Podcast
Questions and Answers
What hormone regulates water reabsorption in the collecting duct?
What hormone regulates water reabsorption in the collecting duct?
Which of the following ions is primarily involved in maintaining pH balance in the body?
Which of the following ions is primarily involved in maintaining pH balance in the body?
What is the primary function of vasopressin (ADH) in the nephron?
What is the primary function of vasopressin (ADH) in the nephron?
Which system integrates with the renal system to maintain blood pressure?
Which system integrates with the renal system to maintain blood pressure?
Signup and view all the answers
What are osteoblasts primarily responsible for?
What are osteoblasts primarily responsible for?
Signup and view all the answers
Which hormone is released in response to low blood pressure and low blood volume?
Which hormone is released in response to low blood pressure and low blood volume?
Signup and view all the answers
What aspect of fluid and electrolyte balance involves the excretion of excess water and sodium?
What aspect of fluid and electrolyte balance involves the excretion of excess water and sodium?
Signup and view all the answers
What triggers the release of vasopressin (ADH)?
What triggers the release of vasopressin (ADH)?
Signup and view all the answers
Which ion is crucial for cardiac and muscle function?
Which ion is crucial for cardiac and muscle function?
Signup and view all the answers
What role does aldosterone play in the nephron?
What role does aldosterone play in the nephron?
Signup and view all the answers
Which part of the kidney is primarily responsible for sodium reabsorption?
Which part of the kidney is primarily responsible for sodium reabsorption?
Signup and view all the answers
How does angiotensin II influence the nephron?
How does angiotensin II influence the nephron?
Signup and view all the answers
How much fluid is approximately found in the human body?
How much fluid is approximately found in the human body?
Signup and view all the answers
What mechanism is NOT involved in maintaining normal pH in the body?
What mechanism is NOT involved in maintaining normal pH in the body?
Signup and view all the answers
What is the effect of high plasma osmolarity on ADH secretion?
What is the effect of high plasma osmolarity on ADH secretion?
Signup and view all the answers
Which of the following statements about the hypothalamus is true?
Which of the following statements about the hypothalamus is true?
Signup and view all the answers
What is the primary site of action for aldosterone in the nephron?
What is the primary site of action for aldosterone in the nephron?
Signup and view all the answers
What is the role of type A intercalated cells in the renal compensation for acid-base balance?
What is the role of type A intercalated cells in the renal compensation for acid-base balance?
Signup and view all the answers
Which of the following best describes the function of aquaporin-2 (AQP2) in the nephron?
Which of the following best describes the function of aquaporin-2 (AQP2) in the nephron?
Signup and view all the answers
How does the body initially respond to increased H+ concentration?
How does the body initially respond to increased H+ concentration?
Signup and view all the answers
Which component is NOT part of the extracellular matrix in bone?
Which component is NOT part of the extracellular matrix in bone?
Signup and view all the answers
ANG II acts primarily on which structure to exert a vasoconstrictor effect?
ANG II acts primarily on which structure to exert a vasoconstrictor effect?
Signup and view all the answers
Which of the following processes is responsible for the immediate regulation of blood PCO2?
Which of the following processes is responsible for the immediate regulation of blood PCO2?
Signup and view all the answers
What is the primary function of the buffering system in maintaining pH homeostasis?
What is the primary function of the buffering system in maintaining pH homeostasis?
Signup and view all the answers
What is the primary function of osteoblasts?
What is the primary function of osteoblasts?
Signup and view all the answers
Which hormone is primarily responsible for increasing calcium reabsorption in the kidneys?
Which hormone is primarily responsible for increasing calcium reabsorption in the kidneys?
Signup and view all the answers
What is the role of calcitonin in calcium homeostasis?
What is the role of calcitonin in calcium homeostasis?
Signup and view all the answers
Which structure in long bones is associated with growth?
Which structure in long bones is associated with growth?
Signup and view all the answers
What is the main component of the calcified extracellular matrix in bones?
What is the main component of the calcified extracellular matrix in bones?
Signup and view all the answers
How does calcitriol contribute to calcium homeostasis?
How does calcitriol contribute to calcium homeostasis?
Signup and view all the answers
Which of the following best describes the diaphysis of a long bone?
Which of the following best describes the diaphysis of a long bone?
Signup and view all the answers
What effect does parathyroid hormone (PTH) have on calcium levels?
What effect does parathyroid hormone (PTH) have on calcium levels?
Signup and view all the answers
Study Notes
BPK 205: Intro to Human Physiology
- Course covers fluid & electrolyte balance, and calcium homeostasis
- Lecture 30 focuses on fluid and electrolyte balance
- Lecture 31 focuses on calcium homeostasis
Lecture Objectives – Fluid & Electrolyte Balance
- Describe the body's fluid & electrolyte homeostasis
- Water balance: Vasopressin regulates water reabsorption in the collecting duct
- Aldosterone regulates sodium reabsorption in the distal tubule and collecting duct
- Explain how the Renin-Angiotensin-Aldosterone System (RAAS) maintains blood pressure
- Integrating renal and cardiovascular systems
- Explain how acid-base balance is maintained
Lecture Objectives – Calcium Balance
- Structure and growth of bone
- Roles of osteoblasts and osteoclasts
- Calcium homeostasis
- Hormones, role of bone, kidneys, and GI system
Readings
- Chapter 20: Fluid and Electrolyte Balance
- Chapter 23: Tissue and Bone Growth, and Calcium Balance
Fluid & Electrolyte Homeostasis
- Importance: maintaining ECF volume and osmolarity, blood volume, cardiac and muscle function, excitable cells, exocytosis, muscle contraction, bone formation, and pH balance
- Mass balance: Input + cellular production = cellular consumption + excretion
- Excess substances are excreted by the kidneys
- Integration of respiratory, renal, and cardiovascular systems is needed for proper balance
Maintaining Water Balance
- Water gain and loss: 2.2 L intake (food and drink), 0.3 L metabolic production, ~0.9 insensible loss from skin and lungs, 1.5 L urine, 0.1 L from feces
- Kidneys are vital for conserving or removing body fluids. Water reabsorption is regulated to maintain needed homeostasis
Filtrate Osmolarity Changes
- Urine concentration varies from highly dilute to concentrated
- Osmolarity changes through the nephron; this is dependent on hormonal regulation of water reabsorption in the distal nephron
Vasopressin (ADH)
- Hormone released by posterior pituitary gland
- Stimuli for release: high plasma osmolarity, low blood volume, and low blood pressure
- Controls water pores (aquaporin-2) into collecting duct cells.
