Anatomy, Physiology, and Cell Biology: Key Concepts for Students

Anatomy vs. Physiology

Anatomy studies the form and structure of the body, while physiology examines how those parts and the body function.

Traits shared by all living organisms

Organization, metabolism, growth/development, responsiveness, regulation (homeostasis), and reproduction.

Smallest unit of matter

An atom.

Organ system that secretes hormones

The Endocrine system.

Standard anatomic position

Standing upright, feet parallel and flat on the floor, upper limbs at the sides, palms facing forward (anteriorly), head level, and eyes looking forward.

Body plane dividing the body into front and back halves

Frontal (or Coronal) plane.

Directional term for structures located toward the belly

Ventral (or Anterior).

The foot is _________ to the hip

Distal (further from the point of attachment).

The elbow is _________ to the hand

Proximal (closer to the point of attachment).

Parietal layer

The type of serous membrane located on the inner surface of the body wall.

Body cavity containing the lungs

Pleural cavities (within the thoracic cavity).

Mediastinum

The median space in the thoracic cavity containing the heart, thymus, esophagus, trachea, and major blood vessels.

Positive feedback

The feedback mechanism the body uses less frequently in order to maintain homeostasis (used for rapid, climatic events like childbirth).

Tissue level

The level of organization consisting of groups of similar-looking cells with surrounding material working together to perform a function.

Organ system that removes waste from blood, regulates pH and water balance

The Urinary system.

Differentiation

The process involving unspecialized cells changing into cells with a specialized function.

Homeostasis

The body's ability to maintain itself in a steady, consistent internal state.

Receptor (or sensor)

The component of a feedback loop that senses changes (stimuli) in the body.

Directional term for the antebrachium compared to the brachium

Distal (the forearm is farther from the trunk than the arm).

Oblique section

A cut through a tubular organ (like the small intestine) that produces an oval-shaped piece.

Olecranon (or olecranal)

The anatomical term that refers to the point of the elbow.

Diaphragm

The structure that separates the ventral body cavity into the thoracic and abdominopelvic cavities.

Visceral pericardium (or epicardium)

The specific serous membrane that tightly covers the surface of the heart.

Element required for a substance to be considered organic

Carbon.

Isotope

Atoms of the same element with the same number of protons but different numbers of neutrons (e.g., Iodine-131 used medically for thyroid imaging).

Strongest bond at the atomic level

Covalent bond.

Hydrophilic

"Water-loving"; describes substances (like polar molecules and ions) that dissolve easily in water.

Subatomic particles accounting for most of an atom's mass

Protons and neutrons (found in the nucleus).

Cation vs. Anion

A cation is a positively charged ion (lost electrons); an anion is a negatively charged ion (gained electrons).

Activation Energy

The minimal energy needed to start a chemical reaction.

Catalysts (or Enzymes)

Substances that speed up the rate of a chemical reaction without being changed by that reaction.

Buffer

A substance that functions to prevent drastic changes in pH by absorbing or releasing hydrogen ions.

Glycogen

The polysaccharide used for energy storage in humans (stored in liver and muscle cells).

Acid

A substance that frees Hydrogen ions (H+) in solution and has a pH range from 0 up to 7.

Base

A substance that binds Hydrogen ions (or frees OH-) in solution and has a pH range greater than 7 up to 14.

Suspension

A mixture that does not remain mixed unless in motion and scatters light (e.g., blood cells in plasma).

Colloid

A mixture that remains mixed when not in motion and scatters light (e.g., gelatin or cell cytosol).

Solution

A mixture that remains mixed when not in motion and does not scatter light (e.g., saltwater).

Phospholipids (and cholesterol)

The type of macronutrient/lipid that forms the major components of the cell membrane.

Carbohydrates (Glucose)

The macronutrient providing the best and fastest form of short-term energy for the body.

DNA (Deoxyribonucleic Acid)

The nucleic acid that is double-stranded.

Potential to Kinetic energy rule

True: Potential energy must be converted to kinetic energy before it can do work.

Metabolism

The collective term for all chemical reactions in the body.

Exergonic reaction

A reaction where energy is released; the reactants contain more energy than the products.

ATP (Adenosine Triphosphate)

The body's primary "energy currency" used for nearly all general active functions of the cell.

Enzyme influence on reactions

It speeds up chemical reactions by lowering the activation energy required.

Suffix associated with enzymes

"-ase" (e.g., lactase).

Anaerobic step of cellular respiration

Glycolysis (does not require oxygen).

