Name: homeostasis and negative feedback
Uploaded: 2023-06-23T15:38:43.000Z
Duration: 1 min 16 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms- Structures and Processes

LS.Bio.3.1

What is Homeostasis?

הומאוסטזיס הוא יכולתו של הגוף לשמור על תנאים פנימיים יציבים בתגובה לסביבה החיצונית המשתנה.
לדוגמה, כאשר חם בחוץ, טמפרטורת הגוף של אדם עשויה להתחיל לעלות, והגוף חייב להגיב כדי לנטרל את העלייה.
קולטנים, מרכזי בקרה ומשפיעים מתאמים את השינויים הפיזיולוגיים הדרושים כדי להגיב למשתנה.
במקרה של עלייה בטמפרטורת הגוף, קולטני חום על תאי העור מזהים את הטמפרטורה הגבוהה ומעבירים את המסר דרך דחפים עצביים למוח, מרכז הבקרה.
המוח משווה את הגירוי עם נקודה מוגדרת – הטווח הפיזיולוגי של המשתנה. הנקודה שנקבעה לטמפרטורת גוף אנושית רגילה היא כ-37 מעלות צלזיוס.
כאשר טמפרטורת הגוף עולה על הנקודה שנקבעה, המוח מאותת למשפיעים, בלוטות הזיעה, לייצר זיעה. אידוי הזיעה מקרר את הגוף.
ברגע שטמפרטורת הגוף חוזרת לנקודה שנקבעה, הקולטנים שולחים משוב למוח כדי להפחית את ייצור הזיעה, ומבטיחים שמירה על הומאוסטזיס.

מהו הומאוסטזיס?

<div style="direction:rtl">
שמירה על הומאוסטזיס מחייבת שהגוף ישמור ברציפות על התנאים הפנימיים שלו. לכל מצב פיזיולוגי יש נקודת הגדרה מסוימת, מטמפרטורת הגוף, לחץ הדם ועד לרמות של חומרים מזינים מסוימים. נקודת קבע היא הערך הפיזיולוגי שסביבו משתנה הטווח התקין. טווח נורמלי הוא סט מוגבל של ערכים שהוא בריא ויציב בצורה מיטבית. לדוגמה, נקודת ההגדרה לטמפרטורת גוף רגילה היא בערך C37 (98.6F). פרמטרים פיזיולוגיים, כגון טמפרטורת גוף ולחץ דם, נוטים לנוע בטווח תקין של כמה מעלות מעל ומתחת לנקודה זו. מרכזי בקרה במוח ובחלקים אחרים בגוף עוקבים ומגיבים לסטיות מהומאוסטזיס באמצעות משוב שלילי. משוב שלילי הוא מנגנון שהופך סטייה מנקודת ההגדרה. לכן, משוב שלילי שומר על פרמטרי הגוף בטווח התקין שלהם. שמירה על הומאוסטזיס על ידי משוב שלילי נמשכת בכל הגוף בכל עת, והבנת המשוב השלילי היא אפוא בסיסית להבנת הפיזיולוגיה האנושית.

חיישן, המכונה גם קולטן, הוא רכיב של מערכת משוב המנטרת ערך פיזיולוגי. ערך זה מדווח למרכז הבקרה. מרכז הבקרה הוא הרכיב במערכת משוב המשווה את הערך לטווח הנורמלי. מרכז הבקרה מפעיל אפקטור אם הערך חורג מדי מנקודת ההגדרה. אפקטור הוא רכיב במערכת משוב שגורם לשינוי להפוך את המצב ולהחזיר את הערך לטווח הנורמלי.

לדוגמה, כדי להפעיל את המערכת, גירוי חייב להניע פרמטר פיזיולוגי מעבר לטווח הרגיל שלו (מעבר להומאוסטזיס). גירוי זה "נשמע" על ידי חיישן ספציפי. בשליטה על הגלוקוז בדם, תאים אנדוקריניים ספציפיים בלבלב מזהים עודף גלוקוז (הגירוי) בזרם הדם. תאי בטא אלו של הלבלב מגיבים לעלייה ברמת הגלוקוז בדם על ידי שחרור הורמון האינסולין לזרם הדם. האינסולין מאותת לסיבי שריר השלד, תאי שומן (אדיפוציטים) ותאי כבד לקלוט את עודפי הגלוקוז, ולסלק אותו מזרם הדם. כאשר ריכוז הגלוקוז בזרם הדם יורד, הירידה בריכוז המשוב השלילי בפועל מתגלה על ידי תאי אלפא בלבלב, ושחרור האינסולין נפסק. זה מונע מרמות הסוכר בדם להמשיך לרדת מתחת לטווח הנורמלי.

