YEAR 2 PHYSIOLOGY Flashcards
What is human physiology
The science of how humans’ function in an integrated way and is the basis for many biological and clinical sciences
what is exercise physiology
The branch of the biological sciences that is concerned with the way that the body responds to exercise and training
what is homeostasis
- Maintenance of a constant and normal internal environment
- All variables of physiological mechanisms must operate within a narrow range of values
what is steady state exercise
- Physiological variable (HR) is unchanging but not necessarily normal, plateau on graph
- Balance between demands placed on body and the body’s response to those demands
- Eg; HR, Body temp, Arterial BP
at rest what does arterial blood pressure do
fluctuates
at rest what does mean blood pressure do
stays constant due to baroreflex responses and kidney function
what are intracellular control systems
- protein breakdown and synthesis
- energy production
- maintenance of stored nutrients
what are organ systems
- pulmonary and circulatory systems
- replenish oxygen and remove carbon dioxide
in a biological control system what is a sensor for
detects change in a variable
in a biological control system what is a control centre for
asses input and initiates the response
in a biological control system what is an effector for
changes internal environment back to normal
what is negative feedback
- Acts to reduce an effect. When a change occurs in a system it opposes that change and restores the controlled variable back to its usual value
- Eg; respiratory systems control of CO2 conc in extracellular fluid
1. Increase in extracellular CO2 triggers a receptor
2. Sends info to respiratory control centre
3. Respiratory muscles are activated to increase breathing
4. CO2 conc returns to normal
Most control systems work via negative feedback
what is positive feedback
- Acts to increase an effect. When a change occurs, it becomes amplified
- Eg; childbirth
1. Initiation of childbirth stimulates receptors in cervix and sends message to brain to release oxytocin from pituitary gland
2. Oxytocin promotes increased uterine contractions
what is gain
sensitivity of the response
- Degree to which a control system maintains homeostasis
- Pulmonary and cardiovascular systems have large gains (thus more capable of maintaining homeostasis)
what happens to homeostasis at exercise
- Exercise disrupts homeostasis by changes in pH, PO2, PCO2 and temperature in cells
- Inability to maintain steady state = fatigue and end of exercise
what is adaptation
o Changes in structure and function of cell or organ system
o Results in improved ability to maintain homeostasis
o Many adaptive changes occur within cells
what is acclimatisation
o Adaptation to environmental stresses (e.g. heat or hypoxic stress)
o Results in improved function of existing homeostatic system
what is exercise enduced hormesis
process in which a low to moderate dose of a potentially harmful stress (for example a chemical agent or environmental stress) results in a beneficial adaptive response on the cell or organ system.
what is the function of cell signalling
-communication between cells using chemical messengers
-coordinates cellular activities
-important for maintaining homeostasis
five different cell signalling pathways exist in cells
what is intracrine signalling
Chemical messengers inside cell triggers response
what is juxtacrine signalling
chemical messengers passed between 2 CONNECTED cells
what is autocrine signalling
chemical messengers acts on that same cell
what is paracrine signalling
chemical messengers acts on nearby cells
what is endocrine signalling
chemical messengers (that is hormones) released into blood. (affects cells with specific receptor to the hormone)
what is laboratory research
data collection on humans in a lab setting
what is field research
allows physiological data collection in a real world setting
what is applied research
includes studies designed to solve practical problem
what is the scientific method
a systematic approach used to test hypothesis
what is an example of an independent variable
eg exercise intensity
what is an example of a dependant variable
eg heart rate
what is basic research
study of fundamental topics in biology (eg mechanisms of adaptation to exercise)
what is translational research
application of research
also known as bench to bedside
what is experimental research
involves the manipulation of experimental variables
what is power
amount of work performed per unit of time
what is net efficiency
ratio of work output divided by energy expenditure above rest
what is direct calorimetry
measure of metabolic rate via heat production
what is relative VO2
oxygen consumed per kg of body mass
what is 1 MET
a unit of resting metabolic rate
what is running economy
oxygen uptake at specific running speeds
what is oxygen consumption (VO2)
amount of oxygen used by the body
What is indirect calorimetry
measure of metabolic rate via VO2
what is work
product of force and the distance through which that force acts
what type of relationship is there between exercise intensity and HR
linear relationship
what is the function of the blood
carries gases, nutrients and waste products
what is the function of the renal system
conserves water
contributes to maintenance of body pH
what is the function of the CNS
Controls musculo-skeletal system, circulation and body temperature
what is the function of the integumentary system (the skin)
involved in heat loss from body
what is the function of the musculoskeletal system
provides movement under CNS control
what is the function of the respiratory system
provides oxygen and removes carbon dioxide
what is the function of the cardiovascular system
pumps the blood through the circulation
what is the function of the endocrine system
supports circulation control and regulates metabolism
what is the function of the alimentary system
water and nutrient intake
what is feedforward control
results in changes in physiological responses in anticipation of a change in a variable
what type of feedback is clotting of blood after you cut yourself
positive feedback
what type of feedback is control of body temp, BP, and HR
negative feedback
describe afferent information
comes from sensors to brain
describe efferent information
brain to effectors to make change
what is cardiorespiratory fitness
refers to the interactions between the heart (cardiac) and lungs (respiratory) that maximise performance and recovery
what is cardiorespiratory endurance
the ability of an individual to perform a strenuous task for a prolonged period (where large muscle groups are used).
