histology test 1

Levels of organization

Chemicals, cells, tissues, organs, systems, organism

Metabolism

Sum of all chemical reactions that occur in the body

Catabolism

Breakdown chemical substances

Anabolism

Building up chemical substances

Responsiveness

Body's ability to detect and respond to changes ( need protein receptor)

Movement

Motion of anything in the body, kinetic energy

Growth

Increase in body size and number of cells

Differentiation

Development of cell from unspecialized to specialized

Reproduction

Growth, repair, or replacement, new individual, mitosis or meiosis

Apoptosis

Programmed cell death

Necrosis

Tissue death

Homeostasis

Maintaining a constant internalenvironment

Cell structure

Cell membrane, cytoplasm, nucleus

Composition of plasma membrane

Phospholipid bilayer, proteins,cholesterols

Diffusion

Movement of ions or molecules from high concentration to low concentration of same solute in solution ( passive )

Distance, shape, gradient, size, temperature, charge

Factors affecting diffusion rate

Hydrophobic

Hate water, uncharged, nonpolar

Hydrophilic

Love water, charged, polar

Integral protein

Part of the plasma membrane, pumps, channels, receptor, linker, enzymes, structural

Peripheral proteins

Not embedded in plasma membrane, associated with strong ionic interactions

Osmosis

Passive transport of water

What is high water?

Pure, nothing dissolved, no solute

Osmotic pressure

Force required to prevent movement of water across selectively permeable membrane

Hypotonic solution

Water moves into cell causing it to swell ( hemolysis)

Isotonic solution

Solution and cell have equal amounts of solute

Hypertonic solution

Water moves out of the cell causing cell to shrink and appear spikey

Channels

Transmembrane proteins that create pores that ions or small molecules can be passively transported

Aquaporins

Channels used to transport water

Carriers

Transmembrane proteins that bind small molecules and passively move them across the membrane via conformational change ( use facilitated transport)

Endocytosis

Being brought into the cell

Phagocytosis

Bringing in solids

Pinocytosis

Bringing in fluids

Receptor-mediated endocytosis

Integral membrane proteins have high affinity receptors for lipids and proteins, cause binding and pinching off membrane

Cathrin

Used in endocytosis to detect when receptors are filled with a ligand

Dynamin

Detects clathrin and then pulls the membrane in to form a vesicle

Active and vesicular transport

Uses energy ( ATP) to move ions across the membrane from low concentration to high concentration

Exocytosis

Movement of large molecules from inside the cell to outside the cell ( vesicular transport)

What triggers exocytosis?

Triggered by an increase in calcium in the cytoplasm

Membrane trafficking

Process of membrane movement and recycling

Constitutive secretion

Products released from cells continuously as soon as synthesis is complete

Regulated secretion

Response to signals coming to cells, response to specific stimuli( main ways is nervous and endocrine)

Endocrine signaling

Chemical messengers are carried in blood from source to target cells throughout the body

Paracrine signaling

Chemical ligand diffuses in ECF but rapidly metabolized so it only effects target cells near the source

Synaptic signaling

Neurotransmitters act on adjacent cells through synapses

Autocrine signaling

Signals bind to receptors on the same cell it is produced by

Juxtacrine signaling

Communicate through adjacent plasma membrane contact ( induction)

Ion channel

Integral protein that forms a pore through which a specific ion can flow to get across membrane

Carrier

Integral proteins that transport a specific substance across membrane by undergoing a change in shape

Receptor

Integral protein that recognizes specific ligand and alters cell's function in some way

Enzymes

Can be integral or peripheral proteins that catalyze reactions inside or outside cell

Linker

Can be integral or peripheral proteins that anchor filaments inside and outside the plasma membrane providing structural stability and shape for the cell

Cell identity marker

Glycoprotein that distinguishes your cells from anyone else's ( MHCproteins)

