Integumentary System Flashcards
(16 cards)
What is the Integumentary System?
The skin and associated appendages
What 6 functions does this system have?
1) Protection
2) Regulation of Body Temperature
3) Cutaneous Sensation
4) Metanolic funtions
5) Blood reservoir
6) Excretion
what are 3 kinds of Protection?
Chemical: Sebum, acid mental and melanin
Physical: Hardened keratinized and lipid-rich
Biological: Phagocytes
What helps maintain Body temp?
The vasculature and Sweat glands
What is Cutaneous Sensation?
its the sensory receptors that respond to; Temp, touch, pressure and Pain Stimuli.
What is Metabolic functions?
Its when vitamin D is synthesized from cholesterol by epidural cells. Also plays a role in some chemical conversions.
What is Blood Reservoir?
Due to the extensive vascular supply
What is Excretion?
Small amounts of nitrogenous wastes are contained in the sweat.
Type of cells in the Epidermis and what do they do?
Keratinocytes: Produce Keratin, fibrous protein and offers protection. These cells almost always dividing to produce more and more cells as the dead ones are sloughed off.
Melanocytes: Synthesize melanin: a pigment giving skin its color. Accumulates in melanosomes and get transferred to keratinocytes (Sunny side up) protects from UV radiation.
Merkel Cells: Closely associated with the system, Merkel disc acts as a sensory receptor for touch.
Langerhans Cells: Arise from the bone marrow, help to activate the immune system.
Stratum corneum (Horny)
The outer most layer, account for 2/3 of the thickness of the epidermis. shingle-like dead cells that serve to protect from:
Abrasions
Penetration
Water loss
Biological, chemical and physical assaults.
Why does the top layer of the skin contain a lot of dead skin cells?
Protection to keep the living cells healthy
To help prevent water loss
Stratum Iucidium
A few rows of keratinocytes
Present only in thick skin
Stratum Granulosum
the thin layer where the keratinocyte appearance changes a lot and cells are “toughening up”
Nuclei and organelles start to disintegrate and accumulate lamellated granules and keratohyaline granules.
Above this layer, the cells are dead because nutrients from the capillaries (in the dermis) can’t reach farther than this.
Stratum Spinousum (Prickly)
Several layers thick
Keratinocytes start to flatten and look sort of spiny.
Many Langerhans’s cells (Help activate immune system) and also many melanin granules in this layer.
Statum basale
Deepest layer but also the germinal layer
attaches firmly to the dermis mainly a row of the youngest keratinocytes.
Many mitotic nuclei representing rapid cell division.
10-20% of the cells in this layer are melanocytes. (Gives skin color)
Dermis
the second major region, its strong and flexible connective tissue and holds the body together. Many nerve fibers.
Blood and lymphatic vessels
Hair follicles
oil/sweat glands.
