Muscle contraction Public domain image. Muscle has two purposes Generate motion Generate force.

Slides:

Advertisements

Similar presentations

Advertisements

Muscle Specialized for: Types:.

Muscle Function.

Copyright © 2006 Lippincott Williams & Wilkins. Muscular System Chapter 11 Part 2.

Skeletal Muscle Contraction

Muscles n Skeletal muscle organization and how it contracts.

Muscle Microstructure/ Contraction & Relaxation Muscle.

The Muscular System. Muscular System Functions MOVEMENT MOVEMENT Maintain Posture Maintain Posture Stabilize Joints Stabilize Joints Generate HEAT Generate.

Muscular system SKELETAL MUSCLE Skeletal muscle is made up of hundreds of muscle fibers –Fibers consists of threadlike myofibrils –Myofibrils composed.

Chapter 9 Muscular System

Anatomy and Physiology I

Sliding Filament Theory

Physiology of Skeletal Muscle Contraction. The Muscle Action Potential ( AP ) The Muscle Action Potential ( AP ) Muscle RMP = -90 mV ( same as in nerves.

The Muscular System 36-2 BIO 1004 Flora. Types of Muscle Tissue 3 Different Types of muscle tissue: o Skeletal o Smooth o Cardiac o Each type of muscle.

Motor mechanisms. Keywords (reading p ) Bundle, fiber, myofibril, sarcomere Z-line, thick filament, thin filament Actin, myosin, sliding filament.

Muscle fiberMotor neuron Nucleus. SarcolemmaMyofibrils Sarcoplasmic reticulum (SR) T-tubule SR Cistern.

Muscle Structure and Function

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Overview  The three types of muscle tissue are skeletal, cardiac, and.

Contraction of skeletal muscle. Learning objectives What evidence supports the sliding filament mechanism of muscle contraction? How does the sliding.

OBJECTIVES At the end of this lecture the student should be able to: Define different types of muscles Enumerate cellular organization of human skeletal.

7.2 Microscopic Anatomy and Contraction of Skeletal Muscle

Muscle Contraction Tendon – cord of dense fibrous tissue attaching the muscle to a bone. Epimysium – the sheath of fibrous connective tissues surrounding.

MUSCLE CONTRACTION. Microscopic Anatomy of Skeletal Muscle Sarcomere Contractile unit of a muscle fiber Figure 6.3b.

Muscle Cells & Muscle Fiber Contractions

Cardiac Muscle Involuntary –heart only Contracts & relaxes continuously throughout life –Contracts without nervous stimulation! –A piece of cardiac muscle.

11.2.Muscles and movement. State the roles of bones, ligaments, muscles, tendons and nerves in human movement. Label a diagram of the human elbow joint,

Muscle & Muscle Tissue. Types of Muscle Tissue Skeletal Are striated Controlled voluntarily Tires easily.

1 Structure of Skeletal Muscle We will begin our look at the structure of muscle starting with the largest structures and working our way down to the smallest.

Muscle Tissue A primary tissue type, divided into: A primary tissue type, divided into: –skeletal muscle –cardiac muscle –smooth muscle.

Fibers: composed of myofibrils

Hair cells, actin bundles, and unconventional myosins.

Question 1 Explain the primary differences between smooth, skeletal, and cardiac muscle tissue Skeletal muscle fibers are cylindrical, multinucleate cells,

Motor mechanisms.

Dr.Mohammed Alotaibi MRes, PhD (Liverpool, England) Department of Physiology College of Medicine King Saud University.

Sensory and Motor Mechanisms – chpt 49-. I. Anatomy & physiology of Muscular system n A. 3 types of muscle tissue –1. skeletal muscle aka striated muscle–

____ Chapter 49 ~ Sensory and Motor Mechanisms ( Just focusing on motor mechanisms ) Motor Mechanisms.

Sliding Filament.

II. Skeletal Muscle Overview A. Skeletal Muscle Distinguishing Characteristics Striated Voluntary Multi-nucleated B. Functions Movement Maintain Posture.

The Sliding Filament Theory

Physiology of Skeletal Muscle Contraction. The Muscle Action Potential ( AP ) The Muscle Action Potential ( AP ) Muscle RMP = -90 mV ( same as in nerves.

Movement Topic 11.2.

Muscular System Notes. Microscopic Muscle Anatomy  Myfibrils  About 1-2 micrometers in diameter  Length of a muscle fiber  Composed of multiple myofilaments.

Skeletal Muscle Microscopic Anatomy Chapter 10. Microscopic Anatomy Muscle fibers = muscle cells: long and multinucleate Sarcolemma: cell membrane myoglobinSarcoplasm:

Muscular System The 3 Types of Muscles SKELETAL MUSCLE STRUCTURE.

