Form 4 BiologyBiologi Tingkatan 4

Chapter 13: HomeostasisBab 13: Homeostasis

Maintaining internal balance — kidneys, skin, and temperature regulationMengekalkan keseimbangan dalaman — buah pinggang, kulit, dan pengawalan suhu

🎯 What You'll LearnApa yang Anda Akan Pelajari

Define homeostasis and its importanceMendefinisikan homeostasis dan kepentingannya

Explain negative feedback mechanismMenerangkan mekanisme maklum balas negatif

Describe osmoregulation and the urinary systemMenerangkan osmoregulasi dan sistem urinari

Explain blood glucose regulationMenerangkan pengawalan glukosa darah

🦠 Nephron StructureStruktur Nefron

PartBahagianFunctionFungsi
GlomerulusGlomerulusNetwork of capillaries for filtrationRangkaian kapilari untuk penurasan
Bowman's capsuleKapsul BowmanCollects filtrateMengumpul bahan turas
Proximal tubuleTubul proksimalReabsorbs glucose, amino acids, waterMenyerap semula glukosa, asid amino, air
Loop of HenleGelung HenleWater & salt reabsorptionPenyerapan semula air & garam
Collecting ductSaluran pengumpulWater reabsorption (ADH control)Penyerapan semula air (kawalan ADH)
💡 Memory Trick:💡 Trik Ingatan: "ADH = Always Drinking Helps" (ADH makes you retain water) | "Insulin = In = Into cells" (glucose enters) "ADH = Air Ditahan Habis" (ADH tahan air) | "Insulin = In = Masuk ke dalam sel" (glukosa masuk)"

🌡️ ThermoregulationTermoregulasi

ConditionKeadaanResponseGerak Balas
Too hotTerlalu panasVasodilation, sweating, hair lies flatVasodilatasi, berpeluh, rambut rata
Too coldTerlalu sejukVasoconstriction, shivering, hair erectionVasokonstriksi, mengigil, rambut tegak

💧 Osmoregulation Simulator💧 Simulasi Osoregulasi

Osmoregulation Simulator G lomerulus B owman's capsule Proximal tubule Loop of Henle Distal tubule Collecting duct Afferent arteriole Efferent arteriole Urine flow ADH Level: Water Intake: Urine Output: 50%

🩸 Blood Glucose Regulation🩸 Regulasi Glukosa Darah

Blood Glucose Regulation Normal Range: 4.0-7.0 mmol/L High Blood Glucose Detected by pancreas → Insulin released Insulin Low Blood Glucose Detected by pancreas → Glucagon released Glucagon Pancreas Liver Muscle Cells

Regulation of blood glucose by insulin (lowers glucose) and glucagon (raises glucose). Insulin promotes glucose uptake by cells and glycogen storage. Pengawalan glukosa darah oleh insulin (merendahkan glukosa) dan glukagon (meninggikan glukosa). Insulin merangsang pengambilan glukosa oleh sel-sel dan penyimpanan glikogen.

🧴 Skin Structure for Thermoregulation🧴 Struktur Kulit untuk Termoregulasi

Epidermis Dermis Subcutaneous Tissue Nerve Epidermis Dermis Subcutaneous Tissue

Skin structure showing epidermis, dermis (with sweat glands, hair follicles, blood vessels), and subcutaneous tissue. These structures help regulate body temperature. Struktur kulit menunjukkan epidermis, dermis (dengan kelenjar peluh, folikel rambut, pembuluh darah), dan tisu subkutan. Struktur ini membantu mengawal termoregulasi.

Homeostasis: Negative Feedback Loop Normal Set Point Level TOO HIGH Detected by receptors Corrective action ↓ Reduce level Level TOO LOW Detected by receptors Corrective action ↑ Increase level SPM: Blood glucose (insulin/glucagon) + Body temp (sweating/shivering)

⚡ Quick CheckSemakan Cepat

What hormone controls water reabsorption in the kidneys?Hormon manakah mengawal penyerapan semula air dalam buah pinggang?

AInsulinInsulin
BADHADH
CGlucagonGlukagon
DAdrenalineAdrenalina

🇲🇾 Malaysian ContextKonteks Malaysia

Malaysia has one of the highest diabetes rates in Asia! Kidney disease is a major health concern due to diabetes. NKF Malaysia provides free haemodialysis. Hot climate makes hydration essential.Malaysia mempunyai kadar diabetes tertinggi di Asia! Penyakit buah pinggang masalah kesihatan utama akibat diabetes. NKF Malaysia menyediakan hemodialisis percuma. Iklim panas menjadikan hidrasi penting.

📋 SPM Practice📋 Latihan SPM

SPM QuestionSoalan SPM

Explain how the body regulates blood glucose concentration after a meal. [4 marks]Jelaskan bagaimana badan mengawal kepekatan glukosa darah selepas makan. [4 markah]

📌 Exam Tip:📌 Tips Peperiksaan: Blood glucose rises → Pancreas secretes insulin → Glucose converted to glycogen in liver → Blood glucose returns to normal Glukosa darah meningkat → Pankreas rembes insulin → Glukosa ditukar kepada glikogen dalam hati → Glukosa darah kembali normal

🃏 FlashcardsKad Imbas

ADH controls?ADH mengawal?
Water reabsorption in kidneysPenyerapan semula air dalam buah pinggang
Insulin function?Fungsi insulin?
Converts glucose to glycogenMenukarkan glukosa kepada glikogen
Vasodilation?Vasodilatasi?
Blood vessels widen, heat loss increasesSalur darah melebar, haba hilang bertambah
Glomerulus?Glomerulus?
Filtration of blood in nephronPenurasan darah dalam nefron
Negative feedback?Maklum balas negatif?
Changes reversed to restore normalPerubahan dibalikkan untuk pulih ke normal