Mammalian kidney Flashcards
Mammalian kidney (24 cards)
What are the main structures of the mammalian kidney?
Cortex, Medulla, Nephrons
Cortex is the outer layer, Medulla is the inner layer containing loops of Henle, and Nephrons are the functional units of the kidney.
What is the function of the Glomerulus and Bowman’s Capsule?
Filtration of blood
These structures are involved in the initial filtration process of the blood in the nephron.
What is the primary role of the Proximal Tubule in the nephron?
Reabsorbs nutrients, salts, water
This part of the nephron is crucial for reclaiming essential substances from the filtrate.
Fill in the blank: The Descending limb of the Loop of Henle is responsible for _______.
Water reabsorption
Fill in the blank: The Ascending limb of the Loop of Henle is _______-impermeable.
water
What does the Distal Tubule regulate?
Na+, K+, pH
The Distal Tubule is involved in the fine-tuning of electrolyte and acid-base balance.
What is the function of the Collecting Duct in the nephron?
Final water reabsorption (hormonal control)
The Collecting Duct plays a key role in determining the final concentration of urine.
How does the Loop of Henle contribute to osmolarity in the kidney?
Creates a hyperosmotic environment in the medulla
This is essential for water reabsorption and urine concentration.
What system maintains the osmolarity gradient in the kidney?
Countercurrent multiplier system
This system is crucial for enhancing the concentration of urine.
What hormone is secreted by the hypothalamus to promote water retention?
Antidiuretic Hormone (ADH)
ADH is released when blood osmolarity is high, indicating dehydration.
What effect does alcohol have on ADH?
Inhibits ADH, leading to more urine output and dehydration
This can cause increased urination and contribute to dehydration effects.
What triggers the Renin-Angiotensin-Aldosterone System (RAAS)?
Blood volume/pressure drops
This system is activated during states such as dehydration or bleeding.
What is the role of angiotensin II in the RAAS?
Constricts blood vessels and stimulates aldosterone
This action increases blood pressure and promotes Na+ and water reabsorption.
What does Atrial Natriuretic Peptide (ANP) do?
Opposes RAAS
ANP is released when blood pressure is high and inhibits renin and aldosterone.
How do desert mammals adapt their kidneys for water conservation?
Very long loop of Henle → extremely concentrated urine
This adaptation allows them to minimize water loss.
How do aquatic mammals’ kidneys differ from those of desert mammals?
Short loop of Henle → produce dilute urine
Aquatic mammals excrete excess water more effectively.
What is the excretion method used by birds and reptiles to conserve water?
Uric acid excretion
This method is less water-intensive compared to urea or ammonia.
Freshwater fish excrete large amounts of _______ urine to remove excess water.
dilute
Marine fish excrete _______ urine to retain water.
small amounts of concentrated
What is osmoregulation?
Maintaining internal balance
It is crucial for homeostasis in organisms.
Excretion of nitrogenous waste varies by environment. Name the three forms.
Ammonia, Urea, Uric Acid
Different organisms have adapted to excrete nitrogenous waste based on their habitats.
How do kidneys regulate water, salt, and waste excretion?
Through nephrons
The nephron is the functional unit of the kidney responsible for these processes.
What hormones fine-tune kidney function based on body needs?
ADH, RAAS, ANP
These hormones play critical roles in regulating kidney activity.
What adaptations help animals survive in extreme environments?
Kidney structure variations
Different kidney structures allow for efficient water and waste management in varying habitats.
