Integumentary

skin

skin

What is largest organ in the body (by mass)?

protection - makes keratin to support body (germ and waterproof barrier, abrasion-resistant)

sensory - organs are first in contact with the external environment

Homeostasis - thermoregulation (can save and evacuate heat - sweat), too much calcium in our bodies = hyperthyroidism so when sunlight hits our skin, the vitamin D absorbs calcium in our skin

Communication - muscle attachment (facial expressions) secretes pheromones (affect others, sexual attraction; ex. eyes dilate)

What are the functions of skin?

epidermis

• solid cellular, outermost layer

• composed of keratinocytes (create keratin)

• dead skin cells stuffed with keratin

dermis

• thickest layer, multicellular, support for epidermis

• composed of many CTs

• the site for many glands and other epidermal derivatives

subcutaneous layer (hypodermis)

• attaches skin to underlying structures

• mostly made of fat

stratified squamous

The epidermis is composed of 4-5 layers of keratinocytes which is formed into a __________ _________ epithelium.

keratin

water-insoluble protein found in the epidermis

Merkel cells (sensory cells), Langerhans cells (surveillance cells, part of immune defense), melanocytes (make melanin)

What are the cells from the dermis that invade and reside in the epidermis’ deepest layers?

stratum basale, spinosum, granulosum, lucidum, corneum

What are the layers of epidermis from bottom to top?

bitch sucks girthy long cock

thin skin

Where is stratum lucidum not found?

stratum basale

What is the base layer of the epidermis?

stratum spinosum

What layer of the epidermis contains cells that are beginning transcription and translation and begin to make keratin? This layer is also the biggest layer.

stratum lucidum

layer that is translucent/clear, contains cells called eleidin that are then converted to keratin in the stratum corneum

stratum granulosum

layer that is granulated, has keratohyalin, which is a protein

stratum corneum

top layer, forms keratin in the cytoplasm, top of this layer is dead cells, keratin-filled cells

• composed of a mixture of connective tissue including dense irregular, loose areolar, elastic, and adipose tissue

What is the dermis composed of?

papillary (top) and reticular (bottom)

What are the 2 regions of the dermis?

papillary layer

region of the dermis with dermal papillae (make patterns on skin)

reticular layer

region of the dermis that is the thickest layer of skin, provides strengths, elasticity and space for glands, hair follicles, etc.

dermal papillae

arranged in regular patterns in palms and soles

• in sweat glands to help with grip

• increase frictional abilities

epidermis

new layers will grow, blood goes to the area

sunburn that peels

What layer of skin does a 1st degree burn damage?

How does it heal?

What are examples of a 1st degree burn?

starts to impact the dermis in the papillary layer

Where does the 2nd degree burn damage?

2nd degree burn

what degree burn?

• epidermis lifts because water is pumped into the dermis

• blisters form to protect

• epidermis reforms in healing process

epidermis and dermis

nerves (ex. in picture the girl would only feel the pain at her short line)

What layer is damaged from a 3rd degree burns?

What is an important thing that is also damaged?

take skin from other areas and hope it grow (skin grafts)

How are 3rd degree burns treated?

melanoma, basal cell carcinoma, squamous cell carcinoma

What are the skin cancers from greatest severity to least?

melanated bitches squirt

squamous cell carcinoma

type of skin cancer:

• affects the epidermis, least likely to metastasize

• usually can be contained and taken out

basal cell carcinoma

type of skin cancer:

• affects the base of the epidermis, right along the dermis, involves the nerves

• surgery can remove it

melanoma

type of skin cancer:

• most likely to metastasize (spread to muscles, organs)

• found in the dermis

• melanocytes (made in the dermis) invade the lymph system in the area

• can start as a mole

epidermal derivatives

structures which grow from the epidermis but reside mostly in the dermis (grow down into the dermis)

ex. nails, hair, glands of skin

the nail

What is the 2nd hardest substance in the body after teeth?

nail matrix

the part of the nail that starts at the base, forms nail cells, pushes nail forward

eponychium

sealant for the nail, prevents infections, also called cuticle

hyponychium

sealant, preventing infections

nail bed

part that the nail sits on, underlying epidermis and dermis that supports the nail body and root

lunula

part of the nail that the cells are dividing, white part of the base

free edge

part of the nail that you cut off

nail root

part of the nail that is underneath the skin, growing part

epidermis

What part of the skin is responsible for the hair?

