assignment 4 the muscle times needs you

PSK4U Introductory Kinesiology Unit 4: Physiology Activity 1: Muscular Contraction

Time to Move!

Have you ever stopped yourself during something as simple as playing catch or simply walking to really think about what is happening to your body? How you can manipulate a structure made up of bones and muscles to perform the simplest or even the most complex of tasks?

Take a moment and stand up. What did you have to "tell" your body to do in order to accomplish this? Did you have to tell it to produce force? Did your body react quickly? Slowly?

Now carefully sit back down. What did you "hear" from your body as feedback so that you didn’t fall on the floor? What did you do with this information? Which did you find harder to perform, sitting down or standing up? Everything you just did was in a controlled, precise movement involving a large number of bones and muscles. The muscles involved all required the same information, to contract or not, and regardless of size, they all went through the same processes in order to successfully contract.

So how does all this happen? From the moment you tell yourself to move until you actually do, what are the steps that need to happen?

What are the steps involved in movements that are even more complex?

What is this skateboarder "telling" his body to do? How do we accomplish such complex physical tasks?

Assignment 1: Thinking About Design

Thinking back to the last unit, how does the "design" of the different muscles types help with their function? (ie. what kind of control do we have of each type [smooth, cardiac, and skeletal] and how that effects the role of that type of muscle).

For each muscle type, consider why the type of muscle is best suited for its function and location (what it does and where it is located). Add your thinking to your Portfolio.

Now it’s time to take a closer look at what is happening when you finally make the decision to contract a muscle. Keep in mind, this entire process happens every time you blink, take a breath, scratch your nose, let alone perform complex tasks such as riding a bike, throwing a ball or performing a trick on a snowboard. The only difference between any contraction to make it a "stronger" or more "controlled" contraction is the number of muscle fibers that the brain recruits as a response to the task to be performed.

The Central Nervous System (CNS), Peripheral Nervous System (PNS) and a Motor Unit .

Let’s piece together the story of the muscle contraction.

A Time to Contract

"the command centre" - the nervous system.

The story begins when you are ready to move a muscle (ie. blink, throw a ball, jump, etc.). Contraction “commands” are sent from the brain or spinal cord to the muscle and eventually cause a chemical reaction to take place in the muscle(s) you have ordered to move.

Our ability to move faster or slower is all a result of being able to predict and react to stimuli being presented; we call this "Reaction Time". No matter how fast or slow you can react, this seemingly long process, involving the brain, many nerves and muscles, is a choreographed electrical and chemical "dance" that takes milliseconds to orchestrate and perform.

There are 2 main components of the nervous system:

Central Nervous System (CNS)

Includes the main control centre (the brain) and the highway of nerves running down your vertebral column, the spinal cord.

Peripheral Nervous System (PNS)

The PNS is a collection of all the nerves outside the brain and spinal cord. The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs, essentially serving as a communication relay going back and forth between the brain and spinal cord with the rest of the body.

The following video let's you see the Central and Peripheral nervous sytem in action:

"Subway Surfer" - The Motor Unit

We use the term "motor" to make reference to movement. So when you hear the term "motor neuron", you should make the connection that this is a nerve responsible for sending the signal to the muscle to move. These neurons form a network or pathway that an impulse must follow to reach a muscle telling it to contract, much like subway tunnels carry trains from station to station eventually ending up at a main, central station.

Making up only one part of the bigger motor unit, motor neurons help deliver the impulse to control muscular contraction to follow the “all-or-none” principle, which stipulates that once the impulse is sent down the axon that all the muscle fibres connected to that neuron will fully contract or not at all. Thus, the level of control for a muscle is determined by the number of muscle fibres each motor neuron innervates (controls).

Therefore, a motor unit is comprised of the following 3 items:

• The motor cell body
• The axon (pathway)
• The muscle fibres it stimulates

What exactly is the "go message" to contract? Is it chemical? Is it electrical? The answer is quite simple: it’s both.

Let’s examine how the electrical impulse travels in one direction from the neural cell body down the axon to the axon terminals where they will then cause chemicals to cross the neuromuscular junction to the muscle side of the unit. Hover over the titles to find out what each term means. Imagine you were in a big circle of friends holding hands. Where your hands are connected are the Nodes of Ranvier (see diagram) with your body acting as the axon and your clothes as the myelin sheath.

