Histology Test 1

Front 1

most epithelia are derived from?

Back 1

Endoderm

Front 2

Connective tissue is derived from?

Back 2

Mesoderm (mesenchyme)

Front 3

Muscle tissue is derived from?

Back 3

Mesoderm (mesenchyme)

Front 4

Nervous tissue is derived from?

Back 4

nueroectoderm (from ectoderm)--> neural tube

Front 5

most epithelia are derived from?

Back 5

Endoderm

Front 6

Connective tissue is derived from?

Back 6

Mesoderm (mesenchyme)

Front 7

Muscle tissue is derived from?

Back 7

Mesoderm (mesenchyme)

Front 8

Nervous tissue is derived from?

Back 8

nueroectoderm (from ectoderm)--> neural tube

Front 9

Hamburger granule means?

Back 9

it is a granule of a eosinophil

Front 10

Endocrine vs exocrine
-Which has ducts?

Back 10

-Endocrine does NOT have ducts
-Exocrine CAN have ducts and can secrete onto a body surface directly

Front 11

each goblet cell can be regarded as?

Back 11

a unicellular gland "simplest exocrine type gland"

Front 12

Serous vs mucus gland
-Which is darker, why?
-What does each contain

Back 12

Mucus is lighter b/c it contains highly glycosylated proteins (PAS +) --> secretions usually lost during prep. & look empty (white)

Serous stains darker b/c it secretes proteins (enzymes)

Front 13

How do you differentiate serous gland from mucus?

Back 13

Serous gland = nucleus is flattened against basal surface due to accumulated product

Mucus = stain darker, nucleus is not pressed against base

Front 14

what is vascularized?
-epithelial layers?
-Basement membrane?

Back 14

Epithelial layers --> Avascular
BM --> has vasculature

Front 15

which type of gland has ducts?

Back 15

exocrine only (not endocrine or the others)

Front 16

In ducts, what color are the cells and where is the nucleus?

Back 16

pale pink, centered nucleus

Front 17

Acinar nucleus are where?

Back 17

Towards the basal end
-Mucous acinar glands are extremely basal while serous are less basal (but still near base)

Front 18

what happens to ducts as they get larger?

Back 18

They can go from (1-2 layered) cuboidal to stratified cuboidal

Front 19

exocrine gland structures?

Endocrine gland structures?

Back 19

Secretory structure
-Tubular, Acinar, Tubuloacinar
Ductal structures
- (Simple) Unbranched duct
- (compound) branched duct

-Endocrine --> NO DUCTS --> secrete products into connective tissue which then enters blood

Front 20

Exocrine (ONLY) exhibits 3 types of secretion?

Back 20

Merocrine - exocytosis - cells fuse with memo. and release hormones
-Apocrine - vesicles pinch off
-Holocrine - whole cell lyses releasing product

Front 21

where does Ct originate from in embryo?

Back 21

1) mesoderm
2) Neural crest cells --> derived from ectoderm "neuroectoderm"

Front 22

Functions of macrophages?
3

Back 22

1) phagocytosis
2) APC
3) Release IL-1, TNF-alpha (lymphokines of inflammatory reactions)

Front 23

Lymphokines?

Back 23

Lymphokines are a subset of cytokines that are produced by a type of immune cell known as a lymphocyte

Front 24

The terminal web is integrated with?

Back 24

Zona adherens

Front 25

What is the terminal web made of?
-Function?

Back 25

cross-linked actink microfilaments
-Anchors microvilli and integrates with Zona adherens

Front 26

what has a striated border?

Back 26

Microvilii

Front 27

basement membrane is packed full of?

Back 27

densely packed collagen fibrils

Front 28

How can you stain the BM?

Back 28

with PAS, shows as purple/red color (magneta)

Front 29

Basal lamina consists largely of?

Lamina reticularis consists of?

