Figure 50.1
Figure 50.17aa Sclera Suspensory ligament Cornea Iris Pupil Choroid Retina Fovea Optic nerve Aqueous humor Lens Vitreous humor Optic disk Central artery and vein of the retina
Figure 50.26 Muscle Skeletal Muscle contraction Bundle of muscle fibers Single muscle fiber (cell) Myofibril Plasma membrane Z lines Nuclei Sarcomere Thick filaments (myosin) TEM M line 0.5 m Thin filaments (actin) Z line Sarcomere Z line
Figure 50.26b Z lines Sarcomere Thick filaments (myosin) TEM M line 0.5 m Thin filaments (actin) Z line Sarcomere Z line
Figure 50.30 Synaptic terminal Axon of motor neuron 1 T tubule Sarcoplasmic reticulum (SR) Myofibril Plasma membrane of muscle fiber Sarcomere Synaptic terminal of motor neuron Synaptic cleft T tubule Mitochondrion Ca 2 released from SR Plasma membrane ACh 2 Sarcoplasmic reticulum (SR) Ca 2 pump Ca 2 3 6 ATP CYTOSOL 4 7 Ca 2 5
Figure 50.30b 1 Synaptic terminal of motor neuron Synaptic cleft T tubule Plasma membrane ACh 2 Sarcoplasmic reticulum (SR) Ca 2 Ca 2 pump 3 6 ATP CYTOSOL 4 7 Ca 2 5
Figure 50.29 Tropomyosin Actin Troponin complex Ca 2 -binding sites (a) Myosin-binding sites blocked Ca 2 Myosinbinding site (b) Myosin-binding sites exposed
Figure 50.28 Thin filaments Thick filament 1 Thin filament ATP 5 ATP Myosin head (lowenergy configuration) Thick filament 2 Thin filament moves toward center of sarcomere. Actin Myosinbinding sites Myosin head (lowenergy configuration) ADP P i Myosin head (highenergy configuration ADP ADP 3 P P i i Cross-bridge 4
Figure 50.28a-1 1 Thin filament ATP Myosin head (lowenergy configuration) Thick filament
Figure 50.28a-2 1 Thin filament ATP Myosin head (lowenergy configuration) Thick filament Actin 2 Myosinbinding sites ADP P i High-energy configuration
Figure 50.28a-3 1 Thin filament ATP Myosin head (lowenergy configuration) Thick filament Actin 2 Myosinbinding sites ADP P i High-energy configuration ADP P i Cross-bridge 3
Figure 50.28a-4 1 Thin filament ATP Myosin head (lowenergy configuration) Thick filament 2 Thin filament moves toward center of sarcomere. Actin Myosinbinding sites Low-energy configuration ADP P i High-energy configuration ADP P i 4 ADP P i Cross-bridge 3
Figure 50.28a-5 Muscle contraction 1 Thin filament ATP 5 ATP Myosin head (lowenergy configuration) Thick filament 2 Thin filament moves toward center of sarcomere. Actin Myosinbinding sites Low-energy configuration ADP P i High-energy configuration ADP ADP 3 P P i i Cross-bridge 4
If calcium ions are not present in a sarcomere, muscle contraction cannot occur because a) ATP cannot bind to myosin. b) myosin cannot unbind from tropomyosin. c) myosin cannot bind to actin. d) ADP cannot be converted into ATP. 2011 Pearson Education, Inc.
Figure 50.31 Spinal cord Motor unit 1 Motor unit 2 Synaptic terminals Nerve Motor neuron cell body Motor neuron axon Muscle Muscle fibers Tendon
Muscle Twitch Complete cycle of contraction-relaxation in response to stimulus Can be observed using a myogram (laboratory recording of muscle activity) Latent period Contraction Relaxation Summation Tetanic contraction
Muscle force Latent period Contraction Relaxation Summation Tetanus Stimulus 0 Time (msec) 500 Figure 6.10
Figure 50.32 Tension Tetanus Summation of two twitches Single twitch Action potential Pair of action potentials Time Series of action potentials at high frequency Isotonic contraction & isometric contraction
Activity of Muscles Can Vary Isotonic contractions: muscle shortens, movement occurs Isometric contractions: muscle doesn t shorten, no movement Degree of nerve activation influences force
Figure 50.27 Z Sarcomere M Z 0.5 m Relaxed muscle Contracting muscle Fully contracted muscle Contracted sarcomere
During a muscle contraction, a) the A band will increase in length. b) the I band will decrease in length. c) the H zone will increase in length. d) the Z lines will move farther apart.
Length Tension Relationship
Muscle Activity Two types of muscle fibers Slow twitch: endurance, long duration contraction, contain myoglobin Jogging, swimming, biking
Muscle Activity Two types of muscle fibers Fast twitch: strength, white muscle, short duration contraction Sprinting, weight lifting, tennis
Figure 50.33
Figure 50.UN01 Sarcomere Relaxed muscle Contracting muscle Fully contracted muscle Contracted sarcomere Thin filament Thick filament
Extension Flexion Figure 50.34 Human forearm (internal skeleton) Grasshopper tibia (external skeleton) Biceps Extensor muscle Triceps Flexor muscle Biceps Extensor muscle Triceps Flexor muscle Key Contracting muscle Relaxing muscle
Figure 50.35 Longitudinal muscle relaxed (extended) Circular muscle contracted Circular muscle relaxed Longitudinal muscle contracted Bristles Head end 1 Head end 2 Head end 3
Figure 50.36 Clavicle Shoulder girdle Scapula Sternum Rib Humerus Vertebra Radius Ulna Pelvic girdle Carpals Skull Types of joints Ball-and-socket joint Hinge joint Pivot joint Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges
Figure 50.37 Ball-and-socket joint Head of humerus Scapula Hinge joint Humerus Pivot joint Ulna Ulna Radius
Figure 50.38
Figure 50.39
Figure 50.40 Energy cost (cal/kg m) (log scale) RESULTS 10 2 Flying Running 10 1 10 1 Swimming 10 3 1 10 3 10 6 Body mass (g) (log scale)