StripWise A&P Lecture Guide: Cells, Bones & Muscles
The 3 AM Survival Guide
Written like we're cramming in the break room with cold coffee and 14 minutes left. Three units, quick-hit tables, dumb-but-sticky mnemonics, the traps professors love, and practice questions you tap to check. Intro-level college A&P, built from OpenStax and NCBI StatPearls (sources at the bottom).
🔬 Companion: A&P 1 Lab Practical guide (skin, bones & muscles) ↗
How to use it: skim the Quick Take, study the tables, say the mnemonics out loud (yes, out loud), then do the questions before you peek.
Unit 1 · The Cell: The Night Crew Nobody Thanks
↑ Back to indexQuick Take: The cell is the smallest unit of life. Every cell has a plasma membrane, cytoplasm (cytosol + organelles), and (except mature red blood cells) a nucleus. Structure predicts function: lots of mitochondria = high energy demand; lots of rough ER = protein factory.
The plasma membrane
↑ Back to index- Phospholipid bilayer: hydrophilic (water-loving) phosphate heads face out, hydrophobic fatty-acid tails face in. Cholesterol tucked in adjusts fluidity.
- Proteins: integral (span the membrane: channels, carriers, receptors) and peripheral (stuck to one surface). Glycoproteins/glycolipids form the glycocalyx, the cell's ID badge.
- Selectively permeable: small nonpolar stuff (O₂, CO₂, lipids) slides through; ions and big polar molecules need proteins.
Moving stuff across the membrane
↑ Back to index| Process | Energy (ATP)? | Direction | Example |
|---|---|---|---|
| Simple diffusion | No (passive) | High → low concentration | O₂ into cells, CO₂ out |
| Facilitated diffusion | No | High → low, through a channel or carrier | Glucose via GLUT carriers; ions via channels |
| Osmosis | No | Water moves toward higher solute concentration | Water through aquaporins |
| Active transport (primary) | Yes, directly | Low → high (against gradient) | Na⁺/K⁺ pump: 3 Na⁺ out, 2 K⁺ in per ATP |
| Secondary active transport | Indirectly (uses a gradient the pump built) | One substance rides another's gradient | Na⁺–glucose symport |
| Endocytosis / exocytosis | Yes (vesicles) | Bulk in / bulk out | Phagocytosis ("cell eating"), releasing neurotransmitter |
Tonicity (what happens to a red blood cell)
↑ Back to index| Solution | Solute outside vs inside | Water moves | Cell |
|---|---|---|---|
| Isotonic | Equal | No net movement | Stays normal |
| Hypotonic | Less outside | Into the cell | Swells, may burst (lysis) |
| Hypertonic | More outside | Out of the cell | Shrinks (crenation) |
🧠 Memory hook: hYPO = the cell gets fat like a hipPO. hYPER = hyper cell sweats all its water out and shrivels.
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Organelles: who does what on the unit
↑ Back to index| Organelle | Job | Night-shift translation |
|---|---|---|
| Nucleus | Holds DNA; controls the cell; site of transcription (DNA → mRNA) | The charge nurse with the master plan |
| Nucleolus | Makes ribosomal subunits (rRNA) | Supply closet restocker |
| Ribosomes | Translation: build proteins from mRNA (free = cytosol proteins; bound = export/membrane proteins) | The hands doing the actual work |
| Rough ER | Ribosome-studded; makes and folds proteins for export or membranes | Med room prepping orders |
| Smooth ER | Lipid and steroid synthesis, detox, stores Ca²⁺ (called sarcoplasmic reticulum in muscle) | Pharmacy + calcium vault |
| Golgi apparatus | Modifies, sorts, packages proteins into vesicles | Tube station / mailroom |
| Mitochondria | Aerobic cellular respiration → most ATP; has its own DNA | The coffee machine. Everything stops without it. |
| Lysosomes | Digestive enzymes break down worn-out parts and debris | Housekeeping |
| Peroxisomes | Break down fatty acids, detoxify; neutralize hydrogen peroxide | Hazmat team |
| Cytoskeleton | Shape, support, movement (microfilaments, intermediate filaments, microtubules) | The building's framing |
| Centrosome/centrioles | Organize microtubules and the mitotic spindle | Organizes the move when the unit splits |
| Cilia / flagella | Cilia move stuff across a surface; a flagellum moves the cell (sperm) | Transport team |
Charge nurse tip: If an exam describes a cell that "secretes lots of protein," think rough ER + Golgi. "Makes steroid hormones" or "detoxes"? Smooth ER. "Huge energy needs" (muscle, sperm)? Packed with mitochondria.