Long Description

From Neural Cell Body to Terminal Branch:

Electrical impulses are collected from other neurons and centralized to follow down the axon to the muscle.

Travelling down the axon, electrical impulse moves very rapidly through the myelinated section only to slow down and concentrate between each section at the Nodes of Ranvier before moving once again down the axon.

Once the electrical impulse reaches the ends of the axon, the terminal knobs, it causes vesicles filled with the neurotransmitter Acetylcholine (Ach) to move closer to the outer membrane of the knob.

Attaching to the membrane, the vesicle is ready to release the Ach molecules into the synaptic cleft, from the nervous system, into the space across to the muscular system.

• The role of The Neuromuscular Junction

From Neural Cell Body to Terminal Branch

When looking at the movement of an electrical impulse from the central nervous system down to the awaiting muscle, one could use the analogy of a subway ride to see a Toronto Raptors basketball game at the Scotibank Arena in downtown Toronto. Can you match the “Subway trip” description to the actual neuromuscular sequence of events?

Basketball fans collect via bus, car or walking at the furthest subway station, go through the toll booths, get onto an awaiting subway train and head to the Scotiabank Arena for the basketball game.

The train travels quickly in the subway tunnel and makes periodic stops at each station where the conductor makes sure there are enough fans to continue down to the Scotiabank Arena for the game.

Once the train reaches the main station (Union Station), excited basketball fans leave the train via several exits and begin to collect at the doors exiting the subway station.

Exiting the doors of the station, the basketball fans walk across the open space before entering the Scotiabank Arena to watch the Raptors game.

Let's see the motor neuron in action:

Jumping the Gap - The Neuromuscular Junction

Eventually the message to contract needs to transfer from the nervous system to the muscular system. However, this cannot be done by an impulse of electricity crossing through space from one side to another. In order for the command to "Jump the Gap", it must go from electrical, in the form of impulses moving down the axon (presynaptic membrane), to chemical as molecules of Acetylcholine move across the space (synaptic cleft), and then back to electrical once the Ach binds to receptors on the muscle side (postsynaptic membrane).

To control the amount of Ach in the synaptic cleft (space), Acetylcholinesterase is released. Acetylcholinesterase is an enzyme that breaks down Ach into acetate and choline to be reabsorbed and reused by the presynaptic terminal knob. This transition point between the nervous and muscular system is called the NEUROMUSCULAR JUNCTION (NMJ).

Let's see the neurumuscular junction in action.

The Final Movement - The Muscle Contraction

Finally the command to contract has made it to the muscular system. But first, we need to better understand a few things. What exactly is muscle? What is it made of? What the are characteristics of muscle that allow it to function the way it does?

Here are some interesting facts, some of which you will need to know for the next activity:

• When we eat meat, aside from organs like the liver, we are eating muscle.
• The colour of the meat can tell you the type of activity that muscle is best at:
• Dark meat: contains a protein in it (myoglobin) that carries oxygen into the muscle for long duration, low force producing (aerobic) activities.
• Light meat: does not contain oxygen carrying capabilities and thus is good for short burst, high intensity movements. Skeletal muscles contract only if stimulated to do so.
• Skeletal muscles contract only if stimulated to do so.
• Movement is produced by pulling on bones.
• Bones serve as levers, whereas joints serve as fulcrums on these levers.
• Muscles that move a segment do not usually lie over that part (e.g. bicep flexes elbow but is in upper arm).
• Every muscle in the body must have the following characteristics:
• Contractility: the capacity of muscle to contract or shorten forcefully.
• Excitability: muscle responds to stimulation by nerves and hormones, making it possible for the nervous system to regulate muscle activity.
• Extensibility: muscles can be stretched to their normal resting length and beyond to a limited degree.
• Elasticity: if muscles are stretched, they recoil to their original resting length.
• Skeletal muscles almost always act in groups, based on their behaviours, rather than individually in order to perform movements.
• Prime Movers/Agonists
• Muscles considered primarily responsible for generating a specific movement.
• In flexion of the arm at the elbow (bicep curl) the primary mover or agonists is the bicep.
• In extension of the leg at the knee (kicking a soccer ball) the primary mover is the quadriceps.
• Antagonists
• Muscle responsible for movement opposite to the desired movement. It is important to exercise both the agonist and antagonist in order to have proper balance across a joint.
• In flexion of the arm at the elbow (bicep curl) the agonist is the tricep.
• In extension of the leg at the knee (kicking a soccer ball) the hamstrings are the antagonists.
• Stabilizers/fixators
• Acts to stabilize one part of the body during movement of another part.
• When doing a push-up or a bench press, your deltoids act as stabilizers to support the movement.
• Perform, or help perform, the same set of joint motion as the agonists.
• In a push-up or bench press, the triceps help the agonist, the pectoral muscles, in the movement and thus are the synergists to this movement.

