Topic 9 Integumentary System Flashcards
List the components of the integumentary system
Skin, Hair, nails, glands,
Sensory receptors (telling you about the world around you) and
Muscles
What are the different Skin layers
Epidermis (upper) = Superifical
Dermis (lower) = deep
Describe the epidermis of the skin, listing the five strata in order from deepest to most superifical
Epidermis of the skin is stratified squamous epithelium , avascular and it is separated into 4-5 strata (layers)
4-5 strata from deepest to superficial
1) stratum basale (2 cell types keratinocytes and melanocytes)
2) stratum spinosum
3) stratum granulosum
4) stratum lucidum
5) stratum corneum
Describe the structure of the five strata of the epidermis
Stratum basale: single row of cells (next to CT deepest layer of epithelial) - single row of cells
contains 2 cell types
1) keratinocytes (90%)
- undergo mitosis, make keratin (tough protein)
- migrate to surface as new cells are produced in basale
**2) melanocytes (10%) **
- produce pigment (melanin - for uv light protection)
- e.g against sunburns, wrinkles, collagen damage, cancer (DNA damage)
- skin colour: we all have the same relative number of melanocytes but cells produce diff amounts/shades of melanin (e.g freckles - melanin in eyes too
Albinism/achromia = no melanin - in areas of thin skin, blood (hemoglobin) from dermis is visible giving pinkish tinge - nail beds, lips
Stratum spinosum: limited cell division (look like they have spines = “spinosum”)
Stratum granulosum: contains dark-staining granules (very thin, really dark and skinny)
stratum lucidum: flat, dead cells ( grey appearance, too far from blood supply)
- only visible in thick skin
stratum corneum: 20-30 layers of flat,dead cells filled with keratin (tough protein), surrounded by waterproofing glycolipid (prevents water loss from leaking out)
- shed and replaced from below
What’s located in the dermis layer?
Contains blood vessels, nerves, glands, hair follicles
What is areolar CT (review question) what part of the integumentary system is this a part of?
A type of Loose connective tissue proper
* cells are fibroblast/fibrocytes
* Contains loosely arranged collagen and elastic fibres surrounded by a ground substance hyaluronic acid
* Highly vascular
This is a part of the papillary layer of the dermis
What is dense irregular CT (review question) where is this found in the integumentary system
A type of Dense CT
* it contains Collagen fibers arranged iregularly
* e.g dermis of skin
Found in the dermis of skin which is a part of the reticular layer (makes up most of the dermis)
What is adipose CT (review question)
Where is it found in the integumentary system?
A type of loose CT
- has very little matrix
cells are large adiposecytes which stores triglycerides (tissue look like chicken wire
- highly vascular
In skin this is a part of the hypodermis (aka superficial fascia, or subcutaneous layer)
- stores 1/2 of bodys adipose tissue used for insulation
What are the 2 sublayers of the dermis layer? name the tissues in these layers
2 sub layers CT from mesoderm
**1) Papillary layer **
- areolar CT
- Vascular
- Dermal papillae = has projections into the epidermis
- In thick skin, these form epidermal ridges (finger prints = imrpove grip)
**2) Reticular later **
- Most of dermis
- dense irregular CT (look at skin)
Hypodermis characteristics
Not part of the skin
Subcutaneous layer or Superficial fascia (any terms work)
Adipose CT below the skin
store 1/2 of body’s adipose tissue (acts as insulation) - layer of fat under skin
Stratum Basale
next to connective tissue and is the deepest layer of Epithelial which is a single row of cells
contain two cells, keratinocytes and melaninocytes
Keratinocytes
(90% of cells in layer, stratum basale)
A cell type thats a part of the stratum basale
Undergo mitosis
Make keratin (tough protein)
Migrate to surface as new cells produced in basale
Melanocytes
take up 10% of the layer, stratum basale
Produce pigment (melanin) (for uv light protection)
Explain the source of the colour of skin
Melanocytes (take up 10% of the layer, stratum basale)
produces pigment (melanin) for uv light protection
e.g against sunburns, wrinkles (collagen damage), and cancer (DNA damage)
- we all have the same relative number of melanocytes, but cells produce diff amounts/sahdes of melanin (e.g freckles or the melanin in our eyes)
What is Albinism/achromia?
