Gas Exchange and Fluid Regulation Chapter 42

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the sodium-potassium pump in the proximal tubule?

To create a sodium gradient (correct)

To increase potassium levels in the urine

To decrease sodium levels in the blood

To balance water levels in the filtrate

How does the ascending loop of Henle primarily transport salts from the filtrate?

By passive transport only

Using diffusion alone

Through osmosis only

Through both active and passive transport (correct)

Which parameter is NOT a factor in Frick’s Law of Diffusion?

Concentration gradient

Membrane permeability

Molecular weight of the gas (correct)

Thickness of the barrier

What role does the antidiuretic hormone (ADH) play in the kidneys?

It saves water by increasing permeability in collecting ducts Signup and view all the answers

What unique feature do fish gills utilize for efficient gas exchange?

Countercurrent exchange system Signup and view all the answers

What is the typical resting membrane potential of a neuron?

-65 mV Signup and view all the answers

What primarily causes the negative resting membrane potential in neurons?

Higher concentration of negatively charged ions inside the cell Signup and view all the answers

During which stage of action potential do sodium channels quickly open?

Depolarization Signup and view all the answers

What is the primary role of the sodium-potassium pump in resting neurons?

To actively transport Na+ out and K+ in Signup and view all the answers

What is the effect of potassium ions leaking out of a neuron during resting potential?

It contributes to maintaining a negative membrane potential. Signup and view all the answers

What is the correct pathway for lipid soluble signaling molecules after they diffuse into the cytosol?

They form a hormone-receptor complex and are transported to the nucleus. Signup and view all the answers

Which type of signaling molecules requires the presence of hydrophilic carriers in the bloodstream?

Lipid soluble hormones. Signup and view all the answers

How is the signal transduction process characterized?

Conversion of an extracellular signal into an intracellular signal. Signup and view all the answers

What is NOT a consequence of receptor blocking by drugs?

Increased activity of the target proteins. Signup and view all the answers

What is the first step in processing lipid soluble signaling molecules?

Diffusion of the hormone across the plasma membrane. Signup and view all the answers

Which of the following best describes ligand-gated ion channels?

They require a ligand to change their conformation and allow ion passage. Signup and view all the answers

What ultimately results from the interaction of the intracellular signaling molecule with DNA?

Altered gene expression. Signup and view all the answers

What role do relay molecules play in the signal transduction pathway?

They amplify the signal as it moves down the pathway. Signup and view all the answers

What is the main event occurring during the G2 phase of the cell cycle?

Increased synthesis of proteins and organelles Signup and view all the answers

Which structure is formed from hollow tubes made of alpha and beta subunits during the cell cycle?

Microtubules Signup and view all the answers

During which phase does the nuclear membrane completely break down?

Prometaphase Signup and view all the answers

What structure forms in animal cells to initiate cytokinesis?

Cleavage furrow Signup and view all the answers

Which phase of the cell cycle is characterized as the 'resting state'?

G0 Phase Signup and view all the answers

What significant change occurs during anaphase?

Sister chromatids become true chromosomes Signup and view all the answers

What is required at the G1/S checkpoint for a cell to proceed in the cycle?

Adequate ATP levels Signup and view all the answers

Which component is responsible for attaching to kinetochores during prometaphase?

Kinetochore microtubules Signup and view all the answers

What is the primary role of cyclins in the cell cycle?

To initiate the synthesis of cyclin-dependent kinases (CDKs) Signup and view all the answers

Which statement regarding CDK is correct?

CDK acts as a regulatory enzyme by phosphorylating other proteins Signup and view all the answers

What is a characteristic of malignant tumors?

They can invade other tissue types and may cause metastasis Signup and view all the answers

Which factor is NOT essential for cell division to occur?

Mature cells having the ability to divide Signup and view all the answers

What checkpoint assesses if all chromosomes are properly attached to the mitotic spindle?

Late metaphase (spindle) checkpoint Signup and view all the answers

What is the role of E2F in the cell cycle?

To activate the G1 checkpoint for cell cycle progression Signup and view all the answers

Which condition is associated with cancerous cells?

