Body Fluids and Circulation

• Definition of body fluids; types: intracellular fluid, extracellular fluid, blood, lymph.​

• Blood: composition (plasma, formed elements); functions of RBC, WBC, platelets.​

• Plasma: water, proteins (albumin, globulin, fibrinogen), ions, nutrients, wastes.​

• Blood groups: ABO system (antigens, antibodies), Rh factor, erythroblastosis fetalis (concept only).​

• Blood coagulation: clotting factors, role of platelets, basic cascade idea (prothrombin → thrombin → fibrin).​

• Lymph: composition, formation from tissue fluid, functions (drainage, absorption of fats, immunity).​

• Human heart: position, size, external features; chambers, valves, major vessels (aorta, venae cavae, pulmonary artery/vein).​

• Internal circulation: pulmonary vs systemic, oxygenated vs deoxygenated paths.​

• Cardiac cycle: phases – atrial systole, ventricular systole, joint diastole; concept of lub–dub sounds.​

• Heartbeat: myogenic nature, nodal tissue (SA node, AV node, bundle of His, Purkinje fibres), pacemaker.​

• Cardiac output: stroke volume × heart rate; normal values (concept level).​

• Blood vessels: artery vs vein vs capillary (structure and function).​

• Double circulation: pulmonary + systemic circulation; significance in endothermy.​

• Regulation of cardiac activity: role of autonomic nervous system (sympathetic, parasympathetic) and hormones (adrenaline).​

• ECG: basic waves (P, QRS, T) and what they represent (atrial depolarisation, ventricular depolarisation, ventricular repolarisation).​

• Disorders: hypertension, coronary artery disease, angina pectoris, heart failure (basic definition and cause lines).​

Excretory Products and Their Elimination

• Need for excretion; nitrogenous wastes: ammonia, urea, uric acid.​

• Types of animals: ammonotelic, ureotelic, uricotelic (examples).​

• Human excretory system: kidneys, ureters, urinary bladder, urethra – gross anatomy.​

• Nephron: structure – Bowman’s capsule, glomerulus, PCT, loop of Henle, DCT, collecting duct.​

• Urine formation steps:

  • Ultrafiltration at glomerulus.​

  • Selective reabsorption in PCT, loop, DCT.​

  • Tubular secretion in PCT, DCT, collecting duct.​

• Counter-current mechanism: loop of Henle and vasa recta in urine concentration (concept only).​

• Osmoregulation: role of kidney in water and salt balance.​

• Regulation of kidney function:

  • ADH and water reabsorption.​

  • Renin–angiotensin–aldosterone system (RAAS) in BP and Na⁺ balance (basic idea).​

  • Atrial natriuretic factor (ANF) opposing RAAS.​

• Other excretory organs: lungs (CO₂), liver (bile pigments), skin (sweat), intestine.​

• Disorders: uraemia, renal failure, renal calculi, nephritis; dialysis principle.​

Breathing and Exchange of Gases

• Differences between breathing and respiration (external vs cellular).​

• Respiratory organs in animals (only recall): gills, tracheae, skin, lungs (examples).​

• Human respiratory system anatomy: nostrils, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.​

• Alveolus: thin walls, rich capillary network, large surface area.​

• Mechanism of breathing:

  • Inspiration: diaphragm contraction, rib cage expansion, thoracic volume increase, pressure drop.​

  • Expiration: diaphragm relaxation, rib cage moving down, thoracic volume decrease, pressure rise.​

• Lung volumes and capacities: tidal volume, inspiratory reserve, expiratory reserve, vital capacity, total lung capacity (values conceptually).​

• Exchange of gases:

  • At lungs: diffusion of O₂ into blood and CO₂ out, based on partial pressure gradients.​

  • At tissues: reverse diffusion between blood and cells.​

• Transport of gases:

  • O₂: oxyhaemoglobin, oxygen–haemoglobin dissociation curve; effect of pO₂, pCO₂, temperature, pH.​

