Topic 6 & 11: Human Health and Physiology
11.2 Muscles and Movement 1 - Anatomy Read & Consider 11.2.1-11.2.3 What do you know?
What questions do you have? How do skeletons and exoskeletons differ? 1 - Anatomy Read & Consider Draw, label, & annotate the human elbow joint:
Include: Bones Muscles Ligaments Synovial joint features Tendons Cartilage Synovial Joints Pubic Symphysis: Cartilaginous Joint
Skull Suture Joint: Fibrous Joint Antagonistic Pairs Both bones andexoskeletons act asanchors for muscle andlevers for movementwith the use ofantagonistic musclepairs. 2 Muscle Cells / Muscle Fibers
What do you know? What questions do you have? Are all types of muscle the same? 2 Muscle Cells / Muscle Fibers Read & Consider Muscle fibers (cells) are multinucleated cells that mayshorten to half or one-third of their resting length. Fibers (cells) are composed of myofibrils contained in aplasma membrane called thesarcolemma.Cytoplasmbetween myofibrils contains mitochondria. Sarcolemmain-folds to form sarcoplasmic reticulum containingtransverse tubules. Draw and label diagrams of the structure of a sarcomere.
Actin & Myosin Myofibrils are composed of interlocking thick and thinprotein filaments. Thin filaments actin long and about 7nm in diameter.Theare held together by transverse bands called Z lines. Thick filaments myosin short and about 15nm in diameter. Muscles are striped or striated due to the repeating patternof actin and myosin filaments. Draw and label diagrams of the structure of a sarcomere. 3 - Contraction Read & Consider 11.2.7-11.2.9 What do you know?
What questions do you have? 3 - Contraction Read & Consider Sarcomere - Each repeating until of the myofibril (actin and myosin) iscalled a sarcomere. From z line to z line. Contraction: Action potential arrives at the neuromuscular junction.
Acetylcholine (neurotransmitter)released. Action potential is initiated in themuscle cell membrane. T-tubules carry this chemical signalthroughout the muscle. Signal causes a calcium releasefrom the sarcoplasmic reticuluminto myofibrils. Power Stroke Calcium causes troponin (protein) to removetropomyosin exposing cross bridge binding sites. An ATP molecule charges the cross bridgeallowing it to react with the neighboring actinmolecule. The use of the ATP molecule triggers a rowingmovement (cross bridge tilts to 45n angle)pushing the actin filament along = power strokeand shortening the myofibril. The cross bridge then returns to resting position,is blocked by tropomyosin, and a new ATPmolecule recharges in preparation for the nextcontraction. Diagram Muscle Contraction Analysis Works Cited Contracting Muscles. Digital image. Quick 3D Motion. Gizmag, n.d.Web. 03 Jan Hip Joint. Digital image. WiseGEEK. Conjecture Corporation, n.d.Web. 03 Jan Human Skeleton. Digital image. Learn: (by Xinixazi). N.p., n.d.Web. 15 Dec Pubic Symphysis. Digital image. Pix For Pubic Symphysis. Disqus,n.d. Web. 03 Jan Water Beetle - Exoskeleton. Digital image. Insect Exoskeleton -Viewing Gallery. N.p., n.d. Web. 15 Dec Zygote Media Group Inc. Synovial Joint. Digital image. 3D ScienceClip Art. N.p., n.d. Web. 03 Jan