KIN 3515- MIDTERM

resting metabolic rate (RMR)

60-75% of TDEE, the energy costs of the processes essential for life; (fat-free body mass, gender, thryoid hormones, protein turnover)- sleeping metabolism, basal metabolism, arousal metabolism

basal metabolic rate (BMR)

minimum energy level required to sustain vital functions in the waking state, must be measured immediately after waking up without getting out of bed 12-16 hours after the last meal and in theroneutral environment and it reflects the body's total heal production

respiratory quotient (RQ)

indicates fuel utilization at rest and during steady-rate exercise (carbs and lipids require different amounts of O2 for complete oxidation). it is reflective of the O2 consumption and CO2 production at the cellular level and is convenient guide to approximate macronutrient mixture catabolized for energy)

respiratory exchange rate (RER)

reflects CO2 production and O2 consumption when factors other than macronutrient combustion contribute to gas exchange; cellular oxidation is not the only source of CO2 and is calculate during non steady rate and exhaustive exercise

excess CO2 production in relation to O2 uptake

what does an RER>1.0 represent?

following exercise as CO2 is retained to replenish the sodium bicarbonate buffer system

what does and RER<0.7 represent?

steady rate exercise

where you perform the same intensity of exercise for the duration of the activity (usually light to moderate)

non-steady rate/graded exercise

where you perform varying intensity of exercise for the duration of the activity (moderate to high intensities with rest in between sets)

kilocalorie

general unit of measuring energy exoenditure

caloimetry

measurement of heat tranfer directly or indirectly

recommended dietary allowance (RDA)

average dietary nutrient intake sufficient to meet the nutrient requirements of 98% of health people in a partcular group (vitamins, minerals, macronutrients)

estimated energy requirements (EER)

average daily dietary energy intake predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height, and level of physical activity. consistent with good health (energy in vs energy out)

VO2 max

maximal oxygen consumption a person can consume per minute during exercise.
-it is a rate (L/min if the absolute rate and mL/kg/min is the relative rate).
-it is an indicator of maximal endurance/aerobic power/capacity.
-should be tested in a sport specific manner.

(3.9VO2) + (1.1VCO2) *1.44

RMR and BMR calculation...
VCO2=volume CO2 produced
VO2= volume O2 consumed

VCO2/VO2

RQ and RER calculation...

(VI %O2I ) - (VE %O2E

VO2 and VO2max calculation

TDEE, total daily energy expenditure

components of what the body spends its energy on throughout the day or the number of calories burned throughout the day coming from the work the body is doing

resting metabolic rate (RMR)

60-75% of TDEE

diet induced thermogenesis (DIT)

10% TDEE, energy costs from digesting, absorbing, and storing food

activity energy expenditure (AEE)

15-30%, MOST VARIABLE, energy expended during all physcial activity

1. regular physical activity: GREATEST affects on TDEE, and MOST VARIABLE daily, regular activity increases RMR and offsets decline in RMR
2. thermic effect of food (TEF)/DIT: increase in energy expenditure associated with food consumption, TEF of carbs and proteins exceeds the TEF of lipids
3. calorigenic effect of food on exercise metabolism: eating breakfast increases RMR
4. climate: tropical environments have 5-20% higher RMR, exercsing in heat increases VO2 of the activity and cold environments increases energy requirements due to shivering
5. pregnancy: added energy cost for weight transported, reduced economy of movement and increased fuel for fetal development
6. overweight/obesity: increased body mass, raises energy expended in many activities especially weight bearing, exercise efficiency is reduced

6 factors that impact TDEE

variety, balance, and moderation
-average dailty dietary nutrient intake sufficient to meet the nutrient requirements of 98% of healthy people in particular group
-daily food intake should have the adequate amounts of nutrients without excess for tissue maintenance, tissue repair, and tissue growth

What are the general principles of optimal diets? For a physically active individual, what should daily food intake do?

all metabolic processes ultimately result in heat production and the rate of heat production defines the rate of energy metabolism so... to measure energy expenditure we use calorimetry which is the measurement of heat transfer directly or indirectly

what techniques for we use to measure energy expenditure?

direct calorimetry

measuring heat production by changes in water or air temperature, limited practival applcation with humans, especially with exercise applications

indirect calorimetry

measuring O2 consumption, CO2 production and is more practical

compares the O2 vs CO2 content of ambient air (atmospheric air in the natural state)

what can we use open circuit spirometry to measure?

lipid=9 kcal/g
carb= 4 kcal/g
protein= 4 kcal/g

what is the energy content of the 3 macronutrients?

