Final Flashcards
Physiology definition
study of the function of the body’s cells, tissues, organs, and systems
exercise physiology definition
study of how acute and chronic exercise impacts the function of the body’s cells, tissues, organs, and systems
components of a research article
abstract, intro, research methods, results, discussion, references
calorie definition
amount of heat needed to raise 1 gram of water by 1 degree celsius
direct calorimetry
measure of heat production as an indication of metabolic rate
indirect calorimetry
measure oxygen consumption as an estimate of metabolic rate
open-circuit spirometry
measure the uptake of oxygen (air in-air out)
3 factors that influence exercise efficiency
exercise intensity, speed of movement, muscle fiber type
how do we estimate energy expenditure in the gym
power = work/time
direct relationship (heart rate, oxygen consumption)
homeostasis
physiological variables that don’t change at rest (basal state)
steady state
unchanging physiological variable
components of biological control system
sensor, receptor, control center, effector
feedback of most biological control systems
negative feedback
adaptation
change in structure and function of cell or organ over time, allowing improved ability to maintain homeostasis or steady state
acclimation
adapting to environmental stressors (temp, altitude, humidity)
5 mechanisms of cell signaling
intracrine, juxtracrine, autocrine, paracrine, endocrine
intracrine cell signaling
a chemical message sent within a cell
juxtracrine signaling
a chemical message between two cells
autocrine signaling
a chemical message on the same cell, but message leaves the cell first
paracrine signaling
message acts on nearby cells
endocrine signaling
message released into blood stream, usually hormones
hormesis definition
low dose of a potentially harmful stress resulting in beneficial adaptations
which molecules help maintain cellular homeostasis
ATP, glucose, glycogen, oxygen, etc
catabolic reaction
breaks apart molecules
anabolic reactions
builds molecules
why are mitochondria important
make ATP! break down carbs and fatty acids, consume oxygen to generate ATP
2 types of chemical reactions
endergonic and exergonic
endergonic reactions
require energy
exergonic reactions
release energy
oxidation reaction
loss of electrons and protons (hydrogen), gain oxygen
reduction reaction
gain of electrons and protons (hydrogen), loss of oxygen
reducing equivalents
NADH and FADH2 carry electrons that can be released for energy in the mitochondria
enzymes function
speed up the rate of a reaction by decreasing amount of energy needed to start the reaction
3 macronutrients used for fuel
carbs, fatty acids, proteins
how is glucose stored
stored as glycogen in muscles and the liver
glycogen synthases turns glucose into glycogen
glycogenolysis
process of breaking down glycogen into glucose
fatty acids
primary form of fat used for fuel
trigylcerides
storage of fatty acids in muscle tissue and adipose tissue
how does atp provide energy
energy is released when phosphate group is broken off, forming adp
three bioenergetic pathways
phosphocreatine, glycolysis, oxidative phosphorylation
bioenergetic pathway
produces ATP
fastest bioenergetic pathway
phosphocreatine
slowest bioenergetic pathway
oxidative phosphorylation
which bioenergetic pathway produces lactate
anaerobic glycolysis
what does the body do with lactate produced by anaerobic glycolysis
goes into the bloodstream, then the liver, liver converts it back to glucose
where do oxidative phosphorylation and beta oxidation occur
mitochondria
is oxidative phosphorylation driven by supply or demand
demand
oxidative phosphorylation
consumption of oxygen to produce ATP
beta oxidation
break down fats for energy
what is o2 consumption at rest?
