Hi Res (Salivary Glands, Neck & Lymph Nodes) Flashcards
Salivary Glands
- release secretions into ducts that lead to mouth
- 3 main pairs (parotid, submandibular, sublingual)
- also numerous sm salivary glands scattered around mouth
Parotid Glands
- each side of face (below external acoustic meatus)
- each one has a parotid duct opening into the mouth at the second molar
Submandibular Glands
- lie on each side of the face under the angle of the jaw
- 2 submandibular ducts open to the floor of mouth (each side of the frenulum of tongue)
Sublingual Glands
- under mucous membrane of the floor of mouth in front of submandibular glands
- numerous small ducts that open into the floor of mouth
Structure of Salivary Glands
- fibrous capsule
- lobules made of sm acini, lined with secretory cells
- secretions are poured into ductules (join to form larger ducts leading to the mouth)
Arterial Supply
-branches from the external carotid arteries
Venous Drainage
-external jugular veins
Composition of Saliva
-combined secretions from salivary glands and mucus secreting glands of oral mucosa
- water
- mineral salts
- digestive enzymes (salivary amylase)
- mucus
- lysozyme
- immunoglobins
- blood clotting factors
How much saliva is produced each day?
1.5 litres
Mumps
- disease of salivary glands
- acute inflammatory condition of salivary glands (especially parotid)
- caused by mumps virus
Parotitis
-inflammation of parotid gland
May be:
- viral (mumps)
- bacterial (develop into abscess)
- autoimmune (sjogren’s syndrome)
- calculus
Parotitis on US
- usually bilateral
- enlarges
- heterogenous
- increased vascularity
Reactive lymphnodes (embedded in the parotid gland) are ______ to parotitis.
-secondary
Sialtis
-inflammation of salivary gland or duct
Sialectasis
- dilation of salivary duct
- resulting from duct obstruction of parotid or submandibular glands
- pain and swelling
Parotitis
-inflammation of parotid gland
Calculus Formation
- calculi (stones) formed by crystallization of mineral salts in saliva
- partially/completely block ducts (inflammation, swelling, infection, atrophy)
- unknown cause
Where do salivary gland stones occur?
- 8/10 in submandibular
- rare in sublingual
Why are stones less common in parotid glands?
-parotid glands make thinner saliva
The calculus is easily seen in the ______ duct as it exits the main body of the parotid gland heading medially. Parotid duct calculi are ______.
- Stenson’s
- rare
Parotid Adenoma on US
- well circumscribed
- posterior enhancement
Carcinoma
- malignant tumors most commonly affect the parotid glands
- have a tendency to infiltrate nerves in the surrounding tissue (causes pain)
- lymph spread is to cervical nodes
Sjogrens Disease
-autoimmune disorder affecting moisture producing exocrine glands (tears, saliva)
2nd Most Common Rheumatic Disorder
-sjogrens disease
Most Common Rheumatic Disorder
-rheumatoid arthritis
Symptoms of Sjogrens Disease
-dryness of eyes/mouth (sicca syndrome)
What can occasionally develop in the parotid glands of the sjogre’s patients?
-MALT lymphoma
Role of US
- palpable lump in gland/neck
- pain
- mumps
- illness (mouth/dental infections)
- mouth dryness
- abnormality on previous xray, CT or sialogram
- guidance of injection, aspiration or biopsy
Assess the gland for…
- size
- increased vascularity
- abnormality surrounding lymph nodes
- duct dilation (use doppler, so you don’t mistake a vessel to be a dilated duct)
What is between the parotid and submandibular glands?
-kuttner lymph node
Appearance of Glands
- hypoechoic
- homogenous echotexture (similar to muscle)
What do the intraglandular ducts look like on US?
-small, linear hypoechoic parallel stripes
How do you document pathology?
- in 2 planes, with measurements
- measure vascularity as well
Submandibular duct (Wharton’s duct) is generally no more than ______ in diameter and is often not visible along it’s entire length.
2mm
Why is the parotid more attentive than the submandibular?
-fat content
Are ducts easily visualized?
-only if dilated
Are the sublingual glands easy to see?
- very small
- can sometimes only see if there is a pathology
- obscured anteriorly by mandible
Average Size of Normal Sublingual Gland
32 x 12 mm
Sublingual Glands on US
- homogenous, hyperechogenicity similar to the parotid gland
- best seen in TRV and SAG planes obtained from the submental position
Lymphatic System
-network of tissues and organs that primarily consist of lymph vessels, lymph nodes and lymph
What system are the tonsils, adenoids, spleen and thymus part of?