Lecture #21 Date ____ n Chapter 49 ~ Sensory and Motor Mechanisms.

Molecular Basis of Muscle Contraction Standard 9 h. Students know the cellular and molecular basis of muscle ocntraction,including the roles of actin,

MUSCULAR SYSTEM Structure and Function. Skeletal Muscle Properties 1. Excitability = ability to receive and respond to a stimulus  Also called irritability.

Muscle voluntary, striated involuntary, striated auto-rhythmic involuntary, non-striated evolved first multi-nucleated digestive system arteries, veins.

Muscle Contraction.

Muscle System. Root Words 3 Kinds of Muscle Skeletal Smooth (stomach, intestine) Cardiac.

MUSCULAR SYSTEM Part 3: Muscle Structure & Contraction.

How do muscle cells contract ?. What is the structure of a muscle fiber ? The sarcolemma, or plasma membrane contains invaginations called T (transverse)

Muscles Skeletal muscles are stimulated to contract by nerves and act as effectors.

Muscle Physiology ..

Muscle Contraction and the Sliding Filament Theory

EQ: How do our muscles in our body contract?

Introductory Skeletal Muscle – Histology Flash Cards

Introduction The Muscular System.

Introduction The Muscular System.

Muscles and Movement.

Muscle anatomy and Energy

Chapter 3 Support and locomotion – muscles and movement.

Muscle Contraction and the Sliding Filament Theory

Applied Exercise Physiology

MUSCULAR SYSTEM.

Types of Muscle Skeletal Striated Voluntary Multinucleated Smooth

Do now activity #1 What are the 3 types of muscle?

Presentation transcript:

Muscle contraction Public domain image

Muscle has two purposes Generate motion Generate force

3 Muscle types Skeletal Cardiac Smooth Striated

Striated vs Smooth muscle tm?File_name=B33-8F&File_type=GIF m?File_name=19-51&File_type=GIF Images from BIODIDAC

What is meant by involuntary muscle?

Gross structure Image from National Cancer Institute ular/structure.html

Skeletal muscle Is an organ –Composed of connective tissue, muscle, blood vessels and nerves Muscle fibers have a variety of important structures –Sarcolemma, t-tubules, sarcoplasm, multiple nuclei, Sarcoplasmic reticulum, myofibrils, mitochondria, Myofibrils are important in contraction and composed of a variety of proteins –Troponin, tropomyosin, titin, nebulin –Actin and myosin are the contractile proteins

Myofibril and the Sarcomere Arrangement of thick and thin filaments creates a repeating pattern of alternating light and dark bands. One repeat is a sarcomere Image Source: bril.svg

Banding patterns Image Source:

Sliding filament theory of contraction overlapping actin and myosin filaments of fixed length slide past one another in an energy-requiring process, resulting in muscle contraction.

When contraction happens what happens to the size of the I band? Image Source: g/wiki/File:Sarcomere.svg

Titin and Nebulin Image Source:

Image author: Moralapostel Power Stroke Image source:

Regulatory proteins Original drawing by RMB Hoffman (Copyleft 2010). Based on Proteins 2008 Nov 1;73(2): Image source:

Muscle contraction can’t happen without ATP! ATP binds and myosin detaches from actin. ATP hydrolysis occurs, myosin lightly attaches to actin. Energy released allows the myosin to change confirmation and have the power stroke.

Excitation-contraction coupling and relaxation Which second messenger is important to this process?

T-tubules are next in the pathway Action potential is propagated through T- tubules. Image source BIODIDAC: awa.ca/thumbnails/file det.htm?File_name=B 32- 5J1&File_type=GIF

The sarcoplasmic reticulum has a high concentration of this second messenger, which it releases at this point. What is the second messenger?? (Not on your worksheet) Image Source BIODIDAC: humbnails/filedet.htm?File_na me=CELL018B&File_type=GI F

Calcium Binds to troponin and tropomyosin releases its inhibition on actin-myosin interactions. Image Author: Daniel Schwen Source: CH_cow_2.jpg

Calcium concentrations then decrease It is brought into the Sarcoplasmic reticulum (SR) How does this happen?? (the concentration of calcium is lower in the cytoplasm than it is in the SR)

Dissociation of Ca 2+ leads to… Restoration of tropomyosin activity.

Excitation-contraction coupling and relaxation Acetylcholine release from the motor neuron triggers Na + entry into the muscle initiating an action potential. T-tubules Ca ++ entry from the Sarcoplasmic reticculum Ca ++ binds to troponin, actin-myosin interaction is allowed. Power stroke Sliding filaments and contraction

Create a graph based on the data on your worksheet and answer the questions which follow