KINE 301 Chapter 3

Plasmalemma

Another name for the cell membrane, a phospholipid bilayer

Phospholipid bilayer

Two layers of phospholipids with hydrophobic tails facing inward and hydrophilic heads facing outward toward the watery ECF

Glycocalyx

Glycoprotein and glycolipid coating found only on the exterior surface of the cell membrane, used for protection and communication

Cell membrane function 1, Physical isolation

Separates the cell from its external environment, separates ECF from ICF

Cell membrane function 2, Regulation of exchange

Controls entry of nutrients and ions and exit of waste products

Cell membrane function 3, Communication

Membrane proteins recognize and respond to molecules in the external environment

Cell membrane function 4, Structural support

Provided through the cytoskeleton, gives the cell shape and forms junctions with other cells

Fluid mosaic model

Model stating the exact composition of the cell membrane is fluid and can vary by location and over time

Sphingolipid

A fatty acid tail with a phospho or glycerol lipid head that acts as a raft to move proteins around the membrane

Cholesterol in cell membrane

Waterproofs the cell and helps the membrane stay flexible with temperature changes

Peripheral protein

Membrane protein reversibly attached to the outside of the cell membrane

Integral protein

Membrane protein tightly bound to the cell membrane

Membrane spanning protein

A type of integral protein that crosses both sides of the cell membrane

Cytoplasm

Everything inside the cell membrane except the nucleus, contains cytosol, inclusions, protein fibers, and organelles

Cytosol

The fluid portion of the cytoplasm, contains dissolved nutrients, ions, and waste

Inclusion

Insoluble material in the cytoplasm with no membrane, used for nutrient storage

Glycogen granule

An inclusion that stores glycogen, a storage form of carbohydrate

Lipid droplet

An inclusion that stores fat for energy use later

Ribosome

Inclusion responsible for manufacturing proteins, can be free or fixed

Free ribosome

Ribosome that floats freely in the cytoplasm

Fixed ribosome

Ribosome anchored to an organelle like the rough endoplasmic reticulum

Microfilament

Insoluble protein fiber, example is actin

Intermediate filament

Insoluble protein fiber, examples include keratin and neurofilaments

Microtubule

Insoluble protein fiber involved in forming centrioles, cilia, and flagella

Centriole

Structure made of microtubules involved in mitosis, absent in mature non dividing cells

Cilia

Microtubule structures that move fluid across the cell surface and increase surface area for exchange

Flagella

Microtubule structures found only on sperm cells, used for propulsion

Cytoskeleton function 1, Cell shape

Maintains the shape of the cell

Cytoskeleton function 2, Internal organization

Keeps structures in place inside the cell

Cytoskeleton function 3, Intracellular transport

Acts like a railroad system moving materials through the cell

Cytoskeleton function 4, Assemble cells into tissues

Anchors one cell to another to build tissue

Cytoskeleton function 5, Movement

Uses motor proteins and ATP to generate movement

Myosin

Motor protein that binds with actin to create muscle movement

Kinesin

Motor protein responsible for moving vesicles along microtubules

Dynein

Motor protein that moves vesicles along microtubules and creates the whip like movement of flagella and beating of cilia

Mitochondria

Organelle known as the powerhouse of the cell, produces ATP

Rough endoplasmic reticulum

Organelle with fixed ribosomes attached, involved in manufacturing proteins

Smooth endoplasmic reticulum

Organelle without ribosomes, involved in manufacturing fats, fatty acids, lipids, and steroids

Golgi apparatus

Organelle that sorts, modifies, packages, and sends proteins in vesicles to their destination

Vesicle

A membrane bound sac containing a substance such as a protein or waste

Lysosome

Vesicle filled with enzymes that digests old cell material and foreign pathogens, inappropriate release can cause diseases like rheumatoid arthritis

Peroxisome

Vesicle that degrades long chain fatty acids and toxins, produces hydrogen peroxide as a byproduct

Nucleus

Control center of the cell, contains DNA, surrounded by a double membrane nuclear envelope

Nuclear pore complex

Hole in the nuclear envelope that allows controlled communication between the nucleus and cytosol

Nucleolus

Structure within the nucleus that directs synthesis of ribosomal RNA

Protein synthesis pathway

RNA is made in the nucleus and exits through nuclear pores, proteins are made by ribosomes in the cytoplasm, modified in the RER, packaged in a vesicle, sent to the Golgi for further modification, then released for storage or secretion

Cell adhesion molecule (CAM)

