Tissues are groups of cells that are in similar.........
Structure and function➡️ organs ➡️ organ system ➡️ organism
Cells are not all the same
Size, shape, and function very different
cells are organized into 3 main regions
nucleus, cytoplasm, plasma membrane
Nucleus
Control centerofthecell; contains genetic material(DNA)
Three regions in the nucleus
nuclear membrane, nucleolus, chromatin
nuclear membrane
barrier of the nucleus; Consists of selectively permeable, double phospholipids membrane;
Nucleoli
Nucleus contains one or more nucleoli;
Sites of ribosome assembly;
Ribosomes migrate into the cytoplasm through nuclear pores
Chromatin
Compound of unwound DNA and protein used for making proteins; Scattered throughout the nucleus; Chromatin condensestoformchromosomes when the cell divides
plasma membrane
Barrier for cell contents; Semi-permeable, Double phospholipids layer
cardiac muscle
found only intheheart; function is to pumpblood(involuntary); Cells attached to other cardiac muscle cells at intercalated disks; Cells are striated; One nucleus per cell
Hydrophilic head
water loving
hydrophobic head
water hating
Other materials in plasma membrane
protein, cholesterol, glycoproteins
Protein
receptors, cell recognition and communication, channels for transport
Regeneration
replacement of destroyed tissue by the same kind of cells
Cholesterol
keeps membrane fluid and stable
Glycoproteins
receptors, cell-to-cell interactions
Determination of method
1) The type of tissue damaged 2) The severity of the injury
plasma membrane specializations
microvilli, tight junctions, desmosomes, gap junctions
Microvilli
Finger-like projections that increase surface area for absorption
tight junctions
impermeable, leakproof sheets
Desmosomes
that prevent cells from being separated
gap junctions
Allow communication between cells through connexons that span the two cell membranes
Cytoplasm
Material outside the nucleus and inside the plasma membrane
What is cytoplasm?
cytosol, organelles, and inclusions
Cytosol
Fluid containing nutrients dissolved in water that suspends other elements
Cells of reproduction
ovum (egg) and sperm
Solution
A homogeneous mixture of two or more components
Solvent
dissolving medium
Solutes
Components in smaller quantities within a solution
intracellular fluid
nucleoplasm and cytosol
interstitial fluid
fluid on the exterior of the cell
membrane transport
movement of substances into and out of the cell
Transport is by two basic methods
passive transport and active transport
passive transport
no energy required
active transport
the cell must provide metabolic energy
selective permeability
Plasma membrane allows some materials to pass while excluding others; influences movement into and out of the cell
Diffusion
Particles tend to distribute themselves evenly within a solution; Movement is from high concentration, or down a concentration gradient; Movement is due to kinetic energy in the molecules and affected by size and temperature
types of diffusion
simple, osmosis, facilitated
simple diffusion
passive diffusion; Unassisted process; solutes are lipids- soluble materials or small enough to pass through membrane pores