quiz 4 Flashcards
chapter 6&7
Muscle function
Skeletal muscles interact with skeleton, cause our bones to move and prevent them from moving, contract, relax and help us in all our task
Muscle
a group of individual muscle cells with the same origin and insertion and the same function
Synergistic muscle
Those working together to create the same movement (contracting and relaxing together
Agnostic muscles
Oppose each other
Fascicles
Muscle Bundles, Connective tissue (Fascia) covering each one. Whole muscles are covered in fascia layers
Muscle fibers
Muscle cells inside muscle bundles
Skeletal muscle contractile unit
Sarcomere (muscle osteoporosis)
Actin and Myosin
Z lines: attachment point for sarcomeres
4 conditions for a Skeletal muscle to contract and relax
Activation by nerve,
Nerve activation increases the concentration of calcium,
Calcium allows contraction and its absence prevents contraction,
Contraction ends when muscle is no longer stimulated by nerve
Nerve activation
Acetylcholine released, electrical impulse transmitted along t tubes triggers calcium released from Smooth ER, ca2+ diffused into cell cytoplasm and contact myofibrils
Nerve activation detailed
communication via releasing Acetylcholine, bind to receptors on cell membrane which opens ion channel. electrical impulses travel to smooth ER of muscle, Ca2+ travels to contracting protein, binds to troponin-tropomyosin complex. Myosinn binds to protein, pulls and shortens it
1, Acetylcholine
Exocytosis: releases at the neuromuscular junction causes electrical impulses to be generated in the muscle cell plasma membrane
2, Electrical impulse
Carried to the cells interior by the T tubules
3, Ca2+ release
The electrical impulses triggers the release of CA2+ from the sarcoplasmic reticulum,
Filaments
Thick filaments: Myosin
Thin filaments: Strands of actin molecules
Contraction: formation of cross-brides between thin and thick filaments that need to interact
After calcium binds troponin
Troponin+Tropomysin protein complex shifts position, myosin binding site exposed, myosin heads form crossbridges with actin, actin filaments pulled toward center of sarcomere (ATP required)
Energy required of contraction
Released Ca2+ transported back by active transport,
Muscle cells obtain ATP from: Stored ATP, Creatine phosphate, Glycogen, Glucose, and Fats
Myogram
graph representing muscle activity
Latent period, contraction & relaxation
Summation: high rate stimultion, high muscle force
Tetanus: state of max contraction
Muscle relaxation
Nerve activation ends, contraction ends: calcium removed from troponin, pumped back to sarcoplasmic reticulum, myosin binding site covered, no calcium = no cross bridges
Fast switching fibers (White muscles)
Stores more glycogen and creatine phosphate as quick energy sources, short bursts of high intensity, weight lifting and strength training
Slow twitch fibers (red muscles)
more mitochondira, more oxygen&blood, higher concentration of myoglobin. Increased # of blood vessels supplying muscles w/ energy sources, build up of lactic acid, builds endurance
Smooth muscles
Pumps blood, found around blood vessel & controls the blood recieved. Involuntary muscles controlled by autonomic NS, joined by gap junctions, contract in absence of nerve stimulation
Cardiac muscles
Peacemaker cells: cardiac cells with fastest rythm that sets the pace for other cells of the heart.
Joined by gap junctions, involuntary muscle
Muscular dystrophy
Hereditary disease in which the absence of dystrophin (protein), leading to progressive weakening of the muscles. Most people die before age of 30
Fasciitis
Inflammation of connective tissue seath or fascia usually caused by straining or tearing of the fascia
circulatory system overview
consists of heart, blood vessels, and blood. Picks up nutrients from digestive system. Exchanges gases with respiratory system. Delivers nutrients and o2 to every cell. Carries CO2 to lungs. Carries waste and excess water to urinary system. Carries metabolic wastes to liver. Helps regulate body temp.
Functions of blood
Transportation: nutrients, waste, hormones and other cell communication molecules
Regulation: Temperature, water volume, pH
Defense: against infections and bleeding, carries immune cell
Components of blood
Plasma 55%
Platelets and white blood cells 1%
Red blood cells 44%
water 90%
Electrolytes
horomones
gases
nutrients and wastes
Proteins in blood
Albumins (main plasma protein) transport of specific molecules
Globulins (transport different substances)
Clotting proteins (coagulation)
Formed elements in blood
45%, red blood cells (transportation of 02)
White blood cells (defend the body)
Platelets (blood clotting for defense)
Red Blood Cells
origin: Stem cells -> Erthroblasts -> erthrocytes
120 day life span
flexible shape to pass thru small blood vessels, cytoplasm next to cell surface facilitate gas exchange
Red blood cells functions
Transport oxygen and carbon dioxide
Hemoglobin: Oxygen binding protein
Oxyhemoglobin: nuetral pH for 02 uptake (bright red)
Deoxyhemoglobin: acidic pH for o2 release (dark purple)
Regulation of RBC production
a negative feed back control loop that maintain homeostasis,
Erythropoietin
Some kidney cells monitor the availability of o2 and secrete Erythropoietin when o2 is low, it stimulates the stem cells to produce more RBC
White blood cells (Luekocytes)
Protection from infection, regulation of the inflammatory reaction, there are granular and arganular
Granular leukocytes
Neutrophils: first WBC to combat infections
Eosinophils: Defend body against large parasites and releases chems that lower severity of allergic reactions
Agranular Leukocytes
Monocytes: differentiate into macrophages
Lymphocytes: B- produce plasma cell antibodies. T- destroy bacteria
Platelets
form elements, small cell fragments, essential for blood clotting, life span of 5-9 days, production regulated by hormone thrombopoietin
Hemostasis
Stopping blood loss
Stages:
Vascular spasm (30m) constrict blood vessels to reduce blood flow
Platelet plug formation: seal the ruptured blood vessel
Coagulation (<1h) formation of blood clot
Antigen (Ag)
our cells have certain surface proteins that our immune system can recognize and identify as self
nonself cell protein that stimulats the immune system of an organism to defend the organism
Antibody (Ab)
Opposing protein produced by the immune system to counteract the antigen,
Abs are plasma proteins called gamma globulins and produced by B-lymphocytes
Antigen-Antibody reactions
Antibody binds to antigens, antibodies ignore the self surface and binds to antigen of foreign cell. Antigen-Antibody complexes clump together which inactivates the foreign cells
Transfusion reaction
Type A blood are restricted to receiving transfusions from A or O,
Type AB blood recieves from all the 4 groups but can only donate to AB
Type o recieve on;from O but can donate to the rest
Rh factor
another RBC surface Ag, equally considered in blood transfusion, 85% of americans are positive 15% negative
Rh- cannot receive from Rh+
Rh factor in pregnancy
a small amount of fetal blood enters the mothers circulation, the woman develops antibodies and an immune memory against Rh antigen, by her 2nd child her immune system produces antibodies that attack the fetus’s RBC
Blood disorders
carbon monoxide poisoning
anemia
Leukemia
Multiple myeloma
Mononucleosis (kissing disease)
Septicemia (blood poisoning)
Thrombocytopenia
Hemophilia
