Lecture 4 materials - Integumentary/skin Flashcards
What are the functions of the integument?
Protection, sensory information, storage of water and electrolytes, vitamin synthesis, thermoreglation, immunity, intraspecies communication
What is the largest organ system of all mammals?
The integument (this includes but not exclusively skin)
What does the skin consist of?
Epidermis and dermis
Name accessory structures of the integument
Skin glands, hair, pads, claws, mammary glands
Describe the skin
Made from epidermis (top) and dermis (deep)
Melanocytes produce pigment
SKin encloses the body and blends mucus membranes at orifices
Describe the epidermis
Ectodermal with stratified squamous epithelium
Avascular
Thick in non-hairy skin and thin in hairy skin
What are the 5 layers of thick skin
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
Describe the dermis (corium)
Comes from mesoderm, formed from dense connective tissue (collagen)
Papillary and reticular layer
Well vascularized and innervated
What part of the skin does leather come from?
Dermis
What is the difference between the papillar and reticular layer of the dermis?
Cells are more spread out in the papillary layer
Describe the hypodermis
Between skin and superficial fascia
Cutaneous muscles extend tendons in to the hypodermis for skin movement
The subcutis is thin where movement is undesirable
What is the subcutis made of
Collagen, elastic fibers, white fat
What does thickening of the subcutis lead to?
Skin folds
Are there glands on nasal skin of dogs?
No, moisture comes from serous secretions from lateral nasal glands
What is the nasal skin made of?
polygonal plaque areas form the planum nasale
What are the 2 basic skin glands?
Sebaceous, Sweat
Describe sebaceous glands
Produce sebum and drain directly in to hair follicles with apocrine sweat glands
Lubricates and waterproofs skin and coat
Describe Eccrine sweat gland
Eccrine (no hair): found in footpads of dogs, predominantly in primates, secrete water-y sweat by exocytosis
Describe Apocrine sweat gland
Apocrine (with hair): Empties in to hair follicles with sebaceous glands by pinching off part of the cell.
Odorous
Describe ceruminous glands
Produces ear wax (cerumen)
By apocrine and sebaceous (pinching off, oily sebum) secretion
Located in external auditory canal