-lymphatic system
How many lymph nodes are in the body (filter lymph before it returns to circulatory system)?
-600 to 700
Functions of Lymphatic System
- transport clean fluids back to blood
- drains excess fluid from tissue
- removes debris from body cells
- transports fats from digestive system
Which way does lymph flow?
- 1 direction
- towards neck
- into the venous system through the SCV’s
Where are the lymphatic drainage areas (2)?
- Rt drainage area handles the Rt arm and chest
- Lt drainage area handles the rest of the body (legs, lower trunk, upper Lt portion of chest, Lt arm)
Lymphangitis
-inflammation of lymph vessels
Lymphadenitis
-infection of lymph nodes
Lymphadenopathy
-enlargement of lymph nodes
Splenomegaly
-enlargement of the spleen
Lymphoedema
-swelling in tissues whose lymphatic drainage has been instructed in some way
Normal Appearance of Lymph Nodes
- small
- oval
- hilum present
- moderate echogenicity
- sharp margins, no structural changes
- soft tissue edema
- central vessel on doppler
- single vascular pedicle
- regular vascular pattern
- low impedance
What is the difference on US between the appearance of normal and reactive lymph nodes?
-they look the same
Reactive Lymph Nodes
- enlargement of the cervical lymph nodes commonly occurs with viral infections
- usually sm, firm and non tender
- may persist for weeks/months
Abnormal Lymph Node Appearance
- lg
- rounded
- hilum absent
- hypoechoic
- irregular, angular, blurred margins
- structural changes
- no edema
- peripheral vessels on doppler
- multiple vascular pedicles
- chaotic vascular pattern
- high impedance
Lymphoedema
-chronic swelling of limbs caused by accumulation of lymph fluid (if lymphatic system is damaged/not functioning properly)
How may lymphoedema develop?
- following cancer therapy (especially breast)
- recurrent infections
- injuries
What parts of the body are involved in lymphedema?
-limbs, face, neck, abdomen
Tumors
- may grow into and block lymph vessel/node, obstructing the flow
- a lg tumor outside the lymphatic system may cause pressure to stop the flow of lymph
Why might lymph nodes be surgically removed?
- cancer cells may spread to them
- to prevent growth of secondary tumors in local lymph nodes and the spread of disease through the lymphatic system
Minor Lymphadenitis
-accompany infections (measles, typhoid, cat scratch fever, wound, skin infection)
Chronic Lymphadenitis
-follows unresolved acute infections (TB, syphilis, low grade infections)
Lymphomas
- malignant tumor of lymphoid tissue
- classified as Hodgkin’s or non Hodgkin’s lymphomas
Hodgkin’s Disease
- progressive, painless enlargement of lymph nodes
- superficial lymph nodes in the neck are usually noticed 1st
Is Hodgkin’s disease malignant or benign?
-malignant
What is the cause of Hodgkin’s disease?
-unknown
Why does Hodgkin’s disease cause reduced immunity?
-lymphocyte function is depressed, therefore recurrent infection is common
Non Hodgkin’s Lymphoma
- tumors
- multiple myeloma and Burkitt’s lymphoma may occur in any lymphoid tissue and in bone marrow
- expanding lymph nodes may compress adjacent tissues/organs
- anemia and leukopenia
How are non Hodgkin’s lymphomas classified?
- type of cell involved
- degree of malignancy
What is the most common anomaly of the head and neck?
-thyroglossal (duct) cyst
Thyroglossal (duct) Cyst
- cyst beneath the skin of the anterior midline of the neck (below hyoid bone)
- moves superior if patient moves their tongue
- infected cyst ruptures through skin to drain (thyroglossal sinus)
What is the most common benign lymphadenopathy?
-thyroglossal (duct) cyst
What is the 2nd most common cause of a neck mass in children?
-thyroglossal (duct) cyst
Thyroglosssal (duct) Cyst on US
-low level intraluminal reflectors (due to bleeding/infection)
branchial Cleft Cyst
- abnormal persistence of remnant of the branchial apparatus
- results in cysts, sinuses and fistulas
- cystic neck mass, along the medial border of SCM (upper neck)