Did You Know?

In order for a muscle to contract, the nervous system has to send a message to the antagonist muscle(s) telling them not to contract but rather to relax. This is called reciprocal inhibition and it involves muscles working in pairs so as one contracts the other relaxes. Here is a way to use this principle to help you stretch:

Assignment 2: Time To Get Real!

Imagine you were about to pick up a glass of water to drink (flexion of the arm at the elbow). Research and name muscles that fill the role of those listed below and write a brief description of how the muscles work together to pick up the glass.

• prime movers/agonists
• antagonists
• stabilizers/fixators

Add your paragraph to your Portfolio.

Time to complete our story of "A Time to Contract"...

As we last left off, Ach molecules have now crossed the synaptic cleft and bound to receptor molecules on the postsynaptic side of the neuromuscular junction. This combination causes a depolarization of the muscle membrane which now causes an electrical impulse to spread across the Sarcolemma (outer membrane of muscle tissue). But how does an electrical impulse spread across and deep into a muscle to get the entire muscle to contract?

Assignment 3: First Year Anatomy Class

Imagine you are a first year university student sitting in a lecture hall, watching your professor lecturing on "Muscle Cells". As you watch the following video, make point form "lecture" notes summarizing the process of excitation coupling and the sliding filament theory. You can pause and rewind whenever you need to.

Use this organizer to help you take your notes .

Add your explanation of the excitation coupling and sliding filament theory to your Portfolio.

It’s time to assess your understanding of the sliding filament theory of muscle contraction before you complete the final assignment. Use the following learning tools to drag and drop the appropriate words in the spaces to complete the story of muscle contraction.

Assignment 4: The Muscle Times needs you!

You have been chosen to produce the lead paragraph or opening segment for the new hot multimedia platform, the "Muscle Times."

You may wish to write the lead paragraph for their website, create an opening video segment or even an audio file of the lead into a podcast. The choice is yours for the format.

Below are 4 headlines and hooks about a disease or condition related to the 4 chapters of our story "A Time to Contract". You are to research each topic and create only the lead paragraph or opening segment for that topic.

Your paragraph will:

• introduce the stage of muscle contraction you will be focusing on ( i.e. the nervous system, the motor unit etc.)
• briefly explain the chemical and physical processes involved in that stage of muscle contraction and how external factors ( ie. concussion, CTE, disease, poisoning etc.) can affect muscle contraction and human movement

Don’t forget that writing a lead paragraph makes readers want to know more, so peak your reader’s interest in your paragraph.

The following resources may be helpful in writing your lead paragraph:

Add your assignment to your Portfolio.

Chapter, topics and Headlines:

Chapter 1: "The Command Centre" - the effects of concussion, CTE, Alzheimer’s and Parkinson’s disease on the nervous system and human movement.

Headline: From sacks to suicide

How repeated hits to the head has created a neurological nightmare called Chronic Traumatic Encephalopathy (CTE).

Chapter 2: "Subway Surfer" - the effects of multiple sclerosis on the motor unit and human movement.

Headline: Canada has the highest rate of this disease in the world...

Multiple sclerosis, an autoimmune disease that affects the myelin insulation of nerve fibres which then impedes muscle movement.

Chapter 3: "Jumping the Gap - the effects of Botulinum poisoning on the neuromuscular junction and human movement.

Headline: Using poison to be "beautiful"

The use of Botulinum poison in cosmetic surgery.

Chapter 4. "The Final Movement" - the effects of calcium on muscle contraction and human movement.