טקסט זה מותאם מ<a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/">Openstax, Anatomy and Physiology 2e, Section 1.5: </a> Homeostasis 
</div>

שמירה על הומאוסטזיס דורשת כי הגוף ברציפות לשמור על התנאים הפנימיים שלה. לכל מצב פיזיולוגי יש נקודה מוגדרת מסוימת, ...

Education

JoVE Core

Anatomy and Physiology

אנטומיה ופיזיולוגיה

Unit 1

יחידה 1

Introduction to the Human Body

מבוא לגוף האדם

KEY TERMS AND CONCEPTS

מונחים ומושגים מרכזיים

homeostasis and negative feedback

Homeostasis keeps the body’s internal conditions stable. The body does this by holding each physiological condition near a set point. A set point is the value around which the normal range changes, and the normal range is the small group of values that is healthiest and most stable. Human body temperature is a common example. Its set point is about 37°C, or 98.6°F, and it can shift a little above or below that point while still staying in range.

Negative feedback helps maintain homeostasis. This process reverses a change that moves a body value away from its set point. Control centers in the brain and other body parts monitor these changes and respond when conditions drift too far. Because this happens throughout the body all the time, negative feedback is a key idea in human physiology.

A feedback system has three main parts: a sensor, a control center, and an effector. A sensor, also called a receptor, watches a physiological value and sends that information to the control center. The control center compares the value with the normal range. If the value moves too far from the set point, the control center activates an effector. The effector causes a change that brings the value back toward normal.

Blood glucose control shows how this works. When blood sugar rises too high, pancreatic beta cells detect the excess glucose in the bloodstream. These endocrine cells release insulin into the blood. Insulin tells skeletal muscle fibers, fat cells, and liver cells to take up the extra glucose, which removes it from the bloodstream. As glucose levels fall, pancreatic alpha cells detect the drop, and insulin release stops. This keeps blood sugar from falling below the normal range.

Homeostasis and Negative Feedback

overview of anatomy and physiology

How Anatomy and Physiology Work Together

Human anatomy studies the structures of the body. Some body structures are so small that they can only be seen and examined with a microscope. Others are large enough to be viewed, handled, measured, and weighed. The word anatomy comes from a Greek root meaning “to cut apart.” Early study of the human body began with observing the outside of the body and the injuries seen in soldiers and other patients. Later, physicians were allowed to dissect dead bodies to learn more. Dissection means...

structural organization of the human body: an overview

structural-organization-of-the-human-body-an-overview

Levels of Organization in the Human Body

The human body is organized in levels that build from simple parts to a complete living being. These levels increase in complexity from subatomic particles, atoms, and molecules to organelles, cells, tissues, organs, organ systems, and the organism. At the chemical level, scientists study the smallest building blocks of matter. Matter is made of elements, which are pure substances such as hydrogen, oxygen, carbon, nitrogen, calcium, and iron. The smallest unit of an element is an atom, and...

functions of life

How the Human Body Keeps Going

Human life depends on metabolism, movement, development, growth, and reproduction. These functions help the body stay alive, maintain itself, and continue the species. Together, they show how the body uses energy and changes over time. Metabolism is the body’s use of energy and food molecules. It helps the body make fuel for movement, support body functions, and build and maintain body structures. Metabolism includes two kinds of reactions: anabolism and catabolism. Anabolism is the process...

requirements for human life

Human Survival Needs in the Body

Human survival depends on air, water, food, a narrow temperature range, and a narrow range of atmospheric pressure. The Earth and its atmosphere provide these conditions, but the body can only function well when they stay within limits. Oxygen is one of the most important needs. Atmospheric air is only about 20 percent oxygen, but that oxygen supports the chemical reactions that keep the body alive, including the reactions that make ATP. Brain cells are especially sensitive to a lack of oxygen...

what is homeostasis?

