Three categories of hair
1. Primary or Guard hairs
2. Secondary or Wool Hairs
3. Tactile or Sinus Hairs
The three layers of skin
Two types of sweat glands and the difference between them
1. Eccrine Gland - Empties onto the surface
2. Apocrine Gland - Empties into a hair follicle
Where are sebaceous glands not found?
paw pads and planum nasale
Principal cells found in the Epidermis
Keratinocytes, Melanocytes, Merkel, and Langerhans cells
The 4 types of tissue
Epithelial tissue, connective tissue, muscle tissue, and nervous tissue
The part of the hair that is visible above the skin is called the ________, and the portion of the buried within the skin is called the _______.
Shaft & Root
Name the layers of the epidermis from deepest to superficial
Stratum Basale, Stratum Granulosum, Stratum Lucidum, Stratum Lucidum
What is pruritus
What are 6 functions of skin?
1.Protect, cover and line.
2.Filter biochemical substances.
4.Provide sensory input
Made of 4-5 layers
Only found in thick skin
Cells give up vital organelles and nuclei to make room for Which tough, protective substance.
At the epidermal-dermal junction which cells found in small numbers are always associated with a sensory nerve
What layer lies just beneath the epithelial layer of the epidermis and is composed of loose conective tissue with loosely woven fibers and ground substance.
Where can simple epithelium be found?
Protected areas: internal compartments, ducts, vessels, and passageways.
Where can stratified squamous epithelium be found?
Areas where cells must reproduce rapidly: vagina, mouth, anus.
What is the top of a dog's nose also known as?
What are the 3 types of cellular junctions found between epithelial cells?
3. Gap Junctions
Name 4 glands of the skin
What type of muscle is the arrector pili muscle?
What are tail glands thought to assist with?
Recognition and identification of other animals
What glands are found in the external ear canal of dogs?
Apocrine sweat glands
what are the 3 layers of hair
outer layer- cuticle
middle layer - cortex
intermost layer - medulla
what muscle makes the hair stand up
arrector pilli muscle
what kind of muscle is the arrector pilli
The skin is responsible for the production of which vitamin?
Which gland produces sebum?
What 2 layers is the dermis composed of ?
Papillary and Reticular
Why does hair turn grey or white as animals age?
Melanin production decreases. The cortex loses its pigment entirely and the medulla becomes filled with air.
The period of transition between the anagen and telogen phase is called?
The catagen phase
What causes pigmentation of skin?
The presence or absence of melanin granules in the armlike extensions in the melanocytes.
What waterproofs the skin and gives it strength?
Where are keratinocytes found?
Superficial layer of the epidermis
Composed of areolar tissue containing adipose, blood and lymphatic vessels, and nerves
What cells are produced in the bone marrow?
What cell is associated with sensory nerve endings?
Name the principle cells found in the Epidermis?
Keratinocytes, Melanocytes, Merkel cells, and Langerhans cells.
Where is the pacinian corpuscle located?
What protects the keratinocytes from UV radiation?