Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microanatomy 2 > Integumentary System > Flashcards

Integumentary System Flashcards

1
Q

Functions of the Integumentary system

A
  1. Protection against external agents ultraviolet rays, and water loss (desiccation)
  2. Regulate temperature and ions-water balance
  3. Calcium homeostasis because of vitamin D synthesis in the sebaceous gland
  4. Sensory appreciation;

5.fat storage. –> in hypodermis ( not apart of skin technically)

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

Clinical examination of the skin reveals…

A

Clinical examination of the skin reveals ectoparasites and internal disease processes resulting from endocrine and nutritional disorders.

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

General Organization of the skin

A

Made of two components: epidermis and dermis.

Beneath the dermis lies hypodermis (subcutaneous tissue, site for sc injections) that contains loose CT filled with fat and is not considered part of the skin.

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

Epidermis

A

Thickness varies from among areas of the body; generally, thin in hairy skin.

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

The 5 layers of epidermis from inner to outer

A
  1. Stratum (S) basale (germinativum)
  2. S spinosum (basale and spinosum combined termed the malpighian layer)
  3. S granulosum
  4. S lucidum,
  5. S corneum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mitotic Cells

A

Mitotic cells are limited in the Basale and Spinosum layers, continuously divide, and replace cells in other layers, which are then shed as horny cells from the surface of the S corneum.

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

Tonofilaments

A

Cells in the S spinosum have thick keratin bundles called tonofilaments, which terminate at desmosomes

(note, thick skin has a thicker S spinosum and more abundant tonofilaments and desmosomes, which protect against friction and pressure).

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

Keratohyalin granules

A

Cells in the S granulosum contain non-membrane bound, basophilic, keratohyalin granules that become a part of the keratin; and membrane-bound lamellar granules, whose content is released in the intercellular space where it serves as a seal between skin cells.

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

What epidermis layer is absent in thin skin

A

Stratum Lucidum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Keratin

A

Is a filamentous protein, which is present in all epithelial cells, but is more abundant in skin cells (keratinocytes).

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

Epidermal Cell types

A

Keratinocytes
Melanocytes
Langerhans Cells
Merkel’s Cells

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

Keratinocytes

A

Synthesize soft keratin and are continuously replaced by mitotic cells in the malpighian layer.

Protect from invading organism and dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Melanocytes

A
  • Neural crest cells in origin
  • Found in the malpighian layer and hair follicles
  • Posses dendritic like processes, which insinuate between keratinocytes
  • protection from UV light
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The process of melanin synthesis.

A

Melanocytes synthesize melanin (only melanocytes can synthesize melanin because they contain tyrosinase enzyme that is essential for converting tyrosine amino acid, after a series of reactions [dopa, dopaquinone] into melanin).
- After synthesis, melanin granules are transferred into keratinocytes in the malpighian layer.
(Note, keratinocytes do not synthesize melanin, but they contain melanin)

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

How does the process of melanin synthesis differ among races.

A

Numbers of melanocytes do not differ among races,
what differs is the ability of melanocytes to synthesize melanin and transfer melanin into keratinocytes

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

Albinism

A

Albinos lack tyrosinase enzyme and thus their melanocytes cannot synthesize melanin and melanin protects against ultraviolet rays (that is why albinos are more prone to skin cancers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Melanoma

A

Melanoma are malignant growth of melanocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Langerhans Cells

A

Macrophages

Antigen-presenting cells, originate from monocytes, present antigens to T lymphocytes and thus play a role in the immunological skin reactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Merkel’s Cells

A

Sensory mechanoreceptors, present in the thick skin, and are richly innervated by free nerve endings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Dermis

A

An important part of our daily-use leather goods; contains two layers:
1. Papillary layer
2. Reticular layer

21
Q

Papillary Layer

A

Papillary layer is composed of loose CT, contains all CT cell types and abundant blood supply, and constitutes major part of the dermal papilla.

22
Q

Reticular Layer

A

Reticular layer is composed of dense irregular CT, more fibers (mainly type I collagen, also a network of elastic) and fewer cells than the papillary layer; contains smooth muscle (arrector pilorum), nerve fibers (vasomotor, pilomotor, sudomotor), and receptors (touch, heat, cold, pressure).

23
Q

Hypodermis

A

Subcutaneous tissue

Consists of loose CT that contains large blood vessels, nerves, skin glands, and is filled with fat cells, especially in thick skin (foot pad). Note, it corresponds to the superficial fascia filled with formaldehyde in the embalmed animals, not a part of the skin, site for sc injections.

24
Q

Integumentary Blood Supply

A

Deep or subcutaneous plexus

25
Q

Deep or subcutaneous plexus

A

Present in the hypodermis, formed by large blood vessels.

