Elevators (3): Lift throat up when swallowing

6. CLINICAL PINPOINTS:

  • Infected "adenoids" (pharyngeal tonsils) can block eustachian tubes → ear problems

  • Food/liquids can enter nasopharynx if soft palate malfunctions → nasal regurgitation

  • Pressure changes (planes/diving) are relieved by swallowing → opens eustachian tubes

THE 20% YIELDS 80% BECAUSE: If you understand the three sections and how swallowing reroutes food away from air passages, you grasp the pharynx's core purpose. The rest are details supporting this main function.