- Increase in water reabsorption -> more concentrated urine
Stimuli for Vasopressin Release
- Mechanisms that trigger vasopressin release
- Stimulus relates to decreased blood pressure, decreased atrial stretch, and osmolarity greater than 280 mOsM.
Aldosterone & Sodium Reabsorption
- Steroid hormone synthesized by adrenal cortex
- Increases sodium reabsorption in distal tubule and collecting duct
- Main stimuli: Angiotensin II (low BP), High potassium (hyperkalemia)
Low Blood Pressure & Renin Secretion
- Low blood pressure stimulates renin secretion via 3 routes -Direct effect by Cardiovascular control center -Paracrines from macula densa or granular cells -Sympathetic activity on afferent arterioles
The Renin-Angiotensin-Aldosterone System (RAAS)
- Complex hormonal system that regulates blood pressure and water balance.
- Liver releases angiotensinogen—an inactive precursor for angiotensin I
- The enzyme renin converts it to angiotensin I
- Angiotension I is converted into Angiotensin II by ACE (angiotensin-converting enzyme)
- Angiotensin II is a powerful vasoconstrictor and stimulates aldosterone production
- Various targets: cardiovascular system, arterioles, hypothalamus
Low BP & The Renin-Angiotensin System
- Increased sympathetic activity, decreased blood pressure and decreased GFR
- Blood vessels constrict, resulting in increase blood pressure
- Increase in aldosterone and vasopressin release.
Acid-Base Balance
- Maintenance of proper pH levels through physiological mechanisms
- Buffers: HCO3⁻ in extracellular fluid, proteins, hemoglobin, phosphates in cells, phosphates and ammonia in urine to buffer excess protons.
- Ventilation: regulating blood PCO2, and thus H+, regulates rate and depth of breathing
- Kidneys: regulation of H⁺ and HCO₃⁻ secretion and reabsorption
Maintaining pH Homeostasis
- 3 mechanisms used by body
- Buffers (seconds); cellular proteins, hemoglobin, phosphate, and HCO3⁻ are used.
- Regulation of Ventilation (minutes); blood PCO2 and thus H⁺ is regulated/ adjusted.
- Kidneys (hours to days); regulation of H⁺ and HCO₃⁻ secretion and reabsorption.
Maintaining pH Homeostasis: Respiratory Compensation
- Two stimuli: Increased H⁺ and increased PCO₂ trigger the respiratory system adjustment
- Respiratory compensation for pH changes is immediate (rapid effect) and adjusts the breathing rate and depth to compensate for the changes, maintaining a balance of acids and bases.
Maintaining pH Homeostasis: Renal Compensation
- H+ secreted and HCO3⁻ reabsorbed at the proximal tubule during normal conditions.
- Fine regulation of acid-base balance at collecting duct
- Intercalated (I) cells (interspersed between principal cells): High carbonic anhydrase, type A I cells secrete H⁺ and reabsorb HCO3⁻ to adjust to acidosis conditions -> adjusting plasma to be more acidic.. Type B I cells secrete HCO3⁻ and reabsorb H⁺ to adjust to alkalosis conditions -> adjusting plasma to be more basic
Calcium in the Body
- Functions of calcium in extracellular matrix and fluid, and intracellular calcium
- Extracellular matrix: forms calcified matrix of bone and teeth
- Extracellular fluid: neurotransmitter release at synapse, role in myocardial and smooth muscle contraction, cofactor in coagulation cascade, influences excitability of neurons
- Intracellular: muscle contraction, signal in second messenger pathways
Structure of Bone
- Remodeling throughout life: calcified extracellular matrix called hydroxyapatite: Ca10(PO4)6(OH)2 , osteoblasts synthesize bone, and osteoclasts resorb bone. - Both are vital for calcium homeostasis
Calcium Homeostasis
- 3 main mechanisms:
- Parathyroid hormone (PTH): Increases calcium reabsorption from bone; increases calcium absorption from kidney.
- Calcitriol (Vit D₃): Increases calcium absorption from the GI.
- Calcitonin: Increases calcium deposition in bone
Parathyroid Hormone (PTH)
- Origin, chemical nature, biosynthesis, Transport in Circulation, Half-Life, Factors affecting release, Target cells or tissues, Receptor, Whole-body tissue reaction.
Calcitriol (Vitamin D3)
- Origin, chemical nature, mechanism (synthesis and transport), stimulus for synthesis, targets, receptors.
- Roles in whole-body, tissue and molecular levels, feedback regulation.
Calcitonin
- Origin, chemical nature (32 amino acid), biosynthesis, transport, half-life
- Factors affecting release, target cells or tissues, receptor, whole-body and tissue action
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on fluid and electrolyte balance in the human body as covered in BPK 205. This quiz will assess your understanding of key physiological concepts, including water balance, the Renin-Angiotensin-Aldosterone System, and calcium homeostasis. Prepare to explore the critical roles of various hormones and systems in maintaining homeostasis.
