Histology Exam 2

Question 1

epithelium

Answer 1

• outer protective surface of the body and glands
• lines most closed cavities, all passages to exterior and blood/lymphatic vessels

Question 2

what is the function of the epithelium?

Answer 2

barrier- protection withstanding wear and tear from dehydration/hydration
- selective absorption
- transport of ions, O2, CO2

Question 3

what cell is the most common in cancer?

Answer 3

epithelial

Question 4

epithelium pt2

Answer 4

• sheet of polarized cells
• metabolism of body through covering the external and lines of internal surface of body

Question 5

Epithelial Cells

Answer 5

• capable of renewal and regeneration
• form avascular sheets
  held together by junctions
• organelles in cell are polarized

Question 6

3 surface specializations of epithelial cells

Answer 6

• apical
• lateral
• basal

Question 7

microvilli

Answer 7

apical
- bundles of actin filaments extend into terminal web
- increase SA
- core of actin filaments

Question 8

Cilia

Answer 8

apical
- do not have core of actin filaments
- complex arrangements of microtubules (axoneme)
- tubulin= major protein
- facilitate flow of fluid
- stereocilia -male reproductive tract (immotile)

Question 9

ectoderm

Answer 9

epidermis of skin and epithelium of cornea together covers the entire surface of the body; sebaceous and mammary glands

Question 10

endoderm

Answer 10

alimentary tract, liver, pancreas, gastric glands, intestinal glands

Question 11

Apical plasma membrane fn

Answer 11

• regulation of nutrient and water uptake
• regulated secretion (pathway A)
• protection

Question 12

Lateral Plasma Membrane fn

Answer 12

• cell-cell contact/adhesion and communication

Question 13

Basal-lateral membrane fn

Answer 13

signal reception and transduction
- generation of ion gradients - - constitutive secretion (pathway B)

Question 14

function of the basal lamina

Answer 14

• adhesion of CT
• selective permeability
• good substrate for cell migration during wound repair+embryonic development

Question 15

type of cell found in basal lamina

Answer 15

stem cell

Question 16

2 secretion pathways

Answer 16

• regulated
• constitutive

Question 17

regulated secretion

Answer 17

secretory granules accumulate in cells and the granule content is released by exocytosis upon stimulation

Question 18

constitutive secretion

Answer 18

secretory product is not concentrated into granules but is released continuously in small vesicles

Question 19

mesoderm

Answer 19

• Endothelium- lines blood vessels
• Mesothelium- lines serous cavities

Question 20

integrins

Answer 20

trans-membrane linker proteins that fn as matrix receptors

Question 21

Lamina Lucida

Answer 21

closest to cell membrane, translucent, contains strands that connect to lamina densa
- laminin
- against ep membrane

Question 22

lamina densa

Answer 22

electron dense layers, meshwork randomly
- type IV collagen
- against reticular lamina

Question 23

reticular lamina

Answer 23

not always present, contains reticular fibers & is made by underling CT cells
- Fibronectin, collagen type V, collagen type VII(mainly), ends of collagen type III

Question 24

occluding junctions

Answer 24

form seal and are impermeable

Question 25

adhering junctions

Answer 25

glue cells together and are associated with specific cytoskeletal elements

Question 26

communicating junctions

Answer 26

permit x-talk

Question 27

fn of tight junctions

Answer 27

- Forms seal/barrier between cells - Forms epithelial compartments - Polarize the epithelium - Limit diffusion of membrane proteins from apical membrane to baso-lateral plasma membrane

Question 28

desmosomes

Answer 28

- exposed to abrasion - spot attachment sites for adjacent CM -anchoring site for IF

Question 29

hemidesmosomes

Answer 29

found at base of stratified epithelia and connects the PM to the EM via integrins

Question 30

what causes blistering skin disorders

Answer 30

- mutant cytoskeletons due to a failure to form filaments and weakening epithelia - loss of desmosome

Question 31

sensory cells

Answer 31

receive stimuli from external environment which induces a special status in their bodies- irritation

Question 32

endocrine glands

Answer 32

ductless - pour secretion into blood directly

Question 33

exocrine gland

Answer 33

ducts - pour secretions onto an epithelial surface directly through ducts

Question 34

epidermis layers

Answer 34

stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale

Question 35

what are the cells in the epidermis

Answer 35

Keratinocytes Melanocytes Langerhans cells Merkel cells

Question 36

Melanin fn

Answer 36

absorbs UV radiation minimizing damage to cells, absorbs UV radiation reducing the amount available for production of vitamin D

Question 37

Merkel cells

Answer 37

neurosensory cells that synapse with nerve endings

Question 38

Langerhans cell

Answer 38

bone-marrow derived antigen presenting cell

Question 39

fn of the dermis

Answer 39

supplies innervention and vascular networks; binds epithelium

Question 40

collagen fibers

Answer 40

strong, resist stretching but bend easily and provide flexibility

Question 41

elastic fibers

Answer 41

permits stretching, recoils to original length and prevents damage to tissue

Question 42

free nerve endings

Answer 42

unmyelinated axons respond to pain stimuli (nociceptors), temp (thermoreceptors), mechanical displacement (mechanoreceptors)

Question 43

epidermis

Answer 43

stratified squamous epithelium, keratin - thick, thin skin

Question 44

dermis

Answer 44

dense irregular connective tissue with type I and type III collagen/elastic fibers - papillary, reticular and sweat glands

Question 45

hypodermis

Answer 45

subq layer - fatty connective tissue