A&P Module 1.docx

Superior

Toward the head; upper part of a structure

Inferior

Away from the head; toward the lower part or tail of a structure

Anterior

Nearer to/at the front of the body

Posterior

Nearer to/at the back of the body

Medial

Nearer to the midline

Lateral

Farther from the midline

Ipsilateral

On the same side of the body as another structure

Contralateral

On the opposite side of the body from another structure

Proximal

Nearer to the attachment of a limb to the trunk

Distal

Farther from the attachment point of a limb to the trunk

Superficial

Toward or on the surface of the body

Deep

Away from the surface of the body

Sagittal

Longitudinal plane dividing the body into left and right sides

Midsagital

Longitudinal plane dividing the body into equal left and right sides

Frontal (coronal)

Longitudinal plane dividing the body into anterior and posterior portions

Transverse

Horizontal plane dividing the body into superior and inferior portions

Oblique

Plane passing through the body at an oblique angle

Homeostasis

Body's maintenance of a stable internal environment

Feedback loops

Cycles maintaining a constant internal environment

Sensor/ receptor

Monitors changes in a controlled variable

Integrator/ Control Center

Dictates the set point for a controlled variable

Effector

Responds to commands to change the controlled variable

Negative feedback loops

Reverse a change in a controlled variable

Positive feedback loops

Enhance a change in a controlled variable

Atomic

Basic unit of matter

Biomolecules

Proteins, lipids, carbohydrates

Organelles

Subcellular structures

Tissue

Structurally similar cells performing a common function

Organ

Specialized structure composed of different tissues

Physiological system

Organs functioning together

Extracellular fluid

Contains ⅓ of total body water

Intracellular fluid

Fluid inside cells

Interstitial fluid

75% of ESF Fluid surrounding cells outside blood vessels

Proteoglycan filaments

Narrow molecules trapping water in interstitial fluid

Transcellular fluid

Fluid contained by epithelial-lined spaces

Fascia

Thin connective tissue membrane with collagen fibers

Collagen

Protein with high tensile strength in tissues

Elastin

Protein with higher compliance and lower elastance than collagen

Plasma membrane

Lipid bilayer separating intra- and extracellular compartments

Phospholipids

Amphiphilic molecules forming the lipid bilayer in biomembranes

Polar

Molecule with asymmetrically distributed electrons, one end slightly positive and the other slightly negative; e.g., water, urea, glycerol

Nonpolar

Molecules or regions with a preponderance of nonpolar bonds; e.g., C-H bonds

Hydrophilic

Polar chemical groups that can form hydrogen bonds with water molecules, relatively water-soluble and lipid-insoluble (lipophobic)

Hydrophobic

Nonpolar chemical groups with uncharged, nonpolar atoms that can't interact with water molecules, relatively lipid-soluble (lipophilic) and water-insoluble

Lipophilic

Synonymous with hydrophobic, relatively lipid-soluble

Lipophobic

Synonymous with hydrophilic, relatively water-soluble

Water-soluble

Relatively hydrophilic and lipid-insoluble

Lipid-soluble

Relatively hydrophobic and water-insoluble

Oil-water partition coefficient (βx)

Measure of a solute's lipid solubility; βx = 1, equally soluble in water and oil; βx > 1, more soluble in oil; βx < 1, more soluble in water

Conformation

Three-dimensional shape of a protein determined by the folding of its amino acid constituents

Exocytosis

Process where an intracellular vesicle fuses with the plasma membrane, releasing its contents into the extracellular fluid, often triggered by an increase in intracellular Ca2+.

Simple diffusion

Net movement of solute across a membrane due to random thermal motion, described by Fick’s first law of diffusion.

Fick’s first law of diffusion

Mathematical equation describing the flux of a solute across a membrane, influenced by diffusion coefficient, area, concentration difference, and distance.

Stokes-Einstein equation

Defines the diffusion coefficient of a solute based on temperature, solute radius, and solvent viscosity.

Osmosis

Movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Osmotic pressure

Pressure required to prevent osmosis or the height of a fluid column due to osmosis, influenced by solute concentration, temperature, and reflection coefficient.

Carrier-mediated transport

Protein-mediated transport displaying saturation kinetics and specificity, different from channel proteins in that carriers interact with solutes.

Facilitated transport

Movement of solutes down their concentration gradient facilitated by carrier proteins, such as glucose transport through the blood-brain barrier.

Primary active transport

Energy-dependent transport directly coupled to ATP hydrolysis, exemplified by the Na+-K+ ATPase pump.

