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140 Cards in this Set
- Front
- Back
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What is a plasma membrane?
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serves as a barrier between the cell’s contents and it’s environment
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What is a Cytoplasm?
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contains the organelles & performs the cell functions
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What is a nucleus?
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control center.
Possess chromosomes – structural arrangement of DNA |
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All cell possess what?
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ribosomes – molecular complex responsible for protein production
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What is the function of the lipid bilayer?
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It’s hydrophobic interior serves as a barrier to water-soluble substances
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What is the purpose of cholesterol in the plasma membrane?
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Cholesterol decreases the orderliness of the lipid bilayer increasing the mobility of the phospholipids
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What is the purpose of glycolipids in the plasma membrane?
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Glycolipids are always oriented towards the exterior of the cell and presumably aid the cell in interacting with its environment
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Where are integral proteins found?
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Integral proteins are found inserted in the lipid bilayer
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Where are peripheral proteins found?
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Peripheral proteins are loosely attached to integral proteins or membrane lipids
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What is the function of Glycocalyx?
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sugar chains attached to the outside surface of cells. Serve as highly specific biological markers that help cells identify other cells
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What are microvilli and where are they found?
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Minute, fingerlike projections of the plasma membrane
Found on the exposed side of a cell |
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What are tight junctions?
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Link adjacent epithelial cells
Mutual binding of specific proteins in the plasma membrane Prevent substances from moving between cells |
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What are desmosomes?
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Desmosomes are like “spot welds” holding adjacent cells firmly together
Provides mechanical stability between the cells |
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What are gap junctions?
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Allow cells to communicate with one another
Allow the movement of small molecules and ions to pass between cells |
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The plasma membrane is what type of permeability?
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permeable to some particles
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What properties influence permeability?
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1. Relative solubility of the particle in lipid
2. Size of the particle 3. Force - something needs to drive the particle across the membrane |
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What is diffusion?
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tendency of molecules or ions to spread evenly throughout the environment
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What is simple diffusion?
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movement of nonpolar and lipid-soluble substances across the lipid bilayer
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What is facilitated diffusion?
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movement of polar and water-soluble substances through the lipid bilayer (down their concentration gradients) using a transport protein
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What is osmosis?
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movement of a solvent (water) through a selectively permeable membrane
Water will diffuse from the region of higher water concentration (lower solute concentration) to the region of lower water concentration (higher solute concentration). |
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What is filtration?
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movement of water and solutes through a membrane by hydrostatic pressure (e.g. from a high to a low pressure area)
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Isotonic
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same concentration of non-penetrating solutes as a normal cell
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Hypotonic
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below normal concentrations (causes cell to absorb water and swell
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Hypertonic
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above normal concentrations (causes cell to lose water and shrink)
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What is active transport?
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movement of molecules or ions using a carrier molecule against the concentration gradient
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What is primary active transport?
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transport protein requires energy via the hydrolysis of ATP to move solutes against their concentration gradient
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What is Vesicular transport?
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movement of large particles across the plasma membrane utilizing membranous sacs (vesicles)
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What is Exocytosis?
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secretion of large particles from within the cell to the ECF
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What is Endocytosis?
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absorption of substances from the ECF by enfolding of the plasma membrane
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What is the function of clathirin coated vesicles?
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serve to demarcate and help deform the membrane to produce a vesicle
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What is the function of Cell Adhesion Molecules?
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Responsible for anchoring cells (adhesion)
Cell Mobility (migration) Cell signaling (attractant) Mechanical sensors to respond to local tension Transmit intracellular signals (contact signaling) |
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What is the cytoplasma?
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Cellular material encased by the plasma membrane and found outside the nucleus
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What is the cytosol?
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viscous fluid within the cytoplasm where all the cytoplasmic elements are suspended (H2O, salts, sugars, proteins & other solutes)
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What is the organelles?
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Metabolic machinery of the cell
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What is the inclusions?
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Other chemical substances that are present depending on cell type (glycogen, lipid droplets, pigment vacuoles, crystals)
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What is the endomembrane system?
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Includes the endoplasmic reticulum and the Golgi apparatus and associated vesicles.
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What is the mitochondria and what is its function?
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Powerplant of the cell, providing most of the ATP
Possess their own DNA & RNA and can reproduce themselves |
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What is the rough endoplasmic reticulum (RER) and what is its function?
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ribosomes are attached
Produces membanes for the cell. |
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What is the smooth endoplasmic reticulum (SER) and its function?
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more tubular, no ribosomes
Synthesis of lipids and steroids Storage of Ca2+ ions (muscles) |
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What are ribosomes and what is its function?
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Chemically consist of rRNA and proteins
Site of protein synthesis |
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What is the Golgi Apparatus and what is its function?
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Traffic director for cellular proteins
Primary function is to modify, concentrate, and package proteins and lipids made in the ER Receiving side called cis face |
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What are Lysosomes and what is its function?
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Originate from the Golgi apparatus.
Spherical organelles containing digestive enzymes Able to retain hydrolases while allowing the digested substances to be removed and used by the cell |
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What is the peroxisomes and what is its function?
