Lab 6 - LAB 6 LAB Ex 14 – Microscopic Anatomy and Ex...

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Unformatted text preview: LAB # 6 LAB Ex. 14 – Microscopic Anatomy and Ex. Classification of Skeletal Muscle Classification Ex.15 – Gross Anatomy of the Muscular Ex.15 System System Ex. 16 B – Skeletal Muscle Physiology Ex. 14 – Microscopic Anatomy and Classification of Skeletal Muscle Classification •Describe the structure of skeletal muscle going Describe through increasing levels of magnification through •Define: fiber, myofibril, myofilament, actin, Define: myosin, myosin, tendon, aponeurosis, epimysium, perimysium, tendon, endomysium endomysium • Neuromuscular junction: structure, function Neuromuscular Muscle tissue: 3 subtypes Muscle • 1. skeletal ( attached to the skeleton) 1. skeletal • 2. cardiac ( heart ) • 3. smooth ( the walls of hollow organs ) Skeletal muscle = • Voluntary ( can control the contraction) • Striated ( the appearance is stripped) Skeletal Muscle • Multinucle d ce be ate lls causese ral ste ce fuseto produce ve m lls em ach usclefibe r • Plasm m m a m a invaginations s Plasm e brane= sarcole m ; invaginations =T tubule •C ytoplasm= sarcoplasm • S ooth e m ndoplasm re ic ticulum= sarcoplasm re ic sarcoplasm ticulum form t e inal ciste s rnae( de posit C – ne de for contraction) a ed f orm rm de • Mitochondrion • I nclusion of glycoge = glycosom s n glycosom e Inclusion ( glycoge glucose e rgy) n ne glycoge • Multipleoval nucle ( them i usclece / fibe = syncytium=m ll r syncytium ass Multiple of cytoplasmwithin a ce m m ll e branethat contains m ultiple nucle and is ofte there of ce i n sult llular fusion) nucle • Myofilam nts : thin (actin, troponin, tropom e yosin) Myofilam t hin thick ( m t hick yosin) Myoblasts Fusion of myoblasts Skeletal muscle fiber Anatomy of a skeletal muscle fiber / cell Anatomy Fibers Myofibrils->Myofilaments Actin and Myosin T Tubule: A transverse tubule formed by the sarcolemma indenting into the muscle cell at junction of A and I bands. Terminal Cisternae: On either side of T tubule, the tubules of the sarcoplasmic reticulum enlarge, fuse, and form expanded chambers. Triad: The combination of a pair of terminal cisternae plus a T tubule. • • Anatomy of a muscle Anatomy Epimysium perimysium endomysium (connective tissue) Epimysium endomysium Muscle Fascicle Cells(fibers) Muscle Organization of Skeletal Muscle Cells into Muscles • Epimysium surrounds muscle • Perimysium sheathes bundles of muscle fibers called a fascicle (fasciculus) • Epimysium and perimysium contain blood vessels and nerves • Endomysium covers individual muscle fibers • Tendons or aponeuroses attach muscle to bone or muscle The epimysia blends epimysia • Cordlike tendons Cordlike tendons • Sheetlike aponeuroses They connect the muscle to each other or They indirectly to the bones = attachments indirectly • movable = insertion insertion • iimmovable = origin mmovable origin Anatomy of a myofibril ( thick + thin filaments) Anatomy Anatomy of a myofibril ( thick + thin filaments) Anatomy Neuromuscular Junction= Neuromuscular Nerve fiber (axon) + muscle cell Nerve-Muscle Relationship • Skeletal muscles are innervated by motor neurons • Each muscle fiber is innervated by only one motor neuron BUT 1 motor neuron can innervate more than 1 muscle fiber. Neuromuscular Junction Neuromuscular Connection between a nerve fiber and its target cell is called a synapse Junction between a nerve axon and muscle cell and seperated by a small fluid-filled gap called synaptic cleft Motor unit: A neuron + all the muscle cells it stimulates. Neuromuscular Junction Motor Unit :- A single motor neuron and all the cells within a muscle that it activates. A single muscle= multiple motor units and the gradual and coordinated activation of these motor units is called graded contraction. Nervous system controls muscle contraction by two mechanisms:1) Multiple motor unit summation (recruitment) :- gradual activation of more and more motor units 2) Temporal Summation:- an increase in the frequency of nerve impulses for each active motor unit. Tonus:- a constant state of slight excitation of a muscle while it is in a relaxed state to prepare a muscle for possible contraction BIOPAC EMG 1 BIOPAC The combination of a single motor neuron and all of the muscle fibers it controls is called a motor unit (Fig. 1.1). When a somatic motor neuron is activated, all of the muscle fibers it innervates respond to the neuron’s impulses by generating their own electrical signals that lead to contraction of the activated muscle fibers. Surface EMG BIOPAC •An electromyogram (EMG) is a recording of the electrical activity of muscles. When muscles are active they produce an electrical current. The strength of this electrical current is usually proportional to the level of the muscle activity that generated it. The electrical current strength is expressed in millivolts. •Detection amplification and recording of changes in skin voltage is called electromyography •Today we will do SEMG or Surface EMG H ea d p h o n e s (O U T 1 ) P lu g s in to b a c k o f M P 3 0 u n it B IO PA C S S 2 L p lu g s in to C H a n n e l 3 The electrical impulses generated and conducted by each fiber