Cell Physiology and Structure
48 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of total body weight does the plasma account for?

  • 15%
  • 20%
  • 5% (correct)
  • 10%

Which factor contributes to lower total body water percentage in females compared to males?

  • Higher fat content in females (correct)
  • Increased metabolic rate in females
  • Higher muscle mass in females
  • Lower body weight in females

Which fluid compartment constitutes the highest percentage of total body water?

  • Extracellular fluid
  • Transcellular fluid
  • Intracellular fluid (correct)
  • Interstitial fluid

What physiological condition could lead to a lesser total body water percentage?

<p>Obesity (D)</p> Signup and view all the answers

Which of the following fluids is considered transcellular fluid?

<p>Cerebrospinal fluid (C)</p> Signup and view all the answers

At what developmental stage does total body water percentage typically reach adult levels?

<p>Puberty (D)</p> Signup and view all the answers

What is the primary role of water in digestion?

<p>As a solvent for digestive enzymes (A)</p> Signup and view all the answers

What role does osmolarity play in the body?

<p>Regulates fluid movement between compartments (B)</p> Signup and view all the answers

What is the primary energy source for primary active transport mechanisms?

<p>Hydrolysis of ATP (D)</p> Signup and view all the answers

In which type of transport do Na+ ions typically assist in the movement of glucose into the cell?

<p>Secondary active transport (C)</p> Signup and view all the answers

Which of the following correctly describes the function of the Na+/K+ pump?

<p>Transports 3 Na+ out and 2 K+ into the cell (A)</p> Signup and view all the answers

Which type of transport protein is characterized by transporting two different substances in opposite directions?

<p>Antiporter (A)</p> Signup and view all the answers

What type of active transport mechanism primarily uses energy stored in an electrochemical gradient?

<p>Secondary active transport (D)</p> Signup and view all the answers

Which of the following is an example of exocytosis in cells?

<p>Releasing hormones and enzymes (B)</p> Signup and view all the answers

What does the Ca²+ pump primarily function to regulate within the cardiac and skeletal muscles?

<p>Calcium concentrations (C)</p> Signup and view all the answers

The breakdown of which molecule is essential for the functioning of ATPase enzymes?

<p>ATP (C)</p> Signup and view all the answers

What is the primary role of the cell membrane?

<p>Controls the movement of substances in and out of the cell (D)</p> Signup and view all the answers

Which type of lipid primarily makes up the cell membrane?

<p>Phospholipids (A)</p> Signup and view all the answers

How does the presence of cholesterol affect the cell membrane?

<p>Reduces fluidity and increases stability of the membrane (B)</p> Signup and view all the answers

What characterizes transmembrane proteins in the cell membrane?

<p>They span the entire thickness of the membrane (A)</p> Signup and view all the answers

Which of the following correctly describes the arrangement of phospholipids in the cell membrane?

<p>Hydrophilic heads are on the inner and outer surfaces with hydrophobic tails in between (C)</p> Signup and view all the answers

What is a function of the receptors found in the cell membrane?

<p>To stimulate or inhibit cell functions upon binding with chemicals (A)</p> Signup and view all the answers

Which type of protein is associated with the inner or outer surface of the cell membrane?

<p>Peripheral proteins (B)</p> Signup and view all the answers

Which of the following describes the permeability of the cell membrane?

<p>Selectively permeable to ions and organic molecules (D)</p> Signup and view all the answers

What role does interstitial fluid play during periods of hemorrhage?

<p>It provides a reservoir for vascular volume. (B)</p> Signup and view all the answers

Which system is responsible for rapid control of homeostasis through nerve impulses?

<p>Nervous System (C)</p> Signup and view all the answers

What is the primary function of hemoglobin in relation to oxygen concentration in extracellular fluid?

<p>It buffers oxygen concentration. (C)</p> Signup and view all the answers

How is blood glucose level regulated in the body?

<p>Through hormone secretion from endocrine glands. (D)</p> Signup and view all the answers

What characteristic facilitates rapid exchange of water and solutes in the body?

<p>Proximity of cells to blood vessels. (D)</p> Signup and view all the answers

What happens to the affinity of hemoglobin for oxygen when it reaches the lungs?

<p>It increases due to high oxygen tension. (A)</p> Signup and view all the answers

What is the role of water in maintaining pH levels in body fluids?

