Podcast
Questions and Answers
What is one important function of the kidneys mentioned in the text?
What is one important function of the kidneys mentioned in the text?
How do the kidneys help maintain a stable internal environment for cells?
How do the kidneys help maintain a stable internal environment for cells?
Which of the following is NOT a waste product eliminated by the kidneys?
Which of the following is NOT a waste product eliminated by the kidneys?
What is the primary means for eliminating waste products of metabolism according to the text?
What is the primary means for eliminating waste products of metabolism according to the text?
Signup and view all the answers
How do the kidneys clear unwanted substances from the blood?
How do the kidneys clear unwanted substances from the blood?
Signup and view all the answers
What is the main function of the kidneys as described in the text?
What is the main function of the kidneys as described in the text?
Signup and view all the answers
Which hormone is secreted by the kidneys to stimulate red blood cell production?
Which hormone is secreted by the kidneys to stimulate red blood cell production?
Signup and view all the answers
What can happen if the intake of a substance exceeds its excretion in the body?
What can happen if the intake of a substance exceeds its excretion in the body?
Signup and view all the answers
What process do the kidneys perform during prolonged fasting to maintain glucose levels?
What process do the kidneys perform during prolonged fasting to maintain glucose levels?
Signup and view all the answers
Where is the hilum located in each kidney?
Where is the hilum located in each kidney?
Signup and view all the answers
Study Notes
Kidney Functions
- The kidneys maintain the stable internal environment necessary for cells to perform their activities by controlling the volume and electrolyte composition of body fluids.
- The kidneys filter the plasma and remove substances from the filtrate at variable rates, depending on the body's needs.
- The kidneys clear unwanted substances from the filtrate by excreting them in the urine and returning substances needed back to the blood.
Excretion of Waste Products
- The kidneys are the primary means of eliminating waste products of metabolism, such as urea, creatinine, uric acid, and end products of hemoglobin breakdown.
- The kidneys also eliminate toxins and foreign substances produced by the body or ingested, such as pesticides, drugs, and food additives.
Regulation of Body Fluids
- The kidneys regulate water and electrolyte balances by matching excretion to intake precisely.
- If intake exceeds excretion, the amount of the substance in the body will increase, and if intake is less than excretion, the amount will decrease.
- The kidneys regulate body fluid osmolality and electrolyte concentrations.
Regulation of Other Functions
- The kidneys regulate arterial pressure.
- The kidneys regulate acid-base balance.
- The kidneys secrete erythropoietin, which stimulates production of red blood cells by hematopoietic stem cells in the bone marrow.
- The kidneys produce 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, essential for normal calcium deposition in bone and calcium reabsorption by the gastrointestinal tract.
- The kidneys synthesize glucose from amino acids and other precursors during prolonged fasting, a process referred to as gluconeogenesis.
Kidney Structure and Location
- The two kidneys lie on the posterior wall of the abdomen, outside the peritoneal cavity.
- Each kidney weighs about 150 grams and is about the size of a clenched fist.
- The medial side of each kidney contains an indented region called the hilum, which passes through the renal artery and vein, lymphatics, nerve supply, and ureter.
- The kidney is surrounded by a tough fibrous capsule that protects its delicate inner structures.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the vital functions of the kidneys in maintaining the balance of body fluids and electrolytes. Learn how the kidneys control the volume and composition of body fluids by regulating intake and output. Dive into the significant role of kidneys in excreting waste materials and ensuring metabolic balance.
