Unit 2

Question 1

Microscopic Anatomy

Answer 1

-The study of the structure of cells tissues and organs of the body as seen with a microscope

Question 2

Histology

Answer 2

-Study of microscope structure and function of tissue

Question 3

Embryology

Answer 3

-Study of prenatal development

Question 4

Tissue

Answer 4

-Structure formed by grouping of cells with similar characteristics of shape and function

Question 5

A common tissue stain combination is hematoxylin and eosin. What happens to the nuclei, cytoplasm and intercellular substance when epith cells are stained using these materials.

Answer 5

• Hematoxylin turns acidic material blue ex: nuclei, ground substance
• Eosin turns alkaine components pink ex: cytoplasm, collagen

Question 6

What must be done with mineralized tissue in order to slice it with a microtome? Briefly describe this process.

Answer 6

-It must first be demineralized, which needs to be places in an weak acid solution to help soften the tissue

Question 7

How is tooth enamel sectioned and preserved? What are these sections called and how is it different from soft tissue sections?

Answer 7

-It is first softened and then cut, and then placed on a slide and adhesive is used to help preserve

Question 8

Lining Mucosa (identify type of epith, CT and submucosa)

Answer 8

• Epith: non-keratinized SSE
• Lamina Propria: extensive vascular supply, loose CT papillae, some elastic fibers
• Submucosa: present, loose attachment to muscles and bones, minor salivary glands, adipose CT with sublingual and submandibular salivary glands
• Ex: labial and buccal mucosa, alveolar mucosa, ventral surface of tongue and FOM

Question 9

Masticatory Mucosa (identify type of epith, CT and submucosa)

Answer 9

• Epith: keratinized and parakeratinzed
• Lamina Propria: dense CT
• Submucosa: present in hard palate with ant with adipose CT and most with minor salivary glands, not present in attached gingiva
• Ex: hard palate and attached gingiva

Question 10

Specialized Mucosa (identify type of epith, CT and submucosa)

Answer 10

• Epith: vaires and contains taste buds
• Lamina Propria: rich vascular supply, immovable relative to muscles
• Submucosa: minimal submucosa -> minor salivary glands and adipose tissue

Question 11

Describe lamina propria in the various types of oral mucosa?

Answer 11

• Refer to oral mucosa flash cards (lining, masticatory and specialized)
• Papillary layer: forms C papillae, layers of superficial loose CT, located in the lamina propria of oral mucosa
• Dense Fibrous layer: tightly packed CT with regular arrangement, ropey like due to fibres and collagen

Question 12

Functions of lamina propria (CT)

Answer 12

• Movement
• Support
• Protection
• Binding
• Insulation
• Transportation
• Formative
• Nutritive
• Sensory

Question 13

What structures separate the lamina propria from epith?

Answer 13

-Basement membrane

Question 14

What structures are generally below or deep tp the lamina propria?

Answer 14

-Submucosa if present, then muscles, bones, etc

Question 15

Histology of keratinized epith.

Answer 15

• Layers of SSE
• Least common form of epith, associated with masticatory mucosa of the hard palate, attached gingiva and specialized mucosa of the lingual papillae on the dorsal surface of the tongue

Question 16

Histology of parakeratinzed epith.

Answer 16

• Layers of SSE
• Located on the superficial layers of lining mucosa
• Most common form of epith

Question 17

Histology of non-keratinized epith.

Answer 17

• Layers of SSE
• Associated with masticatory mucosa of the attached gingiva in higher level than the pressure of keratinized, also associated with specialized mucosa of lingual papillae on the dorsal surface of the tongue
• Main difference between keratinized and para is in the cells of the keratin layer (para most superficial layers is still being shredded, however, these keratin cells contain a nucleus)

Question 18

What are rete pegs and what is their significance? For the 3 types of epith what one has little to no rete pegs (short) and what one will have several long ones?

Answer 18

• Rete pegs are little blips
• They are epith extensions directed into CT
• Little to no rete pegs are found in non-keratinized epith and long rete pegs are found in keratinized and some in parakeratinzed epith
• Allow nourishment to avascular epith (no veins), which works with the CT papillae to provide that nourishment and it is also and adhesion (stick)

Question 19

Describe the structure and function of the basement membrane.