Cytoskeleton

Cell's internal framework

3 components of cytoskeleton

Microfilaments, intermediate filaments, microtubules

Microfilaments

Reinforce parts of the cell, under the plasma membrane

Intermediate filaments

Add strength and stability and also create compartments that allow for organization, also anchor filaments of actin and myosin

Microtobules

Hollow on the inside and create movement via flagella or cilia

Microvillus

Supported by microfilaments

Ribosomes

Made up of 2 sub units with RNA and protein and can be free or attached, main focus is stringing together amino acids

Smooth ER

Main focus is to build, make, and store carbohydrates and lipids

Rough ER

Main focus is to make and store peptides or proteins

Entry to Golgi

Cis face

Exit the Golgi

Trans face

Golgi complex

Main function is to process, package, and fold proteins and then send them to their target

Lysosomes

Buds from Golgi membrane that contain digestive enzymes that may fuse with vesicles formed at the plasma membrane

Peroxisomes

Contain enzymes that use oxygen to oxidize organic substances

Proteasomes

Destroy unneeded, damaged, or faulty proteins by cutting long proteins into smaller peptides

Mitochondria

The powerhouse of the cell and the site of cellular respiration; contains its own DNA (from mother) and ribosomes

Mitochondria inner membrane

Have folds called cristae where ATP is formed

Mitochondria outer membrane

Allows for a stockpiling of hydrogen ions and the formation of ATP

What are the main parts of the nucleus?

Nuclear envelope, nucleolus, nucleoplasm, chromatin, chromosomes

What are the 3 functions of the nuclear membrane?

Controls what goes in and out of the nucleus, keeps DNA from getting tangled in the cytoplasm, allows the DNA to replicate

Nucleoplasm

Watery portion inside the nucleus

Chromatin

DNA coiled around histones lightly packed

Nucleolus

Where cells make the parts of the ribosomes ( proteins and RNA) to be sent out of the nuclear pore

Epithelial tissue

Lines, wraps, and covers, some form glands

Connective tissue

Fills internal spaces, supports other tissue, transport materials , stores energy

Muscle tissue

Specialized for contraction

What are the 3 types of muscle tissue?

Skeletal, heart, walls of hollow organs

Neural tissue

Carries electrical signals from one part of the body to another

Glands

Structures that produce secretions

What are the 5 characteristics of epithelial tissue?

More cells than matrix with cell junctions between them, have an apical and basal surface attachment to the basement membrane, avascularity, regeneration

Basement membrane

The basal surface of all epithelia rests on a thin extracellular sheet of macromolecules

Tight junctions

Most apical of the junctions and ensures that molecules crossing an epithelium go through the cells, not between

Adherent junctions

Sites of strong cell adhesion usually encircling epithelial cells immediately below tight junctions

Desmosomes

Attach internally to intermediate filaments

Gap junctions

Channels for communication between adjacent cells that permit intercellular exchange of molecules

Microvilli

Projections from the apical surface of epithelial cells made of bundles of actin filaments that increase absorption

Stereocillia

Specialized projections from epithelial cells that increase absorption, are longer than microvilli, and some have motion-detecting functions for the inner ear

Cilia

Long and highly motile apical epithelial structures that contain internal arrays of microtubules

What are the 4 functions of epithelial tissues?

Provide protection, control permeability, monitor environment, produce specialized secretions

What are the 2 main groups of epithelia?

Covering epithelia and secretory epithelia

Squamous epithelia

Thin and flat

Cuboidal epithelia

Square shaped

Columnar epithelia

Tall, slender rectangles

Simple squamous epithelium

Absorption and diffusion (alveoli)

Mesothelium

Simple squamous epithelia that lines body cavities and secretes serous fluid

Endothelium

Simple squamous epithelium that lines heart and blood vessels

Simple cuboidal epithelium

Cells here are roughly as tall as they are wide allowing for high levels of active transport

Examples of simple cuboidal epithelium

Renal collecting tubule, large thyroid follicle, mesothelium covering an ovary