Name: nervous system parts and control
Uploaded: 2019-03-11T09:21:26.000Z
Duration: 1 min 25 s
Channel: JoVE

K12 Standards

Next Generation Science Standards

High School

Life Science

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

From Molecules to Organisms: Structures and Processes

HS-LS1-2

What is a Nervous System?

- [Instructeur] Het zenuwstelsel stelt iemand in staat om de buitenwereld waar te nemen en er gepast op te reageren. Bovendien coördineert het functies gaande van ademen tot geavanceerd redeneren. Dit stelsel wordt verdeeld in twee delen.

Het centraal zenuwstelsel of CZS, dat de hersenen en het ruggenmerg bevat, en het perifeer zenuwstelsel, het PZS, dat de zenuwen omhelst die tussen het CZS en de rest van het lichaam reizen. De hersenen zijn onderverdeeld in gebieden die verschillende functies hebben zoals visuele informatie verwerken of bewegingen coördineren. Maar ze zijn ook sterk verbonden om informatie-integratie mogelijk te maken.

Zoals de rest van het zenuwstelsel is het brein samengesteld uit neuronen. Cellen die neurosignalen genereren en doorgeven, en glia, cellen die neurofuncties ondersteunen. Onder de hersenen ligt het ruggenmerg, CZS weefsel dat zich uitstrekt door het wervelkanaal.

Het faciliteert signalering tussen de hersenen en het PZS en beheerst ook sommige basisfuncties zoals reflexen. In het PZS sturen zenuwen, bundels van zenuwvezels instructies uit naar skeletale spieren om bewegingen te coördineren en naar interne organen om anatomische functies te reguleren zoals vertering. Zenuwen dragen ook sensorische informatie van receptorcellen zoals die in de huid die aanraking detecteren, naar het CZS voor analyse.

wat is een zenuwstelsel?

<h4>Overzicht</h4>

Het zenuwstelsel is de verzameling gespecialiseerde cellen die verantwoordelijk zijn voor het in stand houden van de interne omgeving van een organisme en het coördineren van de interactie van een organisme met de buitenwereld – van de controle over essentiële functies zoals hartslag en ademhaling tot de beweging die nodig is om aan gevaar te ontsnappen.

<h4>Delen van het zenuwstelsel</h4>

Het zenuwstelsel van gewervelde dieren is verdeeld in twee grote delen: het centrale zenuwstelsel (CZS) en het perifere zenuwstelsel (PNS). Het CZS omvat de hersenen, het ruggenmerg en het netvlies – het sensorische weefsel van het visuele systeem. Het PZS bevat de sensorische receptorcellen voor alle andere sensorische systemen – zoals de tastreceptoren in de huid – en ook de zenuwen die informatie transporteren tussen het CZS en de rest van het lichaam. Bovendien draagt een deel van zowel het CZS als het PZS bij aan het autonome zenuwstelsel (ook bekend als het viscerale motorsysteem). Het autonome zenuwstelsel bestuurt gladde spieren, hartspieren en klieren die onwillekeurige acties regelen, zoals de spijsvertering.

De hersenen van gewervelde dieren zijn voornamelijk verdeeld in de grote hersenen, het cerebellum en de hersenstam. Het cerebrum is het grootste, meest voorste deel van de hersenen dat is verdeeld in een linker- en rechterhersenhelft. Elk halfrond is verder verdeeld in vier lobben: frontaal, pariëtaal, occipitaal en temporaal. De buitenste laag van de grote hersenen wordt de cortex genoemd en is betrokken bij het verwerken van complexe sensorische informatie en de meeste cognitieve functies. Dieper in de hersenen liggen andere cruciale componenten, waaronder de hippocampus, hypothalamus, thalamus en basale ganglia. Het cerebellum (de ‘kleine hersenen’) bevindt zich achter en onder de grote hersenen en is verantwoordelijk voor het coördineren van de spierbewegingen. De hersenstam verbindt de hersenen met het ruggenmerg en bevat belangrijke centra voor vitale functies zoals ademen en slikken.

Het ruggenmerg ligt onder de hersenen en loopt door in de hersenstam. Het bevat neuronale cellichamen en bundels axonen die de hersenen en verschillende delen van het lichaam verbinden. Het ruggenmerg is niet alleen een cruciaal kanaal voor informatie, maar kan ook bepaalde functies uitvoeren zonder input van de hersenen, zoals voortbeweging en andere reflexen. De zenuwen van het PZS transporteren motorische commando's van het CZS naar de spieren, en sensorische informatie van receptorcellen naar het CZS voor interpretatie. Naast de beweging van skeletspieren reguleren zenuwen de activiteit van interne organen zoals de longen en darmen via de sympathische en parasympathische delen van het autonome zenuwstelsel.

