CHP6 The Intugumentary System

Phase stage 2 epi rs cells below the bulge undergo

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: muli; animals use for warmth & defense, we get Cold goose bumps goose Hair Growth & Loss Hair Hair growth is a 3-stage cycle= anagen, catagen, & telogen Hair stages stages • Anagen phase= stem cells in bulge multiple & travel down, stem pushing dermal papilla deeper into skin & forming ‘new’ epi root sheath sheath • Root sheath cells directly above dermal papilla form hair matrix Root hair where sheath cells change into hair cells that make keratin where • Cells die as they as pushed upward away from papilla • Catagen phase (stage 2)= epi r.s. cells below the bulge undergo apoptosis (programmed cell death) (programmed • Follicle shrinks, dermal papilla draws up towards bulge causing hair Follicle to lose its anchorage to • Telogen phase (stage 3)= resting stage (dermal papilla is now @ bulge); hair can fall out during either catagen or telogen phases phases • 50-100 hairs lost/day Hair Growth & Loss (cont.) Hair Hair growth slows once in your 40’s, i.e., more follicles in Hair catagen/telogen stages • Scalp follicles of young adults ~6-8 yrs (anagen), ~2-3 wks Scalp (catagen), ~1-3 months (telogen) (catagen), • 90% anagen @ a given time Alopecia= thinning & baldness, occurs in both sexes Pattern baldness= loss from only some...
View Full Document

Ask a homework question - tutors are online