what is vo2 max
the maximal rate of oxygen consumed
what catagories are considered when defining an individuals physical fitness
- cardiorespiratory fitness
- body composition
- musculoskeletal fitness (flexibility, muscular strength, muscular endurance)
what are 2 ways of testing cardiorespiratory fitness
bleep test- compares an individuals performance to population norms
VO2 max test- directly measures cardiorespiratory fitness based on an individuals maximal oxygen consumption in L/min
What does a high vo2 max mean
- The higher the vo2 max, the greater the ability the individual has to sustain aerobic work at a higher intensity for a longer time
how do you know vo2 max has been reached on a graph
plateau in oxygen consumption despite an increase in work rate
what is bioenergetics
- Flow and exchange of energy within a living system
- Role of enzymes as catalysts in cellular chemical reactions
- Processes involved in anaerobic and aerobic ATP production
- Conversion of foodstuffs (fats, proteins, carbs) into useable energy for cell work
what is the cell membrane called in skeletal muscle
sarcolemma
what is the role of the cell membrane
semipermeable membrane that separates the cell from the extracellular environment
what is the role of the nucleus
contains genes that regulate protein synthesis
what is cytoplasm called in muscle
sarcoplasm
what is the function of the cytoplasm
fluid portion of the cell
contains organelles
what is the 1st law of thermodynamics
- Energy cannot be created nor destroyed only transformed from one form to another
what is endergonic
overall increase in energy
picture diagram (reactants lower than product) has to go up
what is exergonic
overall decrease in energy
(picture diagram reactant higher than product) has to go down
what is oxidation
- Removing an electron
- Or adding oxygen
what is reduction
- Addition of an electron
- Or removing oxygen
what are enzymes
they are biological catalysts that lower the activation energy accelerating chemical reactions
They don’t get used up or changed by the reaction they are involved in
what does the enzyme kinase do
add a phosphate group
what does the enzyme dehydrogenase do
remove a hydrogen atom
what does the enzyme oxidase do
catalyse oxidation-reduction reactions involving oxygen
what does the enzyme isomerase do
rearrangement of the structure of molecules
what are the factors that affect enzyme activity
temperature
pH
what is the stored form of carbohydrates
glycogen
where are carbohydrates stored
liver and muscle
what is the breakdown process of carbohydrates
glycogenolysis
what is the stored form of fats
triglycerides
where are fats stored
muscle and adipose tissue
what is the breakdown process of fats
lipolysis
what is the net ATP of glycolysis
2
describe the process of the Krebs cycle (citric acid cycle)
- pyretic acid is converted to acetyl coA, losing a carbon generating co2
- acetyl coA combines with oxaloacetate to form citrate
- citrate is metabolised to oxoloacetate generating two carbon dioxides
- each turn of the cycle creates 1 ATP, 3 NADH and 1FADH2
describe the process of the electron transport chain
- NADH and FAD are re oxidised releasing high energy electrons from the H atoms. Electrons are passed down a series of electron carriers (cytochromes). H is pumped into intermebrane space
- increased conc of H ions in inter membrane space
- movement of H ions through ATP synthase produces ATP
What are electron carriers called
cytochromes
what are the 2 types of metabolism
catabolic and anabolic
what is a catabolic reaction
synthesis of molecules
what is an anabolic reaction
breakdown of molecules
describe the rest to exercise transition in terms of ATP and oxygen
ATP production increases immediately
O2 uptake rapidly increases
Initial ATP production must be anaerobic leading to an oxygen deficit
do trained athletes have a lower oxygen deficit than untrained athletes
yes
why do trained athletes have a lower oxygen deficit than untrained athletes
- Better developed aerobic bioenergetics capacity
- Greater regional blood flow to active muscle
- Increased cellular adaptation and efficiency
- Increased mitochondrial volume in muscle fibers results in less lactate production at beginning of exercise
what does EPOC stand for
excess post exercise oxygen consumption
what is EPOC influenced by
the intensity of exercise
what are the effects of heavy exercise
increased oxygen uptake
cannot be sustained, exhaustion occurs
larger oxygen deficit, therefore longer EPOC
What is the fast component of EPOC
Re-syntheis of stored PC in muscle Replensihing muscle (myoglobin) and blood (Hb) oxygen stores
what is the slow component of EPOC
- elevated HR & breathing increase O2 demand
- elevated body temp = increased metabolic rate
- elevated blood levels of epinephrine and norepinephrine = increase metabolic rate
- conversion of lactic acid to glucose (gluconeogenesis
Responses to short term exercise (<5) in terms of energy systems
- ATP produced via ATP-PC
- Shift to ATP production via glycolysis
Response to events lasting >45s in terms of energy systems
- ATP production though ATP-PC, glycolysis and aerobic systems
- 50% anaerobic/ 50% aerobic at 2mins
Responses to exercise >10 mins in terms of energy systems
ATP production primarily from aerobic metabolism
what is the lactate threshold
the point at which blood lactic acid rises systematically during incremental exercise
in untrained athletes when do you reach the lactate threshold
50-60% of VO2 max
in trained athletes when do you reach the lactate threshold
65-80% of VO2 max
what is OBLA
onset blood lactate accumulation
point at which blood lactate reaches > 4mmol
possible explanations for the lactate threshold
- Low muscle oxygen (hypoxia)
- Accelerated glycolysis
- NADH produced faster than it is shuttled into the mitochondria, therefore NADH accumulates in cytoplasm so is converted from pyruvic acid to lactic acid
what enzyme catalyses the conversion of pyruate to lactate
lactate dehydrogenase
reversible reaction
how do you calculate blood lactate conc
lactate entry into the blood - blood lactate removal
is maximal oxygen intake influenced by training
yes
is lactate threshold influenced by training
yes
what does R stand for
respiratory exchange ratio
what is the crossover concept
the shift from fat to CHO metabolism as exercise intensity increases.
what is the crossover concept due to
recruitment of fast muscle fibres
increasing blood levels of epinephrine stimulate glycogen breakdown
what factors decide fuel selection during exercise
exercise intensity (crossover concept) exercise duration (due to increased rate of lipolysis`)
what happens to glycogen during high intensity exercise
it is depleted
reduced rate of glycolysis and production of pyruvate
what is beta oxidation
the process of oxidising fatty acids into acetyl CoA
what is the influence of exercise intensity on fuel source
- The relative contribution of muscle glycogen and blood glucose varies as a function of the exercise intensity (and duration)
- Increased rate of glycogenolysis due to recruitment of fast twitch fibers and elevated blood epinephrine levels
what is the lactate shuttle
lactate is produced in one tissue and transported to another to be used as an energy source
what is the cori cycle
the cycle of glucose –> pyruvate –> lactate
lactate then released into blood, and carried to liver
In liver it is reconverted to pyruvate and used for gluconeogenisis
what are the 2 parts to the neuroendocrine system
nervous system
endocrine system
how does the nervous system work
uses neurotransmitters to relay messages from one nerve to another. Or from a nerve to a tissue
what is the endocrine system
Releases hormones into blood to circulate to tissues
are the endocrine glands ductless
yes
it means they release the hormones directly into the blood
how do hormones work
and what are thee difference classes of hormone
- Hormones bind to specific protein receptors to exert their effect
Several classes based on chemical makeup..