<h4>Cellen van het zenuwstelsel</h4>

Het zenuwstelsel bestaat uit twee belangrijke celtypen: neuronen en gliacellen. Neuronen zijn de zwaargewichten in het CZS–ze zijn verantwoordelijk voor de communicatie met elkaar en het heen en weer transporteren van informatie van het zenuwstelsel naar de rest van het lichaam. Er wordt geschat dat het menselijk brein ongeveer 100 miljard neuronen bevat en maar liefst 100 biljoen verbindingen daartussen. Ze zijn er in veel verschillende morfologieën en vervullen een breed scala aan functies. Neuronen gebruiken een reeks neurochemicaliën en ionen om te communiceren op kruispunten die synapsen worden genoemd.

Het andere hoofdtype cellen van het zenuwstelsel maakt deel uit van een groep die gliacellen wordt genoemd. Ze omvatten een diverse groep cellen die bijdragen aan de functie van neuronen en ongeveer gelijk zijn aan het aantal neuronen in de hersenen. De belangrijkste typen gliacellen zijn astrocyten, microglia, oligodendrocyten en ependymale cellen in het centrale zenuwstelsel; Schwann-cellen en satellietcellen worden gevonden in het PZS.

<h4>Geestelijke gezondheid is een mondiaal probleem</h4>

Het zenuwstelsel bestuurt vrijwel elke ervaring die we hebben, en de verstoring ervan als gevolg van trauma, ziekte, genetica of blootstelling aan schadelijke chemicaliën kan ernstige gevolgen hebben voor de gezondheid en de kwaliteit van leven. De geestelijke gezondheidsproblemen die uit dergelijke effecten voortvloeien, komen over de hele wereld opmerkelijk vaak voor. Het vergroten van ons begrip van neurologische en neurologische ontwikkelingsstoornissen blijft potentiële behandelingen en therapieën opleveren voor velen die aan psychische aandoeningen lijden. De Wereldgezondheidsorganisatie (W.H.O.) en de National Institutes of Mental Health (NI.I.M.H) in de VS, naast andere organisaties, bieden waardevolle middelen om deze aandoeningen te bestuderen en hun impact op de samenleving te volgen.

Wat is een zenuwstelsel?

Overview

The nervous system is the collection of specialized cells responsible for maintaining an organism&rsquo;s internal environment and coordinating ...

Education

JoVE Core

Biology

Biologie

Human Biology

Menselijke biologie

Nervous System

Zenuwstelsel

KEY TERMS AND CONCEPTS

BELANGRIJKE TERMEN EN CONCEPTEN

nervous system parts and control

The nervous system is a network of specialized cells that keeps the body working and helps it respond to the world around it. It controls essential functions such as heart rate and breathing. It also supports movement that helps an organism escape danger.

In vertebrates, the nervous system has two major parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain, spinal cord, and retina, which is the sensory tissue of the visual system. The PNS includes sensory receptor cells for the other sensory systems, such as touch receptors in the skin, and the nerves that carry information between the CNS and the rest of the body.

Part of both the CNS and PNS also contributes to the autonomic nervous system, also called the visceral motor system. This system controls smooth muscle, cardiac muscle, and glands. It helps govern involuntary actions such as digestion.

The vertebrate brain is divided into the cerebrum, cerebellum, and brainstem. The cerebrum is the largest and most anterior part of the brain. It has left and right hemispheres, and each hemisphere is divided into the frontal, parietal, occipital, and temporal lobes. The outer layer of the cerebrum is the cortex, which processes complex sensory information and many cognitive functions. Deeper brain regions include the hippocampus, hypothalamus, thalamus, and basal ganglia.

The cerebellum, sometimes called the little brain, sits behind and below the cerebrum. It helps coordinate muscle movement. The brainstem connects the brain to the spinal cord and contains important centers for vital functions such as breathing and swallowing. The spinal cord lies below the brain and continues from the brainstem. It contains neuronal cell bodies and axon bundles that connect the brain with the body. It can also carry out some functions without input from the brain, including locomotion and other reflexes.

