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90 Cards in this Set
- Front
- Back
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The Skeletal System includes: Ch. 6 |
Bones, cartilages, ligaments, and connective tissue |
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Five Primary Functions of the Skeletal System Ch. 6 |
1. Support2. Storage of Minerals (calcium) and Lipids (yellow marrow) [yellow marrow has the fat which gives it a yellow color]3. Blood Cell Production (red marrow)4. Protection5. Leverage (force of motion) |
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Bones are classified by: Ch. 6 |
Shape Internal tissue organization (compact or spongy) Bone markings (surface features, marks) (like condyles, protrusions etc) |
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Six Bones Shapes Ch. 6 |
1. Sutural 2. Irregular3. Short4. Flat5. Long 6. Sesamoid |
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Sutural Bones Ch. 6 |
Small, irregular bones (size can be from grain of rice to a quarter) Found between the flat bones of the skull |
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Irregular Bones Ch. 6 |
Complex shapes Examples: spinal vertebrae, pelvic bones |
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Short Bones Ch. 6 |
Small and thick Examples: Ankle and wrist bones (carpals and tarsals, almost cube) |
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Flat Bones Ch. 6 |
Thin with parallel surfaces Found in the skull, sternum, ribs, and scapulae |
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Long Bones Ch. 6 |
Long and thin Found in arms, legs, hands, feet, fingers, and toes |
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Sesamoid Bones Ch. 6 |
Small and Flat Develop inside tendons near joints of knees, hands, and feet |
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Bone Markings Ch. 6 |
Depressions or grooves - Along bone surface Elevations or Projections - Where tendons and ligaments attach At articulations with other bones Tunnels (AKA Foramen) - Where blood and nerves enter bone |
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Three parts for the Structure of a Long Bone Ch. 6 |
Diaphysis Epiphysis Metaphysis |
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Diaphysis Ch. 6 |
- The shaft - A heavy wall of compact bone, or dense bone - A central space called medullary (marrow) cavity (where you find the red or yellow marrow) |
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Epiphysis Ch. 6 |
- Wide part at each end - Articulation with other bones - Mostly spongy (cancellous) bone - Covered with compact bone (cortical bone) |
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Metaphysis Ch. 6 |
Where diaphysis and epiphysis meet |
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Structure of a Flat Bone Ch. 6 |
- Resembles a sandwich of spongy bone between two layers of compact bone - Within the cranium, the layer of spongy bone between the compact bone is called the diploë Cortex-diploë-Cortex is the same as Compact-spongy-Compact |
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Bone (Osseous) Tissue Ch. 6 |
- Dense, supportive connective tissue - Contains specialized cells - Produces solid matrix of calcium salt deposits around collagen fibers |
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Characteristics of Bone Tissue (3 different parts) Ch. 6 |
- Dense Matrix: Deposits of calcium salts, Osteocytes (bone cells) within lacunae organized around blood vessels - Canaliculi: Extend between lacunae and nearby blood vessels, Exchange nutrients and wastes - Periosteum: Covers outer surfaces of bones expect at joints, Consists of outer fibrous and inner cellular layers |
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Bone Cells Ch. 6 |
Make up only 2% of bone mass Bone contains four types of cells 1. Osteocytes (other three, maintaining, repairing and bone) 2 .Osteoblasts 3 .Osteoprogenitor cells (like bone stem cells) 4. Osteoclasts |
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Osteocytes Ch. 6 |
-Mature bone cells that maintain the bone matrix - Live in lacunae Are between layers (lamellae) of matrix - Connect by cytoplasmic extensions through the lamellae - Do not divide |
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Two Major Functions of Osteocytes Ch. 6 |
1. To maintain protein and mineral content of matrix 2. To help repair damaged bone |
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Osteoblasts Ch. 6 |
-Immature bone cells that secrete matrix compounds (osteogenesis) -Osteoid - matrix produced by osteoblasts, but not yet calcified to form bone (osteoid —> calcified then becomes matrix) - Osteoblasts surrounded by bone become osteocytes |
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Osteoprogenitor Cells Ch. 6 |
-Mesenchymal stem cells that divide to produce osteoblasts - Located in endosteum, the inner cellular layer of periosteum -Assist in fracture repair |
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Osteoclasts Ch. 6 |
- Secrete acids and protein-digesting enzymes - Giant, multinucleate cells - Dissolve bone matrix and release stored minerals (osteolysis - bone breaking) - Derived from stem cells that produce macrophages |
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Osteon Ch. 6 |
(Structure of Compact Bone) -Osteocytes are arranged in concentric lamellae -Around a central canal containing blood vessels -Perforating canals (the nerves that are going across the bone and through the periosteum) -Perpendicular to the central canal -Carry blood vessels into bone and marrow |
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Circumferential Lamellae Ch. 6 |
- Lamellae wrapped around the long bone - Binds osteons together |
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Structure of a Spongy Bone Ch. 6 |
