Appendages and Vasculature
What layer of skin is hair located in?
Epidermal layer
What are the 5 layers of the epidermis? (list in order from most superficial to deep)
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
What cells are found in the stratum basale and are sensory neurons/part of the nervous system?
Merkel cells
What are two primary functions of skin?
(bonus points if you list all 5 I have listed)
thermoregulation, barrier immunity, homeostasis, sensory information, Vitamin D production
What is the structure of a sweat gland?
simple coiled tubular
What types of glands are found in the skin?
sebaceous and sweat glands
Which layer of the epidermis appears translucent and is often only found in thick skin?
Stratum lucidum
What cells produce skin pigmentation and protect the cells from UV radiation?
melanocytes
In what ways is skin a chemical barrier?
antimicrobial peptides and complement proteins
pH (acidic)
sweat and oil secretions
What does it mean to lose heat through radiation?
loss of electromagnetic energy to cooler objects
transfer of heat via electromagnetic waves
Where are lymphatic vessels found in skin?
dermal papillae
Which layer of epidermis looks spiky under a microscope and include immunocompetent Langerhans cells?
stratum spinosum
What process do cells go through as the push to the top layer of the skin and slough off?
keratinization
Stereocilia
What does it mean to lose heat through evaporation?
loss of heat through a phase change, like liquid ot gas (sweating)
Where is the deep plexus of the blood supply found?
between dermis and hypodermis
What is the difference between thin skin and thick skin?
(besides the extra layer that thick skin has)
Thin skin: contains sweat glands, lacks hair follicles, sebaceous glands and smooth muscle fibers.
Thick skin: thicker corneum layer, contains hair follicles, smooth muscle fibers, and sebaceous glands
When epithelial cells are stacked on top of each other, what kind of configuration is this?
stratified
What is the purpose of adherens junctions (zonula adherens)?
forms a "belt" to resist physical stress
What is the purpose of arteriovenous shunts?
the vasoconstriction of the shunt forces blood through capillaries to the surface, where heat is lost through radiation
Where is the superficial plexus of the blood supply found?
between papillary and reticular layers of the dermis
Which layer of the epidermis contains cells undergoing mitosis?
stratum basale
When epithelial cells are tall and skinny and appear to be stacked on top of one another, but are not actually, what is this called?
pseudostratified
What is the difference between the mechanisms of secretions of the sweat and sebaceous glands?
(name the mechanism of secretion and describe it)
(you should have one for each sweat and sebaceous gland)
Sweat - merocrine secretion: vesicles of product are secreted from the cell
Sebaceous - Holocrine secretion: parts of the cell bleb off and the cell dies to become the secretory product
Sympathetic cholinergic nerves release the neurotransmitter _________ which cause myoepithelial cells in eccrine sweat glands to ____________.
acetylcholine; contract