Electron Transport System / Oxidative Phosphorylation

The step of cellular respiration that nets the most ATP and is the reason we need to breathe in oxygen.

Glycolysis location

The step of cellular respiration that takes place in the cytosol, NOT inside the mitochondrion.

Phospholipids

The molecules that make up the bilayer core found in the cell membrane fluid mosaic model.

Leak channels

Channel proteins that are always open and responsible for the continuous permeability of the plasma membrane to ions.

Substances that diffuse directly through the lipid bilayer

Small, nonpolar (hydrophobic) substances like oxygen, carbon dioxide, and lipids.

Mitochondrion

The organelle responsible for producing large amounts of cellular ATP.

Smooth Endoplasmic Reticulum (Smooth ER)

Cells that synthesize large amounts of lipids would have large amounts of this organelle.

Cell in a Hypotonic solution

Water moves into the cell, causing it to swell and potentially burst (lyse).

Cell in a Hypertonic solution

Water moves out of the cell, causing it to shrink (crenate).

Cell in an Isotonic solution

No net water or solute movement occurs; the cell size stays the same.

Passive transport

A type of transport that does not require cellular energy (e.g., simple diffusion, osmosis).

Organelles containing DNA

The Nucleus and the Mitochondria.

Transcription

The process inside the nucleus where a DNA sequence is copied into a complementary strand of mRNA.

Translation

The process in the cytoplasm where a ribosome reads mRNA to assemble a specific chain of amino acids (protein).

Interphase

The phase of the cell cycle where cells spend the majority of their life cycle performing normal metabolic activities.

Apoptosis

Programmed cell death ("cellular suicide").

Tissue vs. Histology

A tissue is a group of similar cells working together; histology is the microscopic study of tissues.

Four primary tissue types

Epithelial, Connective, Muscle, and Nervous tissue.

Vascularity of Epithelial tissue

False: Epithelial tissue is completely avascular (lacks blood vessels) and relies on diffusion.

Epithelial cell naming features

Differentiated and named by the number of cell layers (Simple vs. Stratified) and the shape of cells at the apical surface.

Shapes of epithelial cells

Squamous (flat), Cuboidal (cube-like), and Columnar (tall/column-like).

Simple vs. Stratified epithelium functions

Simple epithelium is suited for absorption/filtration; Stratified epithelium is suited for protection against friction/wear.

Exocrine vs. Endocrine glands

Exocrine glands secrete products into ducts; Endocrine glands are ductless and secrete hormones directly into the bloodstream.

Simple vs. Compound ducts

Simple ducts are unbranched; Compound ducts have a branched duct system.

Methods of exocrine secretion

Merocrine, Apocrine, and Holocrine. Holocrine secretion uses up and destroys whole cells to release its product.

Three basic components of connective tissue

Cells, protein fibers, and ground substance.

Protein fibers in connective tissue

Collagen fibers (strength), Elastic fibers (flexibility/recoil), and Reticular fibers (structural framework).

Three types of loose connective tissue

Areolar, Adipose (fat), and Reticular connective tissue.

Three types of dense connective tissue

Dense Regular, Dense Irregular, and Elastic dense connective tissue.

Two types of supporting connective tissue

Cartilage and Bone.

Three types of cartilage

Hyaline cartilage, Fibrocartilage, and Elastic cartilage.

Lacunae

The microscopic chambers/spaces that house mature Chondrocytes (cartilage cells) and Osteocytes (bone cells).

Two types of fluid connective tissue

Blood and Lymph.

Three types of muscle tissue and their nuclei

Skeletal muscle (multinucleated, peripheral), Cardiac muscle (1-2 central nuclei), and Smooth muscle (single central nucleus).

Striated muscle tissues

Skeletal muscle and Cardiac muscle.

Voluntary muscle tissue

Skeletal muscle tissue.

Intercalated discs

Specialized cellular junctions unique to Cardiac muscle tissue.

Two types of cells in nervous tissue

Neurons (signal conductors) and Neuroglia/Glial cells (support cells).

Three units of a neuron

Dendrites (receive incoming signals), Cell Body/Soma (processes information), and the Axon (transmits outward signals).

Four types of body membranes

Mucous, Serous, Cutaneous (skin), and Synovial membranes.

Atrophy

Tissue alteration marked by a decrease in cell number and/or size.

Hyperplasia

Tissue alteration marked by an increase in the total number of cells.

Hypertrophy

Tissue alteration marked by an increase in the physical size of individual cells.

Necrosis

Uncontrolled or accidental tissue/cell death.

Neoplasia

Tissue growth that is abnormal and completely beyond cellular control (tumor formation).