0.25L/min
3.5ml/kg/min
1 MET
what is 1 MET
oxygen consumption at rest, metabolic equivalent
when does ATP consumption increase at the start of exercise?
immediately
Oxygen deficit definition
lag in usage of oxygen at the start of exercise (endurance trained individuals have a lower deficit)
why do trained individuals have a lower oxygen deficit?
better developed aerobic bioenergetic capacity due to cardiovascular (more capillaries) and muscular adaptations (greater mitochondrial volume)
what is EPOC
excessive post-exercise oxygen consumption, repay oxygen dept and resynthesis of phosphocreatine in muscles, replenish myoglobin and hemoglobin stores
what is VO2 max
maximal oxygen uptake, increases linearly during exercise until ceiling is reached, influenced by training and genetics
what physiological factors influence VO2 max
ability of the cardiorespiratory system to deliver oxygen, ability of muscles to use oxygen to produce ATP
Lactate threshold definition
the work rate at which blood lactic acid rises systematically during incremental exercise
what three factors influence fuel selection during exercise
intensity, duration, availability of fuels
what fuel source do we use more of the longer we exercise
fat
hormone definition
chemical message that travels through the blood to target tissues and cells
what are classed of hormones
based on chemical makeup, amino acids (catecholamines), peptides/proteins, steroids
what is hormones role in the body
fine tune physiological processes like growth, metabolism, BP, and reproduction
how are hormones regulated
homeostatically
what effects the effect of a hormone
concentration, number of receptors, affinity of receptors
how do steroid hormones signal
travels to the nucleus to activate genes
where are hormones secreted from
endocrine glands: hypothalamus and pituitary glands, thyroid and parathyroid glands, adrenal gland, pancreas, testes and ovaries
what does the hypothalamus do
exerts homeostatic control over hormone secretion
what does somatostatin do
exerts negative feedback on hormone secretion from various glands
what does growth hormone do
stimulates the release of insulin-like growth factors, reduces the use of plasma glucose, increases gluconeogenesis, mobilizes fatty acids
what does IGF-1 do?
amino acid uptake and protein synthesis, long bone growth
what does the thyroid gland do
secreted triiodothyronine (T3) and thyroxine (T4) which increase metabolic rate
Adrenal medulla gland
secretes catecholamines epinephrine and norepinephrine
what is the effect of catecholamines on beta receptors
increases heart rate, breathing and metabolism
what is the effect of catecholamines on alpha receptors
counters the effects on beta receptors, more selective
what does the adrenal cortex gland do
secretes steroid hormones: sex steroids and glucocorticoids
what does cortisol do
slow-acting catabolic, increased by stress, peak in am, stimulates breakdown of triglycerides
what does testosterone do
anabolic steroid, promotes tissue building, increases strength and power, androgenic: promotes masculine characteristics
what does estrogen and progesterone do
establish and maintain reproductive function
what does the pancreas do
secretes insulin (from beta cells) and glucagon (from alpha cells)
what does glucagon do
promotes the production/release of fatty acids and glucose
what does insulin do
promotes the storage of glucose, amino acids, and fats
how is blood glucose homeostasis maintained during exercise
release of glucose from liver, production of new glucose, decrease in glucose uptake in cells that aren’t the brain, release of free fatty acids from adipose tissue
which hormones does adipose tissue secrete
leptin and adiponectin
what does leptin do
suppresses appetite, enhances insulin sensitivity
what does adiponectin do
increases insulin sensitivity and fatty acid oxidation
what hormone does skeletal muscle produce
myokines
immunity definition
protects the body against foreign agents (pathogens)
what is the adaptive immune response
the body learns to identify pathogens
what do B cells do
produce antibodies in response to an antigen
what do T cells do
respond to antigens based on protein receptors on their surface
what do killer T cells do
attack out own cells that are infected with a virus
what do helper T cells do?
