Test 2 Integumentary system Flashcards
- Organ
a. Consists of tissues working together to perform certain function
- Skin (integument) and its appendages (sweat glands, oil glands, hairs and nails) considered an organ?
a. Yes
- What makes up the integumentary system?
a. Skin and its appendages – sweat glands, oil glands, hair and nails
b. Covering
- What is the largest of all organs?
a. Skin
b. Accounts for 7% of total body weight
c. Varies in thickness from 1.5 – 4 mm
- Skin’s two distinct region
a. Epidermis – thick epithelium
b. Dermis – fibrous connective tissue
- Epidermis and dermis are firlmy cement3ed together along?
a. An undulating border
- What happens if epidermis and dermis separates?
a. Results in a blister
- Where is hypodermis located?
a. Deep to the dermis
- Is hypodermis part of integumentary system?
a. No, but it shares some of the skin’s function
- Function of skin: integumentary system
a. Protect body from bumps scrapes and cuts
b. Screens out harmful UV rays from the sun
c. Metabolic duties…synthesis of vitamin D
d. Insulates/cushions underlying body tissues
e. Protects the body from water loss
f. Helps regulate body temperature
g. Excretes wastes (urea, salt)
h. Contains sense organs
- What are the four cell types found in the epidermis
a. Keratinocytes
b. Melanocytes
c. Merkel cells
d. Langerhans’ cells
- Keratinocytes
a. The most abundant epidermal cell
b. Connected to one another by desmosomes
- What is keratinocyte’s role?
a. To produce keratin
b. Produce antibiotics and enzymes that detoxify harmful chemicals
- Keratin
a. A tough fibrous protein that gives the epidermis its protective properties
- Melanocytes
a. Located in stratum basale
b. Spidershaped cells which make the dark skin pigment melanin
- Where is the melanin transferred to after the melanocytes makes them?
a. Transferred to nearby keratinocytes where it clusters on the superficial side of the cell
- Significance of position of melanin on light skinned people?
a. The melanin is digested by lysosomes a short distance above the basal layer
- Significance of position of melanin on dark skinned people?
a. No digestion occurs and melanin occupies keratinocytes throughout the epidermis
- Merkel cells
a. Located in stratum basale
b. Hemisphere-shaped cells that are associated with a disc-like sensory nerve ending and serves as a receptor for touch
- Langerhans’ cells - location
a. Stratum spinosum
b. Belong to a class of macrophages like cells
c. Part of the immune system
- Langerhans’ cells function
a. Police the outer body surface, using rece3ptor mediated endocytosis to take up foreign proteins (antigens) that have invaded the epidermis
- What does the Langerhans’ cells do after it has performed endocytosis on foreign antigens?
a. Leaves the skin and travel to a nearby lymph node, where they present the antigens to killer T lymphocytes, which proceed to attack all foreign cells that carry the antigen
- The layers of epidermis is composed of?
a. Avascular epithelium stratified squamous
- What are the four or five distinct layers of the epidermis?
a. Stratum basale (basal layer)
b. Stratum spinosum (spiny layer)
c. Stratum granulosum (granular layer)
d. Stratum lucidum (clear layer)
e. Stratum corneum (horny layer)
- Stratum basale
a. Basal layer
b. Deepest epidermal layer
c. Attached to the underlying dermis along an undulating borderline
- Stratum basale consists of?
a. A single row of cells, mostly stemcells representing the youngest keratinocytes
- Cells in stratum basale layer rapidly divide via?
a. Rapidly divide via mitosis
- Stratum spinosum
a. Spiny layer
b. Several cell layers thick
c. Mitosis occur here but less often than in the basal layer
- Stratum spinosum cells contains?
a. Thick bundles of intermediate filaments, called tonofilaments (tension filaments)
- Stratum granulosum
a. Granular layer
b. 1 to 5 layers of flattened keratinocytes
- What granules does stratum granulosum contain?
a. Keratohyaline granules
b. Lamellated granules
- Keratohyaline granules function
a. Form keratin in the higher strata
- Lamellated granules
a. Contain a waterproofing glycolipid that is secreted into the extracellular space and plays a major role in slowing water loss
- Cells above what layer are dead?
a. Stratum granulosum
- Stratum lucidum
a. Clear layer
b. Occurs only in thick skin
c. Consists of few rows of flat dead keratinocytes
- Stratum corneum
a. Horny layer
b. Most external part of the epidermis
- Stratum corneum is composed of?
a. Many layers of dead keratinocytes…which resembles flat sacs filed with keratin because their nuclei and organelles disintegrated upon death
- Function of keratin and thickened plasma membrane of cells?
a. Protect the skin against abrasion and penetration
- How much skin does a person shed in a lifetime?
a. 40 lbs
- Dermis
a. Second major layer of the skin
b. Strong, flexible connective tissue
- Function of dermis
a. Binds the entire body together like a body stocking
b. It is your “hide” and corresponds to animal hides that are used to make leather products
- Cells and fibers of the Dermis: a strong flexible CT
a. Cells: fibroblasts, macrophages, mast cells and white blood cells
b. Fibers: collagen, elastic, and reticular
- The dermal blood vessels consists of?
a. Two vascular plexus – a network of convering and diverging vessels
b. 1. Cutaneous plexus
c. 2. Subpapillary plexus
- Cutaneous plexus
a. Deep
b. Located between the hypodermis and the dermis
c. Nourishes the hypodermis and the structures located within the deeper portions of the dermis
- Subpapillary plexus
a. Superficial
b. Located just below the dermal papillae
c. Supples the more superficial dermal structures – the dermal papillae and the epidermis
- The vascular plexuses plays a role in?
a. Thermal regulation
- What are the two layers of dermis?
a. Papillary layer
b. Reticular layer
- Papillary layer
a. Superficial 20% of the dermis
b. Composed of areolar connective tissue (think collagen/reticular fiber)
- Within the papillary layer is the dermal papillae, what is it?
a. Fingerlike projection that extend into the overlying epidermis
- What functions do the dermal papillae perform?
a. Holds epithelial cells tightly together
b. Increase surface area for nutrients