Secondary active transport

Coupled transport where one solute moves downhill with its gradient, providing energy for another solute to move uphill, like the Na+-glucose cotransporter.

Ribosomes

Organelles involved in translation, sequencing amino acids into polypeptides based on mRNA information.

Rough Endoplasmic Reticulum (RER)

Membrane network with ribosomes attached, involved in protein translation, folding, modification, and packaging.

Golgi Complex

Membrane-bound sac stack near RER, involved in protein modification, sorting, and packaging into vesicles.

Lysosomes

Membrane-bound vesicles with acid hydrolase enzymes for intracellular digestion and autophagy.

Proteasomes

Organelles for degrading proteins, removing improperly folded ones, and linked to diseases like Parkinson's.

Smooth Endoplasmic Reticulum (SER)

Membrane network without ribosomes, involved in lipid synthesis, detoxification, and calcium storage.

Mitochondria

Organelles for ATP production through oxidative phosphorylation, containing the Krebs cycle and electron transport chain.

Cytoskeleton

Three-dimensional protein structure in the cytosol, composed of microfilaments, intermediate filaments, and microtubules.

Nucleus

Contains DNA, histones, and RNA, with euchromatin for active transcription and heterochromatin for less active regions.

Chromosomes

DNA double helix structures, with autosomes (1-22) and sex chromosomes (X, Y), determining ploidy in cells.

Genes

DNA sequences containing information for RNA production, located at specific loci on chromosomes, with alleles from each parent.

Gene Transcription

Process of transferring genetic code from DNA to RNA molecules, including mRNA, rRNA, and tRNA.

Mitosis

Cell division for somatic cells, producing two identical diploid daughter cells.

Meiosis

Cell division for reproductive cells, producing four genetically diverse haploid daughter cells.

Epithelial cells

Cells found in the epidermis of the skin or lining of the gastrointestinal tract that divide continuously at a rate equal to cell death.

Neoplastic cells

Cells that have lost control over cell division frequency, leading to rapid and continuous division.

Interphase

The period between cell divisions where chromosomes replicate for daughter cells.

Mitosis

Cell division process resulting in two identical diploid daughter cells from a single diploid somatic cell.

Meiosis

Cell division process in ovaries or testes producing four unique haploid daughter cells through two rounds of division.

Allele

Alternative versions of a gene at a specific chromosome locus.

Genotype

Set of alleles constituting an individual's genetic makeup.

Phenotype

Observable expression of a genotype, such as anatomical or biochemical traits.

Autosomal recessive inheritance

Genetic inheritance pattern where two mutant alleles are needed for the disorder to manifest.

Autosomal dominant inheritance

Genetic inheritance pattern where a single mutant allele leads to the expression of the disorder.

X-linked recessive inheritance

Genetic inheritance pattern where the mutant allele is located on the X chromosome.

Paracrine signaling

Cell communication where chemical signals diffuse to nearby cells.

Endocrine signaling

Cell communication where hormones travel through the blood to reach distant target cells.

G protein-coupled receptor

Receptor dependent on G proteins for signal transduction, with seven membrane-spanning regions.

Second messengers

Molecules that relay signals from cell surface receptors to target molecules inside the cell.

cAMP

Cyclic adenosine monophosphate, a second messenger involved in intracellular signaling pathways.

Ca2+

Calcium ion, another second messenger that plays a crucial role in cell signaling pathways.

Adenylyl Cyclase (AC)

A membrane enzyme complex that converts adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a second messenger.

cAMP-dependent Protein Kinases

Enzymes activated by cAMP, responsible for mediating most effects of cAMP.

G Proteins

Proteins that regulate AC; Gs stimulates AC, while Gi inhibits AC.

Phospholipase C (PLC)

A membrane enzyme activated by certain agonists and receptors, converting phosphatidylinositol bisphosphate into IP3 and DAG.

IP3 and DAG

Second messengers produced by PLC; IP3 releases Ca2+ from the endoplasmic reticulum, while DAG activates protein kinase.

Phospholipase A2 (PLA2)

An effector enzyme activated by various pathways, converting membrane phospholipids into arachidonic acid.

Ion Channels

Effectors regulated directly by G proteins or indirectly by protein kinases in cell signaling pathways.

Voltage

Measure of electrical potential energy between charged objects, commonly referred to as electrical pressure.

Current

Flow rate of charges past a point per unit time, basis of cell excitability in biological systems.