Chapter 3: Tissues and Skin Flashcards
what is a tissue
layers or groups of similar cells
what are the four main types of tissue
epithelial tissue, connective tissue, muscle tissue, and nervous tissue
what is a tight junction
a tight junction is like seams on clothing. no spaces, the cell membranes are fused
what is a desmosome
acts like a buttoned shirt, allowing small holes for solutes to pass. it is found on the epidermis
what is the purpose of a gap junction
allows for cytoplasmic exchange, allowing contents of one cell to go t another
what is the purpose of a hemidesmosome
it anchors the cell to something extracellular (protein fibers, etc)
where is epithelial tissue found
it is always found on the surface
which tissues are dependent on diffusion
epithelial tissues because they lack blood vessels
what are characteristics only epithelial tissues have
tightly packed single (simple) or multiple (stratified) layer(s) of cells, cells are squamous(like a laptop), cuboidal, or columnar. they cover organs, line body cavities, form protective barriers, attach to the basement membrane, reproduce rapidly, and lack blood vessels
which tissues may never touch?
connective tissue
what is a collagenous (collagen) fibers?
bundles of thick, flexible fibers. collagen is found in bundles and tears if there is too much resistance
what is elastic fibers
are stretchy fibers, but go back to normal after being stretched
what are characteristics of a muscle tissue
not all require neural input, capable of contraction (gets shorter not longer), many proteins filaments in the cytoplasm, muscle cells = muscle fibers
is a fiber and filament the same thing
no, a whole muscle is a fiber, and within the cell are filaments
what are the differences between the proteins in connective tissue and the proteins in muscle tissue?
in connective tissue the proteins are outside the cell membrane in the matrix, and in the muscle tissue the proteins are inside the cell
what is exteroception
the ability to feel things at the surface
why is vitamin d production important
vitamin D absorbs calcium
what are the general functions of the integumentary system?
- protection and immunity
- exteroception: ability to feel things at the surface
- regulation of body temp: changing of blood flow, sweating
- vitamin D production
- excretion (minimal) : loss of metabolic waste product
what are sweat glands
they are glands that have ducts
what does SIMPLE cuboidal epithelium tell us?
simple tells us that there is one layer of cells
what does STRATIFIED squamous epithelium tell us?
stratified tells us there is many layers of cells
what does a squamous cell look like
long and flat
where is adipose tissue found
layer right under the skin found on the palms and bottoms of feet
what’s an adipocyte?
individual cell name for adipose
what does the word dense mean in dense fibrous connective
tightly packed
what does irregular mean
no pattern
what shape is a smooth muscle
spindle shape with fat in the center
what are the proteins in smooth muscle bound by?
cell membranes
what are the two layers of the skin
dermis and epidermis
what is the subcutaneous layer
it is a layer beneath the skin, but not an actual layer of the skin
what are the layers of the epidermis defined by
life versus death of the skin cells
what is keratin
protein
what is the stratum basale
its the base, these cells undergo cell division
what happens in the stratum granulosum
cells are starting to suffer, therefore the cell organelle begin to shrivel
what is the purpose of the stratum lucidum
prevents blistering, they are found where callus’s are
what is the stratum corneum
dead cells, sacks of keratin are found here which makes our skin water proof
what does keratinocyte do
makes keratin
what attaches to the basement membrane
cells
what is a melanosome
a spherical structure; membrane on the outside, and melanin on the inside
how many layers does the dermis have
2; the papillary layer and the reticular layer. there is no line or barrier separating the two. the reticular layer contains irregular dense fibers
what are some features of the dermis
- dermal papillae: raised up mounds
- upper papillary layer
- lower reticular layer
- arrector pili muscle (smooth muscle)
- some skeletal muscle attachments
- blood vessels
- sensory receptors
- accessory organs (hair, glands)
what does hypodermis mean
the layer is beneath the skin
what is a sebaceous gland mean
only associated with hair follicles, and it secretes product by the same process as holocrine glands