- Amino acid derivatives (thyroid hormones, catecholamines)
- Peptides/ protein (adrenocorticotrophic hormone – ACTN, Antidiuretic hormone- ADH)
- Steroids (glucocorticoids, mineralocorticoids)
what is the effect of a hormone on a tissue determined by
THE PLASMA CONCENTRATION AND THE NUMBER OF ACTIVE RECEPTORS!
what is plasma conc determined by
- Rate of secretion of hormone from endocrine gland
- Magnitude of slimulatory input
- Stimulatory versus inhibitory output - Rate of metabolism or excretion of hormone
- inactivation near the receptor and/ or metabolized by the liver and kidneys - Quantity of transport proteins
- Steroid hormones are transported bound to plasma proteins - Changes in plasma volume – can drop during exercise
What tissues can hormones effect
Hormones only affect tissues that contain specific hormone receptors!
what is the magnitude of the hormones effect dependant on
- Concentration of hormone
- Number of target receptors of the cell
- Affinity of the receptor for the hormone
what are the 3 mechanisms of hormone action
- Activation of genes to alter protein synthesis
- steroid hormones - activating ‘second messengers’ in the cell via G protein
- cyclic AMP
- Calcium
- Inositol triphosphate
- Diaglycerol - altering membrane transport
- insulin via tyrosine kinase
name some examples of steroids
estrogen
cortisol
testosterone
do hormones act fast or slow
slow
are hormones effects short or long lasting
long lasting
what are the main endocrine glands
- hypothalamus and pituitary
- thyroid and parathyroid
- adrenal
- pancreas
- testes and ovaries
what is the function of the hypothalamus
controls secretions from pituarity gland
what does the anterior pituitary gland secrete
- ACTH (adrenocorticotropic hormone)
- FSH (follicle stimulating hormone)
- LH (luteinising hormone)
- MSH (melanocyte-stimulating hormone)
- TSH (thyroid stimulating hormone)
- GH (slow acting)
what does the posterior pituitary gland secrete
oxytocin
ADH (antidiuretic hormone)
what is growth hormone
- GH increases protein synthesis in muscle and long bone growth
- Used to treat childhood dwarfism
- Also used by athletes and elderly
- No evidence that GH promotes strength gains
- Difficult to detect usage by athletes
- High dose; more adverse effects than benefits
what is ADH
- Secreted from the posterior pituitary gland
- Reduces water loss from the body to maintain plasma volume
- Favors reabsorption of water from kidney tubules to capillaries
- Release of ADH stimulated by..
1. High plasma osmolality
2. Low plasma volume - Due to sweat loss without water replacement
what does the adrenal medulla secrete
epinephrine and norepinephrine
fast acting and part of fight or flight response
what does the adrenal Cortex secrete
cortisol and androgens
what does aldosterone do
control of Na+ reabsorption and K+ secretion
Regulation of BP & Blood volume
what does cortisol do
Maintenance of plasma glucose
- promotes protein breakdown for gluconeogenisis
- stimulates FFA mobilisation
- stimulates glucose synthesis
- blocks uptake of glucose into cells
- promotes the use of free fatty acids as fuel
what is aldosterone stimulated by
increased plasma K+ conc, decreased plasma vol, ACTH and angiotensin 2
what is cortisol stimulated by
stress via ACTH hormone
Exercise
what is the function of the pancreas
Secretes counter-regulatory hormones from the islets of Langerhans
- Has both exocrine and endocrine functions
what’s the function of insulin
from Beta cells
- Promotes the storage of glucose, amino acids and fats
what’s the function of glucagon
from Alpha cells
- Promotes the mobilization of fatty acids and glucose
- Stimulates gluconeogenesis in the liver
what rate does cortisol increase compared to exercise
cortisol increases proportionally to exercise
what happens to blood glucose homeostasis during exercise
- mobilisation of glucose from liver glycogen stores
2. mobilisation of free fatty acids (FFA) from adipose tissue
what do thyroid hormones do
- influences the number of receptors on the surface of a cell
- influences the affinity of the receptor for the hormone
what are catecholamines
fast acting hormones
what happens to epinephrine and norepinephrine during exercise
they increase during exercise
leading to increased HR and BP
What does endurance training do to catecholamines
causes a very rapid decrease in catecholamine responses to a fixed intensity bout
do trained athletes have a greater capacity to increase catacholamines?