Homeostasis keeps the body’s internal conditions stable. The body does this by holding each physiological condition near a set point. A set point is the value around which the normal range changes, and the normal range is the small group of values that is healthiest and most stable. Human body temperature is a common example. Its set point is about 37°C, or 98.6°F, and it can shift a little above or below that point while still staying in range. Negative feedback helps maintain homeostasis.

negative and positive feedback

Feedback Loops in Body Balance

Negative and positive feedback help keep body conditions stable. These feedback loops control many body processes and support homeostasis, which is the maintenance of a steady internal environment. Negative feedback reduces a change and brings a system back toward its normal state. Positive feedback increases a change and pushes a process further in the same direction. Together, they show how the body can fine-tune responses when conditions shift. These control systems are important in many...

homeostatic imbalance

How Feedback Failure Disrupts Homeostasis

Homeostasis keeps the body’s internal conditions stable so cells, tissues, organs, and organ systems can work properly. The body uses control systems to regulate temperature, blood pressure, pH balance, and fluid balance. These controls depend on feedback loops, which can be positive or negative. Homeostatic imbalance happens when those feedback loops fail and the body can no longer maintain a stable internal environment. Injury, disease, environmental changes, genetic mutations, and aging can...

anatomical terminology

Anatomical Terms and Body Position

Anatomical terms help describe the human body clearly in biology and medicine. Health care professionals and anatomists use this standard language to avoid confusion and to make descriptions more precise. Most anatomical words come from Greek and Latin roots, and these roots usually stay the same because the languages are rarely used in everyday conversation. Many anatomical words are built from a root plus a prefix or suffix. The root often names an organ, tissue, or condition. The prefix or...

anatomical positions

Body Positions Used in Anatomy

Body positions used in anatomy give a shared way to describe where body parts are and how they face. These standard references help people talk about anatomical structures with the same meaning. The anatomical position is the main reference point for body orientation. In anatomical position, the body stands upright and faces forward. The feet are parallel and flat on the floor. The arms rest at the sides with the palms facing forward, and the head and eyes point forward. The most common...

regional terms

Anatomy Regions and Body Landmark Terms

Anatomy regions and body landmark terms help identify specific parts of the human body. These regional terms divide the body into areas with structures that support similar functions. They also make it easier to describe the exact area affected by an injury or disease. The human body is organized into two major regions: the axial region and the appendicular region. The axial region includes the body from the head to the abdomen and forms the central body axis. The appendicular region includes...

directional terms

Anatomical Direction and Body Position

Anatomical direction and body position terms help describe where one body structure is located in relation to another. These terms use comparisons, such as one tissue being inferior to another or a tumor being superficial to a deeper structure. They are based on the standard anatomical reference position, which uses the body in an upright pose. Anterior and posterior are a common pair of directional terms. Anterior, also called ventral, means toward the front of the body. Posterior, also...

body planes

Anatomy Sections and Body Planes

Anatomy sections and body planes are imaginary flat surfaces used to divide the body for study. They help show the orientation, relationships, and spatial layout of anatomical structures. These reference planes are also useful for describing organs and body parts in a standard way. The sagittal plane divides the body or an organ vertically into right and left sides. When that cut goes through the middle and makes equal halves, it is called the midsagittal or median plane. When it makes unequal...

anatomical movements

Body Joint Motion Terms

Body joint motion terms describe how bones and muscles move at different joints. These standard names make it easier to talk about range of motion in the body. They are used to describe actions at the shoulder, hip, elbow, knee, wrist, fingers, toes, and spine. Flexion and extension are movements in the sagittal plane, also called the anterior-posterior plane. Flexion is the forward bending motion of the head or vertebral column. Extension is the backward movement or straightening of a joint,...

abdominal regions and quadrants

Abdominal Pain and Organ Location

The abdominal cavity is divided into quadrants and regions to help locate organs and describe pain clearly. Clinicians and anatomists use imaginary lines to mark the abdominopelvic cavity. This system makes it easier to communicate about a patient’s symptoms or a suspicious mass. The simpler method divides the area into four quadrants. One horizontal line and one vertical line cross at the umbilicus, or navel. These quadrants are the right upper quadrant, right lower quadrant, left upper...

key terms and concepts

Learn how homeostasis stays stable through negative feedback, set points, sensors, control centers, and the insulin response to blood glucose.

