IHP 1001 Histology Unit 1
- the fundamental units of life, believed to have evolved from a common ancestral cell over 3 billion years ago.
- prokaryotic cells are small, primitive with circular DNA, no nucleus or membrane-bound organelles; include bacteria and archaea.
- eukaryotic cells are large, sophisticated, with linear DNA stored in a nucleus, and membrane-bound organelles; and include animals, plants, fungi, protists.
- protoplasm is the living substance of the cell (subdivided into the cytoplasm and the nucleus)
- cytoplasm is the contents of the cell between the plasma membrane to the nuclear envelope
- karyoplasm is the substance forming the the content of the nucleus
- organelles are metabolically active cellular structures that execute specific functions
- inclusions are nonliving components of the cell that do not possess metabolic activities and are not bound by membranes
- the sequential flow of genetic information that occurs in all living cells
- transcription is the process of synthesizing RNA from DNA
- translation is the process of synthesizing proteins from RNA
- a bilayer containing phospholipids (amphipathic), cholesterol (controls fluidity), proteins (integral and peripheral) and some carbohydrates (externally)
- functions as a selectively permeable membrane of the cell; acts as a physical barrier to enclose the cell contents, regulates movement of material in and out of the cell, functions in cell signaling and communication.
- short, numerous membrane extensions supported by microtubles, which occur on exposed membrane surfaces of some cells; at its base is a basal body (derived from a centriole) that controls the axoneme
- functions to move substances over the cell surface (e.g. mucus dissolved materials)
- long, singular membrane extension supported by microtubules; at its base is a basal body (derived from a centriole) that controls the axoneme; present in sperm cells
- functions to propel sperm
- numerous thin membrane folds projecting from the free cell surface, supported by microfiliments
- functions to increase membrane surface area for greater absorption (e.g. in the digestive tract)
- large structure enclosed within a double membrane; contains chromatin, nucleolus, and nucleoplasm
- functions to house DNA that serves as the genetic material for directing protein synthesis
- a double membrane boundary between the cytoplasm and nuclear contents; continuous with rough endoplasmic reticulum
- separate the nucleus from the cytoplasm
- openings through the nuclear envelope
- functions to allow passage of material between the cytoplasm and nucleaoplasm (e.g. RNA, proteins, ions, small water-soluble molecules)
- large prominent structure within the nucleus
- functions in synthesis of ribosomes
rough endoplasmic reticulum
- extensive interconnected membrane network that varies in shape (e.g. cisternae, tubles) with ribosomes attached on the cytoplasmic surface
- functions to modify, transport, and store proteins produced by attached ribosomes; these proteins are secreted, become components of the plasma membrane, or serve as enzymes of lysosomes
- within a neuron, it is called Nissl body
smooth endoplasmic reticulum
- extensive interconnected network membrane lacking ribosomes
- functions to synthesize, transport, and store lipids (e.g. steroids); metabolizes carbohydrates; detoxifies drugs, alcohol, and poisons; forms vesicles and peroxisomes
- within muscle, it stores calcium and is called the sacroplasmic reticulum
- series of several elongated, flatted saclike membranous structures
- functions to modify, package, and sort materials that arrive from the ER in transport vesicles (cis face); forms secretory vesicles for export (trans face)
- spherical-shaped membrane-bound sacs; contain various types of material to be transported through the cell
- function to transport cellular material
- spherical-shaped membrane-bound organelles formed from the golgi apparatus; contain digestive enzymes
- function to digest microbes or materials (e.g. ingested by the cells, worn-out cellular components, or an entire cell)
- primary lysosomes are those not involved in a digestive event; secondary lysosomes are those that have fused with a phagosome; indigestible compounds following digestion are called residual bodies.
- a type of lysosomal storage disorder, which are a group of diseases that stem from defects in one or more of the digestive enzymes present in lysosomes
- occurs mostly in children of Northeast European Jewish ancestry and in certain individuals of Cajun ancestry in Louisiana.
- deficiency of enzyme hexaminidase in the lysosomes inhibits catabolism of GM2 gangliosides; ganglioside accumulation in the lysosome in the CNS and PNS disrupts nerve conduction; children usually die by 3-5 years old.
- characterized by infantile onset (3-6 months), doll-like faces, cherry-red macular spot, early blindness, hyperacusis, macrocephaly, seizures, and hypotonia.
- smaller, spherical-shaped membrane bound organelles formed from the ER or through fission; contain oxidative enzymes
- function to detoxify specific harmful substances either produced by the cell or taken into the cell; engage in beta oxidation of fatty acids to acetyl CoA
- a double membrane bound organelle with folds (cristae) in the inner membrane, which separates the intracellular space from the matrix
- functions in ATP synthesis during aerobic cellular respiration by digestion of fuel molecules (e.g. glucose) in the presence of oxygen
- has its own circular mitochondrial DNA (maternal origin) and is responsible for its own replication
- organelles composed of both protein and ribosomal RNA (rRNA) that are organized into large and small subunits; may be bound to a membrane or free in cytosol
- function in protein synthesis; bound ribosomes produces proteins that are secretes, incorporated into the plasma membrane, and within lysosomes; free ribosomes produce proteins used within the cell
- organized network of protein filaments and hollow tubules, including microfilaments, intermediate filaments, and microtubes
- functions to maintain intracellular structure and organization of cells; participates in cell division; facilitates movement
- relatively thin actin protein monomers organized into two thin, intertwined protein filaments
- function to maintain cell shape; support microvilli; separate cells during cytokinesis; facilitate change in cell shape; participate in muscle contraction
- medium width filaments composed of various protein components
- provide structural support; stabilize junctions between cells
- the presence of specific types of intermediate filaments in tumor can reveal which cell originated the tumor
- relatively thick hollow cyclinders composed of tubulin protein
- function to maintain cell shape and rigidity; organize and move organelles; support cilia and flagella; participate in vesicular transport; separate chromosomes durin cell division
- amorphous region adjacent to the nucleus; contains a pair of centrioles
- organizes microtubles; participates in mitotic cell division
- large, barrel-shaped protein complexes located in the cytosol and nucleus
- degrade and digest damaged or unneeded proteins; ensure quality of exported proteins
- aggregates of specific types of molecules (e.g. melanin protein, glycogen, or lipids)
- serve as temporary storage for these molecules
- endocytosis is cellular uptake of macromolecules or fluid by plasma membrane engulfment or invagination, followed by the “pinching off” of a filled membranous vesicle in the cytoplasm.
- major types of endocytosis include phagocytosis (uptake of particulate material), pinocytosis (uptake of dissolved substances), and receptor-mediated endocytosis (uptake of specific molecules bound to integral membrane receptor proteins).
- exocytosis is a type of cellular secretion in which cytoplasmic membrane vesicles fuse with the plasma membrane and release their contents to the extracellular space.
glycogen storage disease
immotile cilia syndrome