  • CO₂: dissolved, bicarbonate, carbamino-haemoglobin (relative percentages).​

• Regulation of respiration: respiratory centre in medulla and pons; role of CO₂/H⁺ concentration.​

• Disorders: asthma, emphysema, occupational lung diseases (basic cause and effect).​

Locomotion and Movement

• Movement vs locomotion; biological significance.​

• Types of movement: ciliary, flagellar, muscular (examples for each).​

• Skeletal muscle structure: muscle → fascicles → muscle fibres → myofibrils → sarcomere.​

• Contractile proteins: actin, myosin; A band, I band, Z line, H zone.​

• Mechanism of muscle contraction (sliding filament theory):

  • Role of Ca²⁺ and troponin–tropomyosin complex.​

  • Cross-bridge formation, power stroke, ATP requirement.​

• Types of muscle: skeletal, smooth, cardiac – structure and control (voluntary/involuntary).​

• Skeletal system: axial vs appendicular skeleton (major bones and functions).​

• Joints: fibrous, cartilaginous, synovial; examples and basic features.​

• Disorders: myasthenia gravis, tetany, muscular dystrophy, arthritis, osteoporosis, gout (one line description each).​

Neural Control and Coordination

• Need for control and coordination; neural vs hormonal control.​

• Neuron: structure – cell body, dendrites, axon; types – sensory, motor, interneuron.​

• Resting membrane potential: ionic distribution (Na⁺/K⁺) and role of Na⁺–K⁺ pump.​

• Action potential: depolarisation, repolarisation, hyperpolarisation (concept-only graph).​

• Conduction of nerve impulse:

  • Along non-myelinated fibres (continuous).​

  • Along myelinated fibres (saltatory conduction; nodes of Ranvier).​

• Synapse: structure (pre-, post-synaptic membrane, synaptic cleft).​

• Synaptic transmission: chemical synapse, neurotransmitter release (e.g., acetylcholine); steps of transmission.​

• Organisation of human nervous system:

  • CNS: brain and spinal cord – very brief subdivisions (forebrain, midbrain, hindbrain functions).​

  • PNS: cranial and spinal nerves.​

  • Autonomic NS: sympathetic vs parasympathetic (effects examples).​

(Note: Reflex action and detailed sense organs content is reduced/removed in new NEET syllabus; keep as minimal conceptual link if you mention.)​

Chemical Coordination and Integration (Endocrine System)

• Endocrine vs exocrine glands; types of hormones (peptide, steroid, amine – basic).​

• General properties of hormones: act in low concentration, specificity, feedback regulation.​

• Hypothalamus: releasing and inhibiting hormones; link between nervous and endocrine system.​

• Pituitary gland:

  • Anterior lobe hormones: GH, TSH, ACTH, FSH, LH, Prolactin – basic functions.​

  • Posterior lobe: ADH, oxytocin – functions.​

• Pineal gland: melatonin, role in circadian rhythm (concept).​

• Thyroid gland: thyroxine (T₄/T₃) in metabolism and growth; calcitonin in Ca²⁺ regulation.​

• Parathyroid glands: PTH, role in Ca²⁺ and phosphate homeostasis.​

• Adrenal gland:

  • Adrenal cortex: mineralocorticoids (aldosterone), glucocorticoids (cortisol), sex corticoids (basic actions).​

  • Adrenal medulla: adrenaline, noradrenaline – fight or flight responses.​

• Pancreas (Islets of Langerhans): insulin, glucagon; regulation of blood glucose.​

• Gonads:

  • Testes: testosterone – role in male secondary characters, spermatogenesis.​

  • Ovaries: estrogen, progesterone – female cycle, pregnancy, secondary characters.​

• Mechanism of hormone action: receptor concept (membrane vs intracellular), signal generation (only elementary idea).​

• Disorders (hypo/hyper): dwarfism, gigantism, acromegaly, cretinism, myxoedema, simple goitre, exophthalmic goitre, diabetes mellitus, Addison’s disease (one-line cause/effect).​