Nerves in the PNS carry motor commands from the CNS to muscles and sensory information from receptor cells back to the CNS for interpretation. They also help regulate internal organs such as the lungs and intestines through the sympathetic and parasympathetic divisions of the autonomic nervous system.

Two main cell types make up the nervous system: neurons and glial cells. Neurons carry information between nervous system regions and between the nervous system and the rest of the body. The human brain is estimated to contain about 100 billion neurons and about 100 trillion connections between them. Neurons come in many shapes and use neurochemicals and ions to communicate at synapses, which are junctions between cells.

Glial cells are the other major cell type. They support neuron function and are about as numerous as neurons in the brain. Major glial cells in the CNS include astrocytes, microglia, oligodendrocytes, and ependymal cells. In the PNS, Schwann cells and satellite cells perform related support roles.

Because the nervous system affects nearly every experience, damage from trauma, disease, genetics, or harmful chemicals can strongly affect health and quality of life. Problems in this system are linked to many mental health conditions around the world. Research on neurological and neurodevelopmental disorders continues to guide possible treatments and therapies. Organizations such as the World Health Organization and the National Institute of Mental Health help study these conditions and track their impact on society.

Nervous System Parts and Control

what is a nervous system?

The nervous system is a network of specialized cells that keeps the body working and helps it respond to the world around it. It controls essential functions such as heart rate and breathing. It also supports movement that helps an organism escape danger. In vertebrates, the nervous system has two major parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain, spinal cord, and retina, which is the sensory tissue of the visual system. The...

the parasympathetic nervous system

Rest and Digest: Parasympathetic Control

The parasympathetic nervous system helps the body stay calm and return to a rested state. It is one of the two major divisions of the autonomic nervous system, which controls many unconscious functions such as heart rate and digestion. Its neurons are found in the brain and the peripheral nervous system, and they send axons to muscles, organs, and glands. This system is often called the “rest and digest” system because it supports body processes that restore homeostasis. It is most active...

the sympathetic nervous system

Sympathetic Stress Response and Body Changes

The sympathetic nervous system helps the body respond to stress and danger. It is one of the two main divisions of the autonomic nervous system. When it turns on, it prepares the body for action and puts lower-priority functions, such as digestion, on hold. This response is often called the fight-or-flight system. A surprise exam can trigger it, and students may notice a tight stomach, a dry mouth, and a fast heartbeat. In a real threat, the system shifts blood away from the digestive system...

the blood-brain barrier

How the Blood-Brain Barrier Works

The blood-brain barrier is a specialized system of blood vessels that helps control what enters the brain. It delivers nutrients from the blood while tightly regulating ions, molecules, pathogens, and other substances. This semipermeable barrier protects the brain and also makes it harder to deliver some therapies. The blood-brain barrier includes several cellular parts, especially endothelial cells and astrocytes. These cells share a common basement membrane and regulate movement between the...

neuron structure

How Neurons Send Signals

Neurons send signals through a clear set of structures that let them receive, process, and pass on information. They are the main cells of the nervous system and use electrochemical signals to communicate. Neurons also talk to other cells through neurotransmitters at junctions called synapses. Most neurons share three main parts: a cell body, also called the soma, dendrites, and an axon. The soma holds the nucleus and other organelles needed for cell function. Dendrites usually receive...

glial cells

Glial Cells and Nervous System Support

Glial cells support the nervous system and work alongside neurons. They are one of the two main cell types in the nervous system. Unlike neurons, glia do not send electrical signals, but they help with nearly every other part of nervous system function. In humans, glial cells are about as numerous as neurons in the brain. In the central nervous system, glia include astrocytes, oligodendrocytes, microglia, and ependymal cells. Astrocytes are the most common glial cells. They form organized,...

action potentials

How Nerve Signals Travel in Axons

Neurons send signals through action potentials, the rapid electrical changes that move along the axon. These signals lead to neurotransmitter release at axon terminals, which passes information through the nervous system. An action potential is an all-or-none change in membrane potential, the voltage across a cell membrane. A neuron usually has a resting membrane potential of about -70 millivolts. When it receives signals from neurotransmitters or sensory input, the membrane can become more...

the resting membrane potential

How Neurons Keep a Negative Resting Charge

Neurons keep a negative resting charge across their membrane. This electrical difference, called the membrane potential, comes from how ions move and how the membrane lets them pass. In a resting neuron, the inside is typically around -70 millivolts and is more negative than the outside, so the cell is polarized. Two main factors create this resting state. First, the membrane is selectively permeable, which means most ions and molecules cannot cross the lipid bilayer without help from ion...