Answer 19

• Short like border between the basal layer of epith and the underlying CT
• Consists of 2 layers basal lamina and reticular lamina
• Corrugated =wavy design
• CT extensions into epith are called CT papilla
• Function: increase surface area, thereby increase strength and decrease distance between vascular supply and epith, which enhances nourishment
• As epith gets thicker the basement membrane will change shape to help nourishment

Question 20

Gingiva Fibres

Answer 20

• Within CT
• Comes from basement membrane and hold tissues down and keeps it nice and snug to underlying structures
• Hold free gingiva and JE to help keep attachment
• Goes in variety of directions: from cementum to free gingiva and cementum to attached gingiva

Question 21

Describe the histological structure of the junctional epith and of the gingival epith. *Remember how these tissue maintain their thickness. When is the mitotic rate higher?

Answer 21

• A deeper extension of the SE is the JE which lines the floor of the gingival sulcus and is attached to the tooth surface (attachment can occur on the enamel cementum or dentin)
• JE cells are loosely packed with fewer intercellular junction using desmosomes

Question 22

Compare renewal rates of cells of the JE and gingival epith. When in the mitotic rate higher?

Answer 22

• Cells of the JE are replaced with new cells every 1-6 days (renewal rate, basal to surface)
• The gingiva epith renewal rate is 10-14 days
• The mitotic rate of the JE differ from the gingiva because the mitotic rate increases in gingivitis

Question 23

Describe the passive eruption changes in position of the epith attachment. What is the clinical changes of these significance?

Answer 23

• This related greatly to the location of the JE, therefore, the JE moves apical on the roots of the teeth (epith attachment)
• Same as loss of attachment (COL)
• Movement of JE do to disease process of anatomical movements to the teeth
• Measured with probing and the GM to CEJ

Question 24

Identify the 2 types of salivary secretory cells and differentiate the composition of the 2 secretions. *Recall the types of saliva from each of the major and minor salivary glands.

Answer 24

Serous:

• pyramidal shaped
• Enzyme amylase (breaks down carbohydrates)
• Watery Saliva
• Parotid and minor salivary glands produce this
• Function: to flush and clear

Mucous:

• pyramidal shaped
• Thick and frothy saliva
• No amylase enzyme
• Contains mucin
• Function: lubrication and formation of bolus

Question 25

What are the 3 types of ducts in salivary glands and where are they located? *Note the difference in cell shape and location.

Answer 25

Intercalated: - Small cuboidal epith cells - Collect saliva directly from acinar cells - Tube is lined with these epith cells - No other function Striated Cells Interlobular (cells of the excretory ducts) - Transitional forms of epith cells vary from single layers columnar to cuboidal to squamous as the duct gets closer to the oral epith - Saliva exits glands to oral cavity through these ducts: stenson's, wharton's and bartholins - Squamous shaped (flattened) - No other particular function

Question 26

What does the striated duct cell do that the other duct cells do not?

Answer 26

- Function: modifies saliva - Columnar shaped - Fold of epith, with mini mitochondria (powerhouse of cell) in cells in folds, this helps the membrane move across CT to saliva and back across CT - Help to conserve electrolytes and reserve water (helps to keep it in the body) - Straition increase surface area for transfer of ions and metabolites (into bloods vessels as the body requires)

Question 27

What function do the myoepithelial cells have and where are they situated?

Answer 27

- Branched, stellate cells that lie between the basal lamina and acinar cells - Epith contracts around acini (squeezes acini)

Question 28

Describe Basal Lamina and Reticular Lamina.

Answer 28

Basal Lamina: - Most superficial layer of the basement membrane that os produced by epith and is about 40 to 50 um thick - Contains 2 sublayers: lamina lucida -> clear layer close to epith and lamina densa -> dense layer closer to CT Reticular Lamina: - Deep layer of basement membrane that is produced by the CT - Consists of collagen fibres and reticular fibres (which helps to provide attachment) produced and secreted by underlying CT - Fibers come up and weave in and out of basal lamina to help attach the basement membrane to CT

Question 29

Gross Anatomy

Answer 29

-The branch of anatomy that deals with the structure of organs and tissues that are visible to the naked eye

Question 30

What is keratin?

Answer 30

-Keratin are intermediate protein filaments that has no nucleus, they are made by our epith cells and found in epith consisting of opaque waterproof substances

Question 30

Describe hemidesmosomes.

Answer 30

- epith layer (basal lamina) that secretes a goo like substance, which forms hemidesmoses, however in order to produce these tonoalfibral must already be present or made (which form and collect in an area that help stick in basal lamina) - Hemi increase nourishment and attachment - Hemi = cell to no cell (ex: cell to tooth) desmosomes: cell to cell