Back 29

-type 4 collagen
-laminin
-proteoglycans

LR = collagen type 3 & ground substance

Front 30

Major linking proteins of desmosomes vs hemidesmosomes

Back 30

Desmo --> cadherins
DC

Hemidesmo -->Integrins
HI

Front 31

Major linking proteins of desmosomes vs hemidesmosomes

Back 31

Desmo --> cadherins
DC

Hemidesmo -->Integrins
HI

Front 32

Major linking proteins of desmosomes vs hemidesmosomes

Back 32

Desmo --> cadherins
DC

Hemidesmo -->Integrins
HI

Front 33

Integrins?

Back 33

- membrane-spanning receptor proteins
-collagen attaches to plasma membrane receptors (integrins) via linker proteins (fibronectin, laminin)

- Integrins bind cell surface and ECM components such as fibronectin, collagen, and laminin.

-Integrins are receptors that mediate the attachment between a cell and the tissues that surround it, such as other cells or the extracellular matrix (ECM)

Front 34

Fibronectin?

Back 34

-A LINKER protein --> it binds collagen and integrin --> holds them together

glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins.

lagen attaches to plasma membrane receptors (integrins) via linker proteins (fibronectin, laminin)

Front 35

Laminin?

Back 35

-A LINKER protein
-Found in the Basal lamina with collagen type 4, and fibronectin

-LINKS collagen to integrin transmembrane receptors

Front 36

distinguishing feature of a macrophage?

Back 36

kidney shaped nucleus "indented"
-in EM endocytotic vesicles
-in EM finger like projections

Front 37

Adipocytes are the only CT to surround itself with?

Back 37

an external lamina (seen in TEM)

Front 38

pericytes function?

Back 38

synthesize ECM components (like fibroblast) and contractility of smooth muscle cells

Front 39

Ground substance molecules?

Back 39

GAGs and glycoproteins

Front 40

Glycoproteins in the ground substance
-names
-function

Back 40

"adhesive glycoproteins"
-integrins

Integrins link the intracellular cytoskeleton to the Extracellular basal lamina through linker proteins laminin and fibronectin

Front 41

fibronectin

Back 41

mediate cell to fiber adhesion
(chondrocyte to type 2 collagen in cartilage)

Front 42

laminin

Back 42

mediates cell attachment to basement membrane via integrins receptors and type 4 collagen of BL

Front 43

GAGs
-structure
-function

Back 43

-long polysaccharide polymers, sulfated
-highly negative, attract water to make a gel --> provides resistance to compression of a tissue
-most GAGs bind to a core protein to form large proteoglycans

Front 44

name 3 GAGs

Back 44

heparin
chondroitin sulfate
Hyaluronic acid

Front 45

What are elastic fibers made of?
-where are they made

Back 45

fibrillin microfibrils around an elastin core
-made by fibroblasts and SM

Front 46

MMPs
-function
-activated by?

Back 46

zinc dependent
-degrades ECM (collagenase,elastinase)
-activated by ctyokines
-

Front 47

parenchyma vs stroma

Back 47

parenchyma is the functional tissue differentiated from epithelium (lymph nodes, bonemarrow)

Stroma is mesenchymally derived and is the CT and vasculature of an organ

Front 48

types of dense regular tissue

Back 48

tendons
ligaments
aponeuroses

Front 49

Periostium, perichondrium

Back 49

dense irregular CT

Front 50

where are stem cells located in cartilage?

Back 50

Perichondrium --> the chondrogenic layer

-stem cells become chondroblasts then chondrocytes

Front 51

What is a cartilage lacunae?

Back 51

Hole within cartilage matrix
-A shrinkage artifact from preparation, this potential space is where the chondrocyte resided

Front 52

appositional growth vs interstitial growth

Back 52

apo --> form new cartilage at surface of existing cartilage

interstitial --> for new cartilage within existing cartilage

Front 53

where is fibrous cartilage found?

Back 53

fibrocartilage is found:
-annulus fibrosus (of discs)
-knee joint menisci
-Tendon insertino in bone

Front 54

what are clinical implications of articular cartilage and its absence of repair, why can it not repair itself?

