Integument Flashcards
What is an organ
A part of the body made of 2+ tissue layers that work together to perform specific functions (e.g. stomach, skin, lung, sweat gland, etc.)
Is a membrane an organ
Yes but it can also just be part of an organ
What are 4ish functions of the integument
Water-resistant and protects against internal evaporation (sebum/oil and glycolipids create a barrier), excretion of liquids and salts to get rid of excess and regulate temperature, sensory receptors for touch, temperature, and pain, body temp regulation (capillary network, evaporation, and hair), protection against bacteria, dehydration, and UV light absorption
What are the layers of the epidermis
Stratum: corneum, lucidum (thin layer in thick skin), granulosum (full of keratin granuoles), spinosum, basale, and the dermis
What types of cells are in the epidermis
Keratinocytes, melanocytes, merkel cells, and dendritic cells
What are the 5 characteristics of keratinocytes
Most abundant, produce keratin, connected by desmosomes, new cells made at basal surface and oldest cells at apical surface (cells dead at stratum cornieum), replaced every 35-45 days but production sped up by friction
What are the characteristics of melanocytes
They produce pigment/melanin which is transported to adjacent keratinocytes (typically on apical surface to protect nucleus from UV light) and are found in stratum basale
What are the characteristics of merkel cells
They have sensory touch receptors to respond to pressure, with associated nerve endings to send info to the nervous system, only found in the stratum basale layer
What are the characteristics of dendritic cells
Originating in the dermis and moving through the epidermis, a phagocytic cell that engulfs foreign material, protects from pathogens, and mainly found in stratum spinosum
What are keratohyaline granules
Formed of protein keratin that get longer as they fill with keratin
What are lamellated granules
Granules that produce a glycolipid to be once secreted once merged with the plasma membrane
What layer of skin thickens to form a callus
Stratum corneum
What kind of CT is the papillary layer of the dermis
Loose areolar CT
What is the function of the dermal papilla (folds)
Increase surface area and create a stronger connection to the epidermis
What are the layers of the dermis
Papillary and reticular layer (dense irregular CT)
What is the hypodermis made up
Adipose CT
What are the classifications of burns
1st degree (damage to epidermis), 2nd degree (damage to dermis), 3rd/4th degree (damage to hypodermis or deeper)
What are the appendages of the skin
Formed from epidermal tissue: hair, sebaceous glands (oil), sudoriferous glands (sweat), and nails
What is the arrector pili
Smooth muscle that pulls hair up (how they’re able to stand up on end)
What is the root hair plexus
Free nerve ending that wraps around the follicle for sensory input (how you know one of your hairs has been moved)
What are the regions of the hair
Bulb (where new cells are added), root, and shaft (once free of follicle)
What are the 6 characteristics of hair
Made of dead keratinized cells added at the bulb, helping in thermoregulation, providing protection, can be vellus (fine body hair) or terminal (coarse hair like on the head or pubic area), active for months to years (hair in follicle falls out when dormant), not found on soles of feet or palms of hand
What are the layers in a cross section of hair
Medulla (loosely packed large cells/bubbles), cortex (many layers of flattened and pigmented cells), cuticle (one layer of highly keratinized cells), and the follicle wall
How do cross sections of hair affect their pattern
Round = straight, oval = wavy, and rectangular = curly/kinky