yes
35% higher
what ratio effects the mobilisation of glucose and fatty acids
the ratio between plasma insulin and plasma glucagon
what happens to plasma insulin during exercise
it decreases
what happens to plasma glucagon during exercise
it increases
Can the muscle be an endocrine gland
YES
Produces myokines during contractions
- this stimulates glucose uptake and fatty acid oxidation
- promotes blood vessel growth in muscle
- promotes liver glucose production triglyceride breakdown
why does FFA mobilisation decrease during exercise
high levels of lactic acid
elevated H+ conc
inadequate blood flow to adipose tissue
insufficient albumin to transport FFA in plasma
is CO2 produced in glycolysis
NO
where is creatine synthesised
in the liver
what is the enzyme that catalyses the reaction of creatine to phosphocreatine
creatine kinase
can the respiratory quotient ever exceed 1
NO
1 is max
can the respiratory exchange ratio exceed 1
YES
often exceeds 1 during vigorous exercise
what does RQ stand for
Respiratory quotient
What is the function of renin
to convert angiotensinogen to to angiotensinogen 1
what is the function of ACE
to convert angiotensinogen 1 to angiotensinogen 2
what does insulin do to gluconeogenisis
insulin inhibits gluconeogenisis
what are the functions of the nervous system
- Control of internal environment (coordinated with the endocrine system)
- Voluntary control of movement
- Spinal cord reflexes
- Assimilation of experiences necessary for memory and learning
what is the CNS made up of
Brain and spinal cord
what makes up the PNS (peripheral nervous system)
Neurons (sensory and motor division)
describe the sensory neurons in PNS
AFFERENT fibres transmit impulses from receptors to CNS
describe the motor neurons in PNS
EFFERENT fibres transmit impulses from CNS to effector organs
what is somatic sensory information
sensory input that is conciously perceived from receptors (eg eyes, ears and skin)
what is visceral sensory information
sensory input that is not consciously perceived from receptors of blood vessels and internal organs
what is somatic motor control
motor output that is conciously or voluntarily controlled
Effector is skeletal muscle
what is autonomic motor control
motor output that is not conscious or is an involuntary contraction.
Effectors are cardiac muscle, smooth muscle and glands
what is the function of an axon
carries electrical message (action potential) away from cell body
what factors increase neural transmission
increased diameter of the axon
having a myelin sheath
what is a negative resting membrane potential created by
At rest= sodium channels closed, where as some potassium channels are open therefore more potassium ions leaving cell, causing net loss of positive ions leaving cell and makes it more negative
how is the negative membrane potential maintained
by the sodium potassium pump
2K+ IN
3Na+ out
what is depolarisation
return to resting membrane potential
K+ leaves cell rapidly
Na+ channels close
what is an action potential
Occurs when a stimulus of sufficient strength depolarizes the cell
Opens Na+ channels and Na+ diffuses into the cell, making the inside become more positive
what value is resting membrane potential
-70mV
what is a neurotransmitter and how does it work
- chemical messenger released from presynaptic membrane
- binds to receptor on post synaptic membrane
- causes depolarisation of post synaptic membrane
what does EPSP stand for
excitatory post synaptic potentials
what do EPSP do
EPSPs can promote neural depolarisation in 2 ways
- temporal summation - summing several EPSPs from ONE presynaptic neuron
- spatial summation- summing EPSPs from SEVERAL different presynaptic neurons
What does IPSP stand for
inhibitory post synaptic potentials
what do IPSPs do
- causes hyperpolarisation (more negative RMP)
- Neurons with a more negative membrane potential resist depolarisation
give some examples of joint proprioreceptors
- Free nerve endings (touch, pressure) – most abundant
- Golgi type receptors (found in joint ligaments)
- Pacinian corpuscles (tissues around joints/ skin)
give some examples of muscle proprioreceptors
- Muscle spindles
2. Golgi tendon organs
What do we gather sensory information from
Joint proprioceptors
Muscle proprioceptors
Muscle chemoreceptors
what do muscle spindles do
- Responds to changes in muscle LENGTH
what do muscle spindles consist of
- Intrafusal fibers- run parallel to normal muscle fibers (extrafusal fibers)
- Gamma motor neurons- stimulate intrafusal fibers to contract with extrafusal fibers by alpha motor neuron
describe the process of a muscle resisting to be stretched
- Muscle spindles detect stretch of muscle
- Sensory neurons conduct action potentials to the spinal cord
- Sensory neurons synapse with alpha motor neurons
- Stimulation of the alpha motor neurons cause the muscles to contract and resist being stretched
How do the Golgi tendon organs relieve tension applied to the tendon
- Golgi tendon organs detect tension applied to a tendon
- Sensory neurons conduct action potentials to the spinal cord
- Sensory neurons synapse with inhibitory interneurons that synapse with alpha motor neurons
- inhibition of the alpha motor neurons causes muscle relaxation, relieving the tension applied to the tendon
what are the roles of the Golgi tendon organ
- Monitors force development in muscle
Prevents muscle damage during excessive force generation - Stimulation results in reflex relaxation of muscle
Inhibitory neurons send IPSPs to muscle alpha motor neurons
Ability to voluntarily oppose GTO inhibition may be related to gains in strength
what are the roles of muscle chemoreceptors
- Are sensitive to changes in the chemical environment surrounding a muscle
H+ ions, CO2 and K+
- Also known as muscle metaboreceptors
what are muscle chemoreceptors also known as
muscle metaboreceptors
what is the innervation number
number of muscle fibers per motor neuron
for fine motor control do you want a low or high ratio
- Low ration in muscles involved in fine motor control (for example 23/1 in extraocular muscles)
do you want a low or high ratio for movements that DO NOT require fine motor control
- Higher ratio in muscles that do not require fine motor control (for example 1,000/1 or greater in large limb muscles)
define a motor unit
motor neuron and all the muscle fibres that it innervates
are small or large motor units recruited first during exercise
Small motor units recruited first during exercise
what is the mesencephalon and what does it connect
MIDBRAIN
Connects the Pons and cerebral hemispheres
what are the functions of the mesencephalon (midbrain)
controlling responses to sight, eye movement, pupil dilation, body movement and hearing
what is the function of the medulla oblongata
Involved in control of autonomic function, relaying signals between brain and spinal cord and coordination of body movements
what is the function of the pons
Involved in sleep and control of autonomic function
Relays sensory information between the cerebrum and cerebellum
what is the function of the cerebral cortex
- Organisation of complex movement
- Storage of learned experiences
- Reception of sensory info
what is the function of the cerebellum
Implicated in control of movement and integration of sensory information
what is the function of the brainstem
role in cardiorespiratory function, locomotion, muscle tone, posture, receiving information from special senses
what is spinal tuning
refers to intrinsic neural networks (CPGs) within spinal cord that refine voluntary movement after receiving messages from higher brain centers
what is the withdrawal reflex
Means removing a limb from source of pain
Occurs via a reflex arc, whereby a reflex contraction of skeletal muscles can occur in response to a sensory input and is not dependent on the activation of higher brain centers
what is the crossed extensor reflex
is a reflex in which the contralateral limb compensates for loss of support when the stimulated limb withdraws from painful stimulus in the withdrawal reflex.
