01:377:213 Lecture Notes - Lecture 15: Dense Irregular Connective Tissue, Loose Connective Tissue, Elastic Fiber

100 views3 pages
13 May 2018
Department
Professor
I. The Dermis
A. Immediately deep to epidermis which consists of loose connective tissue above
the dense network of connective tissue fibers
B. Dermal Organization
1. The dermis consists of two major layers
a) Papillary layer
(1) Superficial dermis
b) Reticular layer
(1) Deep dermis
C. Dermal Organization
1. Papillary layer
a) Consists of loose connective tissue
b) Specialized to provide mechanical attachment for the more
superficial epidermis
c) Contains capillaries and axons of neurons
(1) Capillaries are branching blood vessels that supply
epidermis
(2) Axons of sensory neurons monitor epidermal receptors
2. Reticular layer
a) Consists of fibers in an interwoven meshwork of dense irregular
connective tissue that surrounds blood vessels, hair follicles,
nerves, sweat glands and sebaceous glands
(1) Sebaceous glands are microscopic exocrine glands that
secrete a oily or waxy matter called sebum
(a) Sebum: lubricates and waterproofs the skin and
hair
(b) Acne: overactive sebaceous glands
b) Arrangement of connective tissue fibers is responsible for the
strength, toughness and elasticity of the skin
c) Reticulum: little net
d) Extend into capillary layer, tying the two together
e) Also extend into the deep subcutaneous layer
(1) Strength, toughness , elasticity of skin
f) The interwoven collagen fibers of the reticular layer provide
considerable tension, and the extensive array of elastic fibers
enables the dermis to stretch and recoil repeatedly during normal
movements
(1) Age, hormones, UV reduce thickness and durability of
dermis producing wrinkles and saggy skin
(2) Tretinoin (retin A) is a derivative of vitamin A that can be
applied as cream or gel
(a) Stimulates blood to dermis and repairs
3. Extensive distortion of the dermis over the abdomen often exceeds the
elastic capabilities of the skin
a) Stretch marks: elastic and collagen fibers break, the skin does not
recoil to normal size
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in