RMR is resting metabolic rate meaning it is the enrgy to maintain normal regulatory balance and body functions wen the body is at rest.
BMR is the minimum level of energy required to sustain vital functions in the waking state, so as soon as the body is aroused and awoken.

RMR is always slightly higher than BMR. they are both maintainin normal balances and functions of the body but just when the body is in rest vs during the day. BMR and RMR decrease with age.

what are similarities and differences between RMR and BMR?

1. body size/surface area
2. health and fitness
3. muscle mass
4. hormones
5. body temp
6. age

6 factors that affect RMR

-both are calculated with VCO2/VO2
-RQ indicates fuel utilization at rest and during steady-rate exercise and REQ is calculated during non-steady rate and exhaustive exercise
-RQ is reflective of the O2 consumption and CO2 production at the cellular level and approximates macronutrients catabolized for energy and RER reflects CO2 production and O2 consumption when factors other than macronutrient combustion contribute to gas exchange

what are the similarities and differences between RQ and RER

1. oxygen supply (pulmonary ventilation)
2. oxygen transport (hemoglobin concentration)
3. oxygen delivery (cardiac output and redirection of blood flow)
4. oxygen use (mitochondria/aerobic metabolism)

what are the 4 functional capacities that VO2 max integrates?

-low, moderate, high/vigorous, all out/maximal
-More scientific terms for intensity - % of VO2max, % of maximal heart rate, % of heart rate reserve, relative to lactate threshold, relative metabolic level/RMR, rate of perceived exertion, work rate/power output

· What are the 4 general categories of exercise intensities that the public quickly understands? What are the ways we can express the intensity of an exercise in more scientific terms?

% max heart rate enables increasing exercise intensity while accounting for improvements due to training adaptations
-meaning it is limited as an estimate by temperature, emotional state, food intake, body position, muscle mass, mode of exercise, and movement type. can only be an estimate because these factors also effect heart rate separately from just exercise

why is use of max heart rate limited as an estimate of classifying/prescribing exercise intensely?

primary motor cortex

important for intiating motor movements and the areas in the cortex correspond precisely to specific body parts; since it is in the frontal lobe part of the brain it is a part of the CNS and the brain has the integrative/control centers

primary somatosensory cortex

area of the brain that receives sensory information from the somatic senses and processing that information

afferent neuron

sensory neuron; afferent nerve tracts are ASCENDING- sensory information from the periphery to the brain, dorsal tract (body position, temp, light, sound, smell, tast, touch, and pain)

efferent neuron

motor neuron; efferent tracts ate DESCENDING- sginals from the brain to the periphery (lateral/pyramidal-skeletal musculature voluntary movement; ventromedial/estrapyramidal-control of posture and muscle tone)

cell body

soma, contains the control center that integrate incoming signals from all dendrites

axon

extends from the spinal cord to deliver an impulse to the muscle

axon terminal

short neural branches that conduct the impulse to the muscle at the motor endplate

dendrites

short neural branches that recieve impulses through numerous connections and conduct them toward the cell body for integration

myelin sheath

fatty layer theinsulate the axon, insulating it to increase the speed of the electrical conduction

node fo ranvier

points between myelin every 1-2mm along an axon length, allows impulses to jump from node to node and trvel faster

neurotransmitter

often AcH or norepinephrine which is released in the synapse and carries signals thoughout the body

temporal summation

repeated subthreshold exciatory impulses in rapis succession ading together to reach threshold and cause and AP

spatial summation

Simultaneous simmulation of different postsynaptic dedrites of the same neuron adding together to reach the threshold and result in AP