- Does not have osteons - The matrix forms an open network of trabeculae - Trabeculae have no blood vessels - The space between trabeculae is filled with: -red bone marrow, which has blood vessels, -forms red blood cells and - supplies nutrients to osteocytes |
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Functions of Periosteum Ch. 6 |
1. Isolates bone from surrounding tissue (helps to reduce friction) 2. Provides a route for circulatory and nervous supply 3. Participates in bone growth and repair |
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Endosteum Membrane Ch.6 |
-Lines the medullary (marrow) cavity - Covers trabeculae of spongy bone - Lines central canals - Contains osteo -blasts, -progenitor cells , & -clasts - Is active in bone growth and repair. |
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Bone Development Ch. 6 |
1) Osteogenesis: (happens in embryo and after bone) Bone formation 2) Ossification (After Osteogenesis): The process of replacing other tissues with bone 3) Calcification: The process of depositing calcium salts. Occurs during bone ossification and in the other tissues |
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Two Kinds of Ossification Ch. 6 |
1 - Endochondral ossification (“inside cartilage”) 2 - Intramembranous ossification (“Inside membranes”) |
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Endochondral Ossification Ch. 6 |
Ossifies bones that originate as hyaline cartilage |
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Appositional Growth |
-Compact bone thickens and strengths long bone with layers of circumferential lamellae (growing in length and width) -Increases diameter of bone |
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Epiphyseal Lines (AKA growth plate) Ch. 6 |
When long bone stops growing, after puberty. Epiphyseal cartilage disappears Is visible on x-rays as an epiphyseal line |
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Mature Bones Ch. 6 |
(long bones) -Osteoclasts enlarge medullary (marrow) cavity -Osteons form around blood vessels in compact bones |
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Intramembranous Ossification Ch. 6 |
AKA dermal ossification Occurs in the dermis Produces dermal bones such as mandible (lower jaw) and clavicle (collarbone) |
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Bone Remodeling Ch. 6 |
Maintains itself Replaces mineral reserves Recycles and renews bone matrix Involves osteocytes, osteoblasts, and osteoclasts |
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Turnover Rate of Bone Remodeling Ch. 6 |
If deposition is greater than removal, bone get stronger If removal is faster than replacement, bones get weaker |
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Calcitriol Ch. 6 |
-Made in the kidneys -Helps absorb calcium and phosphorus from digestive tract -Synthesis requires vitamin D3 |
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Homeostasis is Maintained By: Ch. 6 |
Calcitonin and parathyroid hormone (PTH): which control storage, absorption and excretion of calcium |
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Calcitonin and Parathyroid Hormone Control Affect Ch. 6 |
1. Bones (where calcium is stored) 2. Digestive Tract (where calcium is absorbed) 3. Kidneys (where calcium is excreted) |
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Parathyroid Hormone (PTH) increases calcium ion levels by: Ch. 6 |
1. Stimulating osteoclasts 2. Increasing intestinal absorption of calcium 3. Decreasing calcium excretion at kidneys |
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Where are Parathyroid Hormones produced? Ch. 6 |
Glands in the neck. |
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Calcitonin decreases calcium ion levels by: Ch. 6 |
1. Inhibiting osteoclast activity 2. Increasing calcium excretion at kidneys 3. Decreases rate of absorption through the intestines |
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Where is calcitonin secreted? Ch. 6 |
C cells (parafollicular cells) in thyroid |
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Osteoporosis Ch. 6 |
Severe bone loss Affects normal function |
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Percent Muscle Tissue is of the Human Body Weight Ch. 10 |
30-50% |
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Types of Muscle Tissue Types Ch. 10 |
Skeletal Cardiac Smooth |
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Six Functions of Skeletal Muscle Tissue Ch. 10 |
1. Produce skeletal movement 2. Maintain posture and body position 3. Support soft tissue 4. Guard entrances and exits 5. Maintain body temperature 6. Store nutrient reserves |
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Epimysium (Layer of Connective Tissue) Ch. 10 |
-Exterior collagen layer -Connected to deep fascia -Separates muscle from surrounding tissues |
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Perimysium (Layer of Connective Tissues) Ch. 10 |
-Surrounds muscle fiber bundles (fascicles) -Contains blood vessel and nerve supply to fascicles |
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Endomysium (Layer of Connective Tissue) Ch. 10 |
-Surrounds individual muscle cells (muscle fibers) -Contains capillaries and nerve fibers contacting muscle cells -Contains myosatellite cells (stem cells) that repair damage |
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Muscles Vascular Systems: Ch. 10 |
-Supply large amounts of oxygen -Supply nutrients -Carry away wastes |
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Skeletal Muscle Cells Ch. 10 |
-Are very long -Develop through fusion of mesodermal cells (myoblasts) -Become very long -Contain hundreds of nuclei |
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Sarcolemma Ch. 10 |
-The cell membrane of a muscle fiber (cell) -Surrounds the sarcoplasm (cytoplasm of muscle fiber) -A change in transmembrane potential begins contractions |
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Transverse Tubules (T Tubules) Ch. 10 |
-Transmit action potential through cell -Allow entire muscle fiber to contract simultaneously -Have same properties as sarcolemma |
