A&P 1 Unit 6 (Lab) [Integumentary System] Flashcards
Integumentary System
Composed of:
- Skin: Body’s largest organ
- Accessory structures:
- Hair
- Nails
- Skin Glands
Functions of Skin
-
Protection
- Prevents fluid loss, abrasions and other wounds, microbial entry
-
Body temperature homeostasis
- Evaporative cooling sweat
-
Excetion
- Glands excrete (get rid of) small quantities of salts, water, organic wastes
-
Begins the synthesis of vitamin D
- Stimulated by exposing skin to UV light. (ex. sunshine)
- Liver and kidneys complete synthesis of physiologically active form.
- Vitamin D is required for calcuim sbsorption from gastrointestinal tract.
-
Sensory Detection
- Pain, temperature, touch, and pressure
Skin contains all four primary tissues:
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial Tissue
- Covers surfaces
- Lines structures
- Forms secretory glands
- Exocrine Glands
- Endocrine Glands
Exocrine Glands
Secretion travels through duct to reach an external surface (of cell, or body) [ex. sweat glands]
Endocrine Glands
Secrete hormones into interstitial fluid (NO duct is used)
Epithelial Tissue Naming
- Describes shape of cells, and whether there are layers of cells
- Cell Shape Terms:
- Squamous
- Cuboidal
- Columnar
- Cell Layer Terms:
- Simple
- Stratified
- Pseudostratified
Squamous
Thin, flat cells
Cuboidal
Cell height and width about the same
Columnar
Tall, narrow cells
Apical Surface
Faces body’s exterior, or an internal space
Basal Surface
Attached to the deeper, adjacent connective tissue
Simple Layer
Cells line up in single layer
Stratified Layer
Multiple layers of cells (stacked)
Pseudostratified Layer
Cells are different heights; tissue appears layered, but it is not!
Other Characteristics of Epithelia
- Avascular
- NO blood vessels
- Epithelial cells rely on diffusion of O2 and nutrients from adjacent, vascular tissue.
- Cells are vary close together
- Secure connections between cells
- Little extracellular material between cells
Connective Tissue
- Most diverse primary tissue
- Inclubes bone, cartilage, blod, adipose, and dermis (deep layer) of skin.
- Cells are widely spaced
- Large amount of extracellular material
- In general, called the matrix
- Contains protein fibers (ex. collagen in dermis)
Epidermis
- epithelial tissue
- no blood supply
Dermis
- Connective tissue
- Blood Supply
Hypodermis
Subcutaneous Tissue (deep to skin)
Connects the skin to the underlying tissues and is not considered part of the integument.
Specialized Skin Structures
- Sweat Glands
- Sebaceous (oil) Glands
- Arrector Pili Muscles
- Sensory Receptors
Sweat Glands
- Eccrine
- Exocrine glands; salty solution; evaporation→ temperature regulation
- Apocrine
- Exocrine glands; viscous; bacteria breakdown→ odor; pheromones?
Sebaceous (oil) Glands
Exocrine glands; empty into hair follicle; moisture; antibacterial
Arrector Pili Muscles
Smooth muscle; associated with hair follicle; pull hair “on end)
Sensory Receptors
- Free Nerve Endings- Detect tissue damage via chemicals released (pain, itch)
- Mechanoreceptors- Detect mechanical/physical stimuli (touch, pressure, temperature)
Layers of Epidermis
- Stratum Corneum
- Stratum Lucidum*
- Stratum Granulosum
- Startum Spinosum
- Stratum Basale
- Dermis**