26
Q

Middle of cutaneous plexus

A

Associated with hairs and glands of the dermis.

27
Q

Superficial or subpapillary plexus

A

Supplies papillary layer and epidermis.

28
Q

Superficial arteriovenous anastomoses

A

Thermoregulatory structures, present in the papillary layer of the pig and man but are absent in other domestic species.

This explains why pig’s skin is a good model to study skin diseases in human.

29
Q

Skin Glands

A

Sebaceous and sweat

30
Q

Sebaceous

A
  1. Scattered all over the body, except in the foot pad
  2. Associated with hair follicle, except in the lip, penis and vulva
  3. Cells are aggregated to form alveoli with no apparent lumen, cells near the base divide and cells near the apex die and release their entire contents (holocrine secretion);
  4. The secretion (sebum) lubricates hair shaft, protects skin from drying, diminishes water loss, and contains precursor to vitamin D.
    • Examples: infraorbital, inguinal, and interdigital regions of sheep; the base of the horn of goats; anal sacs of cats; the prepuce and circumanal region of dogs.
31
Q

Sweat

A

Present in the lower dermis or hypodermis.

Two types:
Eccrine (merocrine)
Apocrine

32
Q

Eccrine (merocrine)

A

Develop independently from hair follicles and thus open via a long duct directly on the skin surface, secretory cells are cuboidal to columnar that surround a narrow lumen; active throughout life; secretion is watery and functions in heat and ion regulation.

33
Q

Apocrine

A

Apocrine: associated with hair follicles and thus they open into hair follicles above the opening of the sebaceous gland; low cuboidal cells with or without apical protrusions surrounding a wide lumen; secretion is viscous, seasonal, and becoming active with puberty. Myoepithelial cells surround secretory cells of sweat glands.

34
Q

Species Variation

A

Sweat glands are absent in rats, rabbits, and birds; are poorly developed in dogs and pigs (hence of little use in thermoregulation).

35
Q

Species Variation Apocrine

A

Distributed throughout the skin in most domestic species; they secrete profusely in the horse, while the secretion is scant in most other species; least active in goats and cats.

Function: is to produce a viscous secretion that serves as a sex attractant in some species and to regulate temperature, especially in the horse and cattle.

36
Q

Species Variation Merocrine

A

Present in the foot pads of dogs and cats, the frog of horse hoofs, the planum nostrale and carpal glands of pigs, and the planum nasolabial of the cattle.

37
Q

What controls sweating in all domestic species except for horse

A

Sweating is under the control of sympathetic cholinergic nerve fibers in all domestic species

38
Q

What controls sweating for horses

A

Sweating is under the control of sympathetic adrenergic fibers.

39
Q

Hair

A

Thread-like epidermal structures distributed evenly in the horse and cow, arranged into groups forming hair beds in the pig, dog, and cat; each hair bed contains two to four clusters of hair follicles and has one principal (guard) hair and three to nine auxiliary (wool) surrounding hairs.

40
Q

Hair growth and replacement

A

Hair is formed by germinal matrix covering the dermal papilla, growth is cyclic: anagen (active growth), catagen (involution), telogen (resting). Hair color is created by melanocytes present in the germinal matrix covering the dermal papilla.

41
Q

Complete Hair consists of

A

Hair shaft

Hair root

Hair follicle

Hair bulb

Dermal Papilla

Arector pili

42
Q

Hair Shaft

A

Free threadlike part above the skin and consists of medulla, cortex and cuticle

43
Q

Hair Root

A

Portion of hair beneath the skin

44
Q

Hair follicle

A

A sheath covering the root consists of following parts: CT sheath, glassy membrane, external root sheath (continuation of stratum germinativum), and internal root sheath (composed of Henle’s layer, Huxley’s layer with trichohyalin granules, and cuticle).

45
Q

Hair Bulb

A

The hair bulb is the terminal expanded part of the hair follicle in which hair is rooted. It is indented by a dermal papilla, which contains blood vessels that are necessary for sustaining and growth of the hair.

46
Q

Arector Pili

A

Arrector pili is a bundle of smooth muscle attached at an angle to the CT sheath of the hair follicle and thus its contraction in response to cold or fear or anger is responsible for hair elevation.

47
Q

Types of hairs

A

Cover hairs: most common as described above; wool hairs: form the fleece of sheep and goat; tactile hairs: thick and long, contains blood sinus between outer and inner layers of CT sheath, is highly innervated, examples include whiskers in carnivores.

48
Q

Hair growth and replacement

A

Hair is formed by germinal matrix covering the dermal papilla, growth is cyclic: anagen (active growth), catagen (involution), telogen (resting).

Hair color is created by melanocytes present in the germinal matrix covering the dermal papilla.

Microanatomy 2 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions