Human Biology Final Exam 4 Study Guide Chapter 11 Skeletal System approx of questions on exam 12 15 Functions of Skeletal System Supports the body Produces blood cells Allows for movement by attaching muscles Protects soft body parts Stores minerals calcium phosphate fat Organization of Skeletal System of Bones 206 Axial Skeleton skull hyoid bone vertebral column rib cage ribs sternum Appendicular Skeleton pectoral girdle upper limb arm pelvic girdle lower limb leg Anatomy of Long Bone Epiphysis ends of the bone made mostly of spongy bone Diaphysis shaft of the bone made of compact bone filled with yellow marrow Articular Cartilage hyaline cartilage found on the ends of long bones Yellow Bone Marrow stores fat Red Bone Marrow makes blood cells found in spongy bone fat bones Periostem living outer covering of fibrous connective tissue What does compact bone spongy bone look like Compact Bone composed of osteons with a central canal containing blood vessels contains living bone cells called osteocytes Chambers called lacunae Spongy Bone made of plates with spaces filled with red bone marrow Bone development growth Ossification the formation of bone in 2 distinct ways 1 Intramembranous Ossification bone development between sheets of fibrous connective tissue used in flat bones such as ribs skull 2 Endochondrial Ossification cartilage is replaced by bone used by most bones What are important cells in bone growth remodeling repair Osteoblasts bone forming cells Osteocytes mature bone cells Osteoclasts bone absorbing removing cells Chondrocytes cartilage forming cells How do bones lengthen how do hormones affect bone growth Growth Hormone GH stimulates general bone growth the epiphyseal plates Sex Hormones increases growth during adolescence Vitamin D converted into a hormone to allow calcium absorption in the intestine Bone Remodeling bone renewal at a rate of up to 18 per year allows bones to respond to stress regulates the calcium in the blood through hormones Parathyroid Hormone PTH increases blood calcium by accelerating bone removal calcium leaves bone Calcitonin decreases blood calcium more calcium input bone Bone fractures repair bones put back into position bones immobilized casts plates screws external fixation Bones tell a story aging epiphyseal plates fontanelles sex determination Chapter 12 Muscular System approx of questions on exam 12 15 Function of Skeletal Muscles Support the body by allowing us to stay upright Allow for movement by attaching to skeleton Help maintain a constant body temp Assist in movement of fluids in cardiovascular lymphatic Protect internal organs stabilize joints Arrangement of skeletal muscles by attachments Tendon connective tissue that connects bone to muscle Origin attachment of a muscle on a stationary bone Insertion attachment of a muscle on a bone that moves origin insertion synergistic antagonistic By Action Synergistic muscles working in groups for a common action Antagonistic muscles that work in opposite pairs Skeletal Muscle Terminology Size the gluteus maximus is largest buttock muscle Shape the deltoid is triangular delta Location the fontalis overlies the frontal bone Direction of muscle fiber the rectus abdomiuns rectus means straight Attachment the brachioradialis is attached to the brachium radium Action the extensor digitorum extends the digits of attachments the bicepts brachii has 2 attachments Visualizing muscle structure Muscle fiber muscle cell Terminology for cell structure The plasma membrane is called sarcolemma The cytoplasm is called sarcoplasm The SER of a muscle cell is called sarco plasmic reticulm stores calcium Terminology for structure within a whole muscle Fascicles microscopic bundles of muscle fibers Muscle entire organ Muscle fiber myofiber individual cylindrical muscle cell Myofibrils are bundles of protein stands myofilaments that run the length of fiber Myofilaments are proteins actin myosin that are arrange in repeating units Sarcomeres The Sarcomeres are the repeating units of actin myosin found along a myofibril this is the microscopic unit which can contract shorten Made of 2 protein myofilaments Actin are the thin filaments Myosin are the thick filaments shaped as a golf club these slide over one another during muscle contraction Steps in Muscle Contraction the sliding filament model Ach is released from the neurons bind to the muscle fibers Nerve impulses travel down motor neurons to a neuromuscular junction Acetylcholine This binding stimulates fivers causing calcium to be released from the sarcoplasmic reticula Released calcium causes actin to interact with myosin Myosin heads bind to sites on actin this causes a connection cross bridges ATP is used to bind the myosin head results in pulling the actin filaments towards the center of the sarcomere contraction now occurs myosin head then detaches returns to normal position attachment bending followed by detachment is repeated over over until the sarcomere contracts completely Rigor Mortis When ATP runs out some myosin heads are still attached cannot detach rigor mortis body temperature are used to estimate the time of death Energy sources for muscle contraction Stored in muscle glycogen fat Stored in blood glucose fatty acids Slow vs fast twitch muscle cells Fast twitch fibers rely on CP fermentation anaerobic designed for strength light in color few mitochondria little or no myoglobin fewer blood vessels than slow twitch Slow twitch fibers rely on aerobic respiration designed for endurance dark in color many mitochondria myoglobin many blood vessels Muscular Diseases Fibromyalgia chronic achy muscles that is not too well understood Muscular Dystrophy MS group of genetic disorders in which muscles progressively Myasthenia Gravis autoimmune disorder that attacks ACh receptor weakens muscles degenerate weaken of the face neck extremities Myostatin Diseases found in humans cattle some breeds of dog rare genetic defect Myostatin not present or not functioning Myostatin normally slows or inhibits cell growth Chapter 18 Chromosomes approx of questions on exam 10 12 Chromosome pieces of DNA DNA packaged compacted w proteins found in nucleus of cell How many chromosomes are in human cells 46 chromosomes in 23 pairs of chromosomes within a cell nucleus Autosomes vs sex chromosomes Autosomes the 22 pairs of chromosomes that control traits that DO NOT relate to gender of individual Sex Chromosomes are the 1 pair that contains the genes that do control gender
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