Histology Final - new material only

studied byStudied by 4 people
0.0(0)
get a hint
hint

What is the largest, single organ of the body

1 / 325

Tags and Description

Biology

New histology content for final only

326 Terms

1

What is the largest, single organ of the body

Skin

New cards
2

How much of total body weight does skin account for?

15-20%

New cards
3

What else is the skin known as?

integument, or cutaneous layer

New cards
4

Epidermis

An epithelial layer of ectodermal origin

New cards
5

Dermis

layer of mesodermal CT

New cards
6

Dermal papillae

projections at the irregular junction between the dermis and epidermis

New cards
7

What do dermal papillae interdigitate with?

invaginating epidermal ridges to strengthen adhesion of two layers

New cards
8

Epidermal derivatives

hairs, nails, sebaceous and sweat glands

New cards
9

Subcutaneous tissue AKA hypodermis

LCT layer containing pads of adipocytes, lies beneath the dermis

New cards
10

What is the function of the hypodermis

binds the skin loosely to the underlying tissues

New cards
11

What are the strata of Epidermis?

Layers of the skin

New cards
12

Where do ducts from a sweat gland enter the epidermis?

From a dermal papilla, and coils to a surface pore through all the strata

New cards
13

__ has coarse bundles of collagen

Dermis

New cards
14

What are important nonkeratinocyte cells in the epidermis?

melanocytes, langerhans cells, tactile Merkel cell

New cards
15

What do nonkeratinocyte cells mean?

Not skin cells

New cards
16

How is the dermis of THIN skin different?

more cellular, well vascularized, has elastin, less coars bundles of collagen

New cards
17

Epidermis of thin skin usually has how many layers?

4 layers

New cards
18

What are the 4 layers found in thin skin epidermis?

S. Basale, S. Spinosum, S. Granulosum, S. Corneum

New cards
19

Stratum Basale

one-cell thick containing most MIOTIC cells

New cards
20

Stratum Spinosum

synthesis of much keratin and other proteins take place

New cards
21

Stratum Corneum

consists of dead squames composed of mostly keratin

New cards
22

Epidermal S. Spinosum of thick skin have keratinocytes with what?

numerous short cytoplasmic projections

New cards
23

What type of junctions are present between keratinocytes in the epidermis?

Desmosomes

New cards
24

What are intermediate filaments?

cytoskeleton structures

New cards
25

Keratohyaline Granules

large, amorphous masses of protein

New cards
26

How do granules in the S. Granulosum stain?

Basophilic

New cards
27

Keratin filaments are cross-link with what protein?

Filaggrin

New cards
28

What is Filaggrin?

filament associated protein

New cards
29

What happens when tight bundles fill the cytoplasm in the S. Granulosum?

flattening of cells

New cards
30

What small organs can be found in the S. Granulosum?

lamellar granules

New cards
31

What so lamellar organs undergo?

exocytosis

New cards
32

What do lamellar granules secrete?

lipid-rich layer

New cards
33

What is important about the lipid-layer around our skin cells

makes the epidermis impermeable to water

New cards
34

The lipid envelope and the keratin-filled cells determine what?

Physical properties of the epidermis

New cards
35

S. Lucidum

dense, thin layer of differentiated cells from the S. granulosum

New cards
36

What do S. Corneum lose?

nuclei and cytoplasm (meaning that the cells are dead)

New cards
37

Do squames like water?

NO, they are hydrophobic

New cards
38

What are squames bound by?

hydrophobic, lipid-rich intercellular cement

New cards
39

What makes up the S. Corneum?

flattened, keratinized structures called squames

New cards
40

What happens to thick skin at the surface?

they are worn away

New cards
41

What happens to thin skin at the surface?

they flake off

New cards
42

Where are melanocytes found?

are present in the epidermal basal layer

New cards
43

What are the function of melanocytes?

synthesize melanin granules

New cards
44

Where do the melanin granules usually travel?

into neighboring keratinocytes of the basal and spinous layers

New cards
45

How do melanocytes stain?

pale-staining on the BM, with lower melanin content than the keratinocytes

New cards
46

How do melanocytes transfer melanin to nearby keratinocytes?

through their irregular, cytoplasmic processes

New cards
47

What important cell organelle do melanocytes have?

Golgi complexes

New cards
48

What do the golgi complexes do in melanocytes?

they make the vesicles in which the melanin is synthezied

New cards
49

What do vesicles become as they fill with melanin?

Melanin granules

New cards
50

Where do melanin granules accumulate before transfer?

tips of dendritic cytoplasmic extensions

New cards
51

What are Langerhans cells?

dendritic, APCs of the epidermis

New cards
52

What are the functions of Langerhan cells?

comprise an important defense against pathogens and environmental insults

New cards
53

Where do Langerhan cells develop?

bone marrow (after they migrate into blood then into skin)

New cards
54

Where can Langerhans cells be found?

in hair follicles and throughout epidermis

New cards
55

What color do follicles and keratin of epidermis stain?

green

New cards
56

_____ of Langerhans cells detects invading microorganisms

network

New cards
57

How do Langerhans carry out their immune response?

they activate lymphoctyes to mount a collective immune response

New cards
58

Merkel cell

have high tactile sensitivity and function as mechanoerceptors

New cards
59

Where are merkel cells found?

basal epidermal layer

New cards
60

What is the general structure of Merkel cells?

mass of dense-core cytoplasmic granules near the basolateral cell membrane

New cards
61

What are cytoplasmic granules in Merkel cells connected with?

nerve endings

New cards
62

What are the cytoplasmic granules in Merkel cells similar to?

granules of neuroendocrine cells

New cards
63

Elastic fibers decrease in diameter as they approach what?

the epidermis (then insert into the BM)

New cards
64

How do elastic fibers of the epidermis stain?

darkly, distributed aomng the eosinophilic collagen bundles

New cards
65

Skin contains servel types of ____ receptors

sensory

New cards
66

What type of nerve endings are foundin the epidermis?

free

New cards
67

What are the purpose of epidermal free nerve endings?

detect pain and temperature

New cards
68

Root hair plexus

present around the bases of hair follicles in the dermis, detect light touch or movement of hair

New cards
69

Tactile receptors

Meissner corpuscles, Lamellated (pacinian corpsuscles), Krause end bulbs, Ruffini corpuscle

New cards
70

Purpose of Meissner corpuscle

light touch

New cards
71

Purpose of Lamellated (pacinian) corpuscles

detecting pressure and high-frequency vibration

New cards
72

Purpose of Karise end bulbs

for low frequency vibrations/movements

New cards
73

Purpose of Ruffini corpuscles

detecting tissue distortion

New cards
74

Where do hair follicles derived from? Where do they extend into?

epidermis, deep into dermis

New cards
75

Major parts of hair and its follicle

vascularized, nutritive hair dermal papilla, arrector pili

New cards
76

What does the arrector pili muscle do?

pulls the hair erect

New cards
77

Parts of hair structure

Matrix, Medulla, cortex (in root), epithelial and connective tissue sheaths

New cards
78

what is the outermost layer of the hair

thin cuticle

New cards
79

What is the hair cuticle made up of

shingle-like cells

New cards
80

How do Sebocytes undergo terminal differentiation?

filling with small lipid droplets, and then disintergrating near the ducts opening at the hair shaft

New cards
81

Small progenitor cells

more specific than stem cells, they differentiate into a cell having specific function

New cards
82

Where do small progenitor cells proliferate?

Just inside the capsule

New cards
83

Lumen size of eccrine sweat glands?

small lumens

New cards
84

What appearance do eccrine sweat glands have?

irregular, stratified cuboidal appearance

New cards
85

What do apocrine sweat glands produce?

protein-rich secretion with pheremonal properties

New cards
86

Lumen size of apocrine sweat glands

larger than eccrine glands

New cards
87

Where do aprocrine sweat glands open into?

Hair follicles

New cards
88

Major stages of cutaneous wound healing

  1. cut blood vessels bleed into wound, 2. blood clot forms, leukocytes clean wound, 3. blood vessels regrow and granulation tissue forms, 4. epithelium regenerates and CT fibrosis occurs

New cards
89

Fibrosis

phenomena where parenchymal tissue is replaced by CT, involves extensive tissue remodeling

New cards
90

Psoriasis

T cells attack healthy skin cells by mistake, as if to heal a wound or to fight an infection

New cards
91

What are mostly prescribed for psoriasis, and what do they do?

topical corticosteroids, they reduce inflammation and relieve itching

New cards
92

Immune system

provides defense or immunity against infecions agents ranging from viruses to multicellular parasites

New cards
93

What does our immune system consist of?

large, diverse population of leukocytes

New cards
94

Where are leukocytes located?

every tissue of the body and lymphoid organs

New cards
95

Primary lymphoid organs

thymus, bone marrow

New cards
96

Secondary lymphoid organs

adenoids, tonsils, lymph nodes, spleen, peyer's patches, appendix

New cards
97

What happens in the primary lymphoid organs?

Lymphocytes are formed initially

New cards
98

What happens in the secondary lymphoid organs?

lymphocyte activiation and proliferation

New cards
99

MALT cells are?

immune cells located in digestive, repisratory and urogenital mucosae

New cards
100

Lymphoid nodules

small and spherical, contain proliferating B lymphocytes in the secondary structures of MALT

New cards

Explore top notes

note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 103 people
Updated ... ago
5.0 Stars(5)
note Note
studied byStudied by 244 people
Updated ... ago
4.2 Stars(11)
note Note
studied byStudied by 8 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 14 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 59945 people
Updated ... ago
4.9 Stars(248)

Explore top flashcards

flashcards Flashcard254 terms
studied byStudied by 44 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard48 terms
studied byStudied by 22 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard24 terms
studied byStudied by 2 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard167 terms
studied byStudied by 12 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard44 terms
studied byStudied by 7 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard113 terms
studied byStudied by 8 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard20 terms
studied byStudied by 23 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard188 terms
studied byStudied by 30 people
Updated ... ago
5.0 Stars(1)