1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Biology Sylvia S. Mader Michael Windelspecht Chapter 12 Muscular System Lecture Outline Part 1

2 Muscular System

3 Points to ponder What are the 3 types of muscle tissue? What are the functions of the muscular system? How are muscles named and what are the muscles of the human body? How are skeletal muscles and muscle fibers structured? How do skeletal muscles contract? How do skeletal muscle cells acquire ATP for contraction? What is rigor mortis? What are some common muscular disorders? What are some serious muscle diseases? How do the skeletal and muscular system help maintain homeostasis? How are these 2 systems related to other systems in maintaining homeostasis?

4 Review: Types of muscle tissue 1._________ – involuntary muscle found in hollow organs and vessels 2._________ – involuntary muscle found in the heart 3.__________ – voluntary muscle that is attached to the skeleton 12.1 Overview of the Muscular System

5 Figure 12.1 The three classes of muscles in humans. Review: Types of muscle tissue Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skeletal muscle has striated cells with multiple nuclei. occurs in muscles attached to skeleton. functions in voluntary movement of body. striation nucleus a.b.c. 250X Cardiac muscle has branching, striated cells, each with a single nucleus. occurs in the wall of the heart. functions in the pumping of blood. is involuntary. Smooth muscle has spindle-shaped cells, each with a single nucleus. cells have no striations. functions In movement of substances in lumens of body. is involuntary. is found in blood vessel walls and walls of the digestive tract. 400X 250X Smooth muscle cellnucleus Intercalated disknucleus (smooth): © The McGraw-Hill Companies, Inc. Dennis Strete, photographer; (cardiac, skeletal): © Ed Reschke;

6 What are the functions of skeletal muscles? 1._______ the body by allowing us to stay upright 2.Allow for ___________ by attaching to the skeleton 3.Help maintain a constant body ___________ 4.Assist in movement in the ____________ and __________ vessels 5.________ internal organs and ________ joints 12.1 Overview of the Muscular System

7 How are skeletal muscles attached? ________ – connective tissue that connects muscle to bone _______ – attachment of a muscle on a stationary bone _______ – attachment of a muscle on a bone that moves Figure 12.2 Connecting muscle to bone Overview of the Muscular System muscle fiber fascicle tendon radius dense connective tissue Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

8 How do skeletal muscles work? Antagonistic – muscles that work in _________ pairs Synergistic – muscles working in groups for a ___________ action Figure 12.3 Skeletal muscles often work in pairs Overview of the Muscular System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. tendon origin radius ulna a. biceps brachii (contracted) triceps brachii (relaxed) humerus insertion biceps brachii (relaxed) triceps brachii (contracted) b.

9 Examples of how skeletal muscles are named _____ – the gluteus maximus is the largest buttock muscle _______ – the deltoid is triangular (Greek letter delta is Δ) ___________ – the frontalis overlies the frontal bone ________ of muscle fiber – the rectus abdominis is longitudinal (rectus means straight) 12.1 Overview of the Muscular System

10 Examples of how skeletal muscles are named ____________ – the brachioradialis is attached to the brachium and radius __________________ – the biceps brachii has 2 attachments ________ – the extensor digitorum extends the digits 12.1 Overview of the Muscular System