Histology > Integument > Flashcards

Integument Flashcards

(80 cards)

Study These Flashcards
1
Q

what is the integument?

A

the largest organ in the body that generally functions as a protective barrier against injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the integument composed of?

A

skin and skin appendages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the skin appendages?

A
  • nails
  • hair
  • sweat glands
  • sebaceous glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

at mucocuntaneous junctions, the skin is ____________ with mucous membranes that line ___________, __________, and ____________ tracts.

A

continuous
digestive, respiratory, urogenital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

functions of the skin

A

protective barrier against:
- injury (abrasions, cuts, burns)*
- infectious pathogens*
- UV radiation
- body temp regulation*
- vitamin D synthesis
- ion excretion
- sensory reception*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why is vitamin D important?

A

helps with normalizing blood levels of calcium and phosphorous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is an important quality of the skin?

A

it has a remarkable regenerative capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what type of epithelia is the integument composed of on the epidermis?

A

stratified squamous keratinized epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the general organization of the layers of integument:

A
  • epidermis
  • dermis
  • hypodermis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

embryologically, what does the epidermis and its appendages derive from?

A

surface ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

embryologically, what does the dermis derive from?

A

mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the skin composed of?

A
  • keratinocytes (90%)
  • melanocytes
  • Merkel cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

embryologically, what does the Merkel cells and the melanocytes derive from?

A

the neural crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

which layer produces vitamin D?

A

the epidermis
- sunlight catalyzes the reaction of vitamin D3 production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

schematic of skin and its appendages

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what structures are included in the epidermis layer:

A
  • hair shaft
  • pore of sweat gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the layers of the epidermis?

A
  • stratum corneum
  • stratum lucidum
  • strautm granulosum
  • stratum spinosum
  • stratum basale
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

stratified corneum

A
  • most superficial layer
  • 20-30 layers
  • cells are flat, dead, anucleated, and keratin filled karatinocytes
  • protects against friction and water loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

stratum lucidum

A
  • 2-3 layers of dead, anucleated cells
  • only seen in thick skin
  • see through
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

stratum granulosum

A
  • 3-5 layers of keratinocytes
  • distinct keratino-hyaline granules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

stratum spinosum

A
  • several layers of keratinocytes
  • all joined by desmosomes (“spines”)
  • when integument is fixed, they shrink but stay attached to desmosomes and appear to look like they have spines
  • Langerhans cells present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

stratum basale

A
  • deepest, single layer
  • cubodial to low columnar cells
  • in contact with basement membrane
  • mitosis occurs here
  • has merkel and melanocytes
    “germinal layer”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

layers of the dermis

A
  • papillary layer
  • reticular layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

