Integumentary system Part II Flashcards
What is pilosebaceous unit?
is the hair that is produced in a follicle associated with the sebaceous glands and a smooth muscle bundle (arrector pili).
what does the hair compose of?
The hair composes of thin, long, cylindrical shaft of keratin.
The function of the hair.
Hair funtion in thermoregulation, particulary heat conservation.
Contraction of the arrector pili muscles causes what?
Causes the hair to stand up which creates the appearance of goosebumps.
when does the skin appendages develops?
Skin appendages develop in the second trimester as simple downgrowths of the epidermis into the subepithelial layers of the mesoderm – eventually the dermis and subcutis
Name the two types of hair?
Soft body hair (vellus hair)
Coarse hair (terminal hair)
What tissues make up hair?
perifollicular connective tissue and epithelium
The superficial part of follicles are known as what?
Infundibulum
Tubular structure with bulb-like expansion at base –——–a—– enclosing the ——–b—–
a. Hair bulb
b. hair papilla
In the hair bulb the cells start as a mass called the ——– which forms five epithelial layers as it grows.
Hair matrix
Name the five epithelial layer the hair matrix forms.
in detailed form.
Two outer layers:
Internal sheath
External sheath
Three inner layers:
Cuticle – keratinised, hard thin layer that surrounds cortex
Cortex – highly keratinised, surrounds medulla
Medulla – innermost layer, core of hair shaft
A. Skin overlying the nail
B. Skin beneath free end of the nail
a. Eponychium
b. Hyponychium
The nail plate and dermis beneath it are firmly attached to what?
distal phalanx
At the proximal end of the nail bed is the……?
nail root
The nail plate rests on the—–A—– which is composed of stratified ——B——
A. nail bed
B. squamous epithelium
The nail root and underlying nail bed extends deep into the dermis to lie in opposition to the ….?
distal interphalangeal joint
The nails Consist of a dense keratinised plate known as the…..?
nail plate
Where do we find the sebaceous gland and is classified as what type of gland?
Found all over the body except in the palms and soles
Classified as simple branched acinar
The majority of the sebaceous gland are associated with what?
Some are independent of the hair follicles, they open directly to the skin found where?
- Majority are associated with hair follicles
- Others are independent of the hair follicle, they open directly on to skin -found in the areolae, nipples, vulva (labia minora) and eyelids
The acinar has a ——- secretion
holocrine mode of secretion
Function of sebaceous gland?
Secretes sebum which mixes with lipids to maintain and waterproof the stratum corneum and hair shafts
The eccrine glands are classified as what type of gland?
found where?
Classified as simple coiled tubular
Found in the dermis, abundant in the soles of the foot, palms and axillae
The eccrine is essential for what?
Essential for thermoregulation through production of sweat
Has an outer layer of contractile ——–A—— that form a discontinuous layer between the ——B—– and the ——-C——-
A. myoepithelial cells
B. secretory cells
C. basement membrane
The eccrine has two portion name those portion?
Two portions: Secretory component and Duct component
secretory component
1. what does clear cells secretes and what does dark cells secretes?
2. What does the myoepithelial cells do?
- Made up of clear cells (secrete watery sweat and electrolytes) and dark cells (secrete macromolecules in sweat using merocrine secretion)
2.Myoepithelial cells - they contract to expel secretion into the duct
Duct components characteristics?
Lined by dark cells which form a layer of stratified cuboidal epithelium with microvilli in the lumen)
- secretion of duct components are passed where?
2.As eccrine duct passes through dermis it becomes coiled ?
1.Secretions are passed into a coiled duct which ascends through dermis to surface
2.(acrosyringium)
Apocrine gland Limited distribution, connected to
infundibulum
Where do we find apocrine glands?
Type of the gland and describes the organelles?
Mainly found in the axillae and groin
Coiled tubular gland with dilated lumen and distinct budding appearance of apical cytoplasm
Apocrine gland Secretory component is consists of and found where?
simple cuboidal epithelium found in deep reticular dermis or subcutis
True or false
apocrine gland Not functional until puberty
True
Apocrine glands produces a slightly what?
Produces a slightly viscous secretion by exocytosis (apocrine mode of secretion) that may acquire an odour with bacteria activation
- Layer of connective tissue derived from mesoderm?