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Protein synthesis in two moves
↑ Back to index- Transcription (in the nucleus): DNA is copied into mRNA.
- Translation (at the ribosome): mRNA codons are read three bases at a time; tRNA brings matching amino acids; the ribosome links them into a polypeptide.
Cell cycle & mitosis
↑ Back to indexInterphase (G₁ grow → S copy DNA → G₂ prep) takes up most of the cycle. Then mitosis (nuclear division) + cytokinesis (cytoplasm splits) → two identical diploid daughter cells.
| Phase | What happens |
|---|---|
| Prophase | Chromosomes condense; spindle forms; nuclear envelope breaks down |
| Metaphase | Chromosomes line up at the Middle (metaphase plate) |
| Anaphase | Sister chromatids pulled Apart to opposite poles |
| Telophase | Two new nuclei form; chromosomes decondense (cytokinesis usually overlaps) |
🧠 Mnemonic: "I Pee More At Twilight" → Interphase, Prophase, Metaphase, Anaphase, Telophase. (Relatable at 0300.) Bonus: Metaphase = Middle, Anaphase = Apart.
⚠️ Exam traps
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- Interphase is not a phase of mitosis; it's the part of the cell cycle between divisions. DNA replicates in the S phase, not during mitosis.
- Mitosis = 2 identical diploid cells (body cells). Meiosis = 4 genetically different haploid gametes.
- Osmosis is about water moving, and water moves toward the higher solute concentration.
- The Na⁺/K⁺ pump is 3 Na⁺ out, 2 K⁺ in. Flipping that is a classic wrong answer.
- Mature red blood cells have no nucleus and no mitochondria.
Unit 1 practice questions
↑ Back to index🔒 All 33 practice questions are in the full guide. This free preview includes Unit 1 and 5 practice questions.
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
↑ Back to index
↑ Back to index
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
Unit 2 · The Skeletal System: The Building Is Always Under Renovation
↑ Back to index🔒 Unit 2 · The Skeletal System is in the full guide. This free preview includes Unit 1 and 5 practice questions.
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
↑ Back to index
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
Unit 3 · The Muscular System: Code Team Mechanics
↑ Back to index🔒 Unit 3 · The Muscular System is in the full guide. This free preview includes Unit 1 and 5 practice questions.
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
↑ Back to index
Get the full guide on Gumroad · or save with the A&P 1 Bundle (Lecture + Lab guides)
Sources
↑ Back to indexFacts checked against these references (accessed October 2026). Your professor's textbook and lecture always win if they differ.
- OpenStax, Anatomy and Physiology 2e (Betts et al.), Ch. 3 "The Cellular Level of Organization": openstax.org/books/anatomy-and-physiology-2e/pages/3-introduction
- OpenStax, Anatomy and Physiology 2e, Ch. 6 "Bone Tissue and the Skeletal System": openstax.org/books/anatomy-and-physiology-2e/pages/6-introduction
- OpenStax, Anatomy and Physiology 2e, Ch. 9 "Joints": openstax.org/books/anatomy-and-physiology-2e/pages/9-introduction
- OpenStax, Anatomy and Physiology 2e, Ch. 10 "Muscle Tissue": openstax.org/books/anatomy-and-physiology-2e/pages/10-introduction
- NCBI StatPearls, "Physiology, Bone Remodeling": ncbi.nlm.nih.gov/books/NBK499863
- NCBI StatPearls, "Physiology, Skeletal Muscle": ncbi.nlm.nih.gov/books/NBK537139
- NCBI StatPearls, "Physiology, Osmosis": ncbi.nlm.nih.gov/books/NBK557609