7.1: Anatomy of the Integumentary System Flashcards
What is the integumentary system made of?
- hair
- nails
- skin
What is the largest organ of the body?
The skin is the largest organ of the body.
What are the three layers of the skin?
The three layers of the skin are the epidermis (outer layer), dermis (middle layer), and hypodermis (inner layer, also called subcutaneous tissue).
What role does skin play in vitamin D production?
Skin cells absorb ultraviolet radiation to produce vitamin D, which is used to promote bone development.
What are the functions of the integumentary system?
The integumentary system protects internal organs from extreme temperature changes and pathogenic microorganisms.
What types of sense organs are found in the skin?
The skin contains mechanoreceptors (Merkel’s cells and Meissner’s corpuscles), nociceptors, Pacinian corpuscles, and thermoreceptors.
What do mechanoreceptors detect?
- mechanical sensory information
- light touch
- vibration
What is the function of nociceptors?
Nociceptors detect pain, such as from a pin prick.
What do Pacinian corpuscles detect?
- mechanical sensory information
- pressure applied to the skin
What do thermoreceptors detect?
Thermoreceptors detect hot and cold.
What is the role of sensory organs in the skin?
- detect sensory information
- relay it to the brain for interpretation
What do endocrine glands secrete?
- hormones
- into the bloodstream
- body-wide distribution
How do exocrine glands release their secretions?
- through a duct
- into an epithelial surface
- onto the surface of the skin
What do sebaceous glands produce?
- sebum
- moisturizes the skin and hair
- inhibits the growth of harmful microorganisms
What is the function of sweat glands?
- produce sweat
- helps the body regulate its temperature through perspiration
What is the epidermis made of?
- stratified squamous epithelium
- avascular
- receiving nutrients from the basement membrane
What are the four distinct layers of the epidermis?
The four distinct layers of the epidermis, from superficial to deep, are stratum corneum, stratum granulosum, stratum spinosum, and stratum basale.
What are fingerprints formed from?
Fingerprints are formed from epidermal ridges, which are unique to each person and consistent throughout a person’s lifetime.
How long does it take for a cell to move from the stratum basale to the stratum corneum?
It takes about 30 days for a single cell to move from the stratum basale to the stratum corneum.
What types of cells are found in the epidermis?
Cells found in the epidermis include keratinocytes, Langerhans cells, fibroblast cells, melanocytes, and Merkel cells.
What do keratinocytes produce?
Keratinocytes produce a tough substance called keratin, which protects exposed surfaces of skin.
What is the role of Langerhans cells?
Langerhans cells are involved in the body’s immune responses and help identify microorganisms before they reach the bloodstream.
What do fibroblast cells produce?
Fibroblast cells produce collagen, which helps adhere the cells of the epidermis to each other and gives the skin elasticity.
What pigment do melanocytes produce?
Melanocytes produce a pigment called melanin.
What is the function of Merkel cells?
Merkel cells are a type of sensory receptor that respond to light touch.
What does the dermis contain?
- sweat glands
- oil glands
- sensory organs (Meissner corpuscles and Pacinian corpuscles)
What are the two regions of the dermis?
The two regions of the dermis are the superficial papillary region and the deeper reticular region.
What is the main blood supply for the skin?
The deeper reticular region of the dermis contains the main blood supply for the skin.
What happens to the skin of a dehydrated person?
A dehydrated person has decreased water content in the dermal layer of their skin.
What is a contusion?
A contusion is damage to blood vessels that creates a black and blue bruise due to blood leaking into the dermis.
What is the hypodermis primarily made of?
The hypodermis is primarily made of fat cells (adipocytes) that help insulate and regulate body temperature.
What is a subcutaneous injection?
A subcutaneous injection is when medication or vaccination reaches deep into the dermis, superficial to the muscle, and is absorbed more slowly than if given directly into a vein.
What is a dermatome?
A dermatome is a region of skin innervated by one sensory nerve.
How are sensory signals processed?
Sensory signals are sent from the skin to the spinal nerve, through the spinal cord, and to the brain for processing.
Which cranial nerve innervates the face?
The face is innervated by the trigeminal nerve (CN V).
What is hair made of?
Hair is made up of dead epidermal cells that are converted to keratin.
What are the two parts of hair?
- root (in the dermis layer)
- the shaft (extending through the epidermis to the external surface)
What is the function of sebaceous glands?
Sebaceous glands hydrate hair with oil.
What muscle connects each hair follicle?
- arrector pili muscle
- contracts when the body is cold or experiences emotional responses.
What changes occur in hair properties after puberty?
changes in properties after puberty due to circulating hormones:
- armpits
- groin
- head
What are nails composed of?
Nails are composed of dead epidermal cells converted to keratin.
What is the visible portion of a nail called?
nail body
What is the cuticle?
The cuticle is the stratum corneum of the epidermis that extends from the nail root covering the visible portion of the nail.
What is the lunula?
- visible portion of the nail bed
- near the nail root
- crescent-shaped
- thumbs
