Foundations Exam 3 histology

Question 1

What is the protein in the stratum granulosum that aggregates keratin tonofilaments and allows keratinization in more superficial layers

Answer 1

Filagrin

Question 2

Dark brown spots on the surface of the skin is from

Answer 2

keratohyaline plaques from over prodiction of keratohyaline granules in the stratum granulosum

Question 3

eledin is

Answer 3

the protein in the stratum lucidium that is thought to be a etabolite of keratohyaline. it makes the stratum lucidium light staining

Question 4

lamellar bodies are found where

Answer 4

in the keratinocytes of the stratum spinosum and granulosum

Question 5

what do lamllar bodies do?

Answer 5

they extrude glycproteins which coat the cell surface

Question 6

what is psoriasis

Answer 6

is it a result of a decrease in the regeneration time fo the epidermis and an increase in mitotic cells in the stratum basale and spinosum. It presents as a patchy red lesion

Question 7

how do you control psoriasi

Answer 7

with corticosteroids

Question 8

Addisons disease is

Answer 8

a lack of cortisol from the adrenal cortex causing overproduction of ACTH leading to pigmentation of the skin

Question 9

vitiligo

Answer 9

genetic mutation leading to degredation and regression of menalocytes and depigmentation

Question 10

Albinism

Answer 10

lack of production of tyrosinase and so they lack melanin

Question 11

How do you identify a langerhan cell?

Answer 11

identify the berbeck granules which are paddle shaped

Question 12

Langerhan cells are important in

Answer 12

delayed hypersensitivity

Question 13

What does a merckel cell do and where are they found

Answer 13

clear cells found in the stratum basale near connective tissue which are involved in Krude touch and in hair folliKles

Question 14

how do you recognize a merkel cell?

Answer 14

have dense secretory vesicles in the cytoplasm

Question 15

where is blood supply of the epidermis?

Answer 15

in the papillary layer of the dermis

Question 16

Meissner’s

Answer 16

In the papillary layer of the dermis and are used for fine touch in hairleSS region. unmyelinated nerve endings and in vibraSSions

Question 17

Pacinian corpuscle

Answer 17

Pressure and vibration in the reticular dermis

Question 18

Ruffinis corpuscle

Answer 18

endings respond to stretch

Question 19

Krause end bulbs

Answer 19

cold and pressure detection

Question 20

which glands are associated with hair follicles?

Answer 20

subaceous glands

Question 21

subaceous glands strucutre is

Answer 21

a branched acinar gland with a short ductal system that release contents in a holocrine fashion

Question 22

which sweat gland is associated with sweat glands?

Answer 22

apocrine

Question 23

Epidermal Bullosa

Answer 23

defects in intermediate filments that anchor the epidermis to the underlying BM

Question 24

Epidermal Bullosa simplex

Answer 24

where blistering occurs in the epidermis and basal epidermal cells separate. This is the most common type of EB,and tends to be milder than the other types.

Question 25

junctional epidermolysis bullosa

Answer 25

caused by defects in IFs where blisters form between the dermis and epidermis

Question 26

distropic epidermolysis bullosa

Answer 26

type VII collage mutation resulting in separation of the papillar from the reticular dermis that heals with scarring

Question 27

how do you tell the difference between the basal cell carcinoma and squamous cell carcinoma

Answer 27

the squamous cell is making alot more hyaline and lamellar bodies since they are from more mature kertinocytes

Question 28

The A band is

Answer 28

the length of the myosin molecul in the center. It does not change . microscopically it will appear as a single thick filament surrounded by the thin filaments

Question 29

What does the I band look like microscopically

Answer 29

It will be the thin filaments surrounded by titin

Question 30

titin

Answer 30

extends from the z-line to the H band and anchord the myosin filaments to the Z-line

Question 31

what will the M band look like ?

Answer 31

It will have a myosin thick filament with myomesin holding them together

Question 32

myomesin

Answer 32

holds the myosin filaments in register @ the M line

Question 33

alpha actinin

Answer 33

anchors actin to the Z-lne

Question 34

tropomodulin

Answer 34

caps the free end of actin thus regulating its length

Question 35

costamere

Answer 35

attach myofirils to the sarcolemma at the Z-line

Question 36

Dystrophin

Answer 36

links actin to the sarcolemma and to the lamina of the ECM

Question 37

in Muscular Dystrophy, how is it inherited and what protein is malfunctioning

Answer 37

dystrophin and is X-linked recessive and is assocaited with a replacement of degenerating skeletal muscle with fatty firous connective tissue

Question 38

what s a t-tubule

Answer 38

an invagination of the sarcolemma at the AI j(x) between two terminal cisternae

Question 39

explain the calcium binding in a cell to allow muscle contraction

Answer 39

calcium binds to troponin which undergoes a confrmationl change resulting in the moving of tropomyosin on the actin molecule which exposes the myosin binding sites. now the myosin head can bind to actin

Question 40

myasthenia gravis

Answer 40

autoimmune diease where Abs block Ach receptors of the motor end-plates leading to a gradual weakening

Question 41

botulism inhibits

Answer 41

the release of Ach from the motor end plate

Question 42

the efferents of the spindle fiber are what kind of nerves

Answer 42

gamma motor

Question 43

the extrafusal fibers in the muscle are innervated by

Answer 43

alpha nerves

Question 44

what does MyoD do?

Answer 44

myoblasts epxress it and turn on muscle specific genes

Question 45

what inhibits muscle development

Answer 45

myostatin

Question 46

fascia adherens in cardiac muscle attaches to

Answer 46

skeletal muscle

Question 47

in cardiac muscle where is the t-tubule?

Answer 47

the z-line

Question 48

in smooth muscle what binds to calcium?

Answer 48

caldesmon and calponin

Question 49

what activates myosin in the smooth muscle cells?

Answer 49

Myosin light Chain Kinase

Question 50

what activates the MLCK (myosin light chain kinase?

Answer 50

calcium-calmodulin complex