Sweat & Mechanoreceptors Flashcards
Where are the exocrine glands located for sweat?
The reticular dermis
What are the three types of exocrine glands found on skin?
Holocrine, apocrine, and merocrine
Describe the exocrine glands found on the face, chest, and back?
Holocrine glands function to lubricate skin and slow bacterial growth. They secrete sebum (an oily lipid substance) by disintegrating the entire cell
Describe apocrine glands.
Apocrine glands secrete proteins, lipids, and steroids via releasing the top portion of the cell (the apex) onto hair follicles. They are found in the armpits, groin, and around the nipples. They become active during puberty.
What integumentary exocrine glands aid in thermoregulation? What else do they help with?
Merocrine glands release watery/salty sweat via exocytosis, and are found all over the body (espeically hands, feed, and palms). They also function to release waste products and lysozymes +antibodies to fight bacteria and pathogens.
What are the five mechanoreceptors involved in the perception of touch?
Meissner’s corpuscles, hair follicle receptors, Pacinian’s corpuscles, Merkel’s disks, and Ruffini’s endings.
Describe hair follicle receptors: structure, function, and location
They are found in the reticular dermis, wrapped around the base of hair follicles. Their function is to detect changing light touch on hairy skin. When hair is initially deflected, the stretch opens sodium channels and allows the afferent nerve to fire. After, collagen fills in the gaps.
What mechanoreceptors detect changing light touch on glabrous (non-hairy) skin?
Meissner’s corpuscles, comprised of stacked disks located in the papillary dermis. When nudged, sodium leaks down towards the a-beta fiber.
Describe Pacinian’s Corpuscles
They are onion-shaped rings of lamellar disks, which rotate when pushed to allow sodium to leak down to the A-beta fiber. They percieve changing deep touch in all skin and are thus located in the hypodermis.
Describe Merkel’s disks.
Specialized keratinocytes that hold vesicles of serotonin. Continuous light touch causes the release of these vesicles, activating ion channels for the afferent nerve fiber. As they percieve light touch, they are located between the stratum basale and the papillary dermis.
What are Ruffini’s endings and what do they percieve?
A collagen coated cell with a branching afferent nerve fiber dendrites. When stretched, mechanically gated ion channels open, allowing them to detect sustained stretching. They are found between the reticular dermis and the hypodermis, especially around the fingers and hands as they aid in grip.