sebaceous glands

gland that is related to hair; oil-secreting, makes sebum (the grease on hair), prevents dehydration

• too much “oil”

• infection/fungus

• this is why it is important to wash hair regularly

What happens if there is an overproduction of sebum on hair?

hair root

part of the hair that is deep in the dermis

hair bulb

part of the hair that is the enlarged area at the end of hair root

hair shaft

part of the hair that protrudes from skin

hair follicle

part of the hair that sits at an angle to the surface of the skin

hair papilla

part of the hair that supplies blood to the hair; melanocytes are here

arrector pili muscle

part of the hair; pulls the hair upright (contracts), goosebumps, function is to insulate better to keep warm when cold

smaller, larger

When the arm hair is down the air layer is __________.

When the arm hair is up the air layer is ___________. (more insulation)

medulla

part of the hair: center, air pockets are here to determine hair color (this is responsible for hair being able to float on water)

cortex

part of the hair: outer part, around the medulla

cuticle

last outer layer of the hair

melanocyte

secrete melanin into the growing cells, controls color of hair

keratinized

Hair is highly __________. (like skin) *ends are dead

internal and external root sheaths

what two things are supported by the dermis in the hair?

hair matrix

What part of the hair is metabolically active?

terminal and non-terminal

What are two types of hairs?

arms hairs

What is an example of terminal hair?

hair on head

What are examples of non-terminal hair?

It becomes dormant.

What happens to the hair follicle when someone goes bald?

• pheomelanin (yellow-reddish)

• eumelanin (brown-black)

What are the two types of melanoctyes?

Carotenoids (orange/yellow)

pigments associated with fat and subcutaneous areas

(ex. accessory versions of these cause a change in blood for example, when your skin turns green when you are sick)

melanin

protects against the sun, absorbs ultra-violet radiation

acne rosacea

• interaction of blood vessels

• pigmentation reddening of skin (on face, especially)

drugs, alcohol, spicy foods, TB, syphilis, lupus

What are some things that can cause acne rosacea?

wine stain

birthmark due to overgrowth of blood vessels in the skin

• can use laser treatments

epidermis, toxic

Tattoos involve an injection of ink below the ___________.

Inks used in tattooing contain heavy metals that are ______ at high levels.

exocrine glands

glands made in the epidermis but are housed in the dermis

• they secrete product into the duct or external surface

Goblet

example of an exocrine gland: only single cell gland in humans is the _________ cell (secretes mucous)

exocrine

All other glands besides the ________ gland can be classified by structure or type of secretion method used

merocrine secretion

functional classification: gland that secretes by exocytosis using vesicles

apocrine secretion

functional classification: gland that secretes by storing product in cell’s tip (apex) then breaking the entire tip

holocrine secretion

• think “whole”

functional classification: gland where the entire cell is secreted with its product

simple

structural classification (by duct structure) : a single duct leads from the secretory unit to the surface

compound

structural classification (by shape of secretory unit): duct branches to connect the surface to the secretory unit

tubular

structural classification (shape of secretory unit): tube-shaped

alveolar

structural classification (shape of secretory unit): flask-like sac

think alcohol flask

mucous, bulbourethral (male reproductive)

Where are compound tubular glands found?

mammary

Where are compound alveolar glands found?

salivary, pancreas

Where are compound tubuoalveolar glands found?

sebaceous

epidermal gland: secretes sebum (oil), is used to maintain skin and hair moisture (ex. areola)

ceruminous

epidermal gland: secretes cerumen (ear wax which is really just an oil)

used to keep foreign objects out of ear

What is the function of the ceruminous gland?

sudoriferous

epidermal gland: secretes sweat (water with some salts)

heat regulation and pheromone secretion

What is the sudoriferous gland used for?

apocrine and eccrine (merocrine)

What are the two types of sudoriferous glands?

apocrine

type of sudoriferous gland: larger gland, found in the axilla and groin, functional at puberty

eccrine (merocrine)

type of sudoriferous gland: most abundant, thermoregulation, smaller glands

milk line

where mammary tissue forms

(Ex. a dog has more nipples than a human)

secrete milk

What do mammary glands do?

lactiferous duct

What duct is the milk in?

hold breasts up, if they get too stretched breasts sag (with age)

What do suspensory ligaments (on the superior side of the body, for the most part) do?