Back 54

-Articular cartilage has no perichondrium (perichondrium contains the stem cells that become either chondrocytes of fibroblasts)
-no repair means bone-to-bone contact (pain/disability)

Front 55

What is the chondrogenic layer?

Back 55

Within the perichondrium of cartilage, contains stem cells that give rise to fibroblast and chondroblasts

Front 56

what is the name of bone-lining cells on internal bone surfaces?
on external bone surfaces?

-What is there function?

Back 56

endosteal
periosteal

-Progenitor cells --> give rise to all bone cells except osteoclasts

Front 57

What is the name of the organic and inorganic material of the bone matrix?

Back 57

organic = osteoid

inorganic = Hydroxyapetite crystal

Front 58

What is the most abundant structural protein found in bone?

Back 58

collagen type 1

Front 59

What is the major protein osteoid of the bone matrix is comprised mainly of?
What is the major component by weight of the bone matrix?

Back 59

collagen type 1

-Hydroxyapetite

Front 60

what is a lacunae?

Back 60

the space where a osteocyte resides

Front 61

what are canaliculi of bone?

Back 61

crevices within the bone matrix that radiate out from lacuna, where osteocyte projections/tentacles enter and run

Front 62

Function of canaliculi?

Back 62

allow processes of osteocytes to run through and contact each other through GAP Junctions

-molecules/nutrient/ hormones can pass through canaliculi from the capillaries to nurish the bone, nutrients CANNOT diffuse through the matrix as they can in cartilage

-

Front 63

where do osteocyte progenitor cells derive from?

Back 63

periosteum or endosteum

Front 64

what is osteoid?
What makes it?
-Function?

Back 64

organic material of bone matrix (made of type 1 collagen & GAGs)
-Produced by osteoblasts
-Provide tensile strength & promotes crystal nucleation

Front 65

Osteon vs osteoid?

Back 65

Osteon = haversion system

Osteiod = organic material of the bone matrix (type 1 collagen, GAGs)

Front 66

Howship's lacuna?

Back 66

a depression on bone caused by osteoclast erosion

Front 67

What cells are responsible for forming new osteoblast?
-Where are they located?
-what else can these cells make?

Back 67

Osteoprogenitor cells
-located in periosteum and endosteum (osteogenic layer)
-Periosteum is made of a inner osteogenic layer and outer fibrous producing layer
-the progenitor cells can differentiate into fibroblasts, osteoblasts, or chondroblasts

Front 68

Sharpey's fibers

Back 68

collagen of tendons/ligaments/joint capsules insert into the periosteum and the underlying bony matrix, forming an integrated continuum of collagen fibers (resembles fibrocartilage)

Front 69

how are osteoclasts activated?

Back 69

PTH receptor on Oblast (not Oclast) release factors causing mononuclear macrophages to fuse together and form osteoclasts

Front 70

ruffled border?

Back 70

area of osteoclast that degradation on bone takes place

Front 71

osteoclasts form what 2 types of structures?

Back 71

Resorption tunnels & howship's lacunae

Front 72

what is the name of the region that follows the osteoclasts?

Back 72

The closing with many osteoblasts cone

Front 73

What is the clear "sealing" zone?

Back 73

region on the perimeter of osteoclasts where osteclasts integrate with the ECM of bone via integrins

Front 74

How does bone vs cartilage grow?

Back 74

Bone = grows only appositionally (on pre-existing surfaces)

Cartilage = appositionally via perichondrium and within the cartilage matrix when chondrocytes divide (interstitially)

Front 75

2 origins of bone tissue?

Back 75

both ways derive from mesenchymal cells
1) "intramembranous" bone formation, embryonic osteoblasts directly lay down osteoid (later compact lamellar bone is formed on top appositionally

2) "Endochondral bone formation"
-most bone forms from hyaline cartilage "templates" from chondroblasts