Terms - integumentary system Flashcards
Skin system
Integumentary system
composed of the skin, hair, nails, glands, and some nerve ending
What is the skins function
- Protection: skin acts as a physical barrier to bacteria, dehydration, chemicals, and more
- Environmental sensory input: skin gathers information about environment by sensing temperature, pressure and pain
- Excretion: water and salt can be excreted through the skin
- innate Immunity: specialized cells in the skin are part of the immune system (T cell and Langerhans cells)
- Vitamin D synthesis: UV radiation activates skin molecules that is a precursor to Vitamin D
- Thermoregulation: helps to regulate body temperature via capillaries and sweat glands
Thermoreguakltion
regulates the body temperature by using Sweat glands, Piloerection reflex (goosebumps), and blood vessels.
-Sweat glands: uses ATP, loses water
- Piloerection reflex: response to cold, stress, or emotion
- Blood vessels: dilating will cause body to lose heat (useful in hot temps). Constricting causing the body to preserve more heat in cold weathers. 10%
what are the layers of the skin
Epidermis, dermis, and hypodermis
Epidermis
- outer layer,
- (superficial avascular tissue
- 5 layers of epidermis: Stratum corneum, Stratum Lucidum, stratum granulosum, stratum spinsum, and stratym basale/germinativum
Stratym Corneum
- filled with keratin (dead cells)
- prevents from the skin from tearing easy
- barrier against water (hydrophobic)
Stratum lucidum
- only in plams of the hands and soles of feet
- dead cells
- thicker layer
Stratum granulosum
layer of dying cells
- cells are filled with keratin
Stratym spinous
- Provides strength and flexibility
- held together by adhesion protein (desmosomes)
Stratum Basale/germinativum
deepest layer and contains merkel cell, stem cells, and melanocytes
- forms new skin cells
what are the important cells found in epidermis
Keratinocytes, melanocytes, langerhans and Merkel cells
Keratinocytes
produce the protein keratin
- makes up the majority of epidermis
- as they are pushed to the surface to the skin they start to produce keratin and the cell starts to die off
melanocytes
- produce melanin
which is a pigment molecule and protects against UV light
langerhans
interact with helper T-Cells
- with T-cells it creates further immune defense
Merkel cells
attach to sensory neurons
Dermis
Connective tissue filled with collagen and elastic fibers
- middle layer
- thicker then the epidermis so it gives a lot of underlaying structural support to the skin
- hair follicles here, glands which let us secrete various substances onto our skin surface
- relies on oxygen and nutrients
Collagen
is the most abundant protein in the dermis
- presented in a triple helix
- repeating pattern of amino acids; every 3rd amino acid is glycine
what are the mechanoreceptors of the skin
- Tactile corpuscles
- lamellar corpuscles:
Tactile corpuscles
detect light tough
- closer to the surface
- found in the dermis
lamellar corpuscles
detect vibrations and pressure
- found in the dermis
sudoriferous Glands
Sweat glands: includes eccrine and apocrine
- allows for evaportative cooling (cools down the body)
sebaceous glands
connected to hair follicles, secretes oils
- connected to follicles, absent in palms and soles
- secretes sebum that helps to moisturize skin
- keeps skin acidic to prevent bacterial growth
Eccrine
regulate temperature. through perspiration, found everywhere
- reducing urea in the body
Apocrine
secretions are more viscous (thick), on the hair fallacious
- found in the armpits and public regions
Ceruminous glands
Wax, found in ear canal
- produces wax-like
Mammary glands
- Found in the breast
- secretes milk
Hair
Column of keratinized cells held tightly together
- stand up via contraction of smooth muscle known as arrector/erector pili muscles
Hypodermis
Loose connective tissue and adipose tissue
- deepest layer cushion
- store fat and insulation
Keratin
- Most abundant protein in the epidermis
- produced via keratinocytes
-Function: to increase the strength of our skin, along with providing us with protection from external factors such as chemical, physical or even microorganism
Papillary region
As the upper 20% of the dermis and is a thin vascular network within upward projecting papillae that helps supply nutrient to the epidermis along with regulating temperature
Meissners corpuscles
described as sensory-type receptors in which their projection creates fingerprint ridges
reticular region
- described as a region containing dense connective tissue, collagen, and elastic fibers
- provides the dermis with strength and elasticity
- contains many gland types
Chameleons
have the ability to use color change fro camouflage and for finding a mate
- located in the dermal chromatophores
