Untitled Flashcards Set

Nutrients

• Chemical substances obtained from food, used by body to maintain different processes

• Materials are body needs to supply energy, regulate cellular activities, and build/repair tissues

Three nutrients-macro molecules

1. Protein

2. Lipids(fat)

3. Carbohydrates- most abundant organic substance in nature ex sugar and starches

• Main function is to provide materials to build cell membrane/provide energy to cells

• Glucose is the usual form which is stored within skeletal muscles and liver as glycogen

ATP- common energy molecule

• Nutrients in the food we eat need to be synthesized into free energy that can be used

• Adenosine triphosphate- common molecule for all living things

• Captures chemical energy resulting from breakdown of food and is used to fuel cellular processes

• Turns macromolecules into muscular work, thermal regulation, and digestion of food

Release of ATP

• Energy is released when a trailing phosphate is broken from ATP molecule

• ATP= ADP+ phosphate+ energy

Problem of synthesizing ATP

• High demand by body used up quick

• Problem becomes how to synthesize ATP to ensure bodily functions continue

1. Anaerobic(without oxygen)

• Can occur in two separate metabolic pathways

• Short-lived but powerful

• Used mostly for fast twitch muscles

2. Aerobic(with oxygen)

• Evolves many enzymes and several complexe pathways

• Leads to complete breakdown of glucose

• More slow twitch muscles used

Three metabolic pathways

ATP-Pc (anaerobic alactic)

• ADP+ phosphocreatine —> T ATP + creating + energy 

• In Draws on processes deep within muscle fibres

• Allows for quick intense muscle contractions

• Lactic meaning lactic acid is not a product

• Phosphocreatine is a high energy molecule where phosphate can be broken off easily to convert ADP to ATP(stored in muscles readily accessible to sustain levels of ADP)

• Does not involve metabolism of glucose

• Ex interval training/sprint training(10 to 15 seconds of activity)

• Supplementation- people may consume creatine supplements to help build muscle’s 

• Advantages- produce larger amount of energy and short amount of time

• Limiting factor- initial concentration of ATPPC stored in muscles is minimal activity can’t be maintained

Glycolysis

• First sequence of reaction in metabolism of glucose

• Glucose—> 2atp+ two pyruvate

• Two molecules of ATP for every molecule of glucose

• Through chemical reactions, glycolysis, transfers, energy from glucose and rejoins phosphate ADP

Lactate fermentation in muscle cells 

• When oxygen is not present, pyruvate will undergo fermentation NADH plus H will be recycled back to NAD so that glycolysis can continue

• Hydrogen ions and lactic acid buildup and muscle fatigue occurs fast, twitch muscles

• Ex 800 m run 200 m swim( 16 seconds to three minutes of activity)

• Advantages- produce energy energy under conditions of inadequate oxygen

• Limiting factor- lactic acid belts, hydrogen ions, buildup in bloodstream and decrease pH, causing quick fatigue and hampering of further activity

Cellular respiration

• Aerobic system(involves oxygen)

• Glucose +02-> CO2 plus H2O plus ATP

• Main source of energy during endurance events

• Complete breakdown of glucose

• Yield large amount of ATP

• Fats are used; after 20 minutes proteins in starvation

• 36 molecules of ATP produced for one molecule of glucose

• Ex endurance training, for soccer game(3+ minutes)

• Advantages- ability to sustain low intensity, physical activity for long periods of time

• Limiting factor- requires low intensity

1. Glycolysis

2. The curb cycle

3. Electron transfer chain

Slow versus fast twitch muscle fibres

Slow twitch, muscle fibre

• Dark and colour

• Generate/relax tension relatively slowly

• They are able to maintain lower levels of tension longer

• Sustain activities like swimming and cycling

Fast twitch, muscle fibre

• Pale in colour

• Tense/relax quickly

• Generate large amounts of tension, low endurance

• Can activate at a rate two times faster than slow twitch

• Ideal for powerful muscles

• EX powerlifting explosive jumps

Type I (slow oxidative muscle fibres)

• Generate energy, slow more fatigue, resistance, and primarily depends on anaerobic processes

Type IIA) (fast oxidative glycolytic muscle fibre) FOG

• Intermediate type muscle fibres allow high-speed energy release, as well as glycollic capacity(use breakdown of glucose)