Membrane spanning protein used in cell to cell and cell to matrix junctions

Gap junction

Communicating cell to cell junction using the connexin protein, allows things to flow through easily

Tight junction

Occluding cell to cell junction that acts like a brick wall, restricts movement between cells

Adherens junction

Cell to cell anchoring junction that uses the cadherin protein

Desmosome

Cell to cell anchoring junction that uses the cadherin protein

Focal adhesion

Cell to matrix anchoring junction that uses the integrin protein

Hemidesmosome

Cell to matrix anchoring junction that uses the integrin protein

Epithelial tissue

Tissue type responsible for protection and exchange, has a basal lamina

Basal lamina

Unique cell junction that anchors epithelial tissue in place

Tight epithelium

Epithelium found in places like the kidneys with highly selective filtration

Leaky epithelium

Epithelium found in places like capillary walls that allows most things to move freely

Structural epithelium

Sheets of tissue that cover or line the surface of an organ

Secretory epithelium

Epithelium that synthesizes and secretes substances

Simple epithelium

Histological classification meaning the tissue has one layer

Stratified epithelium

Histological classification meaning the tissue has more than one layer

Squamous epithelium

Epithelial shape classification described as thin and flat like fish scales

Cuboidal epithelium

Epithelial shape classification described as cube shaped

Columnar epithelium

Epithelial shape classification described as column shaped

Exchange epithelium

Simple squamous epithelium designed for easy exchange, lines blood vessels, lungs, and the heart

Endothelium

Name for exchange epithelium specifically inside the heart and blood vessels

Transporting epithelium

Simple cuboidal or columnar epithelium with apical and basolateral membranes, contains many mitochondria for active transport

Apical membrane

The membrane of transporting epithelium that faces the lumen or inside of a tube

Basolateral membrane

The membrane of transporting epithelium that faces the extracellular matrix

Ciliated epithelium

Epithelium containing cilia that helps move fluid and particles, found in the respiratory system and female reproductive tract

Protective epithelium

Stratified epithelium designed to prevent exchange and protect against chemical and mechanical stress, has a short lifespan and high turnover rate

Retinoid

Chemical that speeds up cell division and surface shedding, used to treat acne and wrinkles but exposes immature cells at the surface

Exocrine gland

Gland that secretes substances through ducts into the external environment, examples are sweat glands, salivary glands, liver, and pancreas

Endocrine gland

Gland that secretes substances directly into the bloodstream, examples are the thyroid, gonads, and pituitary

Goblet cell

Cell responsible for making and secreting mucus, used as a lubricant and protective barrier

Connective tissue

Tissue type responsible for support and forming barriers, has an extensive extracellular matrix

Ground substance

Term describing the extracellular matrix of connective tissue, made mostly of proteoglycans and water

Loose connective tissue

Elastic connective tissue found under the skin, provides support for small glands

Dense regular connective tissue

Connective tissue with fibers running in parallel, offers increased flexibility, found in tendons and ligaments

Dense irregular connective tissue

Connective tissue with fibers running in every direction, offers increased strength

Tendon

Dense connective tissue that connects muscle to bone

Ligament

Dense connective tissue that connects bone to bone

Supporting connective tissue

Connective tissue category consisting of cartilage and calcified bone

Cartilage

Avascular supporting connective tissue that heals very slowly due to lack of blood supply

Adipose tissue

Connective tissue made of fat cells, includes white and brown adipocytes

White fat

Adipose tissue with one large fat droplet per cell, more common in adults

Brown fat

Adipose tissue with multiple fat droplets per cell, more common in infants, involved in non shivering thermogenesis

Blood (as connective tissue)

Fluid connective tissue made of plasma, blood cells, and cell fragments

Blast suffix

Indicates a young or growing cell

Clast suffix

Indicates a cell that removes or remodels tissue

Cyte suffix

Indicates a mature or inactive cell

Osteoblast

Young bone cell that lays down or forms new bone

Osteoclast

Bone cell that breaks down or removes bone

Osteocyte

Mature, inactive bone cell

Muscle tissue

Tissue type that contracts to generate force and movement, includes cardiac, skeletal, and smooth muscle

Nervous tissue

Excitable tissue type that sends electrical signals for communication

Glial cell (neuroglia)

Supporting cell of nervous tissue

Necrosis

Unplanned cell death caused by trauma, toxin exposure, or hypoxia

Hypoxia

A lack of sufficient oxygen to tissue, can lead to necrosis

Apoptosis

Programmed, purposeful cell death used to replace old cells, cells break into membrane bound blebs that get engulfed by other cells