long-term potentiation

Synaptic Strengthening in Learning and Memory

Long-term potentiation, or LTP, is a form of synaptic strengthening in the brain. It changes the strength of chemical synapses over time between pre- and postsynaptic neurons. LTP works against long-term depression, or LTD, which weakens synapses. Together, LTP and LTD are major mechanisms behind learning and memory. LTP can happen when a presynaptic neuron fires again and again and keeps stimulating a postsynaptic neuron. This is called Hebbian LTP, based on Donald Hebb’s idea that neurons...

long-term depression

Synaptic Pruning in Long-term Depression

Long-term depression, or LTD, is a form of synaptic plasticity that weakens chemical synapses over time. It acts between presynaptic and postsynaptic neurons. LTD works in opposition to long-term potentiation, or LTP, which strengthens synapses. Together, LTD and LTP are two of the main mechanisms behind learning and memory. LTD helps the brain avoid staying locked in a fully strengthened state. If synapses were always maximally strengthened, the brain would become less efficient and it would...

the synapse

How Neurons Signal at Synapses

Neurons communicate through synapses, the points where two neurons meet to pass on signals. At a synapse, the sending neuron is the presynaptic cell, and the receiving neuron is the postsynaptic cell. Most neurons can serve in both roles because they send and receive information. Electrical synapses move signals directly between cells. The presynaptic and postsynaptic cells are linked by gap junctions, which are proteins that physically connect them. This type of synapse can pass electrical...

key terms and concepts

Explore how the nervous system is organized, how neurons and glial cells work, and how the brain, spinal cord, and nerves control body functions.

Nervous System Parts and Control | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

new-york-state-science-learning-standards

New York State Science Learning Standards

Structure and Function

HS-LS1-2.

myJoVE Corporation

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Cell Structure

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

Visualizing Onion and Cheek Cells
ExpandImmediately before the experiment, wash and peel onion bulbs for the class.
Remove the entire brown outer skin and ...

Visualizing Onion and Human Cells
ExpandIn this experiment you will prepare different types of cells from a plant and animal, onion and human ...

What are Cells?

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

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 ...

The Central Dogma

The DNA Helix

Nucleic Acids

DNA as a Genetic Template

Structure of a Gene

A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the ...

Chromosome Structure

Base-pairing and DNA Repair

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Protein Families

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Conservation of Protein Domains

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Globular and Fibrous Proteins

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

Intrinsically Disordered Proteins

Ribosomes

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

Protein Complex Assembly

Protein and Protein Structures

Conjugated Proteins

Proteins: From Genes to Degradation

Amyloid Fibrils

What are Proteins?

Proteins are polymers of amino acids linked together by peptide bonds. Proteins and polypeptides are interchangeably used to refer to long chains of amino ...

Ligand Binding Sites

Protein Organization

Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular ...

Protein-Protein Interfaces

Protein Folding

Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to ...

Conserved Binding Sites

Cofactors and Coenzymes

Enzymes are proteins made of amino acids. The functional group of each constituent amino acid catalyzes a wide variety of chemical reactions via ionic ...

Cooperative Allosteric Transitions

Protein Kinases and Phosphatases

GTPases and their Regulation

Covalently Linked Protein Regulators

protein-complexes-with-interchangeable-parts

Protein Complexes with Interchangeable Parts

Mechanical Protein Function

Structural Protein Function

Protein Networks

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life through systems of specialized cells. [Assessment Boundary: Assessment does not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.]

HS-LS1-1

Levels of Organization

Biological organization is the classification of biological structures, ranging from atoms at the bottom of the hierarchy to the Earth&#x27;s biosphere. ...

Animal and Plant Cell Structure

Animal and plant cells not only differ in their structure, function, and mode of nutrition but also in how they reproduce, specialize, and organize into ...

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

Structural Organization of the Human Body: An Overview

It is convenient to consider the body&#39;s structures in terms of fundamental levels of organization that increase in complexity: subatomic particles, ...

Overview of Human Digestion

The human body contains a monogastric digestive system. In a monogastric digestive system, the stomach only contains one chamber in which it digests food. ...

Anatomy of the Intestines

Although digestion of proteins, carbohydrates, and lipids may begin in the stomach, it is completed in the intestine. The absorption of nutrients, water, ...

