Lecture 1 - Neck Anatomy and Physiology Flashcards
What are the anatomical contents of the neck?
Arteries, veins, nerves Lymph nodes and lymphatic channels Thyroid and parathyroid glands Muscles Trachea, larynx, swallowing oesophagus
What are the boundaries of the neck?
Superior - mandible
Inferior - clavicle
Anterior - anterior midline
Posterior - trapezius
What boundaries form the anterior triangle?
Anterior - midline of the neck
Posterior - anterior border of the sternocleidomastoid
Superior - mandible
Can be divided into submandibular, muscular, submental and carotid triangle
What are the boundaries forming the posterior triangle?
Anterior - posterior border of the sternocleidomastoid
Posterior - anterior border of trapezius
Inferior - middle third of clavicle
What are the contents of the anterior triangle?
Common carotid artery, facial artery, hypoglossal nerves, vagus nerves, glossopharyngeal nerves, submandibular nodes, submental nodes, internal carotid artery, internal jugular vein, facial vein, accessory nerves, laryngeal nerves
What are the contents of the posterior triangle?
Accessory nerve, occipital artery, lymph nodes, cervical nerve plexus, external jugular vein
What are the main arteries of the neck and from which common artery do they branch? (At what level?)
Common carotid artery splits into the internal and external carotid arteries at C4 in the neck
How can you differentiate between the ICA and ECA?
ICA lies more laterally than the ECA initially, and the ECA is the only one that will give off branches in the neck - the ICA supplies intracranially
What branches does the ECA give off in the neck?
Superior thyroid Ascending pharyngeal Lingual Occipital facial Posterior auricular Maxillary Superficial temporal
What are the main veins in the neck?
Internal and external jugular
Internal is much larger than the external
Why is it important to understand the anatomy of the veins in the head and neck?
Useful for venous access
Can also be involved in bleeding, tumour spread, venous thrombosis which can track to the brain so must be careful when operating in the neck
What are the indications for central line use?
Struggling to get arterial or venous line in Central venous pressure Drug administration Cardiac pacing Blood sampling Fluid resuscitation Haemodialysis IV nutrition
What are the possible complications of using central lines?
Pneumothorax Air embolism Thrombosis Sepsis Chylothorax Haemotoma Cardiac tamponade False passage Line blockage
Are there many lymph nodes in the neck? What is their use?
600 lymph nodes in the head and neck
Receive lymph/tissue waste product
Drain to cisterna chyli
the drain to thoracic duct on left
How are the lymph nodes in the neck described?
In groups
In levels (I-VI)
Level I - under mandible
Level II, III, IV - thirds of sternocleidomastoid
Level V - posterior triangle
Level VI - anterior/central compartments of the neck
Describe the lymph node drainage of the parotid, occipital, superficial cervical, deep cervical, submandibular, submental and supraclavicular nodes.
Parotid - scalp, face, parotid gland
Occipital - scalp
Superficial cervical - breast and solid viscera
Deep cervical - final drainage pathway to thoracic duct
Submandibular - tongue, nose, paranasal sinuses, submandibular glands, oral cavity
Submental - lips, floor of mouth
Supraclavicular - breast, oesophagus, solid viscera
What are three most common causes of lymphadenopathy?
Infective
Malignant
Inflammatory
What is the thyroid gland?
What substances does it produce and what are the actions of these substances in the body?
Endocrine gland
2 lobes joined by isthmus
Produces thyroid hormone (triiodothyronine (t3) and its pro hormone thyroxine (T4) - responsible for regulation of metabolism) and calcitonin (acts to lower Ca and raise phosphate)
What is hypothyroidism?
Patient not producing enough hormones from their thyroid - patient feels very tired and lethargic
Rx - thyroxine
What are the possible appearances of thyroid masses?
Solitary nodule
Diffuse enlargement
Multi-nodular goitre (large lumps)
In which group of people are thyroid masses more common?
Females
What can cause a solitary thyroid nodule? Who is most likely to get a solitary thyroid nodule?
Cyst - due to localised haemorrhage Adenoma - benign follicular tissue Carcinoma Lymphoma Women between the age of 30-40
What sort of questions do you want to be asking someone presenting with a solitary thyroid nodule?
Red flag symptoms
- Pain (pain going to ear very sensitive marker of malignancy)
- Weight loss
- Voice hoarseness
- Haematemesis
How do you investigate a solitary thyroid nodule?
USS
If USS shows nothing, reassure and discharge them
If shows something, do fine needle aspiration cytology
FNAC cannot distinguish between a follicular adenoma and a follicular carcinoma - therefore tissue required for histology diagnosis (graded 1-5: 1 - unsure; didn’t get enough tissue, 2 - normal tissue, 3 - dysplasia, 4 - most likely cancer, 5 - carcinoma)
How would you treat a solitary thyroid nodule that is going to cause problems?