describe the control of voluntary movement
- Involves cooperation of many areas of brain along with subcortical areas
- Motor cortex receives inputs from a variety of brain areas = basal nuclei, cerebellum, thalamus
- Spinal mechanisms (spinal tuning) results in refinement of motor control
- Feedback from proprioceptors allows for further modification in motor control
what 2 words are associated with sympathetic
fight or flight
what 2 words are associated with parasympathetic
rest and digest
at rest are parasympathetic and sympathetic systems in balance
YES
at exercise are parasympathetic and sympathetic systems in balance
NO
parasympathetic decreases and sympathetic increases
what is role of sympathetic system throughout exercise
regulate blood flow, achieved by increasing CO
in terms of ganglionic neurones
describe the length of the pre and post in sympathetic neurons
shorter preganglionic neuron and longer postganglionic neuron
in terms of ganglionic neurones
describe the length of the pre and post in parasympathetic neurons
longer preganglionic neuron and shorter postganglionic neuron
what is HR variability
- Variation in the time between heartbeats
why is there an initial increase in HR at the onset of exercise
initial increase due to parasympathetic withdrawal
what is low HRV (heart rate variability) a predictor of
cardiovascular morbidity and mortality in patients with existing cardiovascular disease
What 3 things regulate stroke volume
- End diastolic volume (EDV)
- Average aortic blood pressure
- Strength of ventricular contraction (contractility)
What is end diastolic volume (EDV)
- Volume of blood in ventricles at end of diastole (preload)
What is average aortic blood pressure defined as
- Pressure the heart must pump against to eject blood (afterload)
how is strength of ventricular contraction altered
- Enhanced by circulating epinephrine and norepinephrine
- direct sympathetic stimulation of heart
what does the frank starling law suggest
an increased EDV creates. a more forceful contraction
This is due to increased blood flowing, stretching the ventricle walls. The more stretch the more tension/ force
what is venous return increased by and how
- Venoconstriction
- Via SNS - Skeletal muscle pump
- One-way valves in veins prevent backflow of blood - Respiratory pump
- Changes in thoracic pressure pull blood toward heart
what is the cardiac output equation
CO = HR x SV
What is systolic blood pressure (SBP)
Pressure generated during ventricular contraction
What is dyastolic blood pressure (DBP)
Pressure in the arteries during cardiac relaxation
what is pulse pressure
the difference between systolic blood pressure and diastolic blood pressure
what is mean arterial pressure (MAP)
Average pressure in the arteries
When can a MAP reading be taken??
MAP can only be taken at rest
as diastole generally lasts longer than systole. The equation based on timing of cardiac cycle at rest, where systole = 33% of that time but at exercise systole may be up to 66% of total cardiac time
What 2 things determine MAP
CO
Total vascular resistance
What happens to cardiac output during exercise
It increases directly proportional to metabolic rate
A decrease in blood pressure does what to sympathetic nerve activity
INCREASES SNS
An increase in blood pressure does what to sympathetic nerve activity
DECREASES SNS
What is arteriovenous difference
amount of oxygen that is taken up from 100ml of blood
what happens to arteriovenous difference during exercise and why
INCREASES due to higher oxygen uptake
Where is blood flow directed and not directed to at exercise
DIRECTED TO- working muscle
NOT DIRECTED TO- liver, kidneys
What affects HR and BP in terms of when exercising
- Type, intensity and duration of exercise
- environmental conditions
- emotions
At heavy intensity intermittent exercise (HIIE) what does recovery depend on
Fitness level
Temp
Humidity
Duration and intensity of the exercise done
what happens to cardiac output during prolonged exercise
maintained (stays constant)
what happens to stroke volume during prolonged exercise
gradual increase
due to dehydration and reduced plasma volume
what happens to HR during prolonged exercise
Gradual increase particularly in heat due to cardiovascular drift
What is the exercise pressor reflex (EPR)
Peripheral feedback to the medulla oblongata to amend the CV responses to exercise
What is central command
the initial signal to drive the cardiovascular system comes from higher brain centres
in central command theory where is feedback from
- Heart mechanoreceptors
- Muscle mechanoreceptors (GTO & muscle spindles)
- Muscle chemoreceptors
- Baroreceptors
what happens to baroreflex during exercise
baroreflex is reset during exercise
does genetics affect VO2 max
yes but can be modified by training
what’s in the dorsal root ganglia
the neurones of AFFERENT fibres carrying sensory info to the spinal cord have cell bodies in dorsal root ganglia
what’s in the ventral horn of spinal cord
the neurones of EFFERENT fibres carrying info from the spinal cord to skeletal muscles have cell bodies in ventral horn
what forms myelin sheath
glial cells
what are dendrites
extend from the cell body and receive info from synaptic terminals of adjacent cells
what does the axon contain
mitochondria, microtubules and microfilaments
Describe the order of events in an action potential
- Stimulus gated ion channels open, membrane depolarises slightly
- Membrane potential increases to -50mV
- Voltage gated Na+ channels open, increased permeability to Na+ ions
- Voltage gated Na+ channels cose and desactive
- Voltage gated K+ channels close
- Membrane potential returns to -70mV
what do all the axons in the PNS have associated with them
Schwann cells
what does myelin do to the electrical impulse
Mylein reduces the loss of the electrical impulse
is the grey matter in the middle or outside of diagram
grey matter in middle
white matter on outside
how are muscle spindles arranged in relation to the muscle fibres
muscle spindles in parallel with muscle fibre
in muscle spindles do they have a high or low density for fine movement control
high density of muscle spindles for FINE control
how are Golgi tendon organs arranged in relation to the muscle fibres
in series
what are the 5 parts of the spinal cord from top to bottom
Cervical Thoracic Lumbar Sacral Coccygeal
what receptor does acetylcholine bind to
