In-Depth Notes on Swallowing and Dysphagia Symptoms

Dysphagia Symptoms

• Drooling: Represents difficulty in swallowing and can be socially embarrassing.
• Painful swallowing: Individuals avoid eating or drinking to prevent this.
• Heartburn and acid reflux: Can also be symptoms of swallowing difficulties.
• Choking and aspiration: Occurs when food or drink enters the airway, potentially leading to serious conditions.
• Aspiration-induced pneumonia: Results from aspirating food or drink, leading to lung infection due to inflammation and bacteria.

Swallowing Process

• Chewing (Mastication): Initiates the swallowing process.
  • Muscles involved:
  • Cheek muscles (buccinator, platysma) keep food in the mouth.
  • Mandibular muscles (masseter, temporalis) control jaw movement for chewing.
  • Pterygoid muscles assist in the chewing process.
  • Formation of the bolus: The tongue and mylohyoid muscle help gather and shape food mixed with saliva into a bolus.

Phases of Swallowing

1. Oral Phase:
   • The bolus is pushed back by the tongue towards the posterior cavity.
   • Triggered once it hits the anterior facial pillars.
2. Pharyngeal Phase:
   • Reflexive process after the swallowing trigger.
   • Muscles contract to push the bolus down.
   • Velum (soft palate) elevates to prevent food from entering the nasal cavity.
   • Larynx elevates and epiglottis folds down to cover the airway.
   • Bolus moves into the esophagus.
3. Esophageal Phase:
   • The esophagus directs the bolus to the stomach, needing coordination with the diaphragm's position.

Imaging Techniques for Swallowing

• Barium Swallow:
  • Captures the entire swallowing motion and checks for issues. Provides a visual of the swallow in action.
• Endoscopy:
  • Camera positioned in the nasal area, allowing views of the swallowing process but obscured during the swallow itself.
  • Limited visibility of lower esophageal areas unless the camera is advanced further down.

Importance of Healthy Swallowing

• Delayed or weakened swallowing reflex can lead to food pooling and increased risk of aspiration.
• Normal swallowing involves effective closure of the epiglottis to protect airway integrity.

Anatomy of Teeth

• Divide teeth into quadrants.
  • Incisors (2): For cutting food.
  • Canines (1): For ripping.
  • Premolars (2): Mixed function for grinding and ripping.
  • Molars (2+ depending on wisdom teeth): For grinding.

Musculature for Chewing

• All facial muscles can assist in the initial bite.
• Specific muscles:
  • Digastric: Lowers mandible (anterior belly) and elevates hyoid (posterior belly).
  • Mylohyoid: Forms the floor of the mouth and assists in bolus formation.

Salivary Glands

• Main glands include:
  • Parotid: Located at the back of the jaw, secretes saliva through ducts into the mouth.
  • Submandibular: Below the jaw, shares a duct with the sublingual gland.
  • Sublingual: Located under the tongue, responsible for moistening the mouth.
• Newly discovered tubarial glands: Identified in recent studies, may play a role in secretions relevant to swallowing.

Salivary Function

• Saliva contains enzymes like amylase (for starch) and lipase (for fats).
• Assists in initial digestion and provides antimicrobial protection.
• Chewing gum promotes saliva production, beneficial for dental health through increased saliva and trace minerals for enamel strength.
• Chewing progresses the process of digestion even before swallowing occurs.