Headline: Milk does the body good in more ways than one!

Calcium’s role in muscular contractions.

Introduction

Learning goals and success criteria.

View Curriculum Expectations

Curriculum Expectations

Learning skills.

• Lesson Plans
• Technology in Education

Welcome to the Visible Body Blog!

How to teach muscle naming with immersive assignments.

Posted on 2/16/24 by Sarah Boudreau

There are about 600 muscles in the human body—that’s a lot to memorize! When students understand the naming conventions behind muscles, it makes them easier to remember and gives students insights into their characteristics, like location, shape, and fiber orientation. 

However, many students have difficulty learning and staying engaged when staring at static images in a textbook. The human body is in 3D, so learning about it should be in 3D, too! By learning in 3D, students can get a fuller understanding of muscle movement and spatial relationships. 

In this blog post, we’ll explore the premade muscle naming immersive assignments in Courseware , Visible Body’s learning platform. In an immersive assignment, instructions guide students through 3D models, animations, simulations, and more as they progress through a series of activities and quizzes. 

An immersive assignment in Courseware . 

This set of immersive assignments is part of Visible Body’s library of free, premade content. We want to save instructors time and effort so they can focus on what they do best—teaching. Check out other premade content, including: 

• Courses , including popular textbook correlations
• Flashcard Decks

The anatomy of an immersive assignment

Let’s take a closer look at the premade muscle naming interactive assignments. When our team creates premade content, we start by looking at instructors’ needs. That way, we develop content like assignments, quizzes, and labs that align with how instructors actually teach. 

In addition to 3D learning, Visible Body is all about breaking complex concepts down into bite-sized pieces, so to cover muscle naming, our team built six assignments: 

• Introduction 
• Origin, insertion, and number of heads
• Fiber orientation
• Shape and movement
• Location 
• Relative descriptors

Each assignment is made up of activities and quizzes that walk students through concepts with rich, interactive visual aids. 

On the left side of the screen, instructions provide guidance and information, and students can follow those instructions to manipulate the 3D model in the center of the screen. The assignments center around 3D views of the muscular system, and several of them also feature interactive muscle actions. You can pause a muscle action at any time to take a closer look at the structures at play. 

Click on a structure to select it! When a structure is selected, the info box pops up. By clicking on the different icons in the info box, students can... 

• Add a tag to the structure
• Fade or hide the structure
• Read a definition 
• Read about pathologies related to the structure
• Hear a pronunciation of the structure's name
• View attachments and insertions, blood supply, innervation, and other details (if the selected structure is a muscle)

When a student has completed the instructions and is ready to proceed, clicking the Next button will bring them to the next activity. 

At the end of each of these assignments, a short multiple choice quiz checks students’ knowledge. Quizzes are automatically graded, and grades are logged into Courseware’s built-in Gradebook. Courseware can be used as a standalone LMS, or it can be integrated with several other LMS platforms to instantly send grades to your institution’s LMS.

Customize content easily

Premade content can be used straight out of the box, or it can serve as a jumping-off point for customization.

We’ve made the editing process simple and intuitive. Click on an immersive assignment and then click “Edit Assignment” to be brought to the assignment builder. From here, you can search for more content and add it with a click, and you can rearrange the order of activities by dragging and dropping them into place. You can also edit the instructions to better suit your students and your teaching style! 

Editing an immersive assignment in Courseware . 

Bring immersive assignments to your classroom

We're hard at work expanding our library! We currently have immersive assignments for the following subjects: 

• Anatomical terminology
• The plasma membrane
• Excitable tissues
• Muscle naming
• Cranial nerves
• Endocrine organs
• Circulatory system
• Immune cells
• Respiratory conduction
• Digestive system
• Urinary system
• Reproductive system

Immersive assignments are a new (beta) feature in Visible Body Courseware. If you don’t have access to Courseware yet, reach out to our team for a free instructor trial!

If you already have Courseware, follow these steps to add the premade assignments listed above to your course:

• Click on this link to add premade immersive assignments to your Courseware account.
• In this new course, click on the Bulk Editing tool, select the relevant folder(s), and click Copy. Choose the destination course and folder and copy.
• Navigate to your existing course, where you will find the content you copied. Use the bulk editing tool to edit release and due dates and publish. 

