The Muscular System Lab 7 REVIEW What are
The Muscular System Lab 7
REVIEW What are the four tissue types? • • Epithelial Connective Muscular Nervous
Objective 1 Types of Muscle Tissue
SKELETAL MUSCLE
Structure of SKELETAL MUSCLE Muscle Fascicles Muscle Fibers (cells) A muscle cell (fiber) is a bundle of myofibrils Myofibrils
Myofibrils of a Muscle Fiber (Cell) Myofibrils Muscle fiber
SKELETAL MUSCLE Human Body Explorer link
Skeletal Muscle Location Structure Function Attached to the skeleton Long, thin cells (fibers) are: - striated - multinucleated - nuclei are in the periphery of the cell posture, movement, stabilizes joints The plasma membrane of the muscle fiber
Skeletal Muscle Note multi-nucleation Whole mount, oil immersion
Striations in skeletal muscle due to sarcomeres
Striations of the myofibrils are seen through the muscle fiber
Striations: A bands & I bands (dark bands) (light bands)
A-bands, I-bands, & Sarcomere A I Sarcomere A
A-bands, I-bands, Sarcomeres, & Sarcolemma I I I A A I I Sarcomeres Sarcolem ma A I Sarcomere
Skeletal Muscle Note nuclei on the periphery of the cells (fibers) Nuclei A-band I-band Sarcomere Sarcolemma Longitudinal section, oil immersion
CARDIAC MUSCLE
The heart muscle (myocardium) forms the bulk of the heart. It is arranged in a spiral or circular bundles. Cardiac muscle bundles “Helical heart” model
CARDIAC MUSCLE – Lab notes
Cardiac Muscle Location Structure Function Wall of the heart Cells (myocytes) are: provide pressure - faintly striated - branching for the circulation of blood - with one (or two) centrally placed nuclei Cells are connected by intercalated discs (gap junctions/desmosomes) Intercalated Disc Nucleus
Branching cells Heart muscle is made of different cell types that ‘talk’ to each other so the tissue can respond to changing conditions and efficiently pump blood round the body. This image by Patrizia Camelliti and Peter Kohl shows the microscopic architecture of heart muscle, showing the muscle in red closely associated with fibroblast cells in green. http: //news. bbc. co. uk/1/shared/spl/hi/pop_ups/05/health_heart_pictures/html/4. stm
Cardiac Muscle Central nuclei Branching cells are in 3 -D; may not be particularly visible in 2 -D Intercalated disk
Cardiac Muscle Central nuclei Intercalated disk
Cardiac Muscle Intercalated discs
SMOOTH MUSCLE
Smooth muscle is found in the walls of hollow visceral organs. Contractions force fluids and other substances along. Cells are arranged closely to form sheets. Epithelial Tissue C. T. E. T. Connective Tissue T. E. C. T. Epithelial Tissue
Smooth Muscle Location Walls of hollow organs Structure Cells are: - spindle shaped - have a single nucleus - not striated Function move fluids and other contents nucleus
Smooth Muscle Cells are arranged closely to form sheets.
Smooth Muscle Note cell and nucleus shapes
REVIEW Skeletal muscle Cardiac muscle Smooth muscle
Objective 2 Connective Tissue Coverings of Skeletal Muscle
Note that the endomysium surrounds the sarcolemma
Skeletal Muscle, cs & ls A muscle fiber is filled with myofibrils Nuclei
Objective 3 Neuromuscular Junction
Reflex Arc N-M junction (Myoneural junction)
Neuromuscular Junction Axon terminal Skele tal m uscle fiber Motor Neuron Axon
Neuromuscular Junction as you will see it under the microscope Skeletal muscle fiber Motor Neuron Axon Terminal
Neuron Axon le mu l a t Ske Axon Terminal sc ber i f le
Muscles Origin, Insertion, Action, Innervation
Origin The immovable (or less moveable) bone to which the muscle is attached Scapula Biceps brachii
Insertion The movable bone to which the muscle is attached (The bone that the muscle moves) Radius Biceps brachii
Action Joint movement(s) caused by contraction of the muscle Flexes and supinates forearm
Innervation The nerve that acts on the muscle Musculocutaneous
Now the hard part We have to learn the names and locations of a lot of muscles
Objective 4 Human Muscles
Frontalis Orbicularis oculi Orbicularis oris Occipitalis Mentalis Sternocleidomastoid Buccinator Masseter Trapezius
Splenius capitis Trapezius Levator scapulae Supraspinatus Teres minor Infraspinatus Teres major Infraspinatus Latissumus dorsi Rhomboid minor Rhomboid major
Longissimus External intercostals (longest) Iliocostalis (most lateral) Semispinalis Spinalis (most medial) (along spine)
Pectoralis minor Deltoid Subscapularis Biceps brachii Pectoralis major Serratus anterior Brachialis Internal intercostals Brachioradialis External intercostals
Pronator teres Brachioradialis Flexor carpi radialis Palmaris longus Brachioradialis Flexor carpi ulnaris Extensor carpi radialis longus Extensor carpi radialis brevis Supinator Extensor digitorum Extensor carpi ulnaris Pronator teres
Transverse abdominus Internal oblique External oblique Rectus abdominus External oblique
Rectus abdominus Directions of the fibers
Anterior Posterior Anterior deep Iliopsoas Gluteus minimus Psoas major Iliacus Adductor longus Tensor facsiae latae Pectineus Adductor longus Vastus medialis Adductor magnus Hamstrings Vastus lateralis Rectus femoris Adductor brevis Gracilis Quadriceps Gracilis Sartorius Semimembranosis Semitendinosis (Medial) Biceps femoris (Lateral)
Tibialis anterior Extensor digitorum longus Gastrocnemius Tibialis posterior Soleus Fibularis longus Fibularis brevis Extensor halicus longus Flexor digitorum longus Fibularis brevis
How many of these muscles can you name?
http: //www. getbodysmart. com Muscular System http: //www. meddean. luc. edu/lumen/Med. Ed/Gross. Anatomy/ dissector/mml/index. htm Click here
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