Cells Flashcards
Cell- Cell Interaction
Communicate through pores called gap junctions; gaps allow for movement of particles through the cells
Hierarchical Organization of Multicellular Organisms
Functions of Molecules (DNA, RNA, proteins, etc.) -> Cells -> Tissues -> Organs -> Organ Systems
Gap Junction
Made up of 6 proteins; form a channel (connexon) directly connects cytoplasms of 2 cells resulting in the movement of small molecules and electrical communication between the cells
Adherens Junctions
Very strong cell to cell interactions, belts along the cells to connect cells in the epithelial tissue. Comprised of protein complexes that includes transmembrane cadherin protein and the intracellular catenin proteins Connects to the intracellular cytoskeleton
Desmosomes
Spots of adhesion on a cell; much weaker type of binding
Defects: have a defect in water movement in skin cells: blistering disease- too much water going in
Tight Junctions
Sealing; forms a barrier between cells in epithelial tissue that prevents leakage between cells and maintains cell polarity (prevents diffusion of membrane proteins from one side of the cell to the other side)
Apical Surface
Exposed to environment- such as lumen of mammary gland or intestines `
Basal Surface
Attached to basement membrane and can be associated with blood vessels
Basement Membrane
Comprised of various protein fibers (including collagen); plays a role in tissue architecture, filtering waste, and providing routes of migration for cells during development
Epithelial Cells
Cells that grow on a basement membrane; sheets of tightly packed cells that covers the outside of your body and lines the organs and cavities within the body; protect from stress, create barrier, secretion and absorption; forms mucous membrane of digestive and respiratory tracts
Cell Layers
Simple epithelium: single layer of cells
Stratified epithelium: multiple layer of cells
Pseudo stratified epithelium: single layer of cells but looks stratified because of varying length of cells
Shapes of Cells
Cuboidal: cube-like
Columnar: column or brick-like
Squamous: flat or similar to floor tiles
Simple Squamous Epithelia
Thin and leaky, molecule exchange such as blood vessels
Stratified Squamous Epithelia
Many layers that regenerate at basement membrane and sloughed off at free end- skin
Columnar Epithelia
Large cytoplasmic volumes, secretion and or absorption
Simple Columnar Epithelia: intestines
Pseudo- stratified columnar epithelia: nasal passages
Stratified columnar epithelia: line inner surface of urinary bladder
Capillaries
Made up of simple squamous to allow molecules to go back and forth
Skin Cells
Stratified squamous has little bit of leakiness
Cuboidal Epithelia
Specialized from secretion; mammary gland, kidney, and hormone producing glands
Connective Tissue
Binds and supports other tissues, many types of connective tissue cells
Osteoblasts: Extracellular Membrane (ECM) will be bone
Chondracytes: ECM will be cartilage
Adipecytes: ECM lipid droplets
Blood Cells: ECM plasma
Loose Connective Tissue
Binds epithelia to underlying tissues, packing material to hold organs in place, loose weave of fibers, cells scattered in fibrous mess
Fibroblasts
Collagen Fibers most abundant protein
Elastic fibers
Fibrous
Ligaments: bone to bone
Tendons: muscle to bone
Neurons
Nerve cell containing a cell body, dendrite and axon
take a signal from one side of the cell to the other side of the cell
signal gets sent through the cell to the axon and when it gets to the synapse bind to receptors on receptor cells to continue the signal
Dendrites
Processes extending from the cell body that receive stimuli from the environment or other neurons
Axon
Long single process extending from the cell body for the transmission of nerve impulse to other cells via an action potential
Synapse
Neurotransmitters released at site of contact with an effector cell; releases neurotransmitters to the postsynaptic neuron
Glial Cells
Provide nutrients and isolation
Ion Pumps
Sodium channels clos and potassium channels open up and potassium goes out
Resting state: potassium goes out and sodium goes in
Muscle Tissue
Composed of long cells that can contract when stimulated by nerve impulses
produce mechanical force by their contraction
Composed of actin and myosin arranged in parallel within the cytoplasm
Muscle Types
Skeletal: voluntary movement of body (striated muscle which is due to overlapping filaments)
Cardiac: forms contractile wall of the heart, striated, branched cells, ends of cells are joined by intercalated discs that relay signal during a heartbeat
Smooth: lacks striations, spindle- shaped, involuntary body activities locations include walls of digestive tract, bladder, arteries and other organs
Organization of Different Tissue Types
Lumen of Stomach
Mucosa (columnar epithelial cells that line the lumen) Secrete mucus and digestive juices
Submucosa (connective tissue that contains blood vessels and nerves)
Muscularis (smooth muscle)
Serosa (connective and epithelial tissue)
Exterior of Stomach Wall