Once the content is copied to your account, you can customize it to fit your class’s unique needs!

Be sure to subscribe to the   Visible Body   Blog for more anatomy awesomeness! 

Are you an instructor? We have award-winning 3D products and resources for your anatomy and physiology course!  Learn more here.

• Lesson Plans ,

Get free instructor access to Courseware

Subscribe to the visible body blog, most popular.

For students

For instructors

Get our awesome anatomy emails!

When you select "Subscribe" you will start receiving our email newsletter. Use the links at the bottom of any email to manage the type of emails you receive or to unsubscribe. See our privacy policy for additional details.

• Teaching Anatomy in 3D
• Teaching Biology in 3D
• Webcasts & Demos
• For K-12 Instructors
• K-12 Funding Guide
• Premade Courses
• Anatomy Learn Site
• Biology Learn Site
• Visible Body Blog
• eBooks and Lab Activities
• Premade Tours
• Premade Flashcard Decks
• Customer Stories
• Company News
• Support Site
• Courseware FAQ
• Submit a Ticket

©2024 Visible Body. All Rights Reserved.

• User Agreement
• Permissions

• school Campus Bookshelves
• menu_book Bookshelves
• perm_media Learning Objects
• login Login
• how_to_reg Request Instructor Account
• hub Instructor Commons
• Download Page (PDF)
• Download Full Book (PDF)
• Periodic Table
• Physics Constants
• Scientific Calculator
• Reference & Cite
• Tools expand_more
• Readability

selected template will load here

This action is not available.

2.9: Lab Exercise 11- Muscle Fatigue and Physiology

• Last updated
• Save as PDF
• Page ID 72639

Lab Summary: The materials for this lab are included in your lab kit, so you can experiment with factors that affect muscle fatigue and usage.

Your objectives for this lab are:

• Describe the effects of cold, heat, and fatigue upon muscle contraction, fine motor skills/dexterity, and chemical reactions involved in muscle contraction.
• Explain four causes of muscle fatigue on a cellular/molecular level
• Describe different types of muscle fibers (type I and II; red, pink, white), types of muscle in which they are predominant, and why it is beneficial to have mixed types in a muscle belly
• Hypothesize about why warm-ups are advisable to maximize muscle performance.

Many exercise physiologists believe that one of the most important factors determining athletic performance is the cellular composition of the contracting muscles. The average human body is made up of approximately 600 muscles-2000 muscles (depending how one counts them). Therefore, all of those muscles must function properly for us to move about in our ordinary lives. When we consider the functioning of our muscles, we refer to it as muscle contraction. There are three types of muscle tissue in the human body: Skeletal, Smooth, and Cardiac muscles.

Skeletal muscles move the bones in the skeleton and have voluntary control. These muscles contract, it happens by the sliding filament theory. This allows the joints to move and lets us engage in physical activity of all kinds.

Smooth muscles are found in the walls of organs and structures that have involuntary control. When these muscles contract, they also use the sliding filament theory however, they use different proteins to do so compared to skeletal and cardiac muscle systems. The use of smooth muscles allows us to move digested food, move the iris of the eye, or constrict/relax blood vessels.

Cardiac muscle is similar to smooth muscle as it has involuntary movement but has a structure more akin to skeletal and is only found in the heart. Cardiac muscle requires extracellular calcium ions for contraction, which is unlike skeletal muscle. The beating of our heart is due to cardiac muscle contraction.

All of the above-mentioned muscle contractions are due to the different types of muscle fibers that generate tension during the sliding filament process, also referred to as actin and myosin cross-bridge cycling . Muscle cells, which are called fibers, can be broadly classified into categories based on their structural and metabolic characteristics. For example, the biceps muscle in the upper arm, a skeletal muscle. This muscle tissue is composed of distinct fiber types that play a critical role in determining the muscle’s performance capacity.

Three main fiber types are commonly identified, although further sub-groupings are known. For our purposes, we will focus on the three major types described here.

White - fast-twitch, glycolytic fibers (FG) are generally quite large in diameter and can generate energy rapidly for quick, powerful contractions. White fibers rely on anaerobic metabolism to produce ATP and become fatigued with the accumulation of lactic acid, a noxious by-product that interferes with muscle contraction. Consequently, white, fast-twitch fibers are generally activated in short-term sprint or “power” activities, as they fatigue rapidly.