is weak but many fibers conducting simultaneously induce voltage differences in the overlying skin that can detected by a pair of electrodes. BIOPAC Part 1 Calibrate Figure 1.4 Calibration Segments 1 and 2 Data analysisselecting peaks. When selecting numbers fill in the boxes above the graph(s) Segment 1 BIOPAC part 2 H e a d p h o n e s (B IO PA C O U T 1 ) P lu g s in to b a c k o f M P 3 0 u n it D y n a g rip c ro s s b a r H a n d c lo s e to b ra ck et b u t n o t to u c h in g . B IO PA C S S 2 L p lu g s in to C H a n n e l 3 B IO PA C S S 2 5 L p lu g s in to C H a n n e l 1 Figure 2.2 Calibration is shown at rightgrip maximally with dominant hand for 2 seconds, waiting first for 2 seconds Segment 1 data – you will go up in force increments depending on your max. clench from calibration Segment 2 data – you will clench maximally and then hold – fatigue will set in – let it go to ½ of max. clench level (don’t use your other hand to keep it going ;) To analyze segment 1: only pick plateau portion, avoid any spikes, and the rise and fall portions To analyze segment 2: Find the value at peak, then click around to find the ½ max. point. *(use the I-BEAM tool) Then drag select between the two. Naming of the skeletal muscles Naming • Direction of the fibers rectus, transverse , oblique Direction transverse oblique • Size of the muscle maximus, minimus, longus, Size minimus longus brevis brevis • Location ( the bone they are associated with) • Number of origins biceps , triceps , quadriceps Number biceps • Location of the insertion, origin • Shape deltoid, trapezius Shape deltoid, • Action adductor, extensor, flexor Action adductor, Types of muscles Types • Muscles responsible for producing a particular Muscles movement = prime movers /agonists prime • Muscles responsible for producing the reverse Muscles movement = antagonists antagonists • Synergists = aid the agonists by reducing Synergists unnecessary movements Fixators = immobilize the origin of an agonist so Fixators that all the tension is exerted at the insertion that Ex.15- Gross Anatomy of the Muscular System System • • • Identification of the human muscles ( names!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!) names Location ( insertion, origin) Location insertion, Action ( and the relation with the location) 4 regions: 1. head and neck 2. trunk 2. 3. upper limb 3. 4. lower limb 4. Muscles of head and neck : facial expression, mastication, Muscles movement of the eye, movement of the head and shoulder girdle movement Anterolateral Muscles of Neck (Deep) - Digastric - Sternothyroid - Stylohyoid - Omohyoid - Mylohyoid - Sternhyoid - Thyrohyoid The trunk The • Thorax / Abdomen • Superficial / deep Superficial The Upper Limb The • Muscles that move the arm • Muscles that cause movements at the Muscles elbow elbow • Muscles that cause movements at the Muscles wrist and hand wrist Anterior / posterior Superficial / deep Anconeus Origin: Lateral epicondyle of humerus Insertion: Lateral aspect of olecranon process of ulna Action: Abducts ulna during forearm pronation; extends elbow Thorax and Shoulder (Superficial) - Pectoralis major - Serratus anterior - Deltoid - Pectoralis minor Thorax (Deep): Muscles of Respiration Thorax -External intercostals -Internal intercostals -Diaphragm Abdominal Wall Abdominal -Rectus abdominis -External oblique -Internal oblique -Transversus abdominis * Linea alba - white line Posterior Muscles of the Neck, Shoulder, and Posterior ThoraX ThoraX -Trapezius -Latissimus dorsi -Infraspinatus -Teres minor major/minor -Teres major -Supraspinatus -Levator scapulae -Rhomboids Muscles Associated with Vertebral Column -Semispinalis -Splenius Hand and Fingers Anterior Compartment (Superficial) - pronator teres - Flexor carpiradialis - Palmaris longus - Flexor carpi ulnaris - Flexor digitorum superficialis Pronator Teres Origin: Medial epicondyle of humerus and coronoid process of ulna Insertion: Midshaft of radius Action: Pronate forearm Palmaris Longus Origin: Medial epicondyle of humerus Insertion: Palmar aponeurosis; skin and fascia of palm Action: Flexes wrist Hand and Fingers Anterior Compartment (Deep) - Flexor pollicis longus - Flexor digitorum profundus - Pronator quadratus Flexor Pollicis Longus Flexor Origin: Anterior surface of Origin: radius and interosseous membrane membrane Insertion: Distal phalanx of Insertion: thumb thumb Action: Flexes thumb Flexor Digitorum Profundus Origin: Anteromedial surface of ulna, interosseous membrane and coronoid process Insertion: Distal phalanges of 2nd through 5th fingers Action: Flexes distal phalanges Pronator Quadratus Origin: Distal portion of anterior ulnar surface Insertion: Anterior surface of radius, distal end Action: Pronates forearm Hand and Fingers Posterior Compartment (superficial) -Extensor carpi radialis longus -Extensor carpi radialis brevis -Extensor digitorum -Extensor carpi ulnaris Hand and Fingers Posterior Compartment (Deep) -Extensor pollicis longus and brevis -Abductor pollicis longus -Supinator Supinator Origin: Lateral epicondyle of Humerus and proximal ulna Insertion: Proximal end of radius Action: Supinate forearm; Antagonist of pronator muscles ...
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