Body Compartments and Cells: Applied Physiology for Mental Health Nursing

Vocabulary flashcards reviewing human body compartments, cell structures, membrane transport mechanisms, organelles, and homeostatic feedback systems.

Cytology

The study of cell structure and function, which forms part of the broader discipline of cell biology.

Cranial Cavity

The dorsal body cavity enclosed by the cranium that houses the brain and its protective meninges.

Spinal Canal

The vertebral cavity through which the spinal cord extends downward from the base of the brain.

Thoracic Cavity

The superior ventral body compartment containing the heart and lungs, separated from the abdominal cavity inferiorly by the diaphragm.

Abdominal Cavity

The body cavity containing anterior organs (liver, gall bladder, stomach, small intestine, large intestine) and posterior organs (spleen, kidneys, pancreas, and large blood vessels).

Pelvic Cavity

The inferior abdominopelvic compartment containing the urinary bladder, urethra, bowel, and internal reproductive organs.

Prokaryotes

Unicellular organisms whose cells lack a membrane-bound nucleus and other membrane-bound organelles; examples include Bacteria and Archaea.

Eukaryotes

Organisms whose cells contain distinct, membrane-bound organelles, including a defined nucleus; examples include animal cells, plant cells, and fungi.

Somatic Cells

General body cells containing a diploid set of $46$ chromosomes that carry genetic information.

Germ Cells

Specialized reproductive sex cells (sperm and ovum) containing $23$ chromosomes each, uniting to establish the full complement of $46$ chromosomes.

Intracellular Fluid (ICF)

The fluid contained entirely within the interior of cells, accounting for approximately $66\%$ of total body fluid.

Extracellular Fluid (ECF)

All bodily fluid residing outside of cells—constituting approximately $33\%$ of total body fluid—which is subdivided into interstitial fluid and plasma.

Interstitial Fluid

The watery component of extracellular fluid that bathes and surrounds tissue cells, making up approximately $80\%$ of all extracellular fluid.

Plasma Membrane

A selectively permeable phospholipid bilayer containing proteins and carbohydrates that defines cellular boundaries, maintains the internal environment, and facilitates cellular communication.

Phospholipid Bilayer

A two-layered membrane arrangement composed of outer hydrophilic (water-loving) heads in contact with fluid and inner hydrophobic (water-hating) fatty acid tails shielded from water.

Diffusion

The passive net movement of solute particles down a concentration gradient from an area of higher solute concentration to an area of lower solute concentration.

Osmosis

The passive movement of water molecules down their concentration gradient across a semi-permeable membrane from an area of low solute (high water) concentration to high solute (low water) concentration.

Facilitated Transport

A passive transport process wherein solutes cross a membrane down their concentration gradient through specific protein channels that undergo conformational shape changes without expending energy.

Active Transport

The energy-dependent movement of solutes against (up) their concentration gradient across a membrane via transport pumps utilizing adenosine triphosphate ($\text{ATP}$).

Pinocytosis

A form of endocytosis in which the plasma membrane invaginates and pinches off to create a small vesicle containing extracellular fluid droplet.

Cytoplasm

The thick, semi-transparent cellular substance composed of approximately $75\%$ water, electrolytes, and proteins, serving as the site for metabolic chemical reactions and organelle suspension.

Nucleus

The largest, centrally placed spherical cellular organelle surrounded by a nuclear envelope, containing nucleoplasm, the nucleolus, and genetic material ($\text{DNA}$ and $\text{RNA}$).

Rough Endoplasmic Reticulum

A network of cytoplasmic channels studded on its outer surface with ribosomes, primarily responsible for protein synthesis.

Smooth Endoplasmic Reticulum

A network of membranous cytoplasmic channels lacking ribosomes, functioning as the primary site for carbohydrate and lipid synthesis.

Golgi Apparatus

An organelle composed of $4\text{--}8$ flattened, stacked membranous sacs (cisternae) located near the nucleus that modifies, packages, and stores cellular products in vesicles.

Mitochondria

Double-membrane partitioned organelles known as the powerhouses of the cell, serving as the primary site of cellular energy production in the form of adenosine triphosphate ($\text{ATP}$).

Lysosomes

Membranous organelles filled with digestive enzymes that destroy invading bacteria and cellular debris, taking the form of granules when inactive and small sacs when active.

Centrioles

Paired cylindrical structures located near the nucleus consisting of $9$ bundles of microtubules, which form the spindle apparatus during cell division.

Homeostasis

The active maintenance of a stable internal bodily environment, represented by a dynamic state of physiological equilibrium.

Negative Feedback Loop

A homeostatic control mechanism that counteracts a physiological deviation by shutting off or reducing the intensity of the original stimulus to restore balance.

Afferent Pathway

The neural or signaling communication route that transmits sensory data from a receptor to the homeostatic control center.

Efferent Pathway

The communicative route through which commands from the homeostatic control center are directed to an effector organ to execute a corrective response.

Positive Feedback Loop

A relatively rare physiological mechanism that amplifies and accelerates the original stimulus away from the set point toward an outcome goal, such as blood clotting or childbirth.

Shock

A severe clinical condition caused by reduced blood flow and impaired systemic circulation, which triggers cellular dysfunction that can progress to multiple organ failure.