no melanin
in areas of thin skin, blood (hemoglobin)
for demis it is visible giving pinkish tinge - nail beds, lips
Stratum spinosum
Limited cell dviision
Stratum granulosum
contains dark-staining granules
Stratum lucidum
Flat, deadells (too far from blood supply)
visible only in thick skin
Stratum corneum
20-30 layers of flat, dead cells filled with keratin (tough protein) surrounded by waterproofing glycolipid (prevents water loss)
Shed and replaced from below
What is located in the dermis and describe the two layers of the dermis
the dermis contains blood vessels, nerse, gland and hair follicles (THESE ARE JUST LOCATED HERE THEY ARE NOT THE DERMIS)
2 sublayers (Both are from CT and arise from the mesoderm)
1) papillary layer
- areolar CT
- vascular
- has projections into the epidermis = dermal papillae
- in thick skin, these form epidermal ridges = finger prints (improve grip)
2) reticular layer
- most of dermis
- dense irregular CT (look at skin e.g if stretched too much to quickly = stretch marks = little damage to reticular layer of dermis)
Papillary layer
Contains Areolar CT
vascular
has projections into the epidermis = Dermal papillae
Dermal papillae
A part of the papillary layer of the dermis
Dermal papillae are projections into the epidermis of the dermis
Epidermal ridges
- a part of the papillary layer of the dermis
contain dermal papillae (projections into the epidermis) and in thick skin these are finger prints (improve grip)
Reticular layer
Most of the dermis
dense irregular CT
look at skin ex) if stretched too much too quickly = stretch marks = little damage to reticular layer of dermis
Hypodermis is also known as the
subcutaneous layer or superficial facia
Desribe the hypodermis
aka the subcutaneous layer or superficial Fascia
Fascia = CT layers that surround and support organs
- adipose CT below the skin
- store 1/2 of body’s adipose tissue (insulation)
What is the Fascia
CT layers that surround and support organs
explain the difference between thin and thick skin
Thin and thick skin refers to the epidermis
Thin skin:
Lucidim is not apparent (might be there just can’t see it)
has hair follicles, sebaceous glands, arrector pilli muscles
Thick skin
found on the palm of the hand and the sole of the food
lucidum visible (very clearly, thinner in some places)
no hair follicles, sebaceous glands (oil glands) or arrector pilli muscles
What are epidermal derivatives
All derived (formed) from the epidermis
List the Epidermal derivatives of skin
Hair, nails and skin
Describe the structure of Hair and the hair follicles
Hair is an epidermal derivative
Hair is all dead cells
It contains Root, shaft and hair follicles
1) Root: dead cells below the surface of the skin
2)shaft: above the skin surface
3) hair follicle - surrounds root containts epithelial root sheath, bulb and hair matrix
- 1) Epithelial root sheath: several epidermal layers extend into the dermis
- 2) bulb: expanded region at base of foot
- 3) hair matrix: single layer of cells
- derived from basale cells
- site of hair growth and melanin for hair color
What are the different parts of hair
Root, shaft, hair follicle
The hair follicle contains (epithelial rooth sheath, bulb, and the hair matrix)
What is the root
dead cells below the surface of the skin
What is the shaft
above the skin surface
What is the Hair follicle?