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Small membranous sacs containing oxidases and catalases
Responsible for neutralizing free radicals |
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What is the Cytoskeleton and is its function?
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“cell skeleton” and “cell muscles”
Made up of long molecular chains that interact to provide cell support and movement |
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What is the microtubules and is its function?
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Form rigid internal skeleton in some cells, e.g. compression resistance
Act as tracks along which motor proteins move |
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What are centrisomes and what is the function?
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Centrisomes are the site from which microtubules originate
Serves as a compression resistance girder of the cytoskeleton |
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What are the centrioles and what is the function?
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Composed of nine set of microtubule triplets
Involved in formation of the mitotic spindle. |
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What is the cilla and how does it move?
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short, usually many present, move with stiff power stroke and flexible recovery stroke
Moves: use a beating stroke that creates a force perpendicular to the cilial axis |
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What is the flagella and how does it move?
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longer, usually one or two present, movement is snake-like
Moves: use an undulating motion that provides force along the axis of the flagella |
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What are microfilaments and what is the function?
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Solid rod, consisting of a twisted double chain of actin
Help a cell or parts of a cell to move Determine cell shape |
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What is the intermediate filament and what is the function?
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Made of fibrous proteins of the keratin family
Stabilize cell structure and resist tension |
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What is chromatin?
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DNA + proteins
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What is the longest cell cycle: Interphase (G1, S, and G2) or Mitotic phase (prophase, metaphase, anaphase, telophase, and cytokinesis)
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Interphase
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What is mitosis?
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division of the nucleus.
Consists of four phases which define what is occuring to the DNA during that period of time: prophase, metaphase, anaphase, telophase |
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What is cytokinesis?
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division of the cytoplasm.
Begins during late anaphase and continues until after mitosis is complete |
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What are exons?
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coding sequencesW
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What are introns?
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non-coding sequences
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Transfer RNA (tRNA)
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attach to amino acids and are used to add a specific aa to an elongating peptide
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Ribosomal RNA (rRNA)
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part of the ribosome; helps to recognize the codons in an RNA message
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Messenger RNA (mRNA)
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gene transcript from which the protein will be made. mRNA has been processed to exclude the non-coding introns
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Apoptosis
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Programmed cell death (cell suicide)
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Atrophy
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Decrease in the size of an organ or tissue from lack of normal stimulation
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Hypertrophy
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Increase in the size of an organ or tissue from overstimulation
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Hyperplasia
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Localized, accelerated rate of growth
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What are glands?
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One or more cells that make and secrete (export) a particular product (secretion)
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Endocrine
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internally secreting
Ductless glands Produce hormones |
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Exocrine
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externally secreting
Secrete their products onto body surfaces or into body cavities |
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Unicellular exocrine glands
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Secrete their products by exocytosis
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Multicellular exocrine glands
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Two basic units
-Ducts (epithelial derived) -Acinus (Secretory cells) Divided into lobes by connective tissue & surrounded by blood vessels & nerve fibers |
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Four primary function of connective tissue
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Binding & support
Protection Insulation Transportation |
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Cells: Immature form ( -blast)
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actively mitotic & are responsible for producing ground substances & fibers of the tissue
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Cells: Mature form ( -cyte)
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responsible for maintaining the health of the matrix
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Connective tissue proper
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fibroblasts
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Cartilage
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chondroblasts
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Bone tissue
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osteoblasts
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Blood
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hematopoetic stem cells
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cartilage: Hyaline
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most abundant
Provides firm support with some pliability Covers the ends of the long bones, tip of the nose, connects the ribs and sternum, supports the respiratory system |
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cartilage: Elastic
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Nearly identical to hyaline cartilage
More elastin Found where strength & stretchability is needed: external ears, epiglottis |
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cartilage: Fibrocartilage
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Chondrocytes alternate with rows of thick collagen fibers
Compressible, resists tension well Found where strong support & heavy pressure are required |
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Neurons
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highly specialized nerve cells that can conduct
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Glial cells
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responsible for supporting, insulating, protecting the neurons
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Muscle tissue
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Highly cellular, well vascularized
Responsible for most types of body movement Possess myofilaments (actin & myosin) that are responsible for cell contraction |
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Skeleton Muscle
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Form the flesh of the body
Attached to bone & skin When contract cause body movement Muscle fibers – long cylindrical cells, multinucleated Striated – demonstrating the alignment of microfilament Voluntary contractions |
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Cardiac muscle
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Found only in the wall of the heart
Striated Uninucleate Branching cells connected at intercalated discs Involuntary movement |
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Smooth muscle
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No visible striation
Uninucleated Found on the walls of hollow organs – squeezing substances through the organs Involuntary movement |
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Cutaneous membrane
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Skin
Dry membrane Keratinized stratified squamous epithelium (epidermis) Dense irregular connective tissue (dermis) |
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Mucous membrane
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Line body cavities that open to the exterior
Wet membrane Consist of either stratified squamous simple or columnar epithelium Loose connective tissue (lamina propria) Sometimes has an underlying layer of smooth muscle Absorption & secretion |
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Serous membrane
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Simple squamous epithelium (mesothelium)
Loose connective tissue (areolar) Produces a clear serous fluid that acts as a surfactant |
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Tissue repair
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Requires cell division & migration
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Fibrosis
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proliferation of fibrous connective tissue
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Epidermis
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A keratinized stratified squamous epithelium consisting of four distinct cell types and four or five distinct layers.
