BIOL 030 Lecture Notes - Lecture 12: Tyrosinase, Acne Vulgaris, Dermis
16 Sep 2020
School
Department
Course
Professor
Document Summary
Melanocytes in matrix produce pigment which is transferred to the keratinocytes. Eumelanin brown & black, develops from tyrosine. Gray hair melanocytes lack tyrosinase (which is responsible for producing melanin) White hair pigment lacking + air pockets that reflect light. Errector pili muscles smooth muscle which connects basement membrane of dermal papillae to dermal sheath. Sebaceous gland oil gland in acute angle of hair shaft near top. Hair does not grow continuously, it grows in cyclic stages. All hairs are in different phases of the cycle. Anagen phase (growth phase) due to proliferation of matrix. Different length of growth phase in different areas of body. Catagen phase (transitional phase) growth stops, but hair remains in follicle (short time) Telogen phase (resting phase) hair shaft falls out and bulb involutes. Secretory unit single alveolus (is this redundant??) Duct single duct opening into hair follicle. Mode holicrine (entire cell degenerates and is secreted) Clinical connection when infected by bacteria they cause acne.