Red, slow-twitch, oxidative fibers (SO) are smaller in diameter, and generate a greater yield of ATP by aerobic metabolism and without the formation of lactic acid. As the name implies, red, slow-twitch fibers contract less rapidly and powerfully, but they are not easily fatigued and are well suited for prolonged exercise.

Pink, fast, oxidative-glycolytic (FOG), a third intermediate fiber type shares both the oxidative and glycolytic pathways and is intermediate in size when compared to red and white fibers. These characteristics are summarized in the table below.

It is widely known among sport physiologists that the “fiber-type” of elite, world-class athletes is a reliable predictor of performance in athletic events. Sprinters, weight-lifters, wrestlers and others that rely on short, powerful bursts of muscle activity generally have a predominance of__________ -twitch fibers, whereas marathon runners, cross-country skiers, cyclists, and other endurance athletes have a greater abundance of _______ - twitch fibers.

Less widely appreciated is the extent to which these principles of human exercise physiology apply to other animals and their capacity for exercise. Organisms with predominantly white, fast twitch fibers (FG) also use anaerobic metabolism during exercise. They are capable of producing very high levels of muscle power output (e.g., fast sprints and strong bites), but these animals exhaust quickly. Other animals with a greater abundance of red, slow-twitch fibers (SO), which rely on aerobic metabolism, are capable of producing a moderate level of power for long periods of time. The principal disadvantage for “aerobic animals” is that aerobic metabolism is an expensive system to maintain; it requires a large, active heart, an elaborate vascular system to deliver oxygen, and numerous mitochondria in the muscle cells to produce large quantities of ATP. The high costs of maintaining these features are reflected in the higher rates of metabolism when the animal is at rest. “Anaerobic animals” avoid these energetic costs and have relatively low resting metabolic rates, leaving more energy available for growth and reproduction.

Each muscle tissue has specific roles in the body but they all must work together for overall functioning of the human organism.  This is best seen in terms of exercise, specifically maximal exercise. The two main types of exercise are anaerobic (static exercise) and aerobic (dynamic exercise).  During exercise the oxygen demands of skeletal muscle increase significantly.  The heart is responsible for supplying oxygen-rich blood to the skeletal muscles and smooth muscles. Skeletal muscle needs the oxygen to sustain its aerobic cellular respiration.  Skeletal muscle can switch over and use anaerobic mechanisms for ATP production but cannot continue for long once lactic acid accumulates.

Procedure for Activity 11.1:  The Effects of Temperature on Fine Motor Skills: For this exercise, you will need a pencil, a bowl with warm water, a bowl with ice cold water, and a timer or stopwatch.  The small pencil and ice making bags are provided in your lab kit.  You can use a timer/stopwatch on your phone or use this one:  https://www.online-stopwatch.com/countdown-timer/

Directions:

• Using the tiny pencil provided to you, write your signature 3 times under the column labeled “Baseline” in Data Table \(\PageIndex{2}\).
• Submerge your writing hand in ice cold water for 3 minutes, then remove your hand from the water and write your signature 3 times under the column labeled “Cold”.
• Submerge your writing hand in nice, warm water (not hot!) for 3 minutes, then remove your hand from the water and write your signature 3 times under the column labeled “Warm”.

Observations:  In the space below, write your observations about your hand and handwriting as observed under the three conditions above.

Data Analysis for Activity 1:   Enter Your Answers to the following questions in the Muscle Physiology Labs Assignment on Canvas.  In answering the following questions, you should include observations and data from Activity 1 (handwriting variations with temperature). 

• Describe three (3) chemical reactions that occur during muscle contraction.  There are hundreds, so pick 3.
• List 2 factors that increase the rate of a chemical reaction (hint: review chapter 2)
• What conclusions can you make about the effect of temperature on fine motor skills for your subject?  Be sure to explain your answer using your understanding of the physiology of muscle contraction. 

Procedure for Activity 11.2—The Effects of Muscle Fatigue on Fine Motor Skills—Handwriting: For this experiment, you will need a pen or pencil and a few pieces of paper. 