secrete cytokines to recruit more immune cells to the infection site
what does acute inflammation do
short term response to injury, vasodilation, increased blood flow
what does chronic inflammation do
persistent infection, increased circulation of cytokines
what is the risk of exercise on upper respiratory tract infection
J shaped curve, too little and too much is bad
sensory nervous system definition
detects stimuli and transmits information from receptors to CNS (input)
somatic sensory system definition
sensory input that is consciously perceived from receptors
visceral sensory system definition
sensory input that is not consciously perceived from receptors
motor nervous system definition
initiates and transmits information from the CNS to effectors
somatic motor system definition
motor output that is consciously or voluntarily controlled
autonomic motor system definition
motor output that is not consciously or involuntarily controlled
afferent definition
towards the brain
efferent definition
away from the brain
cell body of a neuron
contains the nucleus
dendrites
conduct impulses toward the cell body
axon
carries electrical impulse away from cell body, covered by schwann cells (myelin sheath)
synapse
small gap between presynaptic neuron and postsynaptic neuron
neurotransmitters
chemicals released at synapse changes electrical charge which depolarizes pre synaptic neuron
action potential definition
electrical response of cell, all or none law
proprioceptors definition
tell CNS info about body position, found in joints and muscles
muscle spindle definition
info about length and rate of shortening, stretch promotes reflex contraction
kinesthesia definition
conscious recognition of the position of body parts, recognition of speed of limb movement
Golgi tendon organ definition
provides information about muscle force production
Skeletal muscle chemoreceptors definition
sensitive to changes in the chemical environment surrounding muscle fibers, contraction increases acidity an CO2 which increases HR and breathing
somatic motor function
motor neurons located within spinal cord, carry neural messages from spinal cord to skeletal muscles
motor unit definition
motor neuron and all the muscle fibers it innervates
neuromuscular junction definition
where neuron and muscle meet
innervation ratio
number of muscle fibers innervate per moto neuron
fine motor control has low innervation ratio
joints have high innervation ratio
motor unit recruitment and size principle
recruit more muscle fibers by activation more motor units, smallest motor units recruited first during exercise
three types of motor units
Type S (slow) - smallest
Type FR (fast, fatigue resistant)
Type FF (fast, fatigable) - largest
autonomic nervous system function
maintains homeostasis by effecting organs not under voluntary control
sympathetic division of autonomic nervous system
release epinephrine and norepinephrine, dilate pupils, increase HR, slow digestion
parasympathetic division of autonomic nervous system
releases acetylcholine, constricts pupils and bronchi, slow HR, relax blood vessels, promote digestion
how does exercise enhance brain health
improves learning and memory, neurogenesis, vascular function, reduces depression
what are the three types of muscle actions
concentric, eccentric, isometric
epimysium definition
surrounds entire muscle
perimysium definition
surrounds bundles of muscle fibers
endomysium definition
surrounds individual muscle fibers
satellite cells definition
support growth and repair of skeletal muscle
skeletal muscle fibers definition
multinucleated cells with myofibrils that contain contractile proteins actin and myosin
sarcomere definition
the contractile unit of skeletal muscle
sliding filament theory
muscle contracts because actin and myosin slide along each other, shortening sarcomere length
which muscle cell has the least amount of mitochondria
type 2x - fast fibers
role of calcium in muscle contraction
allows actin and myosin to bind, stored in the sarcoplasmic reticulum
tetanus definition
continuous firing of motor neurons creating maximum force
muscle fatigue definition
decline in muscle power output metabolic or mechanical limitations
how does aging affect muscle mass and function
10% between age 25-50
additional 40% between age 50-80 resistance training can delay loss
sarcopenia definition
age-related loss of muscle mass and function
role of acetylcholine in muscle fibers
causes depolarization of muscle fiber (contraction), released by motor neuron
muscular dystrophy
hereditary defects in muscle protein, results in loss of muscle fibers and weakness
3 functions of the cardiorespiratory system
transport oxygen, remove CO2, regulate body temperature
how does blood flow change during exercise
increased cardiac output, increased blood flow to activate muscle which reduces blood flow to inactive organs
plasma
liquid portion of blood, contains small proteins, nutrients, etc.
