Tissues Flashcards
What are the 4 types of tissue
Epithelia, connective, muscle, nervous
What is epithelia tissue
-tissue that covers surfaces, lines cavities and tubes, forms glands
-consists of loosely packed cells supported by a basement membrane
What are the characteristics of epithelia tissue
Attachment
Avascularity ( doesn’t have its own blood supply )
Polarity apical and basal
Define apical and basal
Apical means away from basement membrane
Basal towards the basement membrane
What does simple and stratified mean
Simple- one layer
Stratified- two or more layers
Define squamous cuboidal and columnar
Flat
Cube
Rectangle
Describe a simple squamous epithelia
-flat cells that have oval shaped nuclei
-one layer cells
-major function is exchange of nutrients and gasses
-location is blood vessels and alveoli
Describe keratinised simple
squamous
-flat surface cells with oval shape nuclei
-many layers
-keratin (tough and waterproof)
-major function-protection and barrier
-location is skin
describe non keratinised simple squamous
-flat surface cells with round nuclei
-many layers
-major function is protection and barrier
-oral cavity and oesophagus
-doesn’t need keratin as its not exposed to the outside world and doesn’t need as much protection
Describe a simple coboidal epithelium
- square cells with round nuclei
-one layer
-major function is secretion and absorption
-glands kidney and tubules
Describe a simple columnar epithelium
-tall cells with oval basalt located nuclei
-one layer
-absorption (nutrients) and secretion (mucus)
-gastrotestinal tract
-has microvilli to increased surface area
Describe pseudostratisfied ciliated columnar epithelium with goblet cells
-tall cells
-appears stratified as some cells dont reach free surface. All cells touch basement membrane
-cillis to move the mucus and goblet cells to act as chamber that produces mucus
-function is mucociliary escalator (cilis and mucus to move bacteria etc)
-trachea and larger respiratory airways
What are the 6 types of epithelia
-simple squamous
-keratinised stratified squamous
-non keratinised stratified squamous
-simple coboidal epithelium
-simple columnar epithelium
-pseduostratified ciliated columnar epithelium goblet cells
What is an intercellular junction
Specialised areas of cell membrane that bind one cell to another
What are the 4 kinds of intercellular junctions
Desmosomes
Hemidesmosomes
Tight junctions
Gap junctions
Describe Desmosomes
Very strong connections between adjacent cells
Resist stretching and twisting
Describe Hemidesmosomes
AttacH cells to the basement membrane
Stabilise the position and anchor cell to the underlying tissue
Describe tight junctions
-interlocking proteins tightly bind cells tougher than near apical edge
-prevent passage of water and solutes between cells (digestive cells)
Describe gap junctions
Cells helps together by an interlocking membrane proteins containing central pore
Allows movement of small molecules and ions between cells- found in cardiac muscle
What is connective tissue
-forms a structural framework for the body
-supports surrounds and interconnects other tissue types
-protects delicate organs
-transport fluids and dissolved materials
-stores energy reserves
-defends body from microorganisms
-consists or cells within an extra cellular matrix
What does an extra cellular matrix consist of
-ground substance
-tissue fluid
-fibres: collagen, reticular (network) and elastic classification of connective tissue
What are the 3 specialised connective tissues
Blood- mainly tissue fluid
Bone- osteoblasts and osteocytes
Cartilage- strong matrix and collagen
What is connective proper tissue
-loose irregular connective tissue
-lots of ground substance
-few fibres (collagen and elastic)
-variety of cells (fibroblasts, adipocytes, macrophages)
-found under the epithelium that covers and lines the body surfaces
What is dense irregular connective tissue
-little ground substance
-many collagen fibre bundles arranged haphazardly
-few cells (mainly fibroblasts)
-resists excessive stretching and distension due to the bundles being haphazardly
-found in dermis (lower levels of skin)
What is dense regular connective tissue
-little ground substance
-many densley packed bundles of collagen fibres arranged in parallel rows
-few cells (mainly fibroblasts)
-found in tendons (non contractile bit of muscle that attatches to bone and ligaments (stabilising function between two bones no muscle)
What is muscle tissue
Consists of muscle cells (fibres)
Capable of contracting and therefore can produce movement
What is skeletal muscle
-moves and stabilises the skeleton
-forms sphincters in digestive and urinary tracts
-involved in respiration (diaphragm and intercostal muscles)
-innervated (involuntary) by somatic nervous system
-long cylindrical cells, striped, may peripherally located and nucleated
What is cardiac muscle
- found in the heart wall and helps to circulate blood and maintain low blood pressure
-innervated (involuntary) by the automatic nervous system
-branched muscle fibres, 1-2 central nuclei, intercalated discs to join them
What is smooth muscle
-located in the walls of organs, blood vessels, and airways
-gastrointestinal movement
-alters diameter of airways and blood vessels
-innervated by automatic nervous system
-short fusiform cells
-non striated
-single centrally located nucleus
