W1 Lab

Week 1 Lab Instructions Lab Safety / Muscle Structure Activity Deliverable Points Part A Basic Laboratory Information and PPE Part B Lab Safety Training and Certification: Digitally Submitted Not Graded but Required Part C Introduction to the Histology of Muscles 10 Part D Muscle Activation Lab 20 All Lab Deliverables Complete Parts A, B, and C 30 References: 1. Saladin Anatomy & Physiology: The Unity of Form and Function Part A: Receive Basic Lab Information and PPE Obtain overview of physical laboratory, facility and receive PPE – disposable laboratory jacket. 1.0 – Attend first physical laboratory during Week 1 1.1 – Pay attention to the instructor 1.2 – Take notes concerning fire exits, fire extinguisher, eye bath, emergency shower, chemical spill kit, red bag waste, broken glass waste, normal waste and MSDS handling documents 1.3 – Receive a disposable laboratory jacket and storage bag to reuse the jacket until it becomes visibly soiled. Part B: Complete Lab Safety Training and Certification Laboratory Safety Training Procedures, Lab Safety Critical Thinking Questions, and Certification Statement Review the Laboratory Safety Training Slides located in the Files 2.0– Review the slides 2.2 – Complete the attached Laboratory Safety Critical Thinking questions 2.3 – Double check your answers to the safety critical thinking questions and submit completed worksheet to your professor or upload into Canvas 2.4– Complete and sign the Lab Safety Training Questions and Sign Digitally before coming to your scheduled lab time in week 1. BIOS252 Week 1 Lab Instructions (B) Page 1 of 10

Part C: Introduction to the Histology of Muscles BACKGROUND – HISTOLOGY OF MUSCLES In the human body, muscles provide the ability of the body to move. Muscles are cells that alternate between contraction and relaxation. This alternation allows the muscles to produce work including but not limited to:  Producing body movements  Stabilizing body positions  Storing and moving substances within the body  Generating heat Muscles have four unique properties to help them contribute to homeostasis in your body:  Electrical excitability  Elasticity  Contractility  Extensibility Muscles or myocytes are divided into three categories based on both their structure and their function: 1. Skeletal muscle 2. Cardiac muscle 3. Smooth muscle Skeletal muscle – is commonly found attached to bone or skin. This type of muscle is responsible for voluntary movement and posture. Skeletal muscle is commonly described as being: long, thin, cylindrical, multinucleated, and striated (stripped in appearance). Skeletal muscle is arranged into contractile units known as sarcomere s. This arrangement allows for the contractile proteins actin and myosin to slide (move) on top of one another causing the muscle to shorten. This is known as the Sliding Filament Theory . BIOS252 Week 1 Lab Instructions (B) Page 2 of 10 a. Skeletal Muscle Striations Multinucleated

PURPOSE: In this lab, you will be asked to look at and describe the three different types of muscle: skeletal, cardiac and smooth, on a histologic level. MATERIALS:  Microscope  Slides of each muscle type: skeletal; cardiac; smooth  A writing utensil of some type (pen, pencil, or colored pencils)  Digital camera or mobile device capable of taking photos  Printed copy of the lab PREPARATION: 1. Read your lab in its entirety before coming to class. 2. Clear your workstation of all unnecessary materials. Book bags and or purses should be hung on hooks or places at the front of class. Make sure all other unnecessary materials (coats, drink containers, unused textbooks, etc.) are all stored and placed in a safe area out of the way. 3. Obtain all materials listed above. 4. Familiarize yourself with your microscope. Make sure it is plugged in and the microscope is in working order. Make sure the light is set to your preferred brightness. Make sure you are aware of where all the adjustment knobs are located and what they do. 5. Be aware of the instructions for documenting your lab work. You will be drawing what you see in the microscope so make sure you have a printed copy of your lab with you as well as your writing utensil(s). ACTIVITY: 1. Observe each of the three types of muscles under the microscope. 2. Make sure to center the muscle each time you are observing them. 3. Use different magnifications to view each muscle type and make sure to note which power gives you’re the best focus. This magnification will be indicated in the Observation Report section of this lab. 4. Make note of what makes each muscle type stand out and record those finding in your Observation Report. What kind of details can you observe? 5. Draw and take a picture of what you can observe. The drawing will be done in the appropriate box in the Observation Report. All photos need to be attached to the submission when turning the assignment in or can be inserted directly into the Observation Report. 6. When finished, make sure to return all items to their appropriate storage place and clean your station with bleach water. Dispose and materials that need to be disposed in accordance with the MSD sheets found at the front of the classroom. 7. Submit your completed lab with pictures to the Week 1 Lab hyperlink in the Unit 1 module. OBSERVATION REPORT: Take a picture or draw a sketch in the appropriate box below. Make sure to indicate the total magnification you used for your observation: total magnification = ocular lens power x objective lens power. BIOS252 Week 1 Lab Instructions (B) Page 4 of 10