aceytlcholine binds to nicotinic receptor
what receptor does norepinephrine bind to
norepinephrine binds to adrenergic receptor
What are metabolic effects of parasympathetic stimulation
- stimulates insulin secretion & glucagon secretion in pancreas
- increase glucose uptake from blood into liver
What are metabolic effects of sympathetic stimulation
- increase metabolic rate of cells
- in liver, stimulate release of glucose into blood
- stimulates lipolysis in adipose tissue
- in pancreas, inhibits insulin secretion
- in pancreas, stimulates glucagon secretion
on the diagram which is in the middle and which is on the outside
adrenal cortex and adrenal medulla
adrenal medulla in middle
adrenal cortex on outside
what does vagal nerve stimulation do to HR
Decreases HR
what is preload determined by
determined by venous return
what is afterload determined by
determined by aortic pressure during systole
what effects BP short term
sprinting
what effects BP long term
high salt diet
dehydration
where are arterial baroreceptors located
carotid sinus
-measure BP to brain
aortic arch
-measure BP of systemic circulation
what is the carotid sinus
dilation of internal carotid artery wall
what is a metaboreflex
- during exercise there is local interstitial fluid accumulation (K+, lactic acid and adenosine)
- This results in an INCREASE IN SYMPATHETIC NERVE ACTIVITY
what is the equation for work
force x distance
The formation of cross-bridges that initiates the contractile process in skeletal muscle is triggered by
calcium binding to troponin
what are the functions of skeletal muscle
- Force production for locomotion and breathing
- Force production for postural support
- Heat production during cold stress
- Increasingly recognized as an important endocrine organ too (myokine release)
what is the epimysium
surrounds the entire muscle
what is the perimysium
surrounds bundles of muscle fibres
fascicles
what is the endomysium
surrounds individual muscle fibres
what do myofibrils contain
contractile proteins (actin and myosin)
is myosin thick or thin
THICK
is actin thick or thin
THIN
What does the sarcomere contain
Z line M line H zone A band I band
what is the function of the sarcoplasmic reticulum
storage sites for calcium (terminal cisternae)
what are the functions of satellite cells
- Play key role in muscle growth and repair
- Contain Myonuclear domain (volume of cytoplasm surrounding each nucleus)
- More nuclei allow for a greater protein synthesis
what is the motor end plate in a NMJ
pocket formed around motor neuron by sarcolemma
when acetylcholine is released from NMJ what happens to end plate
causes an end plate potential (EPP)
leading to depolarisation of the muscle fibre
what’s another name for the sliding filament model
the swinging lever-arm model
in the sliding filament theory when the muscle is contacted what happens to the Z lines
Distance between Z lines of sarcomere becomes smaller
how does muscle shortening occur
due to movement of actin over myosin filament
how is a power stroke generated
formation of cross bridges between actin and mysoin filaments
where is the A band
in the middle
where is the I band
on the outsides
describe excitation contraction coupling
- signal from motor never fibre enters synaptic knob
- synaptic vesicles release aceytlcholine across synaptic cleft and to the acetylcholine receptors on the sarcolemma of muscle fibre
- release of acetylcholine causes excitation of muscle fibre, this travels to T tubules and causes depolarisation
- depolarisation opens calcium ion channels from sarcoplasmic reticulum and terminal cisternae of sarcoplasmic reticulum
- calcium ions bind to troponin on actin molecule, causing a shift in the position of tropomyosin, so that myosin binding sites are exposed on the actin filament
- energised myosin cross-bridge binds to active site on actin and pulls on the actin molecule to produce a back and forth movement
- When neural activity is stopped calcium is removed resulting in tropomyosin moving to cover the active site in the actin filament
- acetylcholine release is stopped and muscle fibre = repolarised
- calcium is pumped from the cytosol into sarcoplasmic reticulum
define fatigue
a decline in muscle power output
what is a decline in muscle power output down to
- decrease in muscle force production at cross-bridge level
- decrease in muscle shortening velocity
describe muscle cramps
- Muscle cramps are spasmodic, involuntary contractions
- Often associated with prolonged, high intensity exercise
how do exercise-associated muscle cramps occur
-most likely due to hyperactive motor neurons in the spinal cord
how do you relieve exercise associated muscle cramps
passive stretching often relieves this type of muscle cramp
give an example of a concentric contraction and what happens to muscle length
upwards phase of a bicep curl
muscle length DECREASES
give an example of an eccentric contraction and what happens to muscle length
downwards phase of a bicep curl
muscle length INCREASES
are type 1 fibres light or dark
DARK
are type 2 fibres light or dark
LIGHT
what are the 3 biochemical characteristics to muscle fibres
OXIDATIVE CAPACITY
-quantity of mitochondria, capillaries and myoglobin around fibre
TYPE OF MYOSIN ISOFORM EXPRESSED
ABUNDANCE OF CONTRACTILE PROTEIN WITHIN FIBRE
-amount of actin and myosin
what are type 1 fibres
slow twitch, slow oxidative fibres
what are type 2a fibres
intermediate fibres
fast oxidative glycolytic fibres
what are type 2x fibres
fast twitch
fast glycolytic fibres
what is the maximal power output equation
force x shortening distance
what is speed of contraction regulated by
myosin ATPase activity
what does muscle fibre efficiency refer to
the amount of ATP used to generate force
the less ATP used the more efficient the muscle is
compare the number of mitochondria in type 1, 2a and 2x fibres
type 1 = high
type 2a = moderate
type 2x = low
compare the resistance to fatigue in type 1, 2a and 2x fibres
type 1 = high
type 2a = moderate
type 2x = low
compare the efficiency in type 1, 2a and 2x fibres
type 1 = high
type 2a = moderate
type 2x = low
what is muscle twitch
a contraction resulting from a single stimulus
describe the events of a muscle twitch
-after stimulation a latent period occurs corresponding to the depolarisation of muscle fibre
-contraction stage
calcium released from sarcoplasmic reticulum (tension developed due to cross bridge binding)
