Histology Quiz 9/14 Part 2

Front 1

Intramembranous osteogenesis

Back 1

mesenchyme --> bone formation

From from a membrane of mesenchymal cells (flat bones of the skull)

Week 8 of development

Front 2

Endochondral osteogenesis

Back 2

Cartilage --> bone

occurs in long bones

1 form cartilage

2 form bone

3 remove cartialge

Front 3

Intramembranous bone formation (week 8 of embryo)

Back 3

mesenchymal cells differentiate into osteoprogenitor cells (form bone blastema)

express Runx2

then express Osx

Bone is formed

Front 4

Intramembranous: dense bones

Back 4

Forms haversian systems

Front 5

Endochondral Bone formation

Back 5

All form from a hyaline cartilage template

Bone of the extremities, vertebral column, pelvis

Front 6

Metaphysis

Back 6

part of the diaphyses (shaft) that's closest to the epiphyses (end); bone at this part is particularly dense, known to have an epiphyseal growth plate and an epiphyseal line

Front 7

Zones in epiphyseal cartilage

Back 7

Reserve zone: primitive hyaline cartilage responsible for the growth in length of bone

Proliferative zone: has actively mitotic chondrocytes (make matrix proteins)

Hypertrophic zone: apoptosis of chondrocytes and calcification of the territorial matrix

Front 8

Indian headgehog (Ihh)

Back 8

stimulates chondrocyte proliferation (type II and XI collgen is made) by stimulating them to produce Runx2 and become osteoblasts of the bony collar & stimulates them to produce parathyroid hormone peptides (inhibits chondrocytes in the proliferating some from becoming hypertrophic & stimulates chondrocyte proliferation in the reserve zone)

Front 9

Hypertrophic zone

Back 9

hypertrophied chondrocytes produce VEGF (important in vascularization), collage X, and then undergo apoptosis

Just before the zone of vascular invasion

Front 10

Vascular invasion zone

Back 10

Blood vessels bring in preosteoblasts and resporptive chondroclasts; preosteoblasts give rise to osteoblasts which start laying down osteoid.. bony spicules form

Front 11

spicule

Back 11

calcified cartilage coated by osteoid

Front 12

Trabecula

Back 12

core of lamellar bone with osteoblasts laying down osteoid

Front 13

Hereditary bone disorders

Back 13

Albers-Schonberg Disease: abnormal osteoclast function (osteopetrosis)

Fibrodysplasia ossificans progressiva: ectopic bone formation

Osteogenesis imprefecta: fragile bones

Front 14

Skeletal muscle

Back 14

Moves the skeleton and other structures such as precise eye movement

Front 15

Cardiac muscle

Back 15

heart muscle; propels blood through the heart and lungs into aorta

Front 16

Smooth muscle

Back 16

contraction of blood vessels, viscera, intrinsic muscle of the eye

Front 17

Characteristic of skeletal muscle

Back 17

Striated; nuclei located at the periphery of the muscle; originates from ventral somite bodies in embryo

Front 18

Differentiation of skeletal muscle

Back 18

Myoblasts fuse --> myocytes fuse --> to make myotubes --> muscle

Myotubes cannot differentiate (terminally differentiated state)

contractile proteins are made in the muscle cells and not elsewhere because of transactivators and transcription factors

Front 19

MyoD

Back 19

in skeletal muscles: family of transactivating proteins (Basic loop helix region)

Front 20

Skeletal muscle Hierarchy

Back 20

repeating Sarcomeres make up myofilaments which make up Myofibrils make up muscle fiber (wrapped in endomysium)

Bunches of muscle fibers make up the fascicle ( fxnal unit of myofiber wrapped in perimysium)

Fascicles make up the whole skeletal muscle (muscle wrapped in epimysium) (voluntary muscle)

Front 21

A band

Back 21

dark band (thick filaments only) Myosin

Front 22

I band

Back 22

Light band (thin filaments only) Actin

Front 23

Z Disc

Back 23

Separates sarcomeres; attachment point for titian and thin filaments

Front 24

M line

Back 24

thick accessory filaments linked by accessory proteins; houses creatine kinase (transfers phosphate ADP --> ATP)

Front 25

Actin

Back 25

made up of G actin monomers which polymerize to form F-actin filament

Front 26

Myosin

Back 26

made up of myosin light and heavy chains

Head associated with MLC (myosin light chain), ATP ATPase

anchored to z disc by titin

hydrolyses ATP

Front 27

Tropomyosin

Back 27

Double helix of two polypeptides lies in the groove between actin molecules

Front 28

Thin Actin filament unit

Back 28

TnT: binds tropomyosin

TnI: inhibits the binding of myosin to actin

TnC: binds calcium

Troponin: three globular subunits

anchored to z line by alpha- actinin

capped by tropomodulin (regulates length of actin filament)

stabilized by nebulin

Front 29

Neuromuscular spindle

Back 29

Detects passive stretch

Intrafusal fibers: made up of chain fibers (sustained stretch) and bag fibers (onset of stretch) ; sensory receptor; associated with sensory neurons;

Extrafusal fibers: cause the contraction of the muscle

Front 30

Satellite cells

Back 30

Skeletal muscle does not divide after it's been damaged; instead satellite cells are adult stem cells that will proliferate and turn into skeletal muscle

Front 31

Purkinje cells

Back 31

conduction tissue of the heart

Front 32

Smooth muscle

Back 32

does not have neural input; no precise neural control; cells interact via gap jxns; enclosed in reticular fibers and basal lamina; can divide when terminally differentiated

Front 33

Neuepithelial cells...

Back 33

give rise to gliablasts. These differentiate into oligodendroglia, fibrillar astrocyte, and protoplasmic astrocytes (supportive cells of the nervous system)

also gives rise to neuroblasts which will become neurons

Front 34

Mantle layer (formed from neuroepithelial cell migration)

Back 34

forms the Gray matter

Front 35

PAX3

Back 35

Increase in this leads to specification of ectoderm cells into neural crest cells

Front 36

SOX10

Back 36

involved in the differentiation of the neural crest cells

Front 37

Neural crest cells form...

Back 37

sensory neurons, parasympathetic and sympathetic autonomic ganglia

Front 38

Neural tube cells form...

Back 38

somatic efferent neurons, preganglionic sympathetic and parasympathetic neurons

Front 39

In maternal diabetes..

Back 39

elevated glucose levels leads to an decline in Pax3

Front 40

Paraxial mesoderm gives rise to...

Back 40

somites which gives rise to skeletal muscle

Front 41

Splanchnic mesoderm gives to...

Back 41

cardiac and smooth muscle

Front 42

Multipotent stem cell + Notch =

Back 42

smooth muscle

Front 43

Multipotent stem cell + BMP =

Back 43

endothelium

Front 44

Multipotent stem cell + Prdm16 =

Back 44

Brown fat

Front 45

Multipotent stem cell + high Shh =

Back 45

cartilage

Front 46

Multipotent stem cell + WNT =

Back 46

skeletal muscle

Front 47

Multipotent stem cell + BMP2/TGFbeta Menin =

Back 47

bone

Front 48

Myogenic progenitor + MyoD ...

Back 48

allows of specialization of myofibre

Front 49

Neuromuscular dystrophy

Back 49

absence of dystrophin (stabilizes the sarcomere during a muscle contraction), without dystrophin the DAP complex is lost