Integument - Downing Flashcards
In the dermis, what kind of tissue is the papillary layer and the reticular layer made out of?
Dense Irregular connective tissue
What is the small layer of skin that sits on the proximal finger nail called?
Eponychium
Epidermal layers?
Deep to superficial!
Stratum Germinativum (or basale)
Stratum Spinosum
Stratum Granulosum
Stratum Corneum
In what cell layer would you expect to find hemidesmosomes
Only in the germinativum - connected to the basement membrane
Which epidermal layers are mitotically active?
Stratum germinativum
Stratum Spinosum
What layer contains dead cells
stratum corneum
Where do you normally see lamellar bodies?
They are in between cells especially in the superficial layers. (not really found in the basal layer
What is psoriasis and how is it caused?
It is an increase of epidermal thickness and turnover of epidermal cells. Makes your skin really itchy.
It is caused by an increase in the number of proliferating cells in the stratum basale and stratum spinosum.
If your body makes antibodies against its own desmogleins. What will be your disease and symptoms?
Pemphigus Vulgaris
Disrupting the desmogleins which make up desmosomes. This causes blistering between cells
What causes bullous pemphigoid?
Autosimmune blistering disorder of the dermis/epidermis junction.
Caused by disruption of hemidesmosomes.
Why do some areas of the junction between dermis and epidermis have move dermal papillae than other areas?
The amount of dermal papillae increase relative to the amount of trauma that this area of skin generally experiences.
Why should a surgeon know langer’s lines?
Sort of shows the direction that skins runs. Cutting with the grain will allow less complicated healing.
What kind of tissue is the hypodermis made of?
Loose connective tissue
- often has a lot of adipose tissue as well!
What is the mechanism behind skin pigmentation??????
In a melanocyte: tyrosine within melanosomes are broken down by tyrosinase into a melanin polymer. These melanosomes are then transferred from the melanocyte to epidermal cells.
Melanin is a dark brown color that makes the skin darker.
What causes the difference between darker and lighter-skinned individuals?
Lighter - Melanosomes are smaller and are degraded much easier
Darker - Melanosomes are larger and dispersed through the karatinocyte. Harder to break down quickly.
** The actual number of melanosomes produced is actually very similar between races **
What happens when you tan?
Your existing melanin is immediately darkened and sun exposure also causes a gradual increase in tyrosinase activity
What autoimmune disease causes depigmentation by destroying melanocytes
Vitiligo
What part of the hair structure contains mitotic activity?
The matrix!
Compare black, brown, blond, red, and gray hair!
Black hair: well-oxidized tyrosine
Brown & blond hair: same pigment, but less of it
Red hair: contains pigment of limited oxidation
Gray hair: mixture of white and black/brown hair
Cure for male-pattern bladness?
Castration.
Because it is hereditary and has to do with male sex hormone
What is lanugo, vellus, and terminal hair?
Lanugo - just fetuses
Vellus - soft, fine hair
Terminal - coarser hair
Function of arrector pili muscle?
It is sympathetically innervated and serves to make hair stand on end and produce goosebumps
Also helps move sebaceous gland products
What causes blackheads and whiteheads?
Both are blockages of the sebaceous glands.
Blackheads are still somewhat open to the surface, whereas whiteheads are closed to the surface.
Sebaceous glands are found where?
Anywhere theres a hair follicle.
AND
eyelids, areolae of mammary glands, labia minora, glans of penis, corners of lips
What hormone is acne associated with
Androgen
from adrenal cortex, testes, and ovaries
What is the easiest way to tell the difference between eccrine and apocrine sweat glands?
Apocrine sweat glands have a giant space for their lumen compared to the small one seen in eccrine sweat glands
Where do you find eccrine and apocrine sweat glands?
Eccrine - everywhere
Apocrine - axillary region, areolae, anogenital region
What are the two types of skin receptors that we need to know?
Meissner’s corpuscles - for touch
Pascinian Corpuscles - for pressure
look like onion!
