Chapter 4 and 5: Tissues and the Integumentary System Flashcards
Tissues
Groups of cells similar in strucutre that perform common or related function
Histology is the study of
Tissues
What are the four primary types of tissue?
Epithelial tissue
- covers
Connective tissue
- supports
Muscle tissue
- produces movement
Nerve tissue
- controls
Is tissue fixed or flexible?
fixed
Main functions of epithelial tissue
- protection
- absorption
- filtrations
- secretion
- sensory reception
Five characterisitics of epithelial tissue
Polarity
Specialized contacts
Supported by connective tissues
Avascular, but innervated
Can regenerate
What is the primary function of epithelial tissue?
Form boundaries
Are cells polar or nonpolar?
Polar
What are the specialized contacts that bind adjacent cells?
- tight junctions
- desmosomes
Epithelial tissues are supported by __ tissue
connective
what is the Basement Membrane is comprised of and what are it’s functions?
- basal lamina + reticular lamina
- reinforces epithelial sheet
- resists stretching and tearing
- defines epithelial boundary
Epithelial tissue is ____ but innervated
avascular
How is epithelial tissue nourished? Why does this happen?
Must be nourished by diffusion from underlying connective tissues
Functions of Epithelial Tissue
- protection
- absorption
- filtrations
- secretion
- sensory reception
Label
In which layer are keratinocytes of the epidermis generated?
The stratum basale is the deepest layer of the epidermis. Mitosis of stem cells within this layer gives rise to the keratinocytes that comprise most of the cells of the superficial layers of the epidermis.
Which cell type found in the epidermis is associated with immune system defenses?
Dendritic cells ingest foreign substances and are key activators of our immune system
made up of strong, flexible connective tissue. Its cells are typical of those found in any connective tissue proper: fibroblasts, macrophages, and occasional mast cells and white blood cells.
The dermis
Two layers of the dermis
papillary and reticular
What type of tissue comprises the papillary layer
Areolar connective
What type of tissue comprises the reticular dermis?
coarse, dense irregular connective tissue
What are striae?
White scars caused by extreme stretching of the skin;stretch marks
The deeper region of the dermis is formed primarily of which tissue type?
The deeper region of the dermis is the reticular layer and is formed primarily of dense irregular connective tissue. The abundance of collagen fibers in this layer gives skin strength and resiliency.
Which of the following are not found within the dermis?
keratinocytes
fibroblasts
tactile corpuscles
blood vessels
Keratinocytes
Keratinocytes occupy the epidermis not the dermis.
Melanin
Dark pigment formed by cells called melanocytes; imparts color to skin and hair.
polymer made of an amino acid called tyrosine. Its two forms range in color from reddish yellow to brownish black
Freckles and pigmented nevi (moles) are local accumulations of ___
Melanin
Carotene
can be converted to vitamin A, a vitamin that is essential for normal vision, as well as for epidermal health
Yellow to orange pigment that accumulates in the stratum corneum epidermal layer and in fatty tissue of the subcutaneous tissue.
Hemoglobin
Oxygen-transporting protein of erythrocytes.
Cyanosis
hemoglobin is poorly oxygenated, the skin may take on a bluish-gray tint, especially in the mucous membranes and nail beds.
Cyanosis can be a sign of respiratory or cardiovascular problems.
Pallor/blanching
During emotional stress, blood may be diverted from the skin to internal organs, causing the person to look “as white as a sheet.
Low blood pressure and anemia (decreased ability of blood to carry oxygen) may also cause pallor.
erythema
Redness of the skin
may indicate embarrassment (blushing), fever, inflammation, or allergy.
Jaundice
Yellowness
Normally the liver eliminates bilirubin, a waste from red cell breakdown. This yellow pigment accumulates in body tissues when the liver doesn’t function properly.
discoloration most obvious in the sclerae, or whites, of the eyes. Eating large amounts of yellow vegetables, which contain carotene, may cause golden skin, but the sclerae remain white.
Brown or black “necklace,” or bruises
sometimes mistaken for a lack of cleanliness. These areas of velvety hyperpigmentation may be a sign of insulin resistance and elevated blood glucose.
Five characteristics of Epithelial tissue
•Polarity
•Specialized contacts
•Supported by connective tissues
•Avascular, but innervated
•Can regenerate
Label
Functions of the Basement membrane
–Basal lamina + reticular lamina
–Reinforces epithelial sheet
–Resists stretching and tearing
–Defines epithelial boundary
Label
Which pigment is localized within the dermis?
Hemoglobin
Hemoglobin is a red pigment found in blood cells circulating through the dermal capillaries that produces the pinkish hue of fair skin.
flexible strands produced by hair follicles and consist largely of dead, keratinized cells
hairs
Peripheral connective tissue sheath (fibrous sheath)
connective tissue sheath originating from the dermis and forming the outer layer of hair follicle wall
connective tissue sheath originating from the dermis and forming the outer layer of hair follicle wall
Peripheral connective tissue sheath (fibrous sheath)
Glassy membrane
at the junction of the fibrous sheath and epithelial root sheath
basically the basement membrane of the follicle epithelium
at the junction of the fibrous sheath and epithelial root sheath
Glassy membrane
Epithelial root sheath
derived from the epidermis and comprised of two parts: external root sheath and internal root sheath
tiny smooth muscles attached to hair follicles that cause the hair to go upright
arrector pili
vellus hair
body hair of children and adult women
terminal hair
course hair of scalp, eyebrows, and eyelashes
terminal hairs grow in response to the stimulating effects of ___
androgens
Which of the following is found outside the wall of the hair follicle?
arrector pili muscle
melanocytes
cortex
hair papilla
arrector pili muscle
a fibrous protein found in the epidermis, hair, and nails that makes those structures hard and water resistant.
keratin
sweat glands that are particularly abundant on the palms, soles of the feet, and forehead. Each is a simple, coiled, tubular gland.
Eccrine sweat glands (ek′rin; “secreting”), also called merocrine sweat glands
Sweating’s major role is to ___
prevent the body from overheating
Emotionally induced sweating—the so-called “cold sweat” brought on by fright or nervousness—begins ____ and then spreads to other body areas.
begins at the palms, soles, and axillae (armpits) and then spreads
- glands that lie deeper in the dermis or even in the subcutaneous tissue, and their ducts empty into hair follicles.
- The secretion is odorless, but when bacteria on the skin decompose its organic molecules, it takes on a musky and generally unpleasant odor, the basis of body odor.
- two important types
apocrine sweat glands
Two important types of modified apocrine glands
Ceruminous glands
- secretion found in the ear canal - mixes with sebum to make cerumen (earwax)
Mammary glands
- secrete milk
Ceruminous glands and Mammary glands are both important types of __ glands
apocrine
brached alveolar glands found all over except area of thick skin and secrete sebum
sebaceous glands