They remain immortal and can divide indefinitely Signup and view all the answers

How does PDGF function during tissue injury?

It promotes cell division to facilitate wound healing Signup and view all the answers

What is the function of the proton-sucrose symporter in the companion cell?

To bring in hydrogen ions and sucrose together Signup and view all the answers

How do developing leaf cells acquire sucrose?

Through passive transport following the sucrose concentration gradient Signup and view all the answers

Which type of soil ions are immediately available for plant use?

Anions that dissolve in soil water Signup and view all the answers

What role do mycorrhizal fungi play in nutrient uptake for plants?

They enhance nutrient availability by increasing root surface area Signup and view all the answers

What is the correct order of the processes through which animals obtain nutrients?

Ingestion, Digestion, Absorption, Elimination Signup and view all the answers

Which jaw adaptation is characteristic of a filter feeder?

Using a sieve-like structure to filter food from water Signup and view all the answers

What happens when hydrogen ions leave the vacuole of the sink cell?

They exit through a proton-sucrose antiporter to bring in sucrose Signup and view all the answers

How do hydrogen pumps in root cells assist in nutrient uptake?

They create electrochemical gradients to facilitate ion transport Signup and view all the answers

What is the primary role of microvilli in the small intestines?

To enhance the absorption efficiency of nutrients Signup and view all the answers

Which process is involved in the breakdown of lipids in the digestive system?

Lingual lipase breakdown Signup and view all the answers

How do osmoregulators maintain constant molarity within their bodies?

Through active transport that utilizes ATP Signup and view all the answers

What is the primary function of the large intestines?

To compact waste and absorb water to form feces Signup and view all the answers

Which nitrogenous waste is most toxic and requires the least amount of energy to produce?

Ammonia Signup and view all the answers

What advantage do osmoconformers have in stable ocean habitats?

They require less energy to maintain constant osmolarity. Signup and view all the answers

Which of the following is NOT a step in the chemical digestion of food?

Absorption of nutrients in the stomach Signup and view all the answers

What defines the metabolic rate in animals?

The energy used per unit of time Signup and view all the answers

Study Notes

Proximal Tubule Lumen

Sodium-potassium pump moves sodium out to blood vessels and potassium in.
Goal: Establish a sodium gradient.

Loop of Henle

Descending loop: Filtrate moves down, water passively moves out (filtrate concentrates).
Ascending loop: Salts move out through concentration gradients (passive and active transport).
Henle loop descends again (ADH comes into play).

Antidiuretic Hormone (ADH)

ADH conserves water in the collecting ducts by making them more permeable.
Water leaves the loop of Henle more than usual.

Gas Exchange (Chapter 42)

Homeostasis depends on respiratory and circulatory systems.
Gas Exchange Steps:
- Ventilation
- Diffusion
- Circulation
- Diffusion
- Cellular respiration
Organisms obtain oxygen and release carbon dioxide through diffusion.

Gas Exchange in Water

Gases dissolve in water from the atmosphere, influenced by several factors.
Fick's Law of Diffusion:
- Rate of diffusion depends on:
  - Gas solubility
  - Temperature
  - Surface area for diffusion
  - Partial pressure differences across the exchange surface
  - Thickness of the diffusion barrier
Increased surface area, decreased membrane thickness, increased concentration gradient, or increased membrane permeability increase diffusion through membranes.

Aquatic Organisms

Not all aquatic organisms have gills; some use simple diffusion through skin.

Gills in Aquatic organisms

Parapodia in some: Function as gills.
Coeloms in others: Gills embedded in coelom (e.g., starfish).
Fish gills: Countercurrent exchange system (blood flows opposite to water flow).
Warm blood transfers heat to adjacent veins.

Billfish

Heater cells warm up neurons in eye cells.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore key concepts from Chapter 42 focusing on the proximal tubule, Loop of Henle, and gas exchange mechanisms in organisms. Understand the role of the sodium-potassium pump, ADH effects, and the principles of diffusion. This quiz will test your knowledge of essential physiological processes.