Physiology Exam 3 (Muscle, Immune, and Digestive systems)
Reasons for muscle fatigue
-Decrease in ATP -Buildup of lactic acid (decrease in pH) -Lack of calcium (decrease in Ca2+) -Buildup of ADP -Decrease in acetylcholine -Decrease in oxygen -Decrease in glucose/glycogen -Central fatigue- mental drive to complete something ends
Properties of muscles
-electrical excitability -contractility -extensibility -elasticity
Muscle functions
-producing body movements -stabilizing body positions -storing and moving substances within the body -generating heat (thermogenesis)
Innate immunity
Non-specific; ability of body to defend itself against microbes and other foreign substances without the use of specific recognition of invading pathogen.
motor unit
Somatic neuron and muscle fiber it innervates, are recruited in progressive way depending on contractile force needed
Pacemaker potentials
Spontaneous potentials that always reach threshold
Contraction cycle
1. ATP hydrolysis 2. Attachment of myosin to actin (crossbridge formed) 3. Power stroke 4. Detachment of myosin from actin due to ATP attaching to mysoin
3 types of muscle proteins
1. Contractile 2. Regulatory 3. Structural
2 signals needed for clonal selection
1. Recognition of antigen 2. Costimulation
Cytotoxic (CD8) T cells
Attack infected body cells, cancer cells, foreign cells
Structural muscle proteins
Contribute to alignment, stability, extensibility, and elasticity
Excitation in excitation-contraction coupling
Electrical event (Muscle action potential)
Antibody mediated immunity
Involves use of B cells
Cell mediated immunity
Involves use of T cells to eliminate specific antigens
Contractile muscle proteins
Made up of myosin and actin
Regulatory muscle proteins
Made up of troponin (binds Ca2+) and tropomyosin (covers myosin-binding sites on actin)
Contraction in excitation-contraction coupling
Mechanical event (Shortening of sarcomere)
Jejunum and ileum
Where absorption occurs in small intestine
Ascending colon, transverse colon, and descending colon
Where in large intestine these processes are done -Bacterial fermentation occurs -Absorption of water and some vitamins -Make feces
Calmodulin
binds Ca2+ in smooth muscle due to lack of troponin
Amylase
chemical digestion enzyme that breaks down carbs
Lipase
chemical digestion enzyme that breaks down lipids
Proteases
chemical digestion enzyme that breaks down proteins
Oral cavity
chew food into smaller bits and where both chemical and mechanical digestion occur
Slow-wave potentials
constant depolarizations and repolarizations that do not necessarily reach threshold
Organization of skeletal muscle
muscle --> fascicle --> muscle fiber --> myofibril --> myofilaments --> sarcomere
Smooth muscle
not striated and involuntary; found in hollow organs
Small intestine
organ in charge of absorption of nutrients (Takes around 7 hours)
Large intestine
organ in charge of absorption of water and production of feces (Takes around 9 or more hours)
Stomach
organ which liquify and chemically and mechanically digest food (Takes about 4 hours)
Liver and pancreas
organs in charge of releasing secretive enzymes into GI tract
Autonomic nervous system
regulates smooth muscle contraction
Helper (CD4) T cells
secrete cytokines
Cardiac muscle
striated and involuntary; found in the heart
Skeletal muscle
striated and voluntary; found attached to bone
Duodenum
where bile and pancreatic juice mostly finish digestion
Anus
where defecation occurs
Electrical excitability
Ability to respond to certain stimuli by producing action potential
Contractility
Ability of muscle to contract forcefully when adequately stimulated
Elasticity
Ability of muscle to return to original shape after contraction or lengthening
Extensibility
Ability of muscle to stretch without being damaged
Adaptive immunity
Ability to defend yourself against SPECIFIC microbes and other foreign agents