• Establish Baseline Handwriting Skills:  The subject should write the following sentence in cursive as neatly as possible one time:  “The quick brown fox jumped over the lazy dog.”
• Now, ask the subject to describe how much they use their hands daily and what activities they do with their hands.  Make note of this information.
• Directions for Observers:   It is important the subject is prompted to write quickly and with consistent speed as much as possible.  In this part, observers should take notes about the subject’s writing mechanics and note the time at which these changes occur.  For example, changes in posture, changes in hand position, is the arm/shoulder/torso being used to move the hand, is there movement in the legs or feet?
• Directions for Subject: Rewrite the sentence “The quick brown fox jumped over the lazy dog.” as many times as possible and as quickly as possible in ten (10) minutes.  If your hand is not fatigued at the end of ten (10) minutes, continue writing for a few more minutes.

Observations:   You will need your observations and the subject’s handwriting pages to answer analysis questions at the end of Activity 3.

Procedure for Activity 11.3—The Effects of Muscle Fatigue on Fine Motor Skills Using Beans:

Materials: beans, a beaker (or a cup or mug, which should have an opening that is smaller than your fist, smaller is better and more fun to observe!).

Directions: The same subject must complete all parts and all three trials of this experiment.

Part A—Fine motor skills before muscle fatigue: In this part of the experiment, you will observe normal fine motor skills by having the subject move beans from a tabletop into a cup using the thumb and ring finger (digits 1 and 4 of the subject’s dominant hand). Beans must be moved one at a time.

The time keeper and observer should record observations and record # of beans moved in the data table below.

When the time keeper says go, the subject will use his/her 1st and 4th digits (thumb and ring finger) to move as many beans as possible one at a time from the tabletop to a cup for 60 seconds. Record the number of beans moved for Trial 1 in Data Table \(\PageIndex{3}\) below.

Part B—Fine motor skills after muscle fatigue: In this part of the experiment, you will observe fine motor skills after muscle fatigue. Please read all directions for this part before you begin.

• Make a tight fist and keep squeezing the fist tightly until the hand feels fatigued. Don’t let the subject shake out the hand before moving the beans as in Step A.1 above, or
• If you have a handgrip exerciser, have the subject continually squeeze the handgrip as fast, tightly, and as long as possible without swinging the arm, until the hand feels fatigued.
• Now, have the subject repeat the exercise of using his/her 1st and 4th digits to move as many beans as possible from the tabletop to the cup for 60 seconds. Record the results for this trial in the “after fatigue” column for Trial 1 in Data Table 2 below.

Repeat for Trials 2 and 3: Repeat the steps of parts A and B two times and record the results for Trials 2 and 3 in the table below.

Observations:

Data Analysis for Activities 11.2 and 11.3: Enter your answers to the following questions in the Muscle Physiology Labs Assignment on Canvas. In answering the following questions, you should also include observations and data from Activity 11.2 (The Effects of Muscle Fatigue on Fine Motor Skills—Handwriting) and Activity 11.3 (The Effects of Muscle Fatigue on Fine Motor Skills Using Beans).

On a cellular/molecular level, explain 3 causes of muscle fatigue.

What conclusions can you make about the effect of muscle fatigue on fine motor skills for your subject? If possible, compare your results to others who use their hands differently than your subject.

In either Activity 2 or 3, did the subject’s performance get better after fatigue? If so, why do you think this could have happened?

What type of muscle fibers (red, white, or pink) do you expect to find the most of in the muscles of the hand? Why?

Procedure for Activity 11.4:  Review of Muscle Physiology on the Molecular Level

If available, you will also perform an online lab simulation to review the biochemistry of muscle physiology.  Online simulations may include any of the following:

• https://www.biointeractive.org/classroom-resources/neurophysiology-virtual-lab
• Labster 
• PHET Simulations

Additional Learning Resources:

• Watch this video to learn more about different types of muscle fibers:           https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-muscles/v/type-1-and-2-muscle-fibers

NBA playoffs 2024: Conference semifinals news, schedule, scores and highlights

Stephen A. Smith and Michael Wilbon have plenty of praise for Anthony Edwards after the Timberwolves' victory over the Nuggets in Game 1. (2:04)

The NBA playoffs' conference semifinals are underway. Expect plenty of drama after a thrilling start to the postseason.