<p>It dissociates into H⁺ and OH⁻ ions. (C)</p> Signup and view all the answers

Which sensation does not require water for its function?

<p>Tactile sensation (B)</p> Signup and view all the answers

What physiological response occurs when arterial blood pressure increases?

<p>Inhibition of vasomotor center. (D)</p> Signup and view all the answers

What is the primary function of the endocrine system in homeostasis?

<p>It secretes hormones for slow regulation. (D)</p> Signup and view all the answers

At what percentage of total body weight loss does thirst sensation typically occur?

<p>1% (D)</p> Signup and view all the answers

Which ions primarily compose the intracellular fluid (ICF)?

<p>Potassium and Phosphate (C)</p> Signup and view all the answers

What characterizes sensible water loss?

<p>It can be measured directly. (B)</p> Signup and view all the answers

What primarily drives the difference in ion composition between intracellular fluid (ICF) and extracellular fluid (ECF)?

<p>Cell membrane integrity and energy supply. (D)</p> Signup and view all the answers

How does the high specific heat of water benefit the body?

<p>It prevents rapid changes in body temperature. (A)</p> Signup and view all the answers

What happens to cardiac output and blood pressure during severe dehydration if not compensated?

<p>They decrease due to reduced blood volume. (C)</p> Signup and view all the answers

What effect does negative feedback control have on homeostatic functions?

<p>It inhibits the function to restore balance. (C)</p> Signup and view all the answers

Which of the following is true about positive feedback control?

<p>It results in an increase of the initiating stimulus. (D)</p> Signup and view all the answers

Which mechanism is involved in the regulation of arterial blood pressure during a rise in blood pressure?

<p>Inhibition of the vasomotor center. (A)</p> Signup and view all the answers

What initiates the positive feedback mechanism during parturition?

<p>Stretch of the uterine cervix. (A)</p> Signup and view all the answers

In the context of blood glucose regulation, what triggers the secretion of insulin?

<p>Elevated blood glucose levels above normal. (D)</p> Signup and view all the answers

What is a characteristic outcome of positive feedback mechanisms in abnormal conditions?

<p>They can lead to life-threatening situations. (D)</p> Signup and view all the answers

How does increased CO2 concentration affect pulmonary ventilation?

<p>It induces an increase in ventilatory response. (A)</p> Signup and view all the answers

What is the overall impact of negative feedback mechanisms on homeostasis?

<p>They lead to a stable and balanced internal environment. (B)</p> Signup and view all the answers

Flashcards

Cell Membrane

A double layer of lipids and proteins that surrounds a cell, separating it from the outside environment and controlling what enters and leaves.

Lipid Bilayer

The basic structure of the cell membrane, made of two layers of phospholipids.

Phospholipids

Lipids with a hydrophilic head and a hydrophobic tail, forming the cell membrane's bilayer.

Selective Permeability

The cell membrane's ability to control which substances enter or leave the cell.

Signup and view all the flashcards

Integral Proteins

Proteins that span the entire cell membrane, often acting as channels or transporters.

Signup and view all the flashcards

Peripheral Proteins

Proteins that are only on the surface of the cell membrane.

Signup and view all the flashcards

Cholesterol

A lipid that strengthens the cell membrane and influences its fluidity.

Signup and view all the flashcards

Cell Function Control

The cell membrane contains receptors that respond to chemical signals to initiate or inhibit cell actions.

Signup and view all the flashcards

Active Transport

Movement of molecules across a cell membrane against their concentration gradient, requiring energy.

Signup and view all the flashcards

Primary Active Transport

Active transport that uses ATP directly for the movement of molecules against their concentration gradient.

Signup and view all the flashcards

Secondary Active Transport

Active transport that uses the electrochemical gradient of one molecule to move another molecule against its gradient.

Signup and view all the flashcards

Na+/K+ Pump

Primary active transport that moves 3 sodium ions out of the cell and 2 potassium ions into the cell.

Signup and view all the flashcards

Uniporter

Transport protein that carries one substance in one direction.

Signup and view all the flashcards

Symporter

Transport protein that carries two substances in the same direction.

Signup and view all the flashcards

Antiporter

Transport protein that carries two substances in opposite directions.