(1 pt) (1 pt) BIOS252 Week 1 Lab Instructions (B) Page 5 of 10 Skeletal Muscle Cardiac Muscle

2.) What are intercalated discs used for in cardiac muscle? (1 pt) Intercalated discs hold adjacent cells together, to allow the heart to beat. 3.) What makes a muscle tissue striated? (1 pt) Muscle tissue is striated because of actin and myosin bands that are repeated along the myofibrils. 4.) What is a motor unit? (1 pt) Motor unit has a muscle fiber neuron, including the innervation of the muscle fibers. 5.) Define the following terms: Electrical excitability, Elasticity, Contractility, and Extensibility. (1 pt) Electrical excitability – electrical transmition to respond to stimulus Elasticity – stretching a muscle to reach full movement range Contractibility – tightening or shortening of the muscle Extensibility – muscle ability to stretch and extend BIOS252 Week 1 Lab Instructions (B) Page 7 of 10

Part D: Muscle Activation Lab OUTCOMES: In this lab, you will be asked to look at and describe the contraction of a skeletal muscle on a microscopic basis. MATERIALS:  Microscope or magnifying glass  Petri dish with segment of skeletal muscle fibers  Microscope slides with coverslips  Dissecting tools kit  Stopwatch  Ruler PREPARATION: 1. Read your lab in its entirety before coming to class. 2. Clear your workstation of all unnecessary materials. Book bags and or purses should be hung on hooks or places at the front of class. Make sure all other unnecessary materials (coats, drink containers, unused textbooks, etc.) are all stored and placed in a safe area out of the way. 3. Obtain all materials listed above. 4. Familiarize yourself with your microscope. Make sure it is plugged in and the microscope is in working order. Make sure the light is set to your preferred brightness. Make sure you are aware of where all the adjustment knobs are located and what they do. 5. Be aware of the instructions for documenting your lab work. You will be drawing what you see in the microscope so make sure you have a printed copy of your lab with you as well as your writing utensil(s). ACTIVITY: 1. Place petri dish containing a segment of skeletal muscle tissue on the stage of a dissecting microscope. Use a teasing needle to gently tease the segment into very thin strands. You will see optimal results with single muscle fibers, but these are difficult to obtain. The thinnest strand that you will likely get is a group of two to four fibers (< 0.2mm in cross-sectional diameter) 2. Mount a thin strand on a microscope slide with coverslip (you will need to add a drop of water on the slide before adding the coverslip). Examine the strand under magnification. Note the striations in the myofibers. 3. Transfer three or more of the thinnest strands to a tiny amount of glycerol on a second microscope slide. Lay the strands out straight and parallel to each other. Do not cover them. (Note the less glycerol used, the easier the fibers are to measure). 4. Using your dissecting microscope, measure the length of the strands with a millimeter scale. Record these lengths. 5. Flood the strands with several drops of the solution containing ATP plus potassium and magnesium ions. Observe the reaction of the fibers. (Note it is essential to avoid cross-contamination between the ATP and the salt solutions. Such contamination will lead to ambiguous experimental results). 6. After 30 seconds or more, re-measure the strands and calculate the degree of contraction. Record your results. Have the fibers changed in width? 7. Remove one of the contracted strands to another slide. Examine it under a compound microscope and compare the fibers with those seen in step 3. What differences to you see? BIOS252 Week 1 Lab Instructions (B) Page 8 of 10

Submit Parts A-D Deliverables – ALL DUE BY DATE GIVEN BY YOUR PROFESSOR Activity Deliverable Points Part A Nothing to submit Part B Lab Safety Critical Thinking Questions and Certification Not Graded but Required Part C Introduction to the Histology of Muscles 10 Part D Muscle Activation Lab 20 BIOS252 Week 1 Lab Instructions (B) Page 10 of 10