Chapter 5: The Integumentary System Flashcards
Functions of the integumentary system
- maintain a constant body temperature
- protects the body
- provides sensory information about the environment
- Stores Blood
- Excretes and absorbs
- Synthesizes vitamin D
This system is composed of the skin, hair, oil and sweat glands, nails and sensory receptors
The integumentary system
What is the cutaneous membrane commonly known as?
Covers approx 2 swuare meteres and weight apprx 10-11 lbs (7% of body weight)
Skin
The superficial, thinner portion, composed of epithelial tissue - keratinized stratified squamous cells
Avascular
Epidermis
The deeper, thicker connective tissue portion
Vascular
The Dermis
Layer deeper to the dermis,but not part of the skin. AKA hypodermis
Areolar and adipose tissue
Storage depot for fat and contains large blood vessels that supply the skin
Subcutaneous Layer
Nerve endings contained in the Hypodermis (subcutaneous layer) and sometimes the dermis, that are sensitive to pressure, are called:
Lamellated corpuscles
Lamellated corpuscles are
Nerve endings in the hypodermis and sometimes the dermis that are sentsitve to pressure
This layer of the integumentary system is composed of keratinized stratified squamous cells
Epidermis
What are the 4 principle types of cells in the epidermis?
- Keratinocytes
- Melanocytes
- Macrophages (langerhan cells)
- Tactile epithelialc cells (merkel cells)
Which type of cell makes up approximately 90% of the epidermal cells?
These cells are also arranged in four or five layers and produce the protein keratin
Keratinocytes
This protein is a tough, fibrous substance that helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals
Keratin
What do keritanocytes produce that realease a water repellent sealant taht decreases water entry and loss and inhibits entry of foreign materials
Lamellar granules
This is a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet light
Melanin
These cells produce melanin and make up about 8% of epidermal cells
They have long slender projections that exxtend between the keratinocytes and transfer melanin granules to them
Are susceptible to damage from uv light
melanocytes
What do melanin granules do in the keratinocytes?
Cluster over the skin side of the nucleus to sheild it from damage from uv light
These cells arise from red bone marrow and migrate to the epidermis
The help with immune responses against microbes on the skin and they are easily damaged by uv light
Intraepidermal macrophages (langerhans cells)
These cells are the epidermis tactile epithelial cells
Located in the deepest layer of the epidermis where they contact the flattened process of a sensory neuron (merkel or tactile disc)
Detect touch sensations
Merkel Cells and merkle discs
or tactile cells and tactile discs
The 4 strata (layers) of the epidermis that makes up “thin skin”
- Stratum basale
- Statum spinosum
- Stratum granulosum
- Thin Stratum corneum
The 5 strata (layers) of the epidermis for thicker skin (heels, palsm, soles, fingertips)
- Stratum basale
- Stratum Spinosum
- stratum granulosum
- Stratum laucidum
- Thick stratum corneum
What layer does 5 strata thick skin have that 4 layer thin skin does not?
Stratum lucidum
What Strata is thicker in 5 layer than 4 layer skin?
Strata Corneum
This is the deepest layer of the epidermis
Composed of a single row of cuboidal or columnar keratinocytes
Contains stem cells that divide to continually produce new keratinocytes
Stratum Basale
Describe the keratinocytes of the basale layer
- nuclei
- mitochondria
- Rough ER
- cytoplasm re: ribosomes
- single large nuclei
- a few mitochondria
- cytoplasm has many ribosomes
- the golgi complex is small
-some rought Er