Type IIB (fast glycolytic muscle fibre) FG 

• Fast glycollic muscle fibres store, lots of oxygen and sufficiently high levels of enzymes necessary for quick contraction without oxygen

Neuromuscular system 

Epimysium- envelopes entire muscle (extends past muscle/becomes bone)

Paramysium- connective tissue bind groups of muscle fibres together

Endomysium- connected tissue that surrounds muscle fibre itself

Skeletal muscle/fiber

• Diameter can be up to 100 UM length over 30 cm

• Can belong single skeletal muscle cells result from fusion of hundreds of embryonic precursors called myoblast

• Have multiple nuclei

Anatomy of skeletal cell

• Sarcolemma- plasma membrane lies beneath Endo. My CM contains transverse T tubes which penetrate through the cell/conduct electrical impulse from surface of cell to cell itself

• Sarcoplasm- muscle cells cytoplasm contained by sarcolemma contains glycogen, myoglobin, calcium, and other organelles

• Sarcoplasmic reticulum- muscles version of endoplasmic reticulum calcium storage used for muscle activation

• Sacromere- unit containing Acton and myosin thousands of repeating individual units thread like structures units overlap muscle contraction occurs

Anatomy of sacrum

• Acton(thin filament) myosin(thick filament)

• Z line- Acton or bond to form border

• I band- straddle composed of thin filaments during contraction is shrink

• A band- composed of thick filaments does not contract/shrink

• H zone- subdivision of a band only thick filament, shrink string contraction

Motor unit

Motor neurons, axon(pathway) muscle fibres

• Nerves transmit impulse waves

• A single nervous impulse and contraction is muscle twitch

• Muscle contraction begins from brain

Neuromuscular junction

• Where nerves and muscles meet (contact point)

• Principle of energy transfer

• Electrical energy moves to surface of muscle fibre where it is converted into chemical energy and eventually into mechanical energy

All or none principal

• When motor unit is stimulated to contract, it will do it to its fullest potential

• . If motor unit consist of 10 fibre turned on all or none of the fibre will contract.

Process of muscle contraction( excitation contraction coupling)

1. Signal originates from spinal cord moves to neuromuscular junction

2. Signal is transferred to muscle fibres via tubular membrane

3. Calcium ions released into sarcoplasm

4. Calcium interacts with troponin signalling tropomyosin

5. Calcium allows coupling effect to unfold resulting in muscle contraction

Sliding filament theory

• Muscle contracts by overlapping acting in my sin, causing sarcomere ( and whole muscle fibre) to contract

Contraction of muscle

• Myosin comprised of head and tail, head has attachment site for Acton, which has binding site for myosin

• Acton has two other proteins troponin (has blinding site for calcium )and tropomysin (stringing looking cord structures covering site for active)

• Myofibril play a role in contraction

Sliding filament

   Myosin, crosses, bridges, small bridges on thick filament, attach rotate detach and reattach

What signals to contract?

1. Nerve action, triggers, nerve impulse to release Ach

2. Ach binds to Ach receptor

3. Calcium becomes activated and is released from sarcoplasmic reticulum into sarcoplast

4. Calcium attaches to troponin and triggers tropomyosin to uncover Acton binding site

5. Myosin head, swivels, and binds actin muscle contracts

6. ATP used to breakdown bonds straighten cross, bridges, and allow cross bridges to form a new bond with another active site

7. ATP is used to actively transport calcium ions out of muscle back to sarcoplasmic reticulum

8. Triggers tram mycin to return to original position

Sliding filament theory(cont)

• Acting and mycin interact under special conditions

• Myosin cross bridges extends to Acton, causing rapid attachment, rotation, detachment, and reattachment

• Result in shortening of muscle/sarcomere

• Trigger mechanisms is the release of calcium and troponin and tropomyosin 

• Calcium release is triggered by ATP

• As muscle works, there is an increase in ATP

ATP

• Re-uptake of calcium muscle relaxation

• Detach myosin from Acton

• Harvested through glucose molecules

• ATP= ADP+ P+ energyCentral nervous system

• Brain and spinal cord

• processes/interprets/stores info and issues orders to muscles glands and organs