Accessory Organs

Accessory organs are those that participate in the digestion of food but do not come into direct contact with it like the mouth, stomach, or intestine do. ...

Lipid Digestion

Lipids are large molecules that are generally not water-soluble. Since most of the digestive enzymes in the human body are water-based, there are specific ...

Protein Digestion

Protein digestion begins in the stomach, where the highly acidic environment can easily disrupt protein structure by exposing the peptide bonds of ...

Carbohydrate Digestion

Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. ...

The Parasympathetic Nervous System

Overview

The parasympathetic nervous system is one of the two major divisions of the autonomic nervous system. This parasympathetic system is responsible ...

The Sympathetic Nervous System

Overview

The sympathetic nervous system&mdash;one of the two major divisions of the autonomic nervous system&mdash;is activated in times of stress. It ...

Oogenesis

In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from ...

What is a Sensory System?

Sensory systems detect stimuli&mdash;such as light and sound waves&mdash;and transduce them into neural signals that can be interpreted by the nervous ...

Fertilization

During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ...

What is the Skeletal System?

Overview

The adult human skeleton comprises 206 bones that are connected through cartilage, tendons, and ligaments. The skeleton provides a rigid ...

an-introduction-to-the-zebrafish-danio-rerio

An Introduction to the Zebrafish: Danio rerio

Zebrafish (Danio rerio) are small freshwater fish that are used as model organisms for biomedical research. The many strengths of these fish include their ...

Physiology of the Circulatory System

Homeostasis
Conditions in the external environment of an organism can change rapidly and drastically. To survive, organisms must maintain a fairly ...

Anatomy of the Circulatory System

The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart ...

Measuring Blood Pressure
ExpandTo prepare for the blood pressure exercise, simply place the appropriate number of alcohol swabs, sphygmomanometers, and ...

Anatomy of the Heart

The human heart is made up of three layers of tissue that are surrounded by the pericardium, a membrane that protects and confines the heart. The ...

Measuring Circulatory System Function in Humans
ExpandBefore starting the experiment go to the front of the room and collect an alcohol swab, a ...

Blood Flow

Blood is pumped by the heart into the aorta, the largest artery in the body, and then into increasingly smaller arteries, arterioles, and capillaries. The ...

What Are Osmoregulation and Excretion?

Organisms must keep bodily fluids at a constant temperature and pH while maintaining specific solute concentrations in order to support life functions. ...

Blood Withdrawal I

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN
Blood collection is a common requirement for ...

Kidney Structure

The kidneys are two large bean-shaped organs located in the upper abdomen. They filter the blood several times a day to remove toxins and rebalance water ...

Blood Withdrawal II

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN
The collection of blood from mice and rats for ...

What is the Immune System?

Overview

The immune system comprises diverse biological structures and processes that protect the body from disease. These processes can be classified ...

Bone Remodeling

Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain ...

Spermatogenesis

Spermatogenesis is the process by which haploid sperm cells are produced in the male testes. It starts with stem cells located close to the outer rim of ...

Bone Structure

Within the skeletal system, the structure of a bone, or osseous tissue, can be exemplified in a long bone, like the femur, where there are two types of ...

Breathing

The process of breathing, inhaling and exhaling, involves the coordinated movement of the chest wall, the lungs, and the muscles that move them. Two ...

Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. [Clarification Statement: Emphasis is on functions at the organism system level such as nutrient uptake, water delivery, and organism movement in response to neural stimuli. An example of an interacting system could be an artery depending on the proper function of elastic tissue and smooth muscle to regulate and deliver the proper amount of blood within the circulatory system.] [Assessment Boundary: Assessment does not include interactions and functions at the molecular or chemical reaction level.]

What is Homeostasis?

Maintaining homeostasis requires that the body continuously maintain its internal conditions. Each physiological condition has a particular set point, ...

Negative and Positive Feedback

Homeostatic Imbalance

Homeostasis is the maintenance of a stable internal environment within the body, which is crucial for the proper functioning of cells, tissues, organs, ...

Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis. [Clarification Statement: Examples of investigations could include heart rate response to exercise, stomate response to moisture and temperature, and root development in response to water levels.] [Assessment Boundary: Assessment does not include the cellular processes involved in the feedback mechanism.]

HS-LS1-3

Nervous System Parts and Control

Description

Transcript

Tags

More videos by Standards