Oral Anatomy & Histology (Review: Outcome 9)

Question 1

Define gland

Answer 1

A structure that produces a secretion necessary for normal body functioning

Question 2

Exocrine gland

Answer 2

A gland having a duct associated with it

Question 3

Duct

Answer 3

A passageway that allows the glandular secretion to be emptied directly into the location where the secretion is to be used

Question 4

Endocrine gland

Answer 4

A ductless gland with its secretion conveyed directly into the blood and then carried to some distant location to be used

• Motor nerves associated with both types of glands help regulate the flow of secretion
• Sensory nerves are also present in the gland

Question 5

Salivary glands

Answer 5

• Produces saliva, which lubricates and cleanses the oral cavity and aids in the digestion of food through an enzymatic process
• Saliva also helps maintain the integrity of tooth surfaces through a process of remineralization
• Salivary glands are classified by their size as either major or minor

Question 6

Properties of salivary glands

Answer 6

• Saliva contains minerals, electrolytes, proteins, buffers, enzymes, immunoglobulins (secretory IgA), and metabolic wastes
• The secretion by these glands is controlled by the autonomic nervous system
• Saliva lubricates and cleanses the oral mucosa, protecting it from dryness and potential carcinogens by way of its mucins and other glycoproteins

Question 7

What are the two types of saliva?

Answer 7

1) Serous
- watery
- mainly protein

2) Mucous
- very thick
- mainly carbohydrate

Question 8

What are the major salivary glands?

Answer 8

1) Parotid salivary gland
- saliva passes from the parotid gland into the mouth through a duct called the parotid duct (also known as Stensen’s duct)

2) Submandibular salivary gland
- Releases saliva into the oral cavity through Wharton’s duct, which ends in the sublingual carnucles

3) Sublingual salivary gland
- Releases saliva into the oral cavity through the sublingual duct (known as Bartholin’s duct)

Question 9

Parotid Salivary Gland

Answer 9

The largest major salivary gland, it provides only 25% of the total salivary volume

Location:
- located in an area behind the mandibular ramus, anterior and inferior to the ear
- Duct: Parotid Duct (Stenson’s duct)

Question 10

Submandibular Salivary Gland

Answer 10

The second-largest major salivary gland, but it provides 60% to 65% of the total salivary volume

Location:
- it lies beneath the mandible in the submandibular fossa, posterior to the sublingual salivary gland
- Duct: Submandibular duct (Wharton’s duct)

Question 11

Sublingual Salivary Gland

Answer 11

The smallest, most diffuse. It provides only 10% of the total salivary volume

Location:
- gland is superior to the mylohyoid muscle and medial to the body of the mandible
- also anterior to the submandibular gland

Question 12

Sublingual Ducts

Answer 12

• The sublingual glands are drained by 8-20 excretory ducts called Ducts of Rivinus
• The largest of all, the sublingual duct (of Bartholin) joins the submandibular duct to drain through the sublingual caruncle
• Most of the remaining small sublingual ducts (of Rivinus) open separate into the mouth on an elevated crest of mucous membrane, the plica sublingualis (aka sublingual fold), formed by the gland and located on either side of the frenulum linguae

Question 13

What are the Minor Salivary Glands?

Answer 13

• Smaller and more numerous than the major salivary glands
• Scattered in the tissues of the buccal, labial, and lingual mucosa; the soft palate; and the floor of the mouth
• Ebner’s salivary gland is associated with the large circumvallate papillae on the tongue

Question 14

What are some disorders of the salivary glands?

Answer 14

1) Xerostomia (dry mouth)
- can result in an increase in dental decay and problems in speech and chewing

2) Salivary stones (sialoliths)
- may block duct openings, preventing saliva from flowing into the mouth

Question 15

Thyroid Gland

Answer 15

• The largest endocrine gland
• Produces and secretes its products or hormones directly into the blood, such as thyroxine
  Thyroxine = a hormone that stimulates the metabolic rate

Location:
- Anterior and lateral regions of the neck
- inferolateral to the thyroid cartilage, at the junction between the larynx and trachea
- consists of two lateral lobes connected anteriorly by an isthmus

Question 16

Lymphatics

Answer 16

• A part of the immune system and help fight disease processes
• Also serve other function in the body
• The lymphatic system consists of a network of lymphatic vessels linking lymph nodes throughout most of the body
• Tonsillar tissue located in the oral cavity and pharynx is part of the lymphatic system

Question 17

Lymphadenopathy

Answer 17

• When a patient has an infection or cancer in a particular region, the lymph nodes in that region will respond by increasing in size and becoming very firm
• Lymphadenopathy results from an increase in both the size of each lymphocyte and the overall cell count in the lymphoid tissue
• With an increase in the size and number of lymphocytes, the body is better able to fight the disease

