tissues Flashcards
Epithelial tissue
sheets of cells that cover and line other tissues
each epithelial cell has an apical surface and a basal surface
lateral surfaces are connected to neighbouring cells by junctional complexes
Apical surface
surface faces the outside of the organ/structure
outer layer
Basal surface
faces the basal lamina and blood vessels
base layer
cellular junctions and what is the three major types
tight junctions - fusion of layers, no leaks
desmosomes - mechanical interlocking, repeated tension and stretching, skin, heart, uterus
gap junctions - tubular proteins connect to allow exchange, intestinal epithelial cells, heart and smooth muscle tissue
classification of epithelial tissue
number of layers of cells: simple or stratified
shape of the cells: squamous, cuboidal, and columnar
prescence of surface specializations: Cilia, keratin, etc
keratin
a protein made by cells
villi
in the s.intestines are made up of cells lined with microvilli
Cilia
help ‘transport’ materials
simple squamous epithelium
- fragile and thin
- found lining surfaces involved in the passage of either gas or liquid
- flat and smooth
simple cuboidal epithelium
- single layer of cube - shaped cells
- round, dark staining nuclei aligned in a single row
- occurs where secretion and absorption take place
simple columnar epithelium
- elongated and closely packed together
- found in many excretory ducts as well as in the digestive tract
stratified squamos epithelium
- multilayered
- occur in areas of the body subject to mechanical and chemical stresses
- protect underlying tissues
- found in skin, oral cavity, and oesophagus
stratified cuboidal epithelium
- usually two layers of cuboidal cells
- found primarily along large excretory ducts
- protects underlying tissues
stratified columnar epithelium
- found only in select parts of the respiratory, digestive, reproductive systems and along some excretory ducts
- function in secretion and protection
pseudostratified columnar epithelium
- cell nuclei are found at different levels across the length of the tissue
- found in respiratory tract and in portions of the male reproductive tract
transitional epithelium
- stratified epithelium with a basal layer of cuboidal or columnar cells and a superficial layer of cuboidal or squamous cells
found in areas of the body required to expand and contract
goblet cell
- unicellular exocrine gland
- ductless and composed of modified columnar epithelial cell
- secretes mucin (mucous)
connective tissue functions
- supports and connects tissues throughout the body.
- makes up a huge proportion of the tissue within the body
-acts as a reserve for energy
-plays a role in healing process and in the control of invading microorganisms
loose tissue
areolar - surrounds every organ, forms the layer that connects skin to muscle
adipose- acts as an energy storehouse and thermal insulator
dense tissue
fibrous/dense
cartilage
dense regular connective tissue
tightly packed, parallel collagen fibers
makes up tendons and ligaments
dense irregular connective tissue
- found in the dermis of the skin and in the fibrous coverings of many organs
forms the tough capsule of joints
fibers are interwoven to form a single sheet
what are connective tissues made up of
- ground substance
cells exchange nutrients and waste with the bloodstream
-cells
fixed cells - involved in production and maintenance of the matrix
transient cells - involved in the repair and protection of tissues
-protein fibres
Collagen - dense, strong, fibrous
Elastin - allows stretch and compliance
what is a tendon?
attach bone to muscle
what is a ligament?
attach bone to bone
dense elastic connective tissue
- composed of elastic fibers
- found in spaces between vertebrae and in areas of the body that require stretching (walls of arteries, stomach, bronchi, bladder
specialised connective tissues
Cartilage
-hyaline cartilage
- elastic cartilage
- fibrocartilage
bone
blood
Cartilage
found in joints and in the ear, nose and vocal cords
forms a framework on which bone is formed
cells - chondrocytes: cartilage cells
Matrix - collagen fibres are most commonly found in the matrix, but elastic fibers are also present in varying amounts
Cartilage
Hyaline - most common type. Found in - between joints and in embryonic skeleton
elastic - higher levels of elastin. Found in larynx and pinna
fibrocartilage - found in between vertebrae
Mucous membranes
- line organs with connections to the outside environment
- usually composed of either stratified squamous or simple columnar epithelium covering a layer of loose connective tissue