list the strucutures of the hair follicle
Surrounds the root
contains epithelial rooth sheath, bulb and hair matrix
What is the epithelial root sheath
contains several epidermal layers that extend (deep) into the dermis (a part of the hair follicle that surrounds the root)
What is the bulb
It is a part of the hair follicle that surrounds the root
The bulb is the expanded region at the base of root
What is the hair matrix
the hair matrix is a single layer of cells thats a part of the hair follicle (surrounds root)
- derived from basale cells
- Site of hair growth and melanin for hair color
List and describe the structures assosciated with hair follicles
Dermal root sheath, hair papilla, root hair plexus, sebaceous (oil) gland, and arrector pili muscle (smooth muscle)
Dermal rooth sheath: CT holds follicle in place (formed from the dermis)
hair papilla: extends upward beneath matrix
- contains blood supply for growing hair and signals for its regulation
- dermal
root hair plexus: free nerve ending (touch)
sebaceous (oil) glands: opens into follicle
Arrector pili muscle (smooth muscle): causes “goosebumps”
Dermal root sheath
assosciated with each hair follicle (surrounds root)
holds follicle in place (formed from the dermis)
hair papilla
assosciated with each hair follicle (surrounds root) extends upward beneath matrix
- contains blood supply for growing hair and signals for its regulation
- dermal
Root hair plexus
assosciated with each hair follicle (surrounds root)
free nerve ending
sebaceous (oil) gland
assosciated with each hair follicle (surrounds root)
opens into follicle
Arrector pili muscle
assosciated with each hair follicle (surrounds root)
smooth muscle that causes goosebumps
Describe the strucutres of nails
very heavily keratinized epidermal cells
Nails consists of:
nail root (buried in skin)
body (visible portion)
free edge
Describe Exocrine glands (review question)
Exocrine glands are a type of glandular epithelium which is used for secretion
- They secret products onto body surface or into a body cavity
There are two types of exocrine glands unicellular or multicellular
**1) unicellular: goblet cells **
- secrete mucus (into a cavity)
- in the digestive, urinary, reproductive and respiratory tracts
2) multicellular:
- consists of secretory and duct cells (ducts connect secretions to surface of cavity)
- e.g glands: sudiferous (sweat), sebacous (oil), mammary and digestive
Describe the characteristics of the exocrine glands of the skin
Sebaceous glands, sudiferous glands, ceruminous and mammary glands
1) Sebaceous glands: connected mainly to hair follicles
- secrete sebum (oily - mix of fats, salts, proteins)
- softens, lubricates hair and skin, prevents drying out, antibiotic
2) sudiferous glands
- sweat glands
- secretory portions in dermis of thick and thin skin
- ducts open onto skin surface
- Sweat: cools the body, is antibiotic, removes wastes (urea, etc.)
3) ceruminous
- modified sweat glands
- in ear canal
- produce ear wax
4) mammary glands
- modified sweat glands
- produce milk
Sebaceous glands
An exocrine gland of the skin
connected mainly to hair follicles
secrete sebum (oily mix of fats, salts, proteins)
softens lubricates hair and skin, prevents drying out, antibiotic
Sebum
what the sebaceous glands (an exocrine gland of the skin) secretes it is an oily mix of fats, salts and proteins
- it softens,lubricates hair and skin, prevents drying out, antibiotic
Sudiferous glands
An exocrine gland of the skin
sweat glands
secrete portions in demris of thick and thin skin
ducts open onto skin surface
sweat:
- cools the body, is antibiotic (acidic), and removes wastes (urea, etc.) - body doesnt like acidic enviornments
Ceruminous
An exocrine gland of the skin
modified sweat glands
in ear canal
produce ear wax (prevents insects etc. from entering)
Mammary glands
An exocrine gland of the skin
modified sweat glands - produce milk
Cutaneous sense receptors
Specialized to respond to stimuli (touch, temperature, pain)
Receptors
ending of a sensory neuron (part of the nervous system) - helps us survive
What are the four major types of cutaneous sense receptors
touch receptors, pressure recepotrs, thermo receptors and nociceptors
Whats found in touch receptors
touch = surface
Touch receptors contain free nerve endings located in the epidermis, root hair plexuses, meisserners corpuscles found in the dermal papillae
Free nerve endings
located in the epidermis layer involved in the major type of cutaneous sense receptors, the touch receptors
They help with senses of itch, pain, tickles, cold or warmth
Root hair plexuses
Part of one of the cutaneous sense receptors, the touch receptors
Meissner’s copuscles
Are encapsuled nerve endings (ct surrounding = corpuscle)
found in the dermal paillae
Corpuscle
connective tissue capsule surrounding the nerve ending
what are pressure receptors
Contain 2 parts
Free nerve endings and pacinian corpuscles
Pacinian corpuscles
deep in dermis or hypodermis
What are thermo receptors
free nerve endings for temperature
ex) hot or cold dont have to be in epidermis but can be in dermis too
What are nociceptors
free nerve endings for pain
3rd degree burns = no pain because noicicpetors are destroyed (hypodermis or to muscle)
1st degree burn
top layer (epidermis)
2nd degree burn
second layer (dermis)
3rd degree burn
hypodermis or to muscle
3rd degree burns = no pain because noicicpetors are destroyed