The Boston Celtics , the No. 1 seed in the Eastern Conference and top overall seed, battle the No. 4 seed Cleveland Cavaliers . In the other East series, the No. 2 seed New York Knicks renew their old rivalry with the No. 6 seed Indiana Pacers .

In the West, the No. 1 seed Oklahoma City Thunder take on the No. 5 seed Dallas Mavericks . The other West clash pits the No. 2 seed and defending NBA Finals champion Denver Nuggets against the No. 3 seed Minnesota Timberwolves .

The four teams from each conference face off in a best-of-7 series to advance. All four rounds of the NBA playoffs are best-of-7, and teams are not reseeded after each round. The team with the better regular-season record in each series will have home court advantage for that series. All series are played in a 2-2-1-1-1 format, with the team with the better record hosting Games 1, 2, 5 and 7 (if necessary).

We'll have complete coverage of the NBA playoffs all the way through the 2024 NBA Finals, which tip off on June 6 on ABC and the ESPN app.

EASTERN CONFERENCE

Boston Celtics (1) vs. Cleveland Cavaliers (4)

Game 1: Tuesday, May 7 at Boston (7:00 p.m. ET, TNT) Game 2: Thursday, May 9 at Boston (7:00 p.m. ET, ESPN) Game 3: Saturday, May 11 at Cleveland (8:30 p.m. ET, ABC) Game 4: Monday, May 13 at Cleveland (7:00 p.m. ET, TNT) Game 5 (if necessary): Wednesday, May 15 at Boston (TNT) Game 6 (if necessary): Friday, May 17 at Cleveland (ESPN) Game 7 (if necessary): Sunday, May 19 at Boston

Stephen A. Smith breaks down the challenges the Celtics could face before the NBA Finals following Kristaps Porzingis' injury.

New York Knicks (2) vs. Indiana Pacers (6)

Game 1: Monday, May 6 at New York (7:30 p.m. ET, TNT) Game 2: Wednesday, May 8 at New York (8:00 p.m. ET, TNT) Game 3: Friday, May 10 at Indiana (7:00 p.m. ET, ESPN) Game 4: Sunday, May 12 at Indiana (3:30 p.m. ET, ABC) Game 5 (if necessary): Tuesday, May 14 at New York (TNT) Game 6 (if necessary): Friday, May 17 at Indiana (ESPN) Game 7 (if necessary): Sunday, May 19 at New York

Relive the best moments from past Knicks-Pacers playoff battles before their upcoming second-round matchup.

WESTERN CONFERENCE

Oklahoma City Thunder (1) vs. Dallas Mavericks (5)

Game 1: Tuesday, May 7 at Oklahoma City (9:30 p.m. ET, TNT) Game 2: Thursday, May 9 at Oklahoma City (ESPN) Game 3: Saturday, May 11 at Dallas (3:30 p.m. ET, ABC) Game 4: Monday, May 13 at Dallas (9:30 p.m. ET, TNT) Game 5 (if necessary): Wednesday, May 15 at Oklahoma City (TNT) Game 6 (if necessary): Saturday, May 18 at Dallas (8:30 p.m. ET, ESPN) Game 7 (if necessary): Monday, May 20 at Oklahoma City (8:30 p.m. ET, TNT)

Take a look at the important stats and sports betting nuggets ahead of the Mavericks-Thunder NBA playoff matchup.

Minnesota Timberwolves (3) lead Denver Nuggets (2), 1-0

Game 1: Timberwolves 106, Nuggets 99 Game 2: Monday, May 6 at Denver (10:00 p.m. ET, TNT) Game 3: Friday, May 10 at Minnesota (9:30 p.m. ET, ESPN) Game 4: Sunday, May 12 at Minnesota (8:00 p.m. ET, TNT) Game 5 (if necessary): Tuesday, May 14 at Denver (TNT) Game 6 (if necessary): Thursday, May 16 at Minnesota (8:30 p.m. ET, ESPN) Game 7 (if necessary): Sunday, May 19 at Denver

Anthony Edwards goes off for 43 points to lead the Timberwolves past the Nuggets and take a 1-0 series lead.