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Keratinocytes
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produce keratin
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keratin
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the fibrous protein that helps give the epidermis its protective properties
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Melanocytes
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the spider-shaped epithelial cells that synthesize that pigement melanin
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Epidermal dendritic cells
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arise from bone marrow and migrate to the epidermis
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Langerhans cells aka Epidermal dendritic cells
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ingest foreign substances and are key activators of our immune system
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tactile (merkel) cells
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present at the epidermaldermal junction. functions as a sensory receptor for touch.
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stratum basale aka stratum germinativum
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the deepest epidermal layer, is attached to the underlying dermis along a wavy borderline that reminds one of corrugated cardboard.
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stratum spinosum
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several cell layers thick. these cells contain a weblike system of intermediate filaments, mainly tension-resisting bundles of pre-keratin filaments, which span their cytosol to attach to desmosomes.
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stratum granulosum
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consist of three to five cell layers in which keratinocyte apperance changes drastically, and the process of keratinization begins
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keratinization
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in which the cells fill with the protein keratin
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stratum lucidum
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consists of two or three rows of clear, flat, dead keratinocytes with indistinct boundaries
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stratum corneum
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a board zone 20 to 30 cell layers thick that accounts for up to three-quarters of the epidermal thickness
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dermis
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major skin region. strong, flexible connective tissue. its cells are typical of those found in any connective tissue proper: fibroblasts, macrophages, and occasional mast cells and white blood cells.
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papillary layer
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a thin superficial, areolar connective tissue in which fine interlacing collagen and elastic fibers form a loosely woven mat that is heavily invested with small blood vessels
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dermal papillae
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superior surface is thrown into peglike projections... that indent the overlying epidermis.
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friction ridges
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increase friction and enhance the gripping ability of the fingers and feet
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reticular layer
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accounting for about 80% of the thickness of the dermis, is coarse, irregularly arranged, dense fibrous connective tissue
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flexure lines
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dermal folds that occur at or near joints, where the dermis is tihgtly secured to deeper structures
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melanin
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a polymer made of tyrosine amino acids. Its two forms range in color from yellow to tan to reddish-brown to black.
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carotene
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yellow to orange pigment found in certain plant products such as carrots. It tends to accumulate in the stratum corneum and in fatty tissue of the hypodermis.
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skin appendages
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includes nails, sweat glands, sebaceous (oil) glands, and hair follicles and hair
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sweat glands aka sudoriferous glands
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distibuted over the entire skin surface except the nipples and parts of the external genitalia.
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eccrine sweat glands aka merocrine sweat glands
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are far more numerous and are particularly abundant on the palms, soles of the feet, and forehead.
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apocrine sweat glands
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approximately 2000 of them, are largely confined to the axillary and anogential areas.
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ceruminous glands
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modified apocrine glands found in the lining of the external ear canal
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mammary glands
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another variety of specialized sweat glands, secrete milk
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sebaceous glands or oil glands
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simple branched alveolar glands that are found all over the body except in the thick skin of the palms and soles.
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sebum
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glands secrete an oily substance
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hair aka pili
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flexible strands produced by hair follicles and consist largely of dead, keratinized cells.`
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cuticle
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formed from a single layer of cells that overlap one another from below like shingles on a roof.
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hair follicles
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fold down from the epidermal surface into the dermis
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nail
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scalelike modification of the epidermis that forms a clear protective covering on the dorsal surface of the distal part of a finger or toe
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nail matrix
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thickened proximal portion of the nail bed, and responsible for nail growth.
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Negative feedback
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causes the variable to change in a direction opposite that of the initial change.
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Positive feedback
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causes the variable to be enhanced in the direction of the initial change.
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superior
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toward the head end or upper part of a structure or the body; above
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inferior
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away from the head end or toward the lower part of a structure or the bodyl below
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ventral (anterior)
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toward or at the front of the body; in front of
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dorsal (posterior)
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the heart is posterior to the breastbone
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medial
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toward or at the midline of the body; on the inner side of
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lateral
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away from the midline of the body; on the outer side of
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intermediate
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between a more medial and a more lateral structure
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proximal
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closer to the origin of the body part or the point of attachment of a limb to the body trunk
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distal
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farther from the origin of a body part or the point of attachment of a limb to the body trunk
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superficial (external)
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toward or at the body surface
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deep (internal)
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away from the body surface; more internal
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A + B -> AB (anabolic)
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Synthesis – creation of more complex molecules
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AB -> A + B (catabolic)
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Decomposition – molecules are broken down to less complex components
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AB + CD -> AC + BD
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Exchange/displacement – Bonds are both made and broken
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