Signup and view all the flashcards

Exocytosis

Process by which a cell expels molecules and other objects too large for the cell membrane to pass through.

Signup and view all the flashcards

Extracellular Fluid (ECF)

Fluid outside of the cells, comprising interstitial fluid, plasma, and transcellular fluid.

Signup and view all the flashcards

Interstitial Fluid (ISF)

Fluid in the spaces between cells, bathing the cells; about 15% of total body weight.

Signup and view all the flashcards

Plasma

Fluid part of blood, inside circulatory system; about 5% of total body weight.

Signup and view all the flashcards

Transcellular fluid

Fluid present in epithelial-lined spaces (e.g., joints, eyes)

Signup and view all the flashcards

Total Body Water (TBW)

Water making up 60% of body weight, distributed between intracellular and extracellular compartments.

Signup and view all the flashcards

Intracellular Fluid (ICF)

Fluid inside cells. Comprises about 40% of total body weight.

Signup and view all the flashcards

Age and TBW

Infants have higher percentage TBW (75%), declining to adult levels (60-65% for men and 50-55% for women) in adulthood, and decreasing further in old age.

Signup and view all the flashcards

Water's Importance in Body Functions

Water is essential for nutrition, digestion, absorption, excretion, maintaining osmotic balance, and facilitating ion & molecule movement.

Signup and view all the flashcards

Homeostasis Definition

Maintaining a stable internal environment.

Signup and view all the flashcards

Interstitial Fluid

Fluid surrounding cells, part of the extracellular fluid.

Signup and view all the flashcards

ECF (Extracellular Fluid)

Fluid outside cells, containing essential nutrients and ions for cells.

Signup and view all the flashcards

Nervous System Homeostasis

Rapid responses to maintain internal balance, using nerve signals.

Signup and view all the flashcards

Endocrine System Homeostasis

Slower control, using hormones to regulate homeostasis.

Signup and view all the flashcards

Blood Pressure Regulation

Nervous system mechanism controlling blood pressure.

Signup and view all the flashcards

Blood Glucose Regulation

Endocrine system response involving insulin to manage blood sugar.

Signup and view all the flashcards

Oxygen Buffering

Hemoglobin's role in controlling oxygen levels in the body, changes affinity.

Signup and view all the flashcards

Water's Ionizing Property

Water dissociates into hydrogen (H+) and hydroxide (OH-) ions, crucial for pH regulation.

Signup and view all the flashcards

Water's Role in Body Temperature

Water's high specific heat, latent heat of evaporation, and conductivity help regulate body temperature.

Signup and view all the flashcards

Sensible Water Loss

Measurable water loss (e.g., urine, sweat, feces).

Signup and view all the flashcards

Insensible Water Loss

Unnoticeable water loss (e.g., skin evaporation, breathing).

Signup and view all the flashcards

ICF vs ECF Composition

The internal fluid (ICF) and extracellular fluid (ECF) compositions differ due to cell membrane integrity and active transport.

Signup and view all the flashcards

Dehydration Risk

Water loss exceeding intake leads to dehydration.

Signup and view all the flashcards

Major ECF Cation

Sodium (Na+) is the dominant positive ion in the extracellular fluid.

Signup and view all the flashcards

Major ICF Cation

Potassium (K+) is the dominant positive ion in the intracellular fluid.

Signup and view all the flashcards

Negative Feedback

A control mechanism where the output of a function inhibits that function, leading to stability.

Signup and view all the flashcards

Positive Feedback

A control mechanism where the output of a function stimulates that function, leading to instability.

Signup and view all the flashcards

Homeostasis

Maintaining a stable internal environment in the body.

Signup and view all the flashcards

Feedback Control

Control of a function by the effect of that function's output.

Signup and view all the flashcards

Blood Glucose Regulation

Negative feedback maintaining blood sugar levels by stimulating insulin secretion for high blood sugar.

Signup and view all the flashcards

Parturition

Positive feedback mechanism of childbirth where uterine contractions increase until the baby is born.

Signup and view all the flashcards

Death Cycle

A positive feedback loop that accelerates a condition that is already abnormal and ultimately leads to death.

Signup and view all the flashcards

Blood Pressure Regulation

Negative feedback mechanism regulating blood pressure by decreasing the heart rate and vasodilation when blood pressure is high.

