Tissue Portfolio
Structures and Functions
Epithelial Tissue
Simple Squamous Epithelial Tissue
- Single layer of thin, flat cells
- Large surface area
- Tightly packed together
- One side of the surface opens to the lumen (apical surface); the other is attached to the underlying cells (basolateral surface)
- Larger, elliptically shaped nuclei
- Mediator of filtration and diffusion
- Allows small molecules to move across the membrane and through the cells
- Helps determine what is able to move from the lumen and into the bloodstream and vice versa
- Thin membrane allows for the passage of small molecules into the body (i.e. when air diffuses into the lungs)
- Tightly bound cells form a selective barrier that helps keep out molecules that don't belong
Simple Cuboidal Epithelial Tissue
- Single layer of cells that are equally wide as they are tall
- Appear hexagonal on the surface
- Tightly packed together
- More organelles (mitochondria, ribosomes, golgi bodies)
- Large, spherical, centrally located nuclei
- Sometimes have microvilli on the surface
- Act like a semipermeable membrane
- Perform active transport
- Provide a layer of protection from abrasion, foreign particles, invading bacteria, and excessive water loss to the underlying tissue
- Tall cells allow for selective permeability, which keeps out harmful substances and retains useful ones
- Cuboidal shape of the cells allows for tight packing, which enables fluids to pass through tubes lined by them
- Cell organelles allow the cells to produce and package large molecules or process substances absorbed by the cell
Muscle Tissue
Smooth Muscle Tissue
- Made up of fusiform (diamond-shaped) cells
- Fibers are small and tapered, with the ends reducing in size
- Centrally located, oval nuclei
- Cells are arranged in sheets
- Contracts hollow organs and keeps the eyes in focus
- Helps move fluids through the body and eliminate indigestible matter from the gastrointestinal system
- Since the relaxed muscle is long and not bundled up, it can easily contract.
Cardiac Muscle Tissue
- Made up of many branch-shaped, interlocking cells
- Nuclei are striated, or striped
- Protein filaments (dark bands made of myosin, light bands made of actin)
- To contract in order to pump blood through the body
- Myosin pulls the actin filaments together like an accordion to shrink the muscle cell and make it contract
- Branch shape connects each cell to three other cells; finger-like extensions of the cell membrane overlap neighboring cells so that they cannot separate under the strain of pumping blood
Connective Tissue
Compact Bone
- Dense
- Layered
- Contains few, tiny spaces
- Permeated by an elaborate system of interconnecting vascular canals
- Provides protection and support to everything around which it is the outer layer
- Helps enable long bones to bear the stress placed on them by the weight of the body and the use to which the limbs are put
- Layered cells make the bone strong so that it can protect and support everything it surrounds and help enable long bones to bear stress.
Hayline Cartilage
- Glassy appearance
- Covered externally by a fibrous membrane that contains vessels that provide the cartilage with nutrition
- Cells of a rounded form
- Reduces friction at joints
- Supports bronchial and tracheal tubes
- Acts as a shock absorper between vertebrae
- Maintains the shape and flexibility of fleshly appendages
- Fibrous membrane provides the cartilage with needed nutrition so that the tissue can function properly
- Strength and flexibility of the cartilage allow it to be constantly pulled and compressed by bone movement
Nervous Tissue
Motor Neuron
- Multipolar, each cell contains a single axon and multiple dentrites
- Dentrites branch out from the cell body
- Cell body (soma) contains cellular components and genetic information
- Axon (nerve fiber) is long and thin
- Project their axons outside of the central nervous system to directly or indirectly control the contraction or relaxation of muscles
- Dentrites can receive electrochemical signals from units of the nervous system because they branch out
- Cellular components and genetic information in the cell body keep the cell functional
- Axon is long and thin to allow it to quickly conduct electrical impulses and send signals where they are needed
Neutrophil
- Made up of white blood cells
- Many lysosomes
- Cytoplasm appears granular
- Lobed nucleus
- Ingest and destroy invading microrganisms
- Lysosomes contain enzymes that kill ingested cells
- Lobed nucleus allows for greater flexibility
- Plasmic membrane traps germs so that the granules can attack them
Works Cited
"Cardiac Muscle Tissue." InnerBody. N.p., n.d. Web. 14 Sept. 2016.
"Cell Specialisation and Organism Organisation." A Level Notes. N.p., n.d. Web. 14 Sept. 2016.
"Compact Bone." Encyclopedia Britannica Online. Encyclopedia Britannica, 1 May 2015. Web. 14 Sept. 2016.
Epithelial Cells. N.p., n.d. Web. 13 Sept. 2016.
"Introducing the Neuron." Boundless. N.p., n.d. Web. 14 Sept. 2016.
Liden, Daniel, and Bronwyn Harris. "What Is a Motor Neuron?" WiseGeek. Conjecture, n.d. Web. 14 Sept. 2016.
Mikesh, Leann, PH.D. "What Are the Functions of Simple Squamous Epithelial Cells?" Livestrong. N.p., 1 Nov. 2013. Web. 13 Sept. 2016.
"Simple Cuboidal Epithelium: Location, Structure, and Function." Buzzle. Buzzle.com, n.d. Web. 13 Sept. 2016.
"Structure and Functions of Bone Tissue." IvyRose Holistic. N.p., n.d. Web. 14 Sept. 2016.
"Structure, Type, and Location of Cartilage." Boundless. N.p., n.d. Web. 14 Sept. 2016.