- What does this layer supports?
- What does this layer responsible for?
- Name the fibres in this layer and the arrangement of the fibres
- Name the two layers this layer has
- Dermis
- Supports the overlying epidermis and anchors it to the hypodermis
- Responsible for tone and texture of skin, contains skin appendages, vascular supply, nerves and nerve endings
- Bundles of collagen fibres and strands of elastic fibres embedded in small amounts of acellular ground substance with fibroblasts
- Has two layers: Papillary dermis and Reticular dermis
Differentiates between papillary dermis and reticular dermis
A. Papillary dermis Thin layer of loose connective tissue with fibroblast, cell and fibres that anchor to the basal lamina and bind the epidermis to the dermis
B. Reticular dermis Thicker layer of dense irregular connective tissue
A. what does the papillary dermis contains
B. What does the reticular dermis contain?
A. Contains arterioles, venules and fine nerve endings from Meissner corpuscles
B. Contains blood vessels and nerves
Classify the dermis
A. Loose, fine, interlacing collagen and elastic fibres
B. Lymphocytes are present but scarce, they increase in number in skin diseases
Varies in thickness depending on area of the body
A. Papillary dermis
B. Reticular dermis
A. Layer of loose connective tissue that binds skin loosely to the subjacent organ (subcutaneous fascia)
B. what does this layer contains?
C. Compartmentalization of this layer
D. what does the extensive vascular supply promotes?
E. In areas with terminal hair the subcutis contains
F. In parts of the face the subcutis contains
A. Hypodermis
B. Contains adipocytes for energy storage and insulation
C. Compartmentalized by vertical fibrous septa running from deep reticular dermis to fascial fibrous tissue that underlies subcutis
D. Extensive vascular supply promotes rapid uptake of compounds injected into this tissue
E. the hair follicle and apocrine and eccrine glands
F. sheets of skeletal muscle, such as the muscles of facial expression
Describe the layers in the scalp
Dermis and hypodermis
Dermis:
Broad layer, upper part contains abundant hair follicles and associated sebaceous glands
Hypodermis:
Similarly broad, contains the deeper aspects of the follicles such as the hair bulb
Fibrous layer is deep to subcutis
A. Skin of soles and palms are
B. Explain the layers of the Sole
C. Acrosyringium is visible –
A. Glabrous (no hair and follicles)
B. Epidermis:
Thick, prominent granular layer with thick layer of compact keratin (stratum corneum)
Elongated epidermal ridges extend into dermis to increase area of attachment and minimise risk of separation
C. intraepidermal aspect of the eccrine ducts (sweat duct)
Explain the skin of the mons pubis, labium majus and labium minus
Mons Pubis:
Skin with abundant hair follicles and apocrine glands, thick layer of subcutaneous adipose tissue
Labium Mujus:
Pilosebaceous units in upper dermis, smooth muscle fibres in deep dermis
Inner surface has no hair follicles but has sebaceous glands
Labium Munus:
No hair follicles
Stratified keratinised squamous epithelium with scattered sebaceous glands that open directly onto skin
What is Naevi?
Also termed “moles”
Common benign accumulation of melanocytes in:
Dermis –intradermal naevus
Epidermis –junctional naevus
Dermis and Epidermis –Compound naevus
A. what is malignant melanoma
B. Particularly affect which people?
A. Malignant melanoma is a dangerous malignant tumour of melanocytes
It is the most invasive skin cancer with the highest risk of death
About 30% of melanoma’s begin existing in naevi, rest on normal skin
B. Particularly affects pale-skinned people exposed to excessive UV Light
A. Transition of keratinocytes from basal cells to granular layer of degenerating cells is an organised maturation process producing tough water-resistant keratin on the skin surface
B. Process takes
C. Process description
D. Clinically the skin?
A. Psoriasis
~ 50-60 Days
Psoriasis manifests as epidermal hyperplasia with accelerated maturation of ~ 7 Days
C. This rushed process does not allow the granular layer to form properly and nuclei remain in the keratinised squamous cells
D. Clinically the skin has a surface of opaque, flaky, white scale overlying a thickened red epidermis
What are skin appendages?
hair, nails, sweat glands, and sebaceous glands.
Which layer of the skin has appendages?
Dermis