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Myofibrils Ch. 10 |
-Lengthwise subdivisions within muscle fiber -Made up of bundles of protein filaments (myofilaments) -Myofilaments are responsible for muscle contraction |
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Types of Myofilaments Ch. 10 |
Thin filaments (made of the protein actin) Thick filaments (made of protein myosin) |
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The Sarcoplasmic Reticulum Ch. 10 |
-A membranous structure surrounding each myofibril -Helps transmit action potential to myofibril -Similar in structure to smooth endoplasmic reticulum -Forms chambers (terminal cisternae) attache to T tubules |
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Triad Ch. 10 |
one T Tubule and two terminal cisternae |
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Sarcomeres Ch. 10 |
The contractile units of a muscle |
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The A Band Ch. 10 |
-M Line -H Band -Zone of overlap |
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M Line Ch. 10 |
-The center of the A Band -At midline of sarcomere |
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H Band Ch. 10 |
-The area around the M line -Has thick filaments but no thin filaments |
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Zone of Overlap Ch. 10 |
-The densest, darkest area on a light micrograph -Where thick and thin filaments overlap |
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The I Band Ch. 10 |
-Z Line -Titin |
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Z Lines Ch. 10 |
-The centers of the I bands -At two ends of sarcomere |
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Titin Ch. 10 |
-Are strands of protein -Reach from tips of thick filament to the Z line -Stabilize the filaments |
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F-Actin of the Thin Filament Ch. 10 |
Protein. -Is two twisted rows of globular G-Action -The active sites on G-actin strands bind to myosin |
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Nebulin of Thin Filament Ch. 10 |
Protein. -Holds F-actin strands together |
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Tropomyosin of Thin Filament Ch. 10 |
Protein. -Is a double stranded protein -Prevents actin-myosin interaction |
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Troponin Ch. 10 |
Protein. -A globular protein -Bind tropomyosin to G-Action -Controlled by Ca(2+) |
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The Myosin Molecule Ch. 10 |
Tail - Binds to other myosin molecules Head - Made of two globular protein subunits, reaches the nearest thin filament |
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During Contraction, myosin heads: Ch. 10 |
Interact with actin filaments, forming cross-bridges and pivot, producing motion |
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The Process of Contraction Ch.10 |
-Neural stimulation of sarcolemma causes excitation-contraction coupling. -Muscle fiber contraction causes interaction of thick and thin filaments -Tension production is built. |
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The Neuromuscular Junction Ch. 10 |
Controls calcium ion release into the sarcoplasm |
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Excitation-Contraction Coupling Ch. 10 |
-Action potential reaches a triad (triggering a contraction) -Requires myosin heads to be in "cocked" position which is loaded by ATP energy |
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The Contraction Cycle Ch. 10 |
1. Contraction Cycle Begins 2. Active-Site Exposure 3. Cross-Bridge Formation 4. Myosin Head Pivoting 5. Cross-Bridge Detachment 6. Myosin Reactivation |
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Motor Units in a Skeletal Muscles Ch. 10 |
Contain hundreds of muscle fibers that contract at the same time and are all controlled by a single motor neuron. |
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Latent Period of Twitches Ch. 10 |
-The action potential moves through sarcolemma -Causing Ca2+ release |
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Contraction Phase of Twitches Ch. 10 |
-Calcium ions bind -Tension builds to peak |
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Relaxation Phase of Twitches Ch. 10 |
-Ca2+ levels fall -Active sites are covered and tension falls to resting levels |
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How does a muscle increase tension? Ch. 10 |
By slowing increasing the size or number of motor units stimulated |
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Maximum Tension Ch. 10 |
-Achieved when all motor units reach tetanus -Can only be sustained only a very short time |
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Sustained Tension Ch. 10 |
-Less than maximum tension -Allows motor units to rest in rotation |
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Muscle Tone Ch. 10 |
-The normal tension and firmness of a muscle at rest -Muscle units actively maintain body position, without motion -Increasing muscle tone increases metabolic energy used, even at rest. |
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Two Kinds of Tension Production Ch. 10 |
Isotonic & Isometric |
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Isotonic Contraction Ch. 10 |
-Skeletal muscle changes length (resulting in motion) -If muscle tension > load = muscle shortens (concentric contraction) -If muscle tension < load = muscle lengthens (eccentric contraction) |
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Isometric Contraction Ch. 10 |
Skeletal muscle develops tension, but is prevented from changing length. |
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Inversely Related of the Load and Speed of Contraction Ch. 10 |
The heavier the load on a muscle the longer it takes for shortening to begin and the less the muscle will shorten |