1. memory and learning
2. maintaining homeostasis
3. monitoring of internal/external environment
4. integrating received information
5. initiating and coordinating responses by activating muscles and glands

what are the 5 functions of the nervous system?

brain: integrative/cotrol centers; primary motor cortex, primary sensory cortex, hypothalamus
spinal cord: conduit for 2-way flow of information from periphery to brain

how is the nervous system organized? both central and periheral.

peripheral system

made up of sensory (afferent) division and motor (efferent) division- cranial nerves and spinal nerves, communication line between CNS and rest body

somatic nervous system (voluntary) and autonomic (visceral/involuntary)
-within autonomic system, the sympathetic (fight or flight) and parasympathetic (conserves energy and promotes housekeeping functions at rest)

what does the motor(efferent) system include?

-afferent: ascending; sensory inforamtion from the periphery to the brain- body position, temp, light, sound, smell, taste, touch, smell, pain
-efferent: descending; signals from the brain to periphery- muscle movements

what are the 2 nerve tracks and what direction to they flow?

motor neruon, sensory neurons, interneurons

what are the 3 key types of neurons?

motor neuron

efferent (brain to periphery) run through ventral horn of spinal cord to skeletal muscle fibers

sensory neurons

afferent (periphery to brain) enter the spinal cord through the dorsal horn

interneuron

afferent/efferent signal conductors depending on their location and what cells they connect together

irritability, excitability, and conductivity

what are the 3 key properties of neurons?

irritability/conductivity

can convert a stimulus to an electrical impulse and stimuli can be mechanical, chemical, or electrical

conductivity

can transmit impulse to another neuron or tissue and impulse move in one direction

-similar: have a cell body, nucleus, mitochondria, and other cellular components
-unique: have dendrites and single axon

how are nerve cells like all cells? what structures are unique to nerve cells?

1. resting cells
2. threshold potential
3. depolarization
4. repolarization
5. hyperpolarization
6. reset to resting potential

what are the 6 steps of AP?

A stimulus is received by dendrites of nerve cell. The nerve cell body integrates all stimuli and receives to determine the action. Sodium channels open and sodium begins to flow into the cell which drives the potential in the cell to become more positive.

what happens in resting cell stage of AP (stage 1)?

The stimuli must be strong enough to drive the interior potential above the threshold for an action potential to develop. This is usually around -55 mV. If the threshold is reached there is no turning back and a full action potential propagates. This is called all or none principle or the all or none law.

what happens in threshold potential stage of AP (stage 2)?

Once the threshold is reached more sodium gates are opened and more sodium flows into the cell rapidly raising the voltage. The positively charged sodium ions are driven by the concentration gradient and the voltage gradient. This occurs in milliseconds and is called depolarization. The internal potential rises to about +30 mV.

what happens in the depolarization stage of AP (stage 3)?

At a certain membrane potential the potassium ion gates begin to open and the sodium ion gates close ending depolarization. Potassium gates remain open and potassium freely diffuses out of the cell driving the electrical potential in the cell negative again. This process is called repolarization.

what happens in the repolarization stage of AP (stage 4)?

With the sodium gates closed and the potassium movement precedes to have more negative potential this is called hyperpolarization and is important in the transmission of information. It prevents the neuron reacting to another stimulus as the threshold to cause an action potential is now greater than resting membrane potential. This also assures initial signal precedes in one direction. During hyperpolarization, potassium gates close and sodium gates remain closed, and the sodium potassium ATPase is able to reset equilibrium potential thus the resting membrane potential in the cell is ready for the next stimulus. During repolarization and hyper these periods are a time called refractory period during this time no new action potentials can be initiated and keeps the action potential traveling in one direction

what happens in the hyperpolarization stage of AP (stage 5)?

