Biology 1410 Lecture Notes UNIT 9

Integumentary System consists of what

skin
hair,nails,glands
muslces
sense receptors(nervous)
hypodermis

The skin has two layers which is

epidermis
dermis

The superficial layer is ???
The deep layer is ??

Epidermis
Dermis

The epidermis is __ __ epithelium and is __

stratified squamous, avascular 

The epidermis is seperated into _-_ sub layers

4-5

What are the 4-5 sub layers of the epidermis

Stratum Basale
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum
Stratum corneum

What has a single row of cells and two cell types keratinocytes and melanocytes 

Stratum Basale

keratinocytes have what percentage and melanocytes have what percentage? 

90% and 10% 

Does keratinocytes actively under which meiosis or mitosis 

Mitosis 

Older keratin gets pushed towards the ssurface as new cells are produced in where 

Basale

what produce pigment(melanin) for UV light protection

melanocytes

What are three examples of damage to our melanocytes

sunburns, wrinkles(collagen damage) , cancer (DNA damage)

we all have the same relative number of melanocytes but cells produce different amount of shades of what

melanin

____ - in dermi scan give people a pinkish tinge like blush or our lips

blood hemoglobin

Stratum Spinosum has low levels of …

mitosis

Which sub layers of epidermis have no mitosis

Stratum Granulosum and Stratum Lucidum

The stratum Granulosum contains __

granules

What produces keratin(strength) and starts to produce waterproofing glycolipids (prevents water loss) 

granules 

Stratum Granulosum is the last layer of _ cells

living

this layer has no mitosis, flat, dead cells 

Stratum Lucidum 

many layers of flat dead cells filled with keratin( tough protein)
glycolipids between cells create water proof layer (prevent water loss) 
shed and replaced from below 

Which layer is this?  

stratum corneum 

This contains blood vessles, nerves,glands, hair follicles, arrector pili muscles 

Dermis 

The Dermis has how many sublayers? (connective tissue)

2

What is connected to the epidermis?

Papillary Layer

The papillary layer has ___ connective tissue 

areolar 

Is the papillary layer avascular or vascular

vascular

the papillary layer has projection into epidermis which is called.. 

dermal papillae 

dermal papillae is thick skin which form these epidermal ridges which is…

fingerprints(improve our grip) 

Reticular Layer is between ____ and ___

papillary layer and hypodermis

The reticular layer forms most of …

dermis

The reticular layer is ___ ___ connective tissue

dense irregular

Any thicknesss will always refer to ???

epidermis (NOT DERMIS)

What covers most of body

thin skin

Whats found on the palm of the hand and sole of the feet 

thick skin 

Where is lucidum absent and present

absent in thin skin and present in thick skin

What has hair follicles, sebaceous glands, arrector pili muscles and what doesn’t 

thin skin has it and thick sin has none 

Hair, Nails, Skin Exocrine glands all come from where?

epidermis

What is all dead cells?

Hair

The Hair has three main parts what is it?

Root, Shaft, Hair follicle

part of the hair embedded within skin is…

Root

surrounds root

Hair folicle

visible part of the hair above the skin surface

Shaft

Epithelial root sheath, bulb, matrix all make up the 

Hair follicle 

expanded region at base of root

bulb

single layer cells (derived from basale cells) - site of hair growth and melanin for hair colour …

matrix

several epidermal layers extend into the dermis 

epithelial root sheath 

Outer CT sheath 
hair papilla
root hair plexus 
sebaceous (oil) gland
arrector pili muscle (smooth muscle) 


Are all….

Associated with each hair follicle(they work with it) 

opens into follicle

sebaceous (oil) gland

extends upward beneath matrix

hair papilla

free nerve ending (touch)

root hair plexus

causes “goosebumps”

arrector pili muscle (smooth muscle)

holds follicle in place ( formed from the dermis)

outer CT sheath

Hair papilla contains __ supply for growing hair
Hair papilla is formed from _

dermis 

What is very heavily keratinized epidermal cells..

Nails 

Nails consists of three main parts

nail root, body, free edge

There are four glands apart of the skin exocrine glands 

sebaceous glands 
sudoriferous glands 
ceruminous glands
mammary glands

This is connected mainly to hair follicles and secretes sebum(oily - mix of fats, salts, protiens)

sebaceous glands

what softens, lubricates hair and skin, prevents drying out, antibiotic 

sebum 

sweat glands, secretory portions(part of sweat gland) in dermis of thick and thin skin, ducts open onto skin surface 

sudoriferous glands 

what are the three functons of sudoriferous glands 

temperature regulation(cooling off body) 
antibotic action( due to sweat being acidic 
waste removal(e.g. urea) 

modified sweat glands
in ear canal 
produce ear wax( prevents insects etc from entering) 

ceruminous glands 

modified sweat glands
produce milk

mammary glands

Cutaneous sense receptors…
sensory receptors are for sensory ___

neuron (part of Nervous System) 

Cutaneous sense receptors
specilized cell that responds to __

stimuli (touch, temp, pain) 

four major types of Cutaneous sense receptors

Touch Receptors
Pressure Receptors
Thermoreceptors 
Nociceptors 

free nerve endings(in epidermis)
Root Hair Plexuses(touch receptors) 
Tactile (Meissner’s) Corpuscles 
Are apart of what type 

Touch Receptors 

What is 
in dermal papillae 
corpuscle is a connective tissue capsule surrounding a nerve ending 

Tactile (Meissner’s) Corpuscles 

free nerve endings and Lamellar (Pacinian) corpuslces… are apart of what? 

Pressure Receptors 

What is in dermis for Pressure Receptors

free nerve endings

What is deep in dermis or hypodermis for Pressure Receptors 

Lamellar (Pacinian) corpuslces

free nerve endings for temperature

Thermoreceptors

free nerve endings for pain
third degree burns destroy nocieptors causing lack of pain sensation in affected areas 

nocieptors

What is not part of the skin

Hypodermis

Is Hypodermis, subcutaneous layer and suerficial fascia different?

NOPE SAME NAME

connective tissue layers that surround and support organs

Fascia

adipose connective tissue below skin that stores ½ of body’s adipose tissue (insulation) 

Hypodermis 

lack of melanin production by melanocytes 

Albinism 

autoimmune disorder that causes accelerated mitosis of keratinocytes in the stratum basale

Psoriasis 

accelerated cell cycle delays maturation and differentiation of ___

keratinocytes 

immature keratinocytes accumulate in epidermis and the __ __ fails to shed resulting in a thick scaly area on the surface of the skin (plaque) 

stratum corneum