Lecture Exam 1 Required Terms to Know

Anatomical Planes, Directional Terms, and Body Cavities

• Abdominal Cavity:

  • Positioned as the superior portion of the abdominopelvic cavity, located inferior to the diaphragm.

  • Houses digestive organs including the stomach, liver, spleen, pancreas, small intestine, and most of the large intestine.

• Cranial Cavity:

  • The dorsal body cavity located within the skull.

  • Functions to house and protect the brain.

• Deep:

  • An anatomical directional term defined as being farther from the body surface.

• Distal:

  • An anatomical directional term defined as being farther from the point of attachment or origin.

• Frontal (Coronal) Plane:

  • A vertical plane that divides the body into anterior (front) and posterior (back) portions.

• Inferior:

  • An anatomical directional term meaning below or positioned toward the feet.

• Mediastinum:

  • The central compartment of the thoracic cavity situated between the lungs.

  • Contains the heart, trachea, esophagus, and major blood vessels.

• Microscopic Anatomy:

  • The branch of anatomy focused on structures visible only with a microscope.

  • Encompasses histology (the study of tissues) and cytology (the study of cells).

• Pelvic Cavity:

  • The inferior portion of the abdominopelvic cavity.

  • Contains the urinary bladder, reproductive organs, and rectum.

• Proximal:

  • An anatomical directional term defined as being closer to the point of attachment or origin.

• Sagittal Plane:

  • A vertical plane dividing the body into right and left portions.

• Superficial:

  • An anatomical directional term meaning toward or at the body surface.

• Superior:

  • An anatomical directional term defined as above or positioned toward the head.

• Thoracic Cavity:

  • The ventral body cavity situated superior to the diaphragm.

  • Contains the lungs and the mediastinum.

• Transverse Plane:

  • A horizontal plane that divides the body into superior and inferior portions.

Cellular Structure, Membrane Composition, and Organelles

• Cell Glycocalyx:

  • A carbohydrate-rich layer present on the extracellular surface of the plasma membrane.

  • Formed by glycoproteins and glycolipids.

  • Functions in cell recognition, protection, and adhesion.

• Cell Membrane (Plasma Membrane):

  • A selectively permeable phospholipid bilayer embedded with proteins.

  • Regulates the movement of substances into and out of the cell.

• Cholesterol:

  • A lipid molecule embedded within the plasma membrane.

  • Stabilizes membrane fluidity and permeability.

• Cytoplasm:

  • Represents all cellular contents located between the plasma membrane and the nucleus.

  • Comprises cytosol and organelles.

• Cytoskeleton:

  • A structural network of protein filaments comprising microfilaments, intermediate filaments, and microtubules.

  • Provides structural support, intracellular transport, and cellular movement.

• Endoplasmic Reticulum (ER):

  • An interconnected membrane network involved in protein and lipid synthesis.

  • Consists of rough ER (studded with ribosomes) and smooth ER (lacking ribosomes).

• Flagellum:

  • A long, whip-like cellular projection.

  • Enables cellular movement (e.g., sperm cell motility).

• Golgi Apparatus (Endomembrane System / Function):

  • A membrane-bound organelle that modifies, sorts, and packages proteins and lipids for secretion or intracellular use.

  • Operates as part of the endomembrane system.

• Integral Protein:

  • A membrane protein embedded within the lipid bilayer.

  • Frequently functions as channels, carriers, or receptors.

• Lipid Bilayer:

  • The double layer of phospholipids forming the structural foundation of the plasma membrane.

• Lysosome:

  • A membrane-bound organelle containing digestive enzymes.

  • Functions to break down waste, pathogens, and damaged organelles.

• Mitochondrion:

  • A membrane-bound organelle that produces ATP through aerobic cellular respiration.

• Nucleolus:

  • A dense region within the nucleus.

  • The site where ribosomal RNA (rRNA) is synthesized and ribosome subunits are assembled.

• Nucleus:

  • A membrane-bound organelle containing DNA that controls cellular activities.

• Peripheral Proteins:

  • Membrane proteins loosely attached to the inner or outer surface of the plasma membrane.

  • Often function in cell signaling or structural support.

• Peroxisomes:

  • Membrane-bound organelles containing oxidative enzymes.

  • Function to detoxify harmful substances and break down fatty acids.

• Phospholipids:

  • Amphipathic molecules composed of a hydrophilic phosphate head and hydrophobic fatty acid tails.

  • Serve as the primary component of cell membranes.

• Ribosome:

  • A non-membrane-bound organelle composed of rRNA and proteins.

  • Acts as the site of protein synthesis.

• Rough Endoplasmic Reticulum (RER) Function:

  • Synthesizes, folds, and begins modification of proteins destined for secretion or membrane insertion.

• Smooth Endoplasmic Reticulum (SER):

  • Organelle involved in lipid synthesis, detoxification, and calcium storage.

• Vesicles:

  • Small membrane-bound sacs used for transport or storage within cells.