Thyroid lobectomy
What are the four types of thyroid cancer?
Papillary - lymphatic metastasis
Follicular - haematogenous metastasis
Medullary - familial agression, 10% arises from parafollicular C cells
Anaplastic - aggressive, local spread, very old, poor prognosis
What are the types of diffuse thyroid enlargement?
Colloid goitre
Grave’s disease
Thyroiditis
What can cause colloid goitre?
Gland hyperplasia
Iodine deficiency
Puberty, pregnancy, lactation
What is goitre?
How do you test for retrosternal goitre?
Swelling in the neck cause by an enlarged thyroid gland (can cause compressive neck symptoms (dysphagia, stridor if compression of trachea)
Retrosternal goitre test - if choking after lifting arms (Pemberton’s sign)
What is Grave’s disease?
Who gets it most commonly?
What does it cause?
How is it treated?
Body creates auto-antibodies against thyroid stimulating hormone receptor - hyperthyroidism results
Most common in middle aged women
Causes thyroid disease, acropachy/clubbing, pre-tibial myxoedema
Rx - anti-thyroids, beta-blockage, radio-iodine, surgery
What are the indications for a thyroidectomy?
Airway obstruction Malignancy or suspected malignancy Thyrotoxicosis Cosmesis Retrosternal extension
What are the complication of thyroidectomy?
Bleeding (primary or secondary) Voice hoarseness Thyroid storm Infection Hypothyroidism Scar (keloid/hypertrophic (excess collagen in scar, causes raised scar)
What does multi-nodular goitre tend to be due to?
Grave’s disease or toxic goitre
What is toxic goitre?
Tends to be in older people
No eye signs
Atrial fibrillation
What tests do you do when a patient presents with multi-nodular goitre?
Thyroid function tests, FNAC, chest X-Ray
How many parathyroid glands are there? Where are they? What are their functions?
Usually 4
Regulate calcium and phosphate levels
Located posterior to poles of thyroid
Can be injured in neck surgery
What are the symptoms involved in parathyroid disease?
Painful stones - renal calculi, polyuria, renal filaure
Aching bones - pathological fractures, osteoporosis, bone pain
Psychic moans - anxiety, depression, confusion, paranoia
Abdominal groans - weight loss, abdominal pain, constipation, peptic ulceration, pancreatitis
What tests do you do if you suspect parathyroid disease?
U&Es, creatinine, calcium, phosphate Parathyroid hormone, bicarbonate Vitamin D deficiency common USS CT/MRI (to identify ectopic glands) Isotope scanning - detects diseased glands
How do you treat parathyroid disease?
Surgery for hyperparathyroid disease only
Medical treatment
Surgery easier if patient is fit - removal of single/multiple adenomas
Remove 3 or 3.5 hyperplastic glands through neck exploration
Carcinomas removed with thyroid gland and lymph nodes
What disease can affect the parathyroid gland?
Adenomas (80% hyperparathyroidism)
Hyperplasia (12% hyperparathyroidism) - common in secondary hyperparathyroidism due to low Ca levels, e.g. renal failure
Malignancy (rare)
What are the four fascial layers of the neck?
Sheaths surrounding the necks
- pre-tracheal
- pre-vertebral
- deep cervical
- carotid sheath
What are the indications for tracheostomy?
Airway obstruction Airway protection Poor ventilation to reduce dead space Need suctioning Need humidification Need long-term care
What is stridor? What are the three types of stridor and what do they indicate?
Clinical sign of airway obstruction
Inspiratory - laryngeal
Expiratory - tracheobronchial
Biphasic - glottis/subglottis
How is stridor treated?
Oxygen, nebulised adrenline, IV dexamethasone, (heliox), (definitive) airway management
What is a branchial cyst? How is it treated?
Remnant of fusion failure of branchial arches or lymph node cystic degeneration
Transilluminates
Anterior to the sternocleidomastoid at junction between upper and middle thirds
Becomes infected, enlarging
Rx - excision to prevent further infection
What is a pharyngeal pouch?
Herniation of pharnygeal mucosa between thyropharnygeus and cricopharnygeus muscles of the inferior constrictor of the pharynx
What are the signs and symptoms associated with a pharyngeal pouch?
Voice hoarseness Dysphagia Aspiration pneumonia Regurgitation Weight loss Neoplasia (1%)
How is a pharyngeal pouch treated?
Barium swallow, excision (open or endoscopic), dilatation
