Human Heart / मानव हृदय
The source describes the human heart as myogenic, meaning its contraction is initiated by a pulse produced by the sino-atrial node.
Human Heart myogenic होता है। Source के अनुसार heart contraction Sino-Atrial Node द्वारा produced pulse से initiate होता है।
SA Node – Pacemaker / एसए नोड – पेसमेकर
The sino-atrial node is located in the right atrium and is called the pacemaker.
SA Node right atrium में located होता है तथा इसे Pacemaker कहा जाता है।
Heart Sounds / हृदय ध्वनियाँ
- First heart sound → Lub
- Second heart sound → Dub
Systole and Diastole / सिस्टोल एवं डायस्टोल
Contraction of the heart is called systole and relaxation is called diastole.
Heart का contraction → Systole तथा relaxation → Diastole कहलाता है।
The source associates 120 mm Hg with systole and 80 mm Hg with diastole.
Excretion / उत्सर्जन
Excretion is the process of eliminating harmful waste products from the animal body and helps regulate the composition of body fluids and tissues.
Body से harmful waste products को eliminate करने की process को Excretion कहते हैं।
Human Excretory System / मानव उत्सर्जन तंत्र
The source states that the human excretory system contains two kidneys.
Human Excretory System में two kidneys होते हैं।
Nephron / नेफ्रॉन
Nephron is the structural and functional unit of the kidney.
Nephron = Structural and Functional Unit of Kidney
Urine / मूत्र
- Colour → Pale yellow
- Pigment → Urochrome
- Water → About 95%
- Salts → About 2%
- Urea → About 2.6%
- Uric acid → About 0.3%
- pH → About 6.0 in source
- Specific gravity → 1.015–1.025
- Daily volume → 1–2 litres
The source states that urine develops a pungent smell on standing because urea is converted into ammonia.
Main Excretory Organs in Animals / जन्तुओं के प्रमुख उत्सर्जी अंग
- Amoeba → Contractile vacuole
- Tapeworm → Flame cells/Solenocytes
- Ascaris → Renette cell
- Earthworm → Nephridia
- Cockroach → Malpighian tubules
- Scorpion → Coxal glands
- Prawn → Green glands
Main Excretory Products / प्रमुख उत्सर्जी पदार्थ
- Ammonia → Most invertebrates and fishes in source
- Urea → Ascaris, earthworm, cartilaginous fishes, amphibians and mammals
- Uric Acid → Insects, land reptiles and birds
Exam Revision / परीक्षा पुनरावृत्ति
- Pacemaker → SA Node
- SA Node location → Right atrium
- Heart contraction → Systole
- Heart relaxation → Diastole
- Kidney unit → Nephron
- Urine pigment → Urochrome
- Earthworm → Nephridia
- Cockroach → Malpighian tubules
- Prawn → Green glands