Four Fundamental Types Of Tissue Part 2 Flashcards
Largest organ of the body
Skin
Skin is also called as
Integument or cutaneous
Two principal layers of the skin
Epidermis and dermis
Superficial protective layer composed of 4-5 layers depending on its location
Epidermis
What type of epithelium does epidermis is composed of
Stratified squamous epithelium
Layers of epidermis
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Compose of single layer of cells which has active mitotic activity
Stratum basale
Several layers of cells which has a spiny appearance due to change shape of keratino sites and with limited mitosis
Stratum spinosum
This layer plus the stratum basily are collectively called as stratum germinativum
Stratum spinosum
Stratton basale and stratum spinosum are collectively called as
Stratum germinativum
3:00 to 4 flattened rose of cells where cells here appear granular due to the presence of kerato hyalin granules
Stratton granulosum or granular layer
Nuclei organelles and cell membranes are no longer visible and contains a translucent substance called eleidin
Stratum lucidum or clear layer
25 to 30 layers of flattened scale like a nucleated cells continuously shed as flick-like residues of cells
Stratum corneum
Friction at the surface of skin stimulates mitotic activity of stratum basale resulting in the formation of
Callus
Types of cells in the stratum basale
Keratinocytes
Melanocytes
Tactile cells/Merkel Cells
Granular dendrocytes or langerhan cells
It produces keratin which toughens and waterproofs the skin
Keratinocytes
Synthesizes the pigment melanin and a protective barrier to UV radiation and sunlight
Melanocytes
Touch receptor
Tactile cells or merkel cells
Skin macrophages
Granular dendrocytes or langerhans cells
Skin color is a combination of three pigments
Melanin
Carotene
Hemoglobin
Brown black pigment produced by the melanocytes which guards skin against damaging effect of ultraviolet trace of the sunlight where the increase exposure to sunlight promotes to the production of this
Melanin
There is a normal number of melanocytes but locks enzyme thyrosinase that converts the amino acid thyrosine to melanin
Albino
Caused by aggregated patch of melanin
Freckles
Lack of melanocytes in localized areas of the skin causing distinct white spots
Vitiligo
A yellowish pigment found in epidermalb cells and fatty parts of the dermis which is abundant in the skin of Asians and is together with melanin for the account of yellowish tan color
Carotene
It is not a pigment but it is the oxygen binding pigment found in RBC which is an oxygenated blood flowing through the dermis which gives the skin its pinkish tones
Hemoglobin
In the forehead and face acquired from continual contraction of facial muscles such as for smiling or squinting in bright light or against the wind
Furrow
Lines of tension in the skin produced by the orientation of collagen and elastic fibers in non-random pattern of arrangement
Langer lines
Deeper and thicker than the dermis which is a strong and stretchy envelope that helps to hold the body together
Dermis
It contains numerous collagenous elastic and reticular fibers that gives support to the skin and is highly vascular and glandular that contains many nerve endings and hair follicles
Dermis
The layers of the dermis
Papillary layer
Reticular layer
In contact with the epidermis which contains capillary loops which furnish nutrients to the epidermis
Papillary layer
The projections are cold dermal papillae
Papillary layer
Touch receptors under the papillary layer
Meissner’s Corpuscles
Deepest skin layer contains blood vessels sweat and oil glands and deep pressure receptors
Reticular layer
Many phagocytes are found here that engulf bacteria and have managed to get through the epidermis
Reticular layer
These are all endocrine glands including sebaceous glands and sweat glands
Cutaneous glands
Found all over the skin except on palms and soles
Ducks usually empty into a hair follicle and experiences secretion called sebum
Sebaceous glands
Active secretion regulated by sex hormones
Sebaceous glands
Sweat glands is also called us
Sudoriferous glands
Widely distributed in the skin numerous in palms soul auxiliary and pubic regions which secretion evaporates and cools the body
Sweat glands
Two types of sweat glands
Merocrine and apocrine
It is a sweat gland that is more numerous and found all over the body especially in forehead back palms and soles it’s secretion reaches skin surface by via adopt that opens directly on surface of skin through sweat pores
Secretion is mostly water with few salts
Merocrine sweat gland
Much larger localized gland found in auxiliary and pubic regions where they secrete into hair follicles not functional until puberty and secretion is thick and rich in organic substances which is other less when released but quickly broken down by bacteria into substances responsible for body odor
Apocrine sweat glands
Found within the breasts specialized through the referrals or sweat gland that secretes milk during lactation
Under the stimulus of pituitary gland
Mammary gland
It is for protection an example given is sculpt here eyebrows are protection from the sunlight
Hair
Parts of the hair
Shaft
Root
Hair bulb matrix
The visible but then portion of hair projecting above surface of the skin
Shaft
It is a part of the hair that is enclosed in the follicle
Root
It is the growth zone of the hair which contains melanocytes that give color to the hair
Hair bulb matrix
3 layers of hair in cross-section
Medulla
Cortex
Cuticle
Converse cortex and forms toughen outer portion
Thick median part of the hair
Inner part of the hair
Cuticle
Cortex
Medulla
Three distinct kinds of hair in humans
Lanugo
Angora
Definitive
Find silky fetal hair that appears during the last trimester of development
Lanugo
Gross continuously in length as on scalp and on face of males
Angora
Gross to a certain length and then ceases to grow most dominant type of hair
Definitive
Found on the distal dorsum of each fingers and toes
Nails
Forms from a hardened transparent stratum corneum of epidermis
Nails
Part of the nails
Visible attach portion
Part of the nail covered by skin
Where nail root and nail body are attached
The distal exposed border attached to undersurface of hyponychium
Beneath the free edge
Covers the nail root frequently splits causing a hangnail
Nail Body
Nail root
Nail bed
Free edge
Hyponychium
Eponychium
Proximal part of the nail bed where the growth of the area of nail
Nail matrix
Whitefish crescent shape area the proximal aspect of nail
Lunula
Nails are___and nearly___but they look pink because of the rich blood supply in the underlying dermis
Transparent
Colorless
