RT Book, Section
A1 Mirmirani, Paradi
A1 Ahdout, Jennifer
A2 Ali, Asra
SR Print(0)
ID 1176103894
T1 Hair Findings
T2 McGraw-Hill Education Specialty Board Review Dermatology: A Pictorial Review, 3e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 9780071793230
LK dermatology.mhmedical.com/content.aspx?aid=1176103894
RD 2024/04/24
AB Follicles  form  during  third  month  of  gestation;  form  first  on  headLining  of  follicle  =  ectodermal  originDermal  papilla  =  mesodermal  originEpidermal  invaginations  occur  at  an  angle  to  the  surface  and  over  sites  of  mesenchymal  cell  collectionsEventually  these  epidermal  cells  form  a  column  that  surrounds  the  mesenchymal  dermal  papilla  to  form  the  bulbThe  dermal  papilla  (along  with  “stem”  cells  in  the  bulge)  induces  hair  follicle  formation  by  the  overlying  epitheliumAdditionally,  2  or  3  other  collections  of  cells  form  along  the  follicle:Upper  collection  becomes  the  mantle  from  which  the  sebaceous  gland  will  developLower  swelling  becomes  the  attachment  for  the  arrector  pili  muscle  and  where  follicle  germinal  cells  reside  in  telogen  phaseIf  a  third  collection  of  cells  exists,  it  is  found  opposite  and  superior  to  the  sebaceous  gland  and  develops  into  the  apocrine  gland