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Human Physiology: SPI Biology

Human Physiology has 13 questions in the SPI bank, the most of any Biology chapter, and eleven of them are EASY. None is from the 2022 paper: they come from the SPI practice paper and the LWS mocks. Every question asks for one named fact from the Class 10 book, such as an enzyme, an organ, a chamber of the heart or a gland, and the wrong options are real body parts placed in the wrong job. So the tables here pair each organ with what it does, and the traps list the swaps the options make.

The handout has every subtopic, worked example, formula and trap with answers shown. The formula sheet is the chapter’s formulas and traps alone, on one page.

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Subtopic notes

Formula & revision sheet

0 formulas · 7 reference tables · 13 gotchas across all subtopics — the exam-eve cheat-sheet

Life Processes in Humans

Reference tables (4)

Digestion: each organ and what it adds8 rows

Organ	Juice or enzyme	What it acts on
Mouth	Salivary amylase	Starch (a carbohydrate)
Stomach	Hydrochloric acid	Kills germs, makes the medium acidic for pepsin
Stomach	Pepsin	Protein
Liver	Bile (no enzyme)	Fat, broken into small droplets
Pancreas	Trypsin	Protein
Pancreas	Lipase	Fat
Pancreas	Pancreatic amylase	Starch (a carbohydrate) Amylase is the one enzyme found in both saliva and pancreatic juice.
Small intestine	Villi	Absorb digested food into the blood

Protein has two enzymes (pepsin, trypsin); starch has two places (mouth, pancreas).

Breathing and respiration3 rows

Where	Oxygen	Pyruvate becomes
Mitochondria of most cells	Present	Carbon dioxide and water, with much energy
Muscle cells during hard exercise	Short	Lactic acid, with less energy Lactic acid building up in the muscle is what causes cramps.
Yeast	Absent	Ethanol and carbon dioxide

Ethanol belongs to yeast; lactic acid belongs to our muscles.

Blood and the four chambers of the heart4 rows

Chamber	Receives blood from	Sends blood to
Right atrium	The body (deoxygenated)	Right ventricle
Right ventricle	Right atrium	The lungs, by the pulmonary artery
Left atrium	The lungs, by the pulmonary veins (oxygenated)	Left ventricle The left atrium is the chamber that receives blood from the lungs.
Left ventricle	Left atrium	The whole body, by the aorta

Right side: body to lungs. Left side: lungs to body.

Excretion: the path of urine4 rows

Step	Organ	Job
1	Kidneys	Filter the blood and make urine (in the nephrons)
2	Ureters	Carry urine down to the bladder
3	Urinary bladder	Stores urine
4	Urethra	Carries urine out of the body Ureter comes before the bladder; urethra comes after it.

Watch out for (8)

Calling bile an enzyme
→ Digestion: each organ and what it adds
Picking a weak acid for the stomach
→ Digestion: each organ and what it adds
Exchange in the windpipe or throat
→ Breathing and respiration
Mixing up the two kinds of anaerobic respiration
→ Breathing and respiration
Water vapour as the lime water gas
→ Breathing and respiration
Iron for clotting
→ Blood and the four chambers of the heart
Thinking the right side of the heart sends blood to the body
→ Blood and the four chambers of the heart
Swapping ureter and urethra
→ Excretion: the path of urine

Control and Coordination

Reference tables (3)

Parts of the brain and voluntary actions5 rows

Part	Region	Controls
Cerebrum	Forebrain	Thinking, memory, senses, voluntary actions The cerebrum is the largest part of the brain.
Hypothalamus	Forebrain	Hunger, thirst, body temperature
Cerebellum	Hindbrain	Balance and posture
Medulla	Hindbrain	Heartbeat, breathing, vomiting (involuntary)
Spinal cord	Below the brain	Reflex actions

Chosen actions: cerebrum. Balance: cerebellum. Heartbeat: medulla.

Neurons, nerves and the direction of an impulse3 rows

Nerve	Carries messages from	Sense
Optic nerve	Eye	Sight
Auditory nerve	Ear	Hearing
Olfactory nerve	Nose	Smell

In a neuron: dendrite, cell body, axon, then across the synapse to the next dendrite.

Endocrine glands and where they sit8 rows

Gland	Where	Hormone or job
Hypothalamus	Brain	Releasing hormones that control the pituitary
Pituitary	Brain	Growth hormone
Pineal	Brain	Melatonin (sleep cycle)
Thyroid	Neck	Thyroxine (needs iodine)
Parathyroid	Neck	Controls calcium in the blood
Thymus	Chest	Helps build immunity in children The thymus is in the chest, not the brain.
Adrenal	On top of the kidneys	Adrenaline
Pancreas	Abdomen	Insulin

Watch out for (5)

Cerebellum for the largest part
→ Parts of the brain and voluntary actions
A skill is not involuntary
→ Parts of the brain and voluntary actions
An impulse crossing into the next axon
→ Neurons, nerves and the direction of an impulse
Parathyroid next to pituitary
→ Endocrine glands and where they sit
Pancreas as only a digestive organ
→ Endocrine glands and where they sit

Question weightage by concept

7 concepts · 13 questions — where the marks actually sit, so you know what to drill first

Life Processes in Humans8 questions · 62%

Concept	Qs	Share
Breathing and respiration	3	23%
Digestion: each organ and what it adds	2	15%
Blood and the four chambers of the heart	2	15%
Excretion: the path of urine	1	8%

Control and Coordination5 questions · 38%

Concept	Qs	Share
Parts of the brain and voluntary actions	2	15%
Neurons, nerves and the direction of an impulse	2	15%
Endocrine glands and where they sit	1	8%

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