Red blood cells (erythrocytes), whit blood cells (leukocytes), and platelets (thrombocytes)
The first two of these are cells '
Platelets are cell fragments
These components are collectively called Formed elementsA thick liquid connective tissue matrix (plasma) surrounds these formed elements.
What does plasma consist of ?
primarily salt water and protiens
What is Lymph
a filtrate of blood with most of the cells and some of the protein removed
White blood cells move around in the lymph to gaurd against invaders.
True or False: In order for cells to combine and form tissues the elements of each cells cytoskeleton must be linked to another cell or to the connective tissue supporting the cell.
True.
Cell Junctions
Need to link cytoskeleton to adjacent cells to each other
Or, need to link cyto skeleton to the extracellular matrix.
Tight Junctions
The Ziploc bags of the tissue world
Form a tight leak proof seal between two or more cells where substances cannot be allow to percolate between cells
Example: in the inestines where it is important to keep the outside out (in the intestinal lumaen) and keep the insides of the intestinal cells from getting stale and moldy.
What are the different types of Cell Juncitons?
Tight junctions
Adherens junctions
Desmosomes
Hemidesmosome
Gap junction
Adherens Junctions
These use a protein called cadherin
These work like a belt on your pants, keeps tissues from separating as they stretch and contract
Desmosomes
are used as "spot welds" to hold tissue together against mechanical disruption.
These junctions are cadherin between the cells, with intermediate filament proteins in each cell to form a continuous, strong, structure.
Hemidesmosome
Half of a desmosome
found between a cell and its basement membrane
On the cell side, intermediate filaments anchor the cytoskeleton to the integrins, which are in turn connected to the basement membrane.
Gap Junctions
The other junctions serve as mainly mechanical links
In contrast, the gap junction serves as an electrical and biochemical link between two cells.
A protein, connexin, forms pore-like structures called connexons (these allow small ions to pass from cell to cell)
Monomers and polymers can pass between cells as well.
If a cell becomes very sick, these connexons can seal off like a ships hatch, isolating the damaged cell so that it can die alone without making others sick.
What are Membranes?
Flat and flexible sheets which form a lining where parts of the body come together
They consist of and epithelium plus underlying areolar connective tissue.
form a lining between the body wall and internal organs.
examples: parietal layer next to body wall, visceral layer next to organs
Cutanous Membrane
or skin, covers the outside of the body away from cavities.
Muscle _______ is present wherever the body needs to generate _____. It ______ the body, ______ posture, and ________ heat.
tissue, force, moves, maintains, generates
Each kind of muscle tissue uses at least two cytockeletal proteins to generate force. These are :
Myosin and actinactin is the same protein that we saw as microfilaments in the cytoskeleton
What are the three main types of Muscle Tissue?
Skeletal muscle alsoe called voluntary muscle
Cardiac muscle
Smooth muscle
Skeletal Muscle/ voluntary muscle
it is under our voluntary controll (that is, we "choose" to use it to generate forces)
a type of striated muscle and it appears to be stripped or straited if we look at it under a microscope
Made up of muscle cells that have fused to form a long, thin tube or myofiber called a syncytium (joined cells), with mutiple nuclei visible on the out side of the muscle fiber.
Cardiac Muscle
also has a striated appearance like skeletal muscle
The fibers are joined in branches
found only in the heart
not under volentqry control
Smooth Muscle
not under voluntary control
Example: the gut tube is lined with smooth muscle tohat keeps digestion proceeding from the mouth to anus. also arteries
There are single cells each with one nucleus
the cytoskeleton is arranged ina random fashoion sto that it does not have a striated apperance
True or False: Nervous tissue manipulates information.
true.
One group of nerv cells (neurons) recieve...
sensory information from energy in the environment.
True or false: the vast majority of the estimated 100 billion nerons in the human nervous system are information procession neurons.
True.
Another neuronal group _________ information to muscle or glandular tissue that makes up the _______ ______ of the body (that is they _______ some sort of output, either the _______ of a muscle or the _______ of a gland.
Individual neurons carry out these three funcitons:
They recieve, process, and transmit informationthey are aided by glial cells, which carry out structural and nutritional support of the nourvous system.
Together, _______ and ______ tissue are call excitible tissue. This is because, by _________ the flow of eledtrical charge, they can produce _____ _________ and other uniqe electrical events inside the cell.
muscle, nerve, manipulating, action potentials
Nervous Tissue
Only tissue in the body that can manipurlate electrical charges to recieve, process and transmit information
-Muscle cells manipulate charges but conract and dont send information
-all other tissues have electrical charges but most can't conrol them
