components of integumentary system (3)
skin
hair
nails
largest organ in the body
skin
layers of skin
epidermis
dermis
hypodermis
outer layer of skin
epidermis
middle layer of skin
dermis
inner layer of skin
hypodermis
functions of skin (3)
1. protection from pathogens
2. production of vitamin D
3. contain sense organs for protection of skin and underlying tissue
merkel cells & meissner's corpuscles
mechanorecptors
mechanorecptor fucntion
detect mechanical sensory information in form of light touch and vibration
where can merkel cells found?
epidermis
nociceptors function
detect pain such as pain from prick
where are nociceptors found?
embedded throughout the nerves
pacinian corpuscles function
detect mechanical sensory information of pressure applied to skin
thermoceptors function
detect hot and cold
sensory organs function
designed to detect sensory information and relay information to brain
true or false: thermoreceptors detect fine touch
false
true or false: merkel's cells and meisner's corpuscles are thermoceptors
false
true or false: pacinian corpuscles detect pressure true
what does an exocrine gland contain and how do its contents reach the surface of the skin
-contains secretions
-released through duct into an epithelial surface or lining
Sebaceous glands
-oil glands
-produce sebum
sebum definition
helps keep skin and hair from drying out and cracking and inhibits growth of harmful microbes
Sweat glands are also called ______
sudoriferous glands
sweat glands
-Produce sweat in almost every part of the skin
-perspiration
thermoregulation
helps body to regulate its temperature
-perspiration is one method
what type of cells make up the epithelium?
stratified squamous
stratified squamous epithelium
layers of flat cells
is the epidermis vascular or avascular?
avascular
receives nutrients from basement membrane
4 distinct layers of epidermis (superficial to deep)
1. stratum corneum
2. stratum granulosum
3. stratum spinosum
4. stratum basale
how long do dead cells remain in the stratum corneum before they slough off?
~2 weeks
true or false: cells of the stratum basale have a high rate of cell division
true
epidermal ridges
-unique to each person and consistent throughout a person's lifetime
-finger prints
cells found in epidermis (5)
1. keratinocytes
2. langerhans cells
3. fibroblast cells
4. melanocytes
5. merkel cells
keratinocytes