Makindo Medical Notes

💡 Note: Being NBM (nil by mouth) does not mean no oral fluid intake is allowed — saliva is still produced and swallowed.

🧩 Anatomy

• Parotid Gland: Produces a watery serous fluid.
• Submandibular Gland: Produces a mixed secretion, predominantly seromucinous (serous + mucus).
• Sublingual Gland: Produces seromucinous fluid. Numerous minor salivary glands are scattered throughout the oral cavity.

💦 Saliva Production

• Normal output: 1–2 litres/day.
• Stimulation: Brainstem salivary nuclei via facial (VII) and glossopharyngeal (IX) nerves.
• Inhibition: Sympathetic activity + anticholinergic drugs (e.g. atropine) → dry mouth (xerostomia).
• 💊 Drugs such as TCAs, SSRIs, antihistamines can reduce salivation.

⚙️ Functions of Saliva

• 👅 Taste & Lubrication: Dissolves food and eases swallowing.
• 🗣️ Speech: Moistens oral cavity for clear articulation.
• 🦷 Oral Health: Antimicrobial enzymes + constant wash protect against caries.
• ⚖️ pH Balance: Slightly alkaline, buffering bacterial acids.
• 🤝 Social Role: Saliva has functions in bonding behaviours (e.g. kissing).

🧪 Saliva Composition

• 💧 99.5% Water + Mucus
• 🍞 Amylase (starch breakdown)
• 🛡️ Lysozyme (antimicrobial enzyme)
• 🧬 Immunoglobulin A (IgA)
• ⚡ Electrolytes (Na⁺, K⁺, Ca²⁺, Cl⁻, HCO₃⁻)

🚨 Pathology

• Autoimmune Infiltration: Sjögren’s syndrome, sarcoidosis → chronic dry mouth, gland swelling.
• Salivary Gland Tumours:
  • 🌱 Pleomorphic Adenoma: Most common benign tumour, parotid, painless lump.
  • 🌿 Warthin’s Tumour: Benign, parotid, may be bilateral. Linked to smoking.
  • 🔥 Mucoepidermoid Carcinoma: Malignant; facial nerve palsy & lymph nodes suggest aggressive disease.
  • 🧬 Adenocarcinoma: Malignant, often with VII palsy & nodal disease.
• Parotid Swelling: Causes include:
  • 🍷 Chronic alcohol use / liver disease
  • 🌸 Sarcoidosis (Mikulicz’s syndrome if lacrimal glands also swollen)
  • 💧 Sjögren’s syndrome
  • 🧪 Lymphoma
  • ⚠️ Malignancy (red flag = facial nerve palsy)
• Parotitis (Parotid Inflammation):
  • 🦠 Bacterial: Often dehydration, poor oral hygiene, duct stones. Commonly Staphylococcus aureus.
  • 🦠 Viral: Mumps — can be bilateral, classically associated with orchitis.
• Sialolithiasis (Salivary Stones): 💎
  • Commonest in submandibular gland.
  • Painful swelling during meals (“mealtime syndrome”).
  • Diagnosis: ultrasound or sialography; treatment may require stone removal or sialendoscopy.
• Xerostomia (Dry Mouth):
  • Causes: 💊 drugs (anticholinergics, antidepressants, lithium), 🦠 Sjögren’s, radiation therapy, dehydration, CKD.
  • Complications: dental caries, oral candidiasis.
• Sialadenitis (Salivary Gland Inflammation):
  • 🦠 Bacterial (Staph, Strep species)
  • 🦠 Viral (mumps, HIV)
  • 🌸 Sarcoidosis → Heerfordt’s syndrome (uveitis, parotid swelling, fever, facial nerve palsy)
• Mikulicz’s Syndrome: Bilateral enlargement of salivary + lacrimal glands, often autoimmune (e.g. Sjögren’s, sarcoid, lymphoma).