red blood cells
carry oxygen via hemoglobin
parts of blood
plasma, white blood cells, platelets, red blood cells
hematocrit definition
percentage of blood as red blood cells, usually 40-45%
heart
create pressure to pump blood, part of circulatory system
arteries and arterioles
carry blood away from the heart, part of circulatory system
veins and venules
carry blood toward the heart, part of circulatory system
capillaries
exchange of O2 and CO2 and nutrients with tissues, part of circulatory system
epicardium definition
connective tissue of the heart
myocardium definition
heart muscle
endocardium definition
acts like a blood vessel
systole definition
contraction phase of cardiac cycle, ejects blood
diastole definition
relaxation phase of cardiac cycle, fills with blood
determinants of mean arterial pressure
cardiac output x total vascular resistance
arterial blood pressure
systolic/diastolic
short term regulation of blood pressure
by sympathetic nevous system and baroreceptors in aorta and carotid arteries
long term regulation of blood pressure
kidneys via control of blood volume
hypertension
blood pressure above 140/90 mmHG
cardiac output
amount of blood pumped by the heart each minute Q=HRxSV
what causes low resting HR
parasympathetic nervous system
how does exercise influence HR
initial ride rue to decreased parasympathetic activity (100bpm), subsequent increase increase in sympathetic activity to SA node
where does gas exchange occur in the lungs
alveoli (alveolar wall)
how does movement of air occur?
pressure differences between intrapulmonary pressure and atmospheric pressure
pulmonary ventilation definition
movement of air into and out of the lungs V=Vt x frequency
Tidal volume (Vt)
volume of gas moved per breath
Oxyhemoglobin definition
Hemoglobin (Hb) bound to oxygen (how 99% of oxygen is transported in the blood)
how is CO2 transported in the blood
dissolved in plasma (10%)
Bound to Hb (20%)
Bicarbonate (70%)
what are the two parts of the control of ventilation
inspiration and expiration
inspiration definition
inhale air, controlled by control center located in medullar oblongata
expiration definition
exhale air, input from higher brain, muscle mechanoreceptors and chemoreceptors
what are the three principles of training
overload, specificity, reversibility
overload definition
training effect occurs when a physiological system is exercised at a level beyond which it is normally accustomed
specificity definition
training effect specific to muscle fibers recruited during exercise, energy systems involved, type of muscle contraction
reversibility definiiton
gains are lost when training ceases
how does endurance and resistance exercise training increase protein synthesis
exercise stress activates gene transcription and protein synthesis
what is the process of training-induced muscle adaptation
- muscle contraction activates signal pathways to promote adaptation
- results in gene expression and synthesis of new proteins
- adaptations dependent on mode, intensity, and duration of activity
what is the recommended training to increase VO2 max
large muscle groups, dynamic activity, 20-60 min 3 or more times per week at greater than 50% VO2 max
what is the average increase in VO2 max with exercise
15-20% (up to 50% in those with low initial)
Cardiac Output
amount of blood pumped to the muscle
a-v O@ difference
amount of oxygen taken up by muscle for ATP production
Cardiac Output equation
Q = SV x HR
what are short-term adaptations to exercise
increase plasma volume (cardiac output)
anaerobic training adaptations
hypertrophy of type 2 muscle fibers and mitochondrial biogenesis
muscular strength
maximal force a muscle group can generate
muscular endurance
ability to make repeated contractions against a submaximal load
muscle hypertrophy
increased muscle mass cause by growth of existing muscle fibers
high resistance / load training
2-8 reps, increase muscle hypertrophy and strength in all individuals
medium resistance / load training
8-15 reps, increase muscle hypertrophy and strength in untrained individuals
low resistance / load trainig
20+ reps, increases muscular endurance but not strength or hypertrophy
where do adaptations to resistance training occur first
nervous system, skeletal system second
training volume equation
set x reps x resistance
when does muscle protein synthesis increase
immediately after exercise
concurrent training
cardio and resistance training performed in the same session, have opposing effects so strength gains decrease
how long for recovery of dynamic strength loss when you begin retraining
as quickly as 3 weeks
2 parts of prescription of medicine
dose, effect
FITT principle
Frequency (days per week), Intensity, Time (minutes of exercise), Type (activity)
how is VO2max measured
Direct: Graded exercise test