Cellular Transport Mechanisms and Fluid Dynamics

• Active Transport:

  • Energy-requiring movement of substances across a membrane against their concentration gradient ($\text{low} \rightarrow \text{high}$).

  • Typically uses ATP and transport proteins.

• Carrier Protein:

  • A membrane transport protein that binds a specific substance and undergoes a conformational change to move it across the membrane.

• Diffusion:

  • Passive movement of molecules from an area of higher concentration to lower concentration due to random molecular motion.

• Endocytosis:

  • An energy-dependent process in which materials are brought into the cell by the formation of a vesicle from the plasma membrane.

• Exocytosis:

  • A vesicular transport process in which substances are released from the cell when vesicles fuse with the plasma membrane.

• Facilitated Diffusion:

  • Passive transport of substances across a membrane through channel or carrier proteins down their concentration gradient.

• Hypertonic Solution:

  • A solution with a higher solute concentration than the cell.

  • Causes water to move out of the cell, resulting in cell shrinkage.

• Hypotonic Solution:

  • A solution with a lower solute concentration than the cell.

  • Causes water to move into the cell, potentially causing swelling or lysis.

• Isotonic Solution:

  • A solution with equal solute concentration compared to the cell.

  • Results in no net water movement.

• Osmosis:

  • Diffusion of water across a selectively permeable membrane from lower solute concentration to higher solute concentration.

• Phagocytosis:

  • A form of endocytosis in which large particles (e.g., bacteria) are engulfed by the cell.

• Pinocytosis:

  • A form of endocytosis in which the cell ingests extracellular fluid and dissolved solutes.

• Primary Active Transport:

  • Transport that directly uses ATP to move substances against their concentration gradient (e.g., sodium-potassium pump).

• Selective Membrane (Selectively Permeable Membrane):

  • A membrane that allows some substances to pass while restricting others.

• Simple Diffusion:

  • Passive movement of small, nonpolar molecules directly through the lipid bilayer without transport proteins.

• Vesicular Transport:

  • Movement of substances into or out of a cell via membrane-bound vesicles (includes endocytosis and exocytosis).

Molecular Genetics and Cell Life Cycle

• Cell Cycle:

  • The ordered sequence of events in a cell's life.

  • Consists of interphase ($\text{G}_1$, $\text{S}$, $\text{G}_2$) and the mitotic phase (mitosis and cytokinesis).

• DNA (Deoxyribonucleic Acid):

  • The hereditary material of the cell composed of a double helix of nucleotides.

  • Stores genetic information.

• Gene:

  • A segment of DNA that contains instructions for synthesizing a specific protein.

• Interphase:

  • The longest phase of the cell cycle.

  • Consists of:

  • $\text{G}_1$: Cell growth.

  • $\text{S}$: DNA replication.

  • $\text{G}_2$: Preparation for mitosis.

• mRNA (Messenger RNA):

  • A single-stranded RNA molecule that carries genetic information from DNA to ribosomes for protein synthesis.

• Transcription:

  • The process by which DNA is used as a template to synthesize mRNA.

• Translation:

  • The process by which ribosomes read mRNA to synthesize a polypeptide (protein).

Organ Systems, Functional Physiology, and Homeostasis

• Cardiovascular System:

  • Organ system composed of the heart, blood, and blood vessels.

  • Transports oxygen, nutrients, hormones, and wastes throughout the body.

• Circulatory System:

  • Another term often used interchangeably with cardiovascular system.

  • May also include the lymphatic component depending on context.

• Digestive System:

  • Organ system that mechanically and chemically breaks down food, absorbs nutrients, and eliminates solid waste.

• Endocrine System:

  • A system of glands that secrete hormones into the bloodstream to regulate growth, metabolism, reproduction, and homeostasis.

• Function of Pancreas:

  • Endocrine functions: Insulin and glucagon secretion for blood glucose regulation.

  • Exocrine functions: Digestive enzyme secretion into the small intestine.

• Homeostasis (How Maintained):

  • The maintenance of stable internal conditions through coordinated physiological processes.

  • Primarily regulated by negative feedback mechanisms involving receptors, control centers, and effectors.

• Homeostasis and Blood Pressure:

  • Blood pressure is regulated through negative feedback mechanisms (e.g., baroreceptors, autonomic nervous system, kidneys) to maintain adequate tissue perfusion.

• Lymphatic System:

  • Network of vessels, nodes, and organs that returns interstitial fluid to the bloodstream and participates in immune defense.

• Negative Feedback:

  • A regulatory mechanism in which a change in a variable triggers responses that counteract the initial change.

• Nervous System:

  • Organ system composed of the brain, spinal cord, and nerves that provides rapid communication and control through electrical and chemical signals.

• Positive Feedback:

  • A regulatory mechanism in which a change in a variable triggers responses that amplify the initial change.

• Respiratory System:

  • Organ system responsible for gas exchange (oxygen and carbon dioxide) between the body and the environment.