Peripheral nervous system

• Transmits infor to and from CNS

Reflexes 

• Important part of all physical movement 

• Automatic rapid unconscious response to stimulus

• Cerebral- command center for reflex located in brain

• Spinal- command is located in spinal cord

• Reflex contraction of skeletal muscles (spinal reflect) is not depenedant on conscious intervention by higher centers of the brain but are a way the body responds to an unexpected stimulus 

Automatic reflex- mediated by automatic division of nervous system and usually involve activation of smooth muscles cardiac muscle and glands 

• Regulate bodily function like

  • Digestion, elimination, blood pressure, sweating 

Somatic reflex- stimulation of skeletal muscles by somatic divison of nervous system

• Ex. stretch reflex and withdrawal reflex

Reflex arc

• Neurons in our body transmit information to each other through a series of neutral connections that form a pathway or circuit

• Is a simple neutral pathway along which an initial sensor stimulus and corresponding message travels

• Stimulus from sensory neurons is sent to CNS, but there is no interpretation of the signal few if any neurons are involved

• Signal is transmitted to motor neuron which ill a response

• Receptor, adjuster, effector

Five steps

1. Receptor receives initial stimulus

2. Sensory nerve carries impulse to spinal column or brain brain

3. Adjuster/neuron, interprets, signal, and issues in appropriate response

4. Nerve carries response from spinal cord to muscle/organ

5. Effector Oregon carries out the response

Monosynaptic- single connection between sensory neuron and motor neuron (no interventions, quick reflect)(knee jerk)

Polysynaptic- neural connections interneurons are present ( ex withdrawal)

Propriception 

• Special receptors, giving ongoing feedback 

• coordination and ongoing feedback is required for proper movement

• Joints, muscles and ligaments are sensitive to stretching tension and pressure

• A person’s ability to position, orientation and movement of body

• Found in muscles, tendons, and joints and inner ear that detect the motion or position of the body or limb, responding to stimuli from within the organism

• Muscle spindles and tendon organs are procripotators That continuously monitor muscle action, and our essential

• They tell the nervous system about the state of the muscle contraction and allow it to respond

Control of movement

Golgi tendon

• Located at end of tendons

• Detect increase tension exerted on tendons

• Help protect muscles from extensive tension that would otherwise result in damage to the muscle/joint

• GOT provide feedback to CNS regardless of magnitude

• Likely a role in the development of strength and power, since it is necessary to overcome obstacles present by tendon organ to exert grade force

Muscle spindles

• Help detect increase muscle length

• Located in muscle belly

• Les parallel to main muscle fibre and send constant signals to spinal cord

• Consist of specialized muscle fibres known as intrafusal muscle fibres smaller than ordinary, skeletal muscles, but they behave the same way and look the same

• They are sensitive to changes in muscle length

• Contain two Afrin and one nerve fibre

• Changes in muscle length and respond to it by sending message to spinal cord leading to appropriate motor responses

Stretch reflex

• Muscle spindles are involved in the stretch reflex

• The stretch reflex is a simplest spinal reflex

• Depends on only one connection between Afrin fibres and motor neurons of the same muscle

• When await a person is caring is suddenly increased. This causes the weight-bearing muscle lengthen which increases the activity of the muscle spindle leads to stimulation of neurons (increased muscle connection)

• The result in a reciprocal inhibition where the opposing muscle is also stimulated because there is a constant adjustment between Agnes and antagonist muscles

• Knee jerk is an example of stretch reflex

Need jerk reflex

• A simple reflex that involves transmission of information from a sensory neuron to the appropriate motor neuron across a single sign apps in the spinal cord

• Knee-jerk reflex action is an example of monosynaptic reflex

Cross extensor reflex

• When one leg or arm automatically compensates for a reflex action in the opposing leg or arm

• Combination of nervous and muscular system has involved greatly from infancy

Withdrawal reflex

• When a person touches something hot and withdraw their hand from it without actively thinking about it, the heat stimulate his temperature and pain receptors in the skin triggering a sensory impulse that travels to the central nervous system

Reciprocal inhibition

• When the central nervous system sends a signal to the antagonist muscle causing movement to contract, the tension in the antagonist muscle opposing movement is inhibit by impulse from motor neurons, and thus must simultaneously relax