Indirect: heartrate, estimations
% Heart rate reserve equation
HR / (HR max - resting HR)
Borg Scale
quantify exercise intensity, originally 6-20 now 0-20
guidelines for improving fitness
screening, progression, warm up, cool down
which diseases involve controlling glucose during exercise
type 1 and 2 diabetes
which diseases involve controlling lung function and immune system during exercise
asthma and COPD
which diseases involve controlling vascular and cardiac function during exercise
hypertension and myocardial infarction
asthma
shortness of breath and wheezing, due to contraction and inflammation of smooth muscle airways
chronic obstructive pulmonary disease
includes bronchitits, emphysemsa, and bronchial asthma, limits activities, may require oxygen
who is cardiac rehabilitation recommended for
angina pectoris, myocardial infraction, coronary artery bypass graft, angioplasty
three phases of cardiac rehabilitation
- inpatient exercise program
- outpatient exercise, close supervision
- less direct supervision, may be home-based
how much does vo2 max decline in older adults
1% per year
major adaptations to pregnancy
*blood volume increases 40-50%
*oxygen uptake and heart rate are higher during rest and during exercise
*cardiac output is higher at rest and during exercise in first two trimesters
what are the exercise recommendations for cancer patients
- multiple short sessions
- preferred aerobic modalities
- strength and flexibility at least 2 days per week
high-intensity interval training
repeated cycles of short duration high intensity exercise with recovery periods
what are the components of metabolic syndrome
increased BP, high triglycerides, large waistline, low hdl cholesterol, elevated fasting blood sugar
hypertension metabolic syndrome measurement
> 130/80 mm Hg
what causes many chronic diseases
inflammation / obesity
glycemic index
measurement of how a specific carb food elevates blood glucose levels (higher is worse for health)
benefits of fiber
promotes bowel movement, reduces risk of diverticular disease, lowers cholesterol levels
protein function
contractile elements for muscle, membrane transporters, enzymes, hormones
how many amino acids does the body need
20, 9 are essential
energy intake of macronutrients
carbs 45-65%
fats 20-35%
protein 10-35%
RDA for protein
0.8g per kg of body weight
what source of protein contains all 9 amino acids
animal sources
three major classes of lipids
- triglycerides (stored form)
- Phospholipids (found in membranes)
- sterols (make hormones and some vitamins
Adequate intake of water
2.7 L per day (women), 3.7 L per day (men)
requirements to be a vitamin
- body can’t synthesize compound or make enough
- compound found naturally in foods
- when compound is missing, results in poor health
two-compartment model of body composition
fat mass, fat free mass
BMI equation
weight (kg) / height (m^2)
equation for energy balance
change in body macronutrient stores = energy intake - energy expenditure
popular low carb diets
atkins, south beach, zone, ketogenic
popular low fat diets
mediterrranean, ornish
popular high protein diets
paleo
popular nutritionally-balanced diets with restricted calories
weight watchers, jenny craig
key factors that influence adherence to diet
sense of full feeling, satiety, a variety of foods
fatigue
inability to maintain power output or force during repeated muscle contractions
central fatigue factors
central nervous system, reduction in motor units activated and firing frequency
peripheral fatigue factors
neural factors, mechanical factors, energetics of contraction
muscle in vivo
measures fatigue of muscle in the body
sarcolemma and transverse tubules on fatigue
altered muscle membrane conduction and action potentials (Na and K pump can’t maintain amplitude and frequency)
action potential block in the T-tubules (reduced sarcoplasmic reticulum Ca release)
how much should training increase per week
less than or 10% increase
progressive resistance exercise
periodically increasing resistance to continue to overload the muscle
linear periodization
shift from high volume/low intensity to low volume/high intensity training
male strength difference over females
upper body 50% stronger
lower body 30% stronger
men exhibit greater hypertrophy long term
common training mistakes
overtraining
undertraining
performing non-specific exercises
lack of a long-term training plan
failure to taper
symptoms of overtraining
decrease in performance
loss of body weight
chronic fatigue
more infections
psychological staleness
elevated HR and blood lactate levels
Tapering
short term reduction in training load prior to competition to allow muscles to resynthesize glycogen and heal from training damage
Female Athlete Triad
low energy availability leading to menstrual dysfunction and low bone mineral density
