Human Body Facts
🔍 Human Body Facts – 60-Second Revision
1. Crude Numbers to Mug
- Bones: 206 (adult) ← new-born 270 (fuse later)
- Muscles: 639 named, 40 % of body weight
- Blood: ~5–6 L (male), ~4–5 L (female)
- RBC life: 120 days; WBC life: few hrs–days; Platelet life: 7–10 days
- Normal pH blood: 7.35–7.45 (slightly alkaline)
- Haemoglobin: M 13–17 g/dL, F 11–15 g/dL
- Heartbeat: 72 min⁻¹ (adult), 120–140 (new-born)
- BP: 120/80 mmHg (ideal)
- Breathing rate: 12–16 min⁻¹ (adult)
- Largest organ: Skin (1.5–2 m², 16 % body wt)
- Smallest bone: Stapes (ear)
- Longest bone: Femur
- Largest muscle: Gluteus maximus
- Largest gland: Liver (1.5 kg)
- Hardest substance: Tooth enamel
- Universal donor: O⁻; Universal recipient: AB⁺
- Normal body temp: 37 °C / 98.6 °F
- ATP yield: 1 glucose → 38 ATP (aerobic)
2. Mnemonics / Memory Tricks
- Cranial nerves (I–XII):
On Old Olympus Towering Top A Finn And German Viewed Some Hops
(Olfactory, Optic, Oculomotor, Trochlear, Trigemal, Abducent, Facial, Auditory, Glossopharyngeal, Vagus, Accessory, Hypoglossal) - Blood groups antigen:
“O has None, A has A, B has B, AB has AB” - Heart valves order (flow):
“Try Pulling My Aorta” → Tricuspid → Pulmonary → Mitral → Aortic - Carb/protein/fat cal value:
“4-4-9, stay fine” (kcal g⁻¹)
3. Quick-Compare Tables
| Fluid / Cell | Chief Function | Normal Count / Feature |
|---|---|---|
| RBC | O₂ transport | 4.5–6 million/µL, biconcave, no nucleus |
| WBC (Neutrophil 60 %) | Defence | 4 000–11 000/µL, nucleus lobed |
| Platelets | Clotting | 1.5–4 lakh/µL, life 7–10 d |
| Plasma | Matrix | 55 % blood volume, 90 % water |
| Vitamin / Hormone | Deficiency Disease | Source / Note |
|---|---|---|
| Vit-C | Scurvy | Citrus; collagen synthesis |
| Vit-D | Rickets (kids) | Sunlight; Ca²⁺ absorption |
| Vit-K | Delayed clotting | Gut bacteria; green leafy |
| Insulin | Diabetes mellitus | β-pancreas ↓ → ↑ blood sugar |
| Thyroxine | Goitre/hypothyroid | Iodine needed for T₃/T₄ |
4. Five-Sentence Science
- Digestion start: mouth (ptyalin) → stomach (pepsin) → duodenum (trypsin)
- Nephrons: functional unit of kidney; ~1 million each kidney
- Synovial fluid: lubricates moveable joints (shoulder, knee)
- CSF: 125 mL, cushions brain/spinal cord, made in choroid plexus
- Sodium–K pump: 3 Na⁺ out, 2 K⁺ in (ATPase) – maintains RMP – 70 mV
BETA