papillary layer of dermis

A
  • more superficial layer of dermis
  • composed of connective tissue
  • forms dermal papillae
  • contains subpapillary vascular plexus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
reticular layer of dermis
- deeper layer of dermis - dense irregular connective tissue - surround hair follciles, sebaceous glands, sweat glands, nerves, deep plexus of blood vessels extending into subcutaneous layer
26
subcutaneous layers
- are not specific layers - are not considered integument - deep to dermis - composed of adipose connective tissue
27
characteristics of thick skin:
- thick epidermis - thick stratum corneum - stratum lucidum - no hair - no arrector pilli - no sebaceous glands - many sweat glands - dermatoglyphs (fingerprints)
27
where is thick skin located?
- palms/soles - finger tips (dermatoglyphs)
28
characteristics of thin skin:
- thinner than thick skin - thin stratum corneum - no stratum lucidum - hair - arrector pilli - sebaceous glands - sweat glands
28
where is thin skin located?
everywhere but palms/soles
28
what is the key difference between thick and thin skin?
thick has stratum lucidum !! and thin does not
29
what layer can you find Meissner corpuscles?
DERMIS
29
histological stain of skin compared to cartoon image
29
characteristics of epidermis
- derived from surface ectoderm - avascular
30
in the stratum basale, keratinocytes form a __________ to __________ epithelial layer
cuboidal, columnar
30
what kind of cells are in the stratum basale
- keratinocytes - melanocytes - Merkel cells
31
characteristics of keratinocytes in stratum basale
- sit on basal lamina - from single layer - mitotic/dividing - cuboidal-shaped - basophilic cells with large nucleus - young, immature - least differentiated - supposed to die - produce keratin
32
keratinocytes connect to each other via ____________ and connect to the basement membrane via ______________.
desmosomes, hemidesmosomes
33
how does the epidermis renew?
1. immature basal cells divide 2. dividing cells differentiate and push cells to surface as they migrate 3. mature/differentiated/ keratinized cells are superficial layers
34
where does basal cell carcinoma and squamous cell carcinoma originate?
keratinocytes
35
melanocytes are restricted to what layer?
stratum basale
36
characteristics of melanocytes
- spider shaped - derived from neural crest - synthesize melanin - determine hair and skin color - same number in all races - protects from UV radiation
37
synthesis of melanin
- UV triggers synthesis - granules of melanin spread by cytoplasm - UV turns on transport by dynein on microtubules to nucleus - melanin protects from UV radiation
38
characteristics of Merkel cells
- located in stratum basale - sensory cells - spikey disc-shaped mechanoreceptors - sense light touch, form, texture - abundant in finger tips
39
types of cells in stratum spinosum
- keratinocytes - Langerhan cells
40
characteristics of keratinocytes in stratum spinosum
- desmosome spines - abundant melanin - lamellar (membrane-coating) granules (glycolipids, released in stratum granulosum, water-proofing, block diffusion of nutrients from dermal blood vessels to superficial cells)
41
characteristics of Langerhan cells
- Epidermis specific macrophages (immune cells) - Antigen presenting - Monocyte-derived from bone marrow
42
how do Langerhan cells present antigens?
presence of CD4+ and CD8+ T lymphocytes
43
cells in stratum granulosum
- keratinocytes
44
characteristics of keratinocytes in stratum granulosum
- several flat layers - last layer with nuclei - anucleate and pyknotic nuclei - keratohyaline granules!!! - lamellar granules
45
why are keratohyaline granules important?
- they help produce keratin - protect epidermis
46
cells in stratum lucidum
- keratinocytes
47
characteristics of keratinocytes in stratum lucidum
- clear, light staining layer - flat, dead cells - thick skin only - keratohyaline and keratin filaments - eleiden = clear protein
48
characteristics of dermis
- derived from mesoderm - HIGHLY vascularized - glomus cells - lots of elastic tissue - contained epidermally-derived structures
49
why are glomus cells important?
- they are modified smooth muscle cells - create a shunt
50
characteristics of superficial papillary layer of dermis
- loose connective tissue - dermal papillae - capillary roots (thermoregulation) - free nerve endings (pain, hot/cold) - Meissner's corpuscles (light touch) - lamellar corpuscles - superficial plexus
51
characteristics of deep reticular layer
- dense irregular connective tissue (collagen, elastic fibers) - majority of dermis - pacinian corpuscles (deep pressure, vibration) - deep dermal plexus
52
vasculature of integument
blood in arteries > arterioles > hypodermis > dermis > each papilla > venules > veins > leave integument
53
why are arterio-venous shunts important?
keep heat in by not bypassing capillaries of the surface and keeping blood in deeper layers
54
what controls opening between arteriole and venule?
glomus body
55
hypodermis
- derived from ectoderm - filled with unilocular adipocytes - attaches to skin underlying structures - permits movement over most body parts
56
tactile receptors
- Merkel cells - free nerve endings - root hair plexuses - meissner corpuscles - lamellated (pacinian) corpuscles - krause and bulbs - ruffini corpuscles
57
merkel cells as tactile receptors
- associated with expanded nerve endings - function as tonic receptors for sustained light touch and for sensing an objects texture
58
free nerve endings as tactile receptors
- in papillary dermis - extend into lower epidermal layers - respond to high and low temperatures - pain - itching
59
root hair plexus as tactile receptors
- innervates the hair and secretion of sebaceous glands - surround bases of hair follicles in reticular dermis - detects movement of hairs
60
meissner corpuscles as tactile receptors
- in fingertips, palms, and soles - decline with age - sensory axons winding among flattened schann cells arranged perpendicular to epidermis in dermal papillae - elliptical structures - initiate impulses with light touch
61
lamellated (pacinian) corpuscles as tactile receptors
- large oval structures - deep in reticular dermis and hypodermis - outer capsule - concentric lamellae of flatted schwann cells and collagen surrounding a highly branched unmyelinated axon - deep touch sense - found in connective tissue of organs - wall of rectum and urinary bladder
62
krause and bulbs as tactile receptors
- simpler encapsulated ovoid structures - thin - collagenous - found in skin of penis and clitoris where they sense low frequency vibrations
63
ruffini corpuscles as tactile receptors
- collagenous, fusiform capsules - anchored firmly to the surrounding connective tissue with sensory axons stimulated by stretch or twisting of skin
64
location of glands of skin
within lower part of dermis/hypodermis
65
types of skin glands
- sebaceous - sudoriferous (eccrine/apocrine)
66
sebaceous (holocrine) glands
- oily secretion (sebum) - release by bursting via holocrine - located in hair follicle - can cause acne
67
eccrine glands
- eccrine/merocrine - almost everywhere - simple, coiled, tubular - stratified cuboidal duct - deep
68
apocrine glands
- axillary and anogential areas - odorless secretion but has bacteria (BO) - active after puberty - larger acini and larger lumen
69
characteristics of hair appendages
- epidermal - penetrate dermis and hypodermis - sebaceous glands are next to the hair shaft - secrete sebum here - arrector pilli (goose bumbs, and raise hair)
70
skin in wound healing
1. blood clotting at wound and release platelets 2. macrophages and neutrophils enter wound as inflammation begins 3. epithelial cells from cut edges begin to migrate through clot 4. fibroblasts proliferate and produce new collagen to for granulation tissue 5. epidermis regenerates
71
psoriasis
- chronic relapsing disorder - at elbows, knees, scalp, and lumbosacral regions - "T lymphocyte autoimmune disease" - red plaques covered by silver to white scales
72
what causes psoriasis?
- T-Lymphocyte autoimmune disease - Increased numbers of Langerhans cells and T-cells - Mitosis above stratum basale
73
treatments of psoriasis
- topical and system medications - UV light - biological therapies
74
what is lamina propria
the layer of connective tissue that connects epithelial cells to smooth muscle in mucous membranes
Histology
flashcards
Decks in class (12)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions