1 - common integument Flashcards
What is the definition of the common integument?
The outer barrier of the organism, not just skin
What does the common integument include?
Subcutaneous tissue
Dermis and Epidermis (skin)
Modified skin structures
Give some examples of modified skin structures
Hair follciles Hair Skin glands, including mammary glands Foot pads Nails/claws/hooves Horns and Antlers
What is the general relevance of the common integument (why is it useful to look at)?
It reflects the underlying health of the animal and is affected often by underlying disease.
What is the subcutaneous tissue?
Loose connective tissue between the skin and muscle fascia.
What does the subcutaneous tissue contain and what is the purpose of these things?
White fat (adipose tissue) - for insulation, as an energy source and for padding and protection. Tiny tendons from underlying muscles for skin movement (skin twitching)
What is the relevance of regional variations in fat and thickness of subcutaneous tissue?
- Causes skin folds that are characteristic of some breeds
- Is important when considering subcutaneous injection sites
What is the skin composed of?
Dermis and epidermis
What is another name for the subcutaneous tissue?
Subcutis
What are other names for the skin?
Cutis and hypodermis
What determines thickness of the skin?
Why
dermis
Because theres regional variations in its thickness
What is the dermis made up of?
Fibrous connective tissue which includes collagen fibres and elastin fibres
What Type of collagen fibres are in the dermis?
Type 1, 3 and 5
Why must the collagen fibres in the dermis be considered?
They are oriented in ways in the dermis called langers lines/tension lines. Tension runs along these lines pulling wounds apart.
Important to consider in surgery planning/wound healing.
What happens to wounds perpendicular to langers lines?
They open
What happens to wounds parallel to langers lines?
They close
Aside from connective tissue what else does the dermis contain?
Blood vessels Lymphatic vessels Nerves Sensory receptors Hair follicles Arrector pili muscles Sebaceous and sweat glands
What do arrector pili muscles do?
Attach to base of hair follcile and flatten and raise the hairs.
Name the layers of the epidermis from bottom to top (give both names)
- Stratum basale/basal layer
- Stratum spinosum/spiny layer
- Stratum granulosum/granular layer
- Stratum lucidum/ clear layer
- Stratum corneum/ corneal layer
What are skin cells called?
Keratinocytes