Question 18

Lymph nodes of the head and neck

Answer 18

• A dental professional must examine and palpate the lymph nodes of the head and neck carefully during extraoral examination
• Enlarged lymph nodes may indicate infection or cancer
• Lymph nodes for the oral cavity drain intraoral structures, such as teeth, eyes, ears, nasal cavity, and deeper areas of throat

Question 19

Structure and Function of Lymph nodes

Answer 19

• Lymph nodes are small and round or oval structures located in lymph vessels
• Major sites of lymph nodes include:
  i. cervical (in the neck)
  ii. axillary (under the arms)
  iii. Inguinal (in the lower abdomen)
• The lymph nodes of the head are classified as superficial (near the surface) or deep

Question 20

Superficial Lymph nodes of the head

Answer 20

There are 5 groups:
- occipital
- retroauricular
- anterior auricular
- superficial parotid
- facial nodes

Question 21

Deep Cervical Lymph Nodes

Answer 21

Located along the length of the internal jugular vein on each side of the neck, deep to the sternocleidomastoid muscle

Question 22

Mucous Membrane

Answer 22

• It is the epithelial tissue that lines a body cavity that opens to the outside of the body
  (Stratified squamous cells)
  (Keratinized vs. non-keratinized areas)
• Rest on connective tissue layer
• Separated by a basement membrane

Question 23

3 Types of Mucosa

Answer 23

1) Masticatory
2) Lining
3) Specialized

Question 24

The Normal Periodontium (Gingiva - focused)

Answer 24

A. Free gingiva (Marginal gingiva)
B. Gingival sulcus (Crevice)
C. Interdental gingiva (interdental papilla)
D. Junctional Epithelium
E. Attached gingiva
F. Mucogingival junction
G. Alveolar mucosa

Question 25

The gingival description - colour

Answer 25

i. Signs of health - Pale pink: darker in people with darker complexions due to melanin pigmentation ii. Changes in disease - in chronic inflammation: dark red, bluish red, magenta, or deep blue - in acute inflammation: bright red

Question 26

The gingival description - size

Answer 26

A. Signs of Health - Free gingiva: flat, not enlarges; fits snugly around the tooth B. Changes in Disease - Free gingiva and papillae: Become enlarged - May be localized or limited to specific areas or generalized throughout the gingiva - the col deepens as the papillae increase in size C. Enlargement from Drug Therapy - Certain drugs used for specific systemic therapy cause gingival enlargement as a side effect such as phenytoin, cyclosporine, and nifedipine

Question 27

The gingival description - shape

Answer 27

A. Signs of health i. Free gingiva: - follows a curved line around each tooth; may be straighter along wide molar surfaces - the margin is knife-edged or slightly rounded on facial and lingual gingiva; closely adapted to the tooth surface ii. Papillae: - facial and lingual gingiva are pointed or pyramidal papillae with a col area under the contact between adjacent teeth - spaced teeth (with diastemata). Interdental gingiva is flat or saddle shaped B. Changes in disease i. Free gingiva: rounded or rolled ii. Papillae: blunted, flattened, bulbous, cratered - "McCall's festoon" - "Stillman's cleft" - Floss cleft

Question 28

The gingival description - consistency

Answer 28

A. Signs of health - firm when palpated with the side of a blunt instrument (probe) - attached gingiva is bound down firmly to the underlying bone B. Changes in Disease i. Soft, spongy gingiva - tissue appears red, may be smooth and shiny with loss of stippling - tissue may be friable or thin and fragile ii. Firm, hard gingiva - tissue may appear pink and well stippled iii. Retraction of the margin away from the tooth - normally, the free gingiva fits snugly about the tooth

Question 29

The Gingival Description - Surface texture

Answer 29

A. Signs of Health - Free gingiva: smooth - Attached gingiva: stippled (minutely "pebbled" or "orange peel" surface) - Interdental gingiva: free gingiva is smooth; center portion of each papilla is stippled B. Changes in Disease - Inflammatory changes: may be loss of stippling, with smooth, shiny surface - Hyperkeratosis: may result in a leathery, hard, or nodular surface - Chronic disease: tissue may be hard and fibrotic, with normal pink color and normal or deep stippling

Question 30

The Gingival Description - Position

Answer 30

A. Signs of health - for the fully erupted tooth in an adult, the apparent position of the gingival margin is at the level of, or slightly below, the enamel contour or prominence of the cervical third of a tooth B. Changes in Disease - gingival enlargement - gingival recession

Question 31

Gingiva of young children

Answer 31

A. Primary Dentition i. Color: pink ii. Shape: thick, rounded or rolled iii. Consistency: less fibrous than adult - not as tightly adapted iv. Texture: may or may not have stippling B. Mixed Dentition - Constant state of change (periods of inflammation related to exfoliation and eruption) - Free gingiva: rounded or rolled, slightly reddened, shiny and a lack of firmness *Gingivitis occurs frequently