30 - the integumentary system Flashcards
(18 cards)
what do the skin, nails, and hair of the integumentary system do?
The skin, nails, and hair of the integumentary system provide a barrier between the environment and tissues and organs within the body.
The skin is the largest organ in the body. It absorbs nutrients, regulates internal body temperature, and eliminates waste.
explain the layers of the skin?
The epidermis is the outermost layer of skin that provides a barrier between the body and the surrounding environment.
The dermis is the middle layer of skin. Sensory nerve receptors in the dermis respond to touch and pass signals to nerves of the peripheral nervous system.
Sweat glands reduce body temperature by releasing sweat.
Sebaceous glands produce an oily substance that lubricates skin and provides protection from bacteria. Blood and lymphatic vessels in the dermis supply the skin.
The hypodermis is the deepest, fatty layer of skin tissue. It is in contact with the muscles underneath it.
what are the integumentary structures?
The integumentary system consist of the skin, fingernails and toenails and hair
what is the function of the integumentary system?
Structures of the integumentary system provide protection from external conditions and contain receptors for tactile sensations.
what are the two layers of the skin?
The skin consists of two layers: a superficial epidermis made of epithelial tissue,
and a deeper dermis made of connective tissue. Beneath the skin is a layer of fatty tissue, the hypodermis.
what are the layers of the epidermis?
The epidermis is made up mostly of keratinocytes, calls that produce the fibrous protein keratin. These cells are arranged in layers: the stratum corneum, stratum granulosum, stratum spinosum, and stratum basale. In the palms of the hands and soles of the feet, there is an additional layer called the stratum lucidum, located between the stratum granulosum and stratum corneum.
what are the cells of the epidermis?
Cells of the epidermis include melanocytes, keratinocytes, Merkel cells and Langerhans cells. Cells of the dermis include fibroblasts which produce collagen.
what are the functions of the epidermal cells?
In addition to keratinocytes, the epidermis contains melanocytes, Langerhans calls and Merkel cells.
- Melanocytes produce melanin, a skin pigment.
- Langerhans cells assist in immune responses.
- Merkel cells act as receptors for touch sensations.
what does the dermis layer consist of?
The dermis consists of papillary and reticular regions and is composed of connective tissue. Touch receptors called Meissner corpuscles exist in the papillary region. The reticular region contains nerves, sebaceous (oil) glands, sudoriferous (sweat) glands, and hair follicles.
how is thick and thin skin different?
Skin can be classified as thin or thick, based on the composition and thickness of its epidermis and dermis. Thin skin covers most of the body, whereas thick skin covers the palms of the hands and soles of the feet.
thick skin has an extra layer.
what are sebaceous glands?
Sebaceous or oil glands produce sebum, or oil. This substance protects the skin and hair from drying and inhibits harmful bacterial growth.
what are sudoriferous glands?
Sudoriferous or sweat glands produce sweat, which allows the body to regulate its temperature by cooling the skin as it evaporates.
what is dermal circulation?
Blood vessels supply the skin with blood and help regulate body temperature.
what is vitamin D synthesis?
Ultraviolet radiation from sunlight causes skin cells to produce vitamin D, which the liver and kidneys modify to promote bone development.
what is integumentary innervation?
Sensory receptors in the skin pass signals to nerves of the peripheral nervous system.
what are dermatomes?
The dermatome is a region of skin that is innervated by the sensory fibres from a single spinal nerve. Sensory signals travel from the skin through the dorsal root of the spinal nerve, into the spinal cord, and up to the brain.
All the sacral, lumbar, thoracic and cervical spinal nerves innervate dermatomes except the first cervical spinal nerve (C1), which does not contain any sensory axons. Instead, the sensory information from the skin of the facial region is conveyed by cranial nerve V, the trigeminal nerve.
how does tissue repair happen?
Soft tissue organs in the body repair injury through a multi-step process that begins as platelets from torn vessels work to form a mesh-like clot that prevents blood loss. Inflammation in the area occurs as tissue repair begins in the damaged area. Mast cells release histamine that dilates blood vessels and increase blood flow to the repair site. White blood cells called neutrophils and macrophages work to consume bacteria and remove damaged tissue and debris. As bacteria and dead cells are removed, the proliferative phase of wound-healing begins.
Fibroblasts build new tissue by secreting collagen that takes the shape of the original tissue. During remodelling, the final phase of healing, the tissue creased by the fibroblasts matures and regains its normal function.
how is tissue repaired?
When tissue is damaged, mast cells release histamine, an inflammatory chemical that dilates blood vessels and increased blood flow to the area. Blood vessels supply the area with platelets, which form a fibrous clot, as well as neutrophils and macrophages, which consume bacteria and remove damaged tissue and debris.
As the inflammatory process continues, the clot hardens into a scab and fibroblasts secrete collagen to form granulation tissue that matured unto scar tissue. The repair process is complete once the epithelium has regenerate to its normal thickness, the blood vessels are restored, and the scab has detached.
