Exam 3 Flashcards
Actin or myosin?
Thin filament protein
Involved tropomyosin & troponin
Actin
Actin or myosin?
Thick filament protein
2 heads and a tail
Binds/ splits ATP to ADP+P
Myosin
What is a muscle twitch?
Single action potential to skeletal muscle that causes brief contraction
Phase 1 or 2 or muscle twitch?
Contraction begins, Ca2+ bound to troponin, cross bridge cycle happens
Phase 1
Phase 1 or 2 of muscle twitch?
Peak of twitch, enough Ca2+ back out of cytoplasm= fewer cross bridges so force production falls, cell turns to resting
Phase 2: relaxation
What is a motor unit?
Single motor neuron and all muscle cells it Innervates
What is tetanus?
No relaxation between muscle summination causes maximal contraction
What are causes of muscle fatigue?
1) ATP production can’t keep pace with ATP use
2) decreased rate of AcH release
4 sources of ATP used in muscle metabolism
1) stored ATP
2) creating phosphate
3) anaerobic glycolysis
4) oxidative metabolism
Four major functions of GI
1) peristalis/ mixing movements
2) secretion into GI tract or bloodstream
3) digestion= chemical, mechanical breakdown
4) absorption from GI tract to blood or lymph
3 phases of digestion in order
Cephilac phase
Gastric phase
Intestinal phase
Six types of cells in gastric pits
1) Surface mucous cells
2) mucous neck cells
3) parietal cells
4) chief cells
5) G cells
6) D cells
What do mucous cells do
Secrete mucin to protect stomachs wall
What do mucous neck cells do?
Secretes acidic mucin
What do parietal cells do?
Secretes hydrochloric acid/ is instrinsic factor
What do chief cells do?
Secretes pepsinogen
What do G cells do?
Secretes gastrin
What do D cells do?
Secretes somatosin
Proteases digest what?
Proteins
Amalyses digest what?
Carbohydrates
What does bile/ lipases digest?
Lipids
How is water and sodium absorbed in the body?
Sodium potassium pump and osmosis
How are lipids absorbed into the body?
Diffusion into lymphatic vessels
How are carbs and proteins absorbed into the body?
Secondary active transport, co transport with sodium ions, facilitated diffusion into capillaries
What digestion occurs in large intestine? Does it have enzymes?
Concentrate feces and absorb water
No enzymes
How does bile play a role in lipid digestion
Emulsifies lipids
Smallest component of carbs
Monosaccharides
Smallest component of proteins
Amino acids
What is hormonal method of hormones?
One hormone triggers the release of another one
Methods for humoral hormones?
Levels of certain substance in blood stimulates release of a hormone
(Negative feedback)
Methods of neural hormones?
A neuron triggers release of a hormone (ex. Adrenaline)
What is gene direct activation? (Hormones)
Directly activated gene in nucleus
Second messenger system (hormones)
Bind receptors on plasma membrane cells
T or F
Calcium is stored in and released from sarcoplasmic reticulum
True
T or F
Calcium bonds to calmodium in smooth muscle
True
T or F
Motor unit is functional unit if skeletal muscle
F
Multi unit smooth muscle cells are linked by gap junctions
F
T or F
Anaerobic capacity is limited by production of lactic acid
T
Passive tension is generated in skeletal muscle by which tissue?
Connective
Which three things can influence single unit smooth muscle to relax or contract
Hormones
Heat/ cold
Metabolic factors