Na+ and K+ pores remain open and enable diffusion of ions. Slow reset to resting membrane potential by the Na+/K+ pumps (require ATP)

what happens in the reset to resting potential stage of AP (stage 6)?

depolarization spreading down the nodes of ranvier on the axon. requires ion movement in 1 Node trigerring voltage gates channel opening the next node within the axon under the membrane and myelin

how does an AP propagate down the axon of a neuron from the dendrites to the axon terminal?

myelination, fiber diamete, and physiologic conditions

what factors influence the speed at which AP/nerve impulse is transmitted down an axon?

myelination

saltatoy conduction, increased permeability to ions at Nodes of Ranvier, increased thickness=increase speed

fiber diameter

increase diameter=increase speed

physiologic conditions

pH-increases (less acidic)=faster
temperature-high temp=faster

-NT that causes depolarization of the dendrite membrane and termed excitatory
-resting membrane potential becomes LESS NEGATIVE with increased permeability to Na+, temporarily INCREASING the tendency to fire (disinhibition)
-Does NOT cause an action potential on the postsynaptic cell unless the threshold is reached

what are excitary postsynaptic potential?

-NT that causes hyperpolarization of the dendrite membrane are termed inhibitory
-resting membrane potential becomes MORE NEGATIVE with increased permeability to K+, temporarily DECREASING the tendency to fire (hyperpolarization)
-Neural inhibition has protective functions, and reduces input of unwanted stimuli to produce a smooth, purposeful response

what are inhibitory postsynaptic potential?

proprioception

the sense of where our body parts are in relation to each other

proprioceptors

sensory receptors that allow continual monitoring of the progress of any sequence of movements and relay information about muscle dynamics, orientation fo body parts and limb movements to the CNS

kinesthesia

conscious recognition of body position with respect to other parts of the body and speed of limb movements

muscle, tendon, and joints

where are proprioceptors located?

muscle spindle and Golgi tendon organ

what are 2 of the skeletal muscle proprioceptors?

muscle spindle

proprioceptors located in the fleshy part of the muscle body; the most active when muscle is stretched
-cigar shaped and connected in parallel with muscle fibers

Golgi tendon organ

proprioceptors located in the junction of the muscle and the tendon; most active when muscle is contracted
-connected to extrafusal fibers near the tendon's junction with muscle

-detect changes in extrafusal muscle fiber length, notice when there is an external load on the muscle/primarily respond to the stretch fo the muscle to initiate a stronger muscle action to counteract the stretch

what signal do muscle spindles respond to, how do they respond to the signal?

efferent nerve fibers activate stretched muscle fibers to contract stronger to hold up against the extra tension or weight applied to the muscle

how do muscle fibers protect the muscle?

detects differences in tension generated by muscle during shortening or passive stretching

what signal do Golgi tendon organ respond to, how do they respond?

-protects muscle and surround connective tissue harness from injury from excessive load
-prevents overstretching and rupture by inhibiting motor neuron drive during excessive load

how do Golgi tendon organ protect the muscle?

endomuysium

connective tissue surrounding each muscle fiber, MOST INNER LAYER

perimysium

connective tissue grouping muscle fibers into bundles

epimysium

connective tissue grouping bundles into muscle fiber, MOST OUTER LAYER

tendon

strong dense combination of epi, peri, and endomysium at the proximal and distal ends of the muscle body; connect MUSCLE TO BONE

origin

location where tendon attaches to stable skeletal location, generally proximal

insertion

point of distal tendon attachment

motor unit

comprised of all motor neurons and all the muscle fibers it innervates
-each muscle fiber is innervated by 1 motor neuron and each motor neuron will only innervate 1 type of skeletal muscle

neuromuscular junction

interface between the end of the motor neuron and a muscle fiber, space where the nerve impulse/AP is transmitted to a muscle fiber to initiate a muscle action

myofibril

ultrastructure name for the cellular components of muscle fiber

sarcolemma

thin elastic membrane enclosing the cellular components of a single multinucleated muscle fiber

T-tubule

transverse tubule, conducts an electrical signal from the sarcolemma to the myofibril components

sarcoplasmic reticulum

expansive network of tubes surround each myofibril that stores calcium

myofilament

protein subunits of a myofibril, lies parallel to the long axis of myofibril, create the striation pattern

sarcomere

functional repeating unit of each myofilament

actin

THIN filament of sarcromere, composes of tropomyosin and troponin

myosin

THICK filament of sarcomere, contain ATPase