Tissue I Flashcards
tissue
a groups of cells which act together to perform a specific function
histology
the study of tissues
tissue composition
cells and intercellular matrix
types of tissue
epithelium, connective tissue, muscle, nervous
epithelium tissue
- covers the surface of the body
- lines the interior of organs and body cavities
- major component of glands
connective tissue
- covers and protects most organs and other body structures (i.e. spinal cord, heart)
- binds structures to one another
- provides metabolic needs (blood)
muscle tissue
- facilitates movement of body skeleton
- involved in movement within organs
nervous tissue
- nerve cells (neurons) provide stimulus that controls body activities
- glial cells support and protect neurons
epithelial tissue general characteristics
- consists of cells held closely together by cellular adhesions resting on a basement membrane
- highly cellular
- has very little inter cellular material
- avascular; cells receive nutrients by diffusion from underlying tissue
what is the surface of the basement membrane called?
apical side
what does avascular mean?
not penetrated by blood vessels
what are epithelial tissue also called?
epithelium
what are two major types of epithelial cells?
membranous and glandular
membranous epithelium function
- protection: covers body surfaces
- lines body cavities
- sensory perception (receptors for pain, temperature, touch)
- absorption and secretion of nutrients
- filtration (i.e. kidney)
what is the structural classification of membranous epithelium based on?
- number of cell layers
- shape of cells
- special characteristics
what are the types of cell layers in the membranous epithelium?
- simple
- stratified
- pseudostratified
simple epithelium cell layer
one cell layer
stratified epithelium cell layer
many cell layers
pseudostratified epithelium cell layer
- considered a “single” layer of cells since each cell contacts the basement membrane
- -> it gives the appearance of multiple layers since cells are not all the same size and nuclear position varies
what are the different shapes of the epithelium?
- squamous
- cuboidal
- columnar
squamous epithelium shape
flat-cells
cuboidal epithelium shape
cube-shaped
columnar epithelium shape
rectangular shaped
what are the different special characteristics of the epithelium?
- cilia
- keratin
cilia epithelium special characteristic
respiratory tract
keratin epithelium special characteristic
hard protein material found in the epidermis, hair and nails that helps prevent water loss from the surface of the body; waterproof protein
what are the eight different types of epithelium?
simple squamous, simple cuboidal, simple columnar, stratified squamous, stratified cuboidal, stratified columnar, pseudostratified ciliated columnar, transitional
simple squamous appearance
- one thin layer of cells
- used for exchange: diffusion (since it’s thin, it’s easy to transport things)
simple squamous location
- blood vessel
- alveoli of lung
simple cuboidal appearance
-one layer of cube/square shaped cells
simple cuboidal location
glands
simple columnar appearance
- single layer of tall rectangular cells
- ideal for production of substances due to room for many organelles and exchange across cells and absorption I
simple columnar location
-located in digestive tract (esophagus; intestines)
stratified squamous appearance
- any layer of thin cells
- protective ( by having many layers of it)
- area of high friction
stratified squamous location
- beginning (mouth) & end (anus) of GI tract
- -> esophagus
- -> vagina
- -> skin
stratified cuboidal location
- glands
- i.e. sweat, salivary
stratified columnar appearance
- many layers of tall cells
- protective
stratified columnar location
larynx
pseudostratified ciliated columnar location
- respiratory epithelium
- -> nasal cavity
- -> trachea
- -> bronchi
transitional appearance
cells appear to change shape as they are stretched
transitional location
- bladder
- uterus
- ureters
- -> found in organs that need to dilate/expand (but not the stomach)
endocrine glands
- produces hormones
- secrete their products through the blood stream (thyroid)
- highly vacularized
goblet cells
unicellular glands
