chapter 4 Flashcards
integumentary system
skin, hair, nails, sweat glands, oil glands, mammary glands (environmental protection, thermoregulation, synthesis and storage of lipid reserves, excretion, synthesis of vit d3, sensory information, immune response against pathogens and cancers in the skin)
cutaneous membrane
epidermis and dermis
accessory structures
hair follicles, exocrine glands, nails
epidermis
protects from trauma, chemicals, controls permeability and prevents water loss, prevents entry of pathogens, synthesize vitamins, detect pressure, pain, temp
dermis
papillary layer and reticular layer
papillary layer
nourishes and supports the epidermis (consists of dermal papillae, capillaries, nerve axons)
reticular layer
restricts spread of pathogens penetrating epidermis, stores lipid reserves, attaches skin to deeper tissue, sensory receptors detect touch, pressure, pain, vibration, temp, blood vessels assist in thermoregulation (consists of interlocking connective tissue made of collagen, hair follicles, sweat glands and sebaceous glands)
hair follicles
produce hairs that protect skull, produce hair that provide delicate touch all over the body(bulbisinthefolliucle)
dermis
hypodermis/ subcutaneous layer is the deep layer of the dermis (hypodermic injections and subcutaneous needles)
subcutaneous layer
contains half of the body’s fat, not technically considered part of the ingeument just helps to stabalize it
thick skin
found on palms and soles, made of five layers
thin skin
found on the rest of the body, made of four layers (eyelids are the thinnest skin)
four cell types of the epidermis
keratinocytes, melanocytes, Merkel cells, langerhans cells
keratinocytes
produces a tough protein called keratin (water resistant and abrasion resistant)
melanocytes
pigment cells located deep on the epidermis, produce melanin (skin color
langerhans cells
fixed macrophages
merkel cells
sensory cells
layers of the epidermic (deep to superficial)
stratum basale -> stratum spinosum -> stratum granulosum -> stratum lucidum (lightest layer) -> stratum corneum (dead skin layer filled with keratin)
stratum basale
attached to basal membrane, contains epidermal stem cells, melanocytes and merkel cells, active reproduction
stratum spinosum
has langerhans cells and melanocytes, keratinocytes are bound by desmosomes (like velcro)
stratum corneum
multiple layers of dead interlocking keratinocytes, kinds dry, water resistant but not waterproof, slow water loss
stratum granulosum
keratinocytes produce lots of keratin
epidermal ridges
stratum germinativum forms epidermal ridges, the ridges (dermal papillae) extend into the dermis, creates ridges we call fingerprints
basal lamina
basement membrane
dermal papilla
increases surface area for blood vessels, no blood flow on epidermis
skin color
due to dermal blood supply, thickness of stratum corneum, various concentrations of carotene (yellow and orange) and melanin