Ch 6 Powerpoint 1a Flashcards
What is the largest organ system in the body?
Integumentary system
Comprises skin and related structures such as hair, hooves, horns, claws, and skin-related glands.
What are the main functions of the integumentary system?
- Covers and protects
- Prevents desiccation
- Reduces threat of injury
- Assists in maintenance of normal body temperature
- Excretes water, salt, organic wastes
- Receives and conveys sensory information
- Synthesizes vitamin D
- Stores nutrients
What are the three layers of the integumentary system?
- Epidermis
- Dermis
- Hypodermis (subcutaneous layer)
Where is the thinnest skin located?
Around the eyes and scrotum
Where is the thickest skin found?
Center of the back, between the shoulder blades, and on paw pads
What are the four main types of cells in the epidermis?
- Keratinocytes
- Melanocytes
- Merkel cells
- Langerhans cells
What is the role of keratinocytes?
Produce keratin, a tough, fibrous, waterproof protein
What is the function of melanocytes?
Produce melanin pigment
What is the role of Merkel cells?
Mechanoreceptors essential for light touch sensation
What is the function of Langerhans cells?
Involved in allergic and cell-mediated immune response in skin
What is the stratum spinosum known for?
Contains several layers of cells held together by desmosomes
What characterizes the stratum germinativum?
Deepest layer consisting of a single row of keratinocytes attached to the basement membrane
What is found in the stratum granulosum?
Two to four layers of flattened keratinocytes containing lamellated granules of glycolipids
What is the significance of the stratum lucidum?
Found in very thick skin, composed of flattened dead cells
What is the stratum corneum?
Outermost layer, constituting up to ¾ of the epidermal thickness and composed of keratocyte remnants
How many epidermal layers are present in hairy skin?
Three layers: stratum corneum, stratum spinosum, stratum basale
What is the dermis primarily composed of?
Dense irregular connective tissue
What are the two layers of the dermis?
- Papillary layer
- Reticular layer
What is the papillary layer?
Thin, superficial layer composed of loose connective tissue
What does the reticular layer consist of?
Dense irregular connective tissue, making up 80% of the dermis
What is the hypodermis also known as?
Subcutaneous layer
What is the primary function of the hypodermis?
Allows skin to move freely over underlying structures
What is pigmentation in the integument related to?
Presence or absence of melanin granules in extensions of melanocytes
What are paw pads composed of?
Tough, thick layers of fat and connective tissue
What is the planum nasale?
Top of the nose in cats, pigs, sheep, and dogs
What are ergots and chestnuts?
Dark, horny structures on legs of the equine family, thought to be vestiges of digits
True or False: The stratum lucidum is present in most skin.
False
Fill in the blank: The _______ layer of the dermis consists of loose connective tissue.
Papillary
Fill in the blank: The epidermis primarily consists of _______ layers.
Five