-relaxation stage
reuptake of calcium into sarcoplasmic reticulum (cross bridge detachment)
why is the speed of shortening greater in fast fibres
Sarcoplasmic reticulum releases calcium at a faster rate
higher ATPase activity
what type of motor units have easily excited motor neurons
SLOW motor units
what type of motor units have higher threshold motor neurons
FAST motor units
what type of motor unit do u need for fine control
Small motor units
what type of motor unit do u need for small and large force production
small motor units for low force
large motor units for high force
HENNEMAN SIZE PRINCIPLE
does a motor unit consist of the same fibre type or multiple fibre types
consists of SAME fibre type
if you want multiple fibre types you need 2 motor units together
How does the structure of a motor neuron relate to its function
if the motor neuron supplies a larger/ faster motor unit it has…
- larger cell bodies
- larger diameter axons
- greater number of axonal branches
what is sarcopenia
a skeletal muscle disorder involving the loss of muscle mass and function associated with older age
strength is lost with age
what muscles decline first (upper or lower body) and why
lower body decline first due to being weight bearing
what is the power equation
force x velocity
what is SF and IF
Subcutaenous fat
Intermuscular fat
describe microgravity
- Wide ranging physiological effects
- Effects vary depending on; space flight duration, mission activities
- Countermeasures required to; maintain astronaut performance, prevent problems upon return
what happens to muscle mass and strength with microgravity
muscle mass and strength decrease
what happens to the heart after space flight
Shrinkage (atrophy)
what happens to SV with mirogravity
SV decreases
what are some strategies to stimulate microgravity
- head down bed rest
- wheelchair
- immobilisation
- parabolic flight
what is direct calorimetry
measures the heat exchange between the human body and environment
what is indirect calorimetry
measures the type and rate of substrate utilization, whereby energy metabolism is estimated from respiratory gas exchange measurements.
is a large HR variability healthy or not
Large HR variability = healthy
give some examples of acute stressors for HR
hard work out
alcoholic drinks
high caffeine intake
Anything thats effects last 24-48 hrs
give some examples of chronic stressors for HR
infection
illness
study related worries
lasts over 48hrs
where are the T tubules
The sarcolemma (muscle membrane) extends deep into the centre of the fibre to form T tubules
in cross bridge cycling what breaks the link between actin and myosin
ATP
In space does a body moving freely have mass or weight
HAS MASS
NO WEIGHT
What systems are affected by microgravity
cardiovascular digestive nervous system (balance) respiratory skeletal urinary endocrine immunological
what does the feeling of being weightless disturb
the semicircular canals
utricle and saccule
what are the 2 parts to the circulatory system
pulmonary circuit
systemic circuit
what are the functions of the cardiorespiratory system
- transport o2 and nutrients to tissues
- removal of co2 wastes from tissues
- regulation of body temperature
what happens to blood flow during exercise
increased cardiac output
redistribution of blood flow from inactive organs to active muscle
describe pulmonary circuit
- RIGHT side of heart
- pumps DEOXYGENATED blood to LUNGS via pulmonary arteries
- returns oxygenated blood to left side of heart via pulmonary veins
describe systemic circuit
- LEFT side of heart
- pumps OXYGENATED blood to the whole body via arteries
- Returns deoxygenated blood to right side of heart via veins
what are the components of blood vessel walls
smooth muscle
collagen
elastin
endothelium
what makes up blood
PLASMA -liquid portion of blood -contains ions, proteins, hormones CELLS -rbc, wbc, platelets (clotting)
what is HEMATOCRIT in blood
percentage of blood composed cells
what is the main resistance to flow provided by
the arteries and arterioles
what is TPR
Total peripheral resistance
sum of resistances to flow in all individual organs
what is the blood flow equation/ darcys law
blood flow = change in pressure / resistance
what is the resistance equation
resistance = (length x viscosity)/ radius4
what does resistance depend on
length of vessel
viscosity of blood
radius of vessel
what is the heart wall made up of
Epicardium
Myocardium
Endocardium
what is a myocardial infarction
a heart attack
what is the function of the epicardium
serves as lubricative outer covering
what is the function of the myocardium
provides muscular contractions that eject blood from the heart chambers
what is the function of the endocardium
serves as protective inner lining of the chambers and valves
describe cardiac conduction
- action potentials originate in SA node
- Action potenial travels across wall of atrium to AV node
- Passes through AV node and along AV bundle going down septum
- AV bundle divides into right and left branches and action potentials go to bottom of each ventricle
- action potentials carried by purkinje fibres to ventricular walls
what is the P wave on an ECG
atrial depolarisation
what is the QRS complex on an ECG
ventricular depolarisation
atrial repolarisation
what is the T wave on an ECG
ventricular repolarisation
describe the heart cycle in terms of depolarising and repolarising
- atria begin depolarising
- atrial depolarising complete
- ventricular depolarisation begins at apex, progresses superiorly as atria repolarise
- ventricular depolarisation complete
- ventricular repolarisation begins at apex and progresses superiorly
- ventricular repolarisation complete, heart = ready for next cycle
what happens to intraventricular pressure as ventricles contract
intraventricular pressure increases
what happens to intraventricular pressure as ventricles relax
intraventricular pressure decreases
what can we diagnose from the use of an ECG
- evalutae cardiac function
- atherosclerosis
- ST segment depression (suggesting ischemia)
is regular exercise good for the heart
YES
its cardioprotective
reduces chance of heart attack, and improves survival from a heart attack (improves hearts antioxidant capacity)
define cardiac output
the amount of blood pumped by the heart each minute
define stroke volume
amount of blood ejected in each beat