Homeostasis and Negative Feedback | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

Pennsylvania State Academic Standards

Life Science

Structure and Function

3.1.9-12.C

Louisiana Student Standards for Science

High School

Life Sciences

From Molecules To Organisms: Structures And Processes

HS-LS1-3

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Cells

Cell structure and function

Human Anatomy and Physiology

Levels Of Organization

Homeostasis

Virginia  Standards of Learning

HIgh School

BIO.2

BIO.2.a

Minnesota Academic Standards in Science

1.2.1 9L.1.2.1.1

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

From Molecules to Organisms: Structures and Processes

Arizona Science Standards

HS.L1

HS.L1U1.20

Alabama Course of Study Science

9-12.B.1.4

Next Generation Science Standards

Texas Essential Knowledge and Skills

BIO.5

BIO.5.C

BIO.12

BIO.12.A

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

B-LS1-3.

new-york-state-science-learning-standards

New York State Science Learning Standards

HS-LS1-3.

Compounds Essential to Human Function

The human body is composed of cells that are fundamentally made up of several different molecules. These molecules are essential to carry out all ...

Macromolecules

Biomolecules
Organisms contain a wide variety of organic molecules with numerous functions which depend on the chemical structures and properties of these ...

Solution Preparation
ExpandCAUTION: It is important to always use care when handling reagents. For example, iodine will stain clothes and skin so wear ...

Identifying Macromolecules with Indicator Solutions
ExpandHYPOTHESES: In this activity, the experimental hypothesis might be that the addition of an ...

pH Regulation in Cells

pH plays a critical role in maintaining normal cellular activities. It helps maintain the structure and function of various proteins, dictates the charge ...

Chemistry of the Cell

Overview of Functional Groups

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of ...

Introduction to Carbohydrates

Carbohydrates, proteins, and fats are the primary macronutrients in the human diet. However, carbohydrates are the most favored source of energy in the ...

Carbohydrate Metabolism

Sugars as Energy Storage Molecules

What are Lipids?

lipid-derived-compounds-in-the-human-body

Lipid-derived Compounds in the Human Body

Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and ...

Fats as Energy Storage Molecules

What are Proteins?

Protein Organization

Globular Proteins

In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins ...

Fibrous Proteins

Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of ...

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. ...

Role of Proteins in the Human Body

Proteins are the building block of life. They are also&#160; the most abundant macromolecules with as many diverse roles in the body. They are part of ...

Nucleic Acids and Nucleotides

Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell&#39;s genetic blueprint and have instructions for its ...

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group ...

ATP Energy Storage and Release

ATP and Macromolecule Synthesis

Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, ...

Construct an explanation to illustrate relationships between structure and function of major macromolecules essential for life.

LS.Bio.1.1

Introduction to Enzymes

The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an ...

Enzymes and Activation Energy

The activation energy (or free energy of activation), abbreviated as Ea, is the small amount of energy input necessary for all chemical reactions to ...

Introduction to Enzyme Kinetics

Enzyme kinetics studies the rates of biochemical reactions. Scientists monitor the reaction rates for a particular enzymatic reaction at various substrate ...

Turnover Number and Catalytic Efficiency

The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from ...

Catalytically Perfect Enzymes

The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at ...

introduction-to-mechanisms-of-enzyme-catalysis

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple &#34;lock-and-key&#34; fashion. This model stated that the enzyme ...

Ligand Binding and Linkage

Cooperative Allosteric Transitions

Ribozymes

Carry out investigations to illustrate how enzymes act as catalysts for biochemical reactions and how environmental factors affect enzyme activity.

LS.Bio.1.2

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Lysosomes

Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Introduction to the Cytoskeleton

Overview of the Cytoskeleton
The cytoskeleton is a network of protein filaments present within the cell, having three distinct filaments ...

Introduction to Actin

Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle ...

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

Use models to explain how the structure of organelles determines its function and supports overall cell processes.

LS.Bio.1.3

Analyze how the relationship between structure and function supports life processes within organisms.

Homeostasis and Negative Feedback

Description

Transcript

More videos by Standards