Signup and view all the flashcards

Study Notes

Physiology of the Cell

  • The human body is comprised of systems (e.g., cardiovascular, respiratory, digestive).
  • Systems are composed of organs with complementary functions.
  • Organs are made of tissues, which are made of cells.
  • Cells are the fundamental structural units in the body.
  • Functions of the body's parts work together to maintain health.

Structure of the Cell

  • A mass of protoplasm, consisting of cytoplasm, cell organelles, and the nucleus.
  • A cell membrane surrounds the cell.

Cell Membrane Structure and Function

  • A double layer of lipids and proteins, separating the cytoplasm from its surroundings.
  • Function:
    • Protects the cell from its environment.
    • Controls movement of substances in and out of cells and organelles (selectively permeable).
    • Contains receptors to stimulate or inhibit cell functions.
  • Structure:
    • Lipids: Primarily phospholipids (polar heads and non-polar tails) and cholesterol (affects membrane fluidity). Arranged in a bilayer.
    • Proteins: Embedded in the lipid bilayer, some combined with lipids (lipoproteins) or carbohydrates (glycoproteins).
      • Peripheral proteins: on the membrane surface.
      • Integral proteins: span the entire membrane.
      • Functions: Membrane receptors relay signals between the cell and external environment.
    • Carbohydrates: Small amount, combined with lipids (glycolipids) or proteins (glycoproteins), on the outer surface of the membrane.
    • Functions Include: cell attachment, receptor sites, and charge regulation.

Transport Across Cell Membranes

  • Passive Transport:
    • Movement of substances down a concentration gradient (no energy required).
    • Types: Simple diffusion, Facilitated diffusion.
    • Simple Diffusion: Movement of molecules from high to low concentration. Factors affecting rate: concentration gradient, molecular weight, and medium solubility.
    • Facilitated diffusion: Movement of substances with the aid of carrier proteins, across the membrane
    • Factors affecting rate: Distance, temperature, membrane thickness.
    • Routes: through lipid bilayer (small molecules), or protein channels (large molecules).
    • Types of protein channels: Non-gated (always open), Gated (open/close based on stimuli).
      • Types of gated channels: Voltage-gated(respond to membrane voltage changes) and Ligand-gated (respond to chemical signaling).
  • Active Transport:
    • Movement of substances against a concentration gradient (requires energy—ATP).
    • Types:
      • Primary active transport: energy directly from ATP breakdown (e.g., Na+/K+ pump).
      • Secondary active transport: uses electrochemical gradient created by primary active transport. (e.g., Na+/glucose cotransporter)

Endocytosis & Exocytosis

  • Endocytosis: Cell taking in large molecules or particles.
    • Types: Receptor-mediated (particles bind to receptors) and non-receptor-mediated (Phagocytosis, Pinocytosis).
  • Exocytosis: Release of large molecules and particles from the cell—through vesicles.

General Physiology

  • Composition of the human body: ~60% water, ~18% protein, ~15% fat, ~7% minerals.
  • Body Fluids: Total body water (TBW): Intracellular fluid (ICF) (40%), Extracellular fluid (ECF) (20%).
  • Water importance: Solvent, nutrition, digestion, absorption, excretion, maintaining body osmolarity, cell membrane function, body temp regulation.
  • Homeostasis: Process of maintaining internal conditions constant
    • Control mechanisms: Nervous, Endocrine, and Chemical
    • Feedback Mechanisms: Negative (response opposes the initial stimulus) or Positive (response amplifies the initial stimulus). Examples provided in the text.

Studying That Suits You

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

Quiz Team

Related Documents

Cell Membrane PDF

Description

Explore the intricacies of cell physiology, including how cells function within various systems of the human body. This quiz delves into the structure and function of cell membranes, illustrating the critical role cells play in maintaining health and homeostasis.

More Like This

Introduction to Physiology
11 questions

Introduction to Physiology

FruitfulTheory avatar
FruitfulTheory
Introduction to Physiology
5 questions

Introduction to Physiology

GodlikeMolybdenum avatar
GodlikeMolybdenum
Introduction to Physiology Quiz
5 questions

Introduction to Physiology Quiz

GodlikeMolybdenum avatar
GodlikeMolybdenum
Use Quizgecko on...
Browser
Open
Browser
Browser