Form 4 BiologyBiologi Tingkatan 4

Chapter 10: Transport in HumansBab 10: Pengangkutan dalam Badan

The circulatory system — heart, blood vessels, and bloodSistem peredaran darah — jantung, salur darah, dan darah

🎯 What You'll LearnApa yang Anda Akan Pelajari

Describe the human circulatory systemMenerangkan sistem peredaran darah manusia

Explain the structure and function of the heartMenerangkan struktur dan fungsi jantung

Describe blood vessels and their adaptationsMenerangkan salur darah dan penyesuaiannya

Explain blood composition and functionsMenerangkan komposisi dan fungsi darah

❤️ Blood Vessels ComparisonPerbandingan Salur Darah

FeatureCiriArteryArteriVeinVenaCapillaryKapilari
WallDindingThick, muscularTebal, berototThinNipisOne-cell thickSetebal satu sel
LumenLumenNarrowSempitWideLebarVery narrowSangat sempit
ValvesInjapNoTiadaYesAdaNoTiada
PressureTekananHighTinggiLowRendahLowRendah
DirectionArahAway from heartKeluar dari jantungTowards heartKe arah jantungGas exchangePertukaran gas
💡 Memory Trick:💡 Trik Ingatan: "Artery = Away" | "Vein = Valley (has valves)" | "Left = Loud (thicker wall)""Arteri = Away (keluar)" | "Vena = Valley (ada injap)" | "Kiri = Kuat (dinding lebih tebal)"
Heart Cross-Section & Blood Flow Right Atrium (deoxygenated) Right Ventricle Left Atrium (oxygenated) Left Ventricle ▼ Tricuspid ▼ Bicuspid Pulm. Artery Aorta Vena Cava Pulm. Vein Blood Flow Path Body → Vena Cava → Right Atrium → Right Ventricle → Pulmonary Artery → Lungs Lungs → Pulm. Vein → Left Atrium → Left Ventricle → Aorta SPM: Trace the full path!
Blood Vessel Comparison Artery Lumen Thick wall, small lumen Carries blood AWAY from heart Vein Lumen Thin wall, large lumen Has valves, carries blood TO heart Capillary 1 cell thick Wall: 1 cell thick Site of gas/nutrient exchange

🩸 Blood CompositionKomposisi Darah

ComponentKomponenPercentagePeratusanFunctionFungsi
PlasmaPlasma55%Transport mediumMedium pengangkutan
Red blood cellsSel darah merah45%Transport O₂ (haemoglobin)Pengangkutan O₂ (hemoglobin)
White blood cellsSel darah putih<1%Defence (phagocytes, lymphocytes)Pertahanan (fagosit, limfosit)
PlateletsPlatlet<1%Blood clottingPembekuan darah
Cardiac Cycle Systole (Contraction) Ventricles contract AV valves CLOSE "lub" sound (S1) Semilunar valves OPEN Blood pumped OUT Diastole (Relaxation) Ventricles relax AV valves OPEN "dub" sound (S2) Semilunar valves CLOSE Blood fills ventricles
Blood Clotting Cascade 1. Vessel damaged 2. Platelets aggregate 3. Thromboplastin 4. Prothrombin → Thrombin 5. Fibrinogen → Fibrin mesh SPM: Ca2+ and Vitamin K needed for clotting

⚡ Quick CheckSemakan Cepat

Which chamber has the thickest wall?Ruang manakah mempunyai dinding paling tebal?

ARight atriumAtrium kanan
BLeft ventricleVentrikel kiri
CRight ventricleVentrikel kanan
DLeft atriumAtrium kiri

🇲🇾 Malaysian ContextKonteks Malaysia

Cardiovascular disease is the leading cause of death in Malaysia! Thalassaemia (blood disorder) and dengue (affects platelets) are common health concerns. National Blood Centre (PDN) always needs donors.Penyakit kardiovaskular punca utama kematian di Malaysia! Thalassaemia (gangguan darah) dan denggi (menjejaskan platlet) ialah masalah kesihatan biasa. Pusat Darah Negara (PDN) sentiasa memerlukan penderma.

📋 SPM Practice📋 Latihan SPM

SPM QuestionSoalan SPM

Explain why the left ventricle wall is thicker than the right ventricle. [3 marks]Jelaskan mengapa dinding ventrikel kiri lebih tebal daripada ventrikel kanan. [3 markah]

📌 Exam Tip:📌 Tips Peperiksaan: Left ventricle pumps blood to the whole body (systemic circulation) — needs more muscle to generate higher pressure. Right ventricle only pumps to lungs (pulmonary) — shorter distance.Ventrikel kiri mengepam darah ke seluruh badan (peredaran sistemik) — perlukan lebih otot untuk menghasilkan tekanan lebih tinggi. Ventrikel kanan hanya mengepam ke paru-paru (pulmonari) — jarak lebih dekat.

🃏 FlashcardsKad Imbas

Artery carries blood?Arteri membawa darah?
Away from heartKeluar dari jantung
Vein has?Vena ada?
Valves to prevent backflowInjap untuk halang aliran balik
Haemoglobin function?Fungsi hemoglobin?
Binds and transports oxygenMengikat dan mengangkut oksigen
Pulmonary artery carries?Arteri pulmonari membawa?
Deoxygenated blood to lungsDarah terdeoksigen ke paru-paru
Capillary adaptation?Penyesuaian kapilari?
One-cell thick for diffusionSetebal satu sel untuk resapan