describe the parasympathetic nervous system
via vagus nerve
SLOWS HR by inhibiting SA and AV node
describe the sympathetic nervous system
via cardiac accelerator nerves
INCREASES HR by stimulating SA and AV node
what is the fick equation
VO2 = cardiac output (Q) x arteriovenous difference
What is hyperaemia
blood flow increases in relation to metabolic activity of a tissue/ organ
is the tricuspid valve an AV or Semilunar valve
AV valve
is the mitral/ bicuspid valve an AV or Semilunar valve
AV valve
how to know where tricuspid and bicuspid valve are
Try before you buy
try comes first therefore on right side
what does the superior vena cava do
returns blood from the head, neck and arms
what does the inferior vena cava do
returns blood from the legs, lower torso
is the largest vein in the body
what does chronotropic mean
heart rate increases
what does inotropic mean
contractility increases
what is the main metabolic vasodilator
adenosine
describe the skin circulation neural control
- ADRENERGIC (vasoconstrictor)
Non hairy skin, eg- palms, sole of foot, lips - CHOLINERGIC (vasodilator)
Hairy skin
What neurotransmitter is used for adrenergic transmission
noradrenaline
What neurotransmitter is used for cholinergic transmission
acetylcholine
what does cold stress lead to
vasoconstriction
what does heat stress lead to in blood vessels
vasodilation
what does splanchnic circulation involve
Liver
GI tract
Pancreas
Spleen
why is blood flow to the brain so important
- Vital for survival
- Stroke caused by not enough oxygen to brain
- Functional consequences; eg decreased performance, cognitive function
what is at the acute side of impaired cerebral flood flow
faint
stroke
what is at the chronic side of impaired cerebral flood flow
hypertension
dementia
concussion
Is exercise good for brain blood flow
regular exercise is good for brain blood flow
reduces the decline in the relationship between getting older and reduced brain blood flow
what are some brain perfusion imaging techniques
- MRI
- Transcranial doppler
- Near infrared spectroscopy (NIRS)
what is the normal body core temp
between 36.5-37.5
what is core temp defined as
the temp of the hypothalamus, the thermoregulatory centre of the body
what are humans known as
clue ….therm
HOMEOTHERM
what is the normal skin temp
32-35 degrees
what does the homeostatic maintenance of body temp require
temp sensors (peripheral and central thermoreceptors) and regulated effectors
describe how heat is lost
- body temp increases
- afferent info to brain
- efferent info to body
- blood vessels dilate
- sweat glands secrete fluid
- heat = lost to environment
describe how heat is retained
- body temp decreases
- afferent info to brain
- efferent info to body
- blood vessels constrict
- sweat glands DO NOT secrete fluid
- shivering generates heat
- heat = conserved
does aerobic fitness effect body temp when exercising
YES
A trained person can exercise with a lower core temp than an untrained person exercising at same intensity
Describe conduction
- Transfer of heat down a thermal gradient via direct contact between objects
- Rate of heat transfer is proportional to the temperature gradient between objects
- Rate of heat transfer is proportional to the conductivity of each object and the area in contact
- Important within cells (cell capillary wall)
- Only 3% heat loss at normal room temp (eg to chair)
describe convection
- Transfer of heat between object and moving fluid or air
- 12% heat loss at normal room temp
- Blood is main mover of heat within the body
- Water conducts heat 25x faster than air
- Rate of heat transfer is proportional to the
1. Temp gradient
2. Thermal conductivity
3. Surface area
4. Velocity of fluid (eg wind chill factor)
describe radiation
- Loss or gain or heat in the form of electromagnetic waves
- 60% heat loss at normal room temp
- Sun is major source of radiant heat
- Rate of radiant heat transfer is proportional to
1. Temp gradient
2. Area of mutually exposed surface
3. Colour & reflectivity (eg space blanket)
Describe evaporation
quantity of heat absorbed by sweat when it evaporates
- 1gm sweat has latent heat of evaporation of 2411J
- 25% heat loss at normal room temp
- Sweat only effective for cooling if it evaporates
what is heat exchange between
the body and the environment
what happens to central blood volume (CBV) and stroke volume (SV) during exercise in HEAT
they decrease in the heat
what happens to HR in the heat
It increases to compensate for decrease in CBV and SV
what are the effects of excessive dehydration
decreases. ..
- sweat rate
- plasma volume
- CO
- Maximal oxygen uptake
- Work capacity
- Muscle strength
- liver glycogen
what are some warning signs of heat stroke
- headache
- nausea
- thirst
- chills/ goosebumps
- faintness/ dizzy
- fatigue
- hot dry skin
- confusion
- weakness
what are some factors affecting heat injury
- fitness
- clothing
- envionmental humidity
- metabolic rate
- environmental temp
- wind
- hydration
- acclimitization
what is cold stress called and describe it
HYPOTHERMIA
- Core temperature below 35 degrees
describe cold acclimatisation
- Results in lower skin temperature at which shivering begins
- Increased non shivering thermogenesis
- Maintains higher hand and foot temperature
- Improved peripheral blood flow
- Improved ability to sleep in the cold, due to reduced shivering
- Adaptations begin in one week
What is another name for the innate immune system
non specific
What is another name for the aquired/ adaptive immune system
specific
what is the main principle for immunity to work
to be able to recognise self v non self
give some functions of the immune system
- fight pathogens
- repair damaged tissues
- eradicate cancer cells
- mediate allergic reactions
- promote successful vaccinations
what responses come under the innate/ non specific immune system
cell mediated (T cells)
Humoral (B cells)
what responses come under the adaptive/ specific immune system
bloodborne (phagocytes)
physical barriers (skin, saliva, tears, stomach, mucas)
what is another name for white blood cells
leukocytes
give examples of lymphocytes
T cells and B cells
what are the cells of the immune system
monocytes
neutrophils
WBC
Lymphocytes
how do physical barriers work in immunity
they PHYSCIALLY prevent a foreign pathogen from entering the site of infection
eg
- trapped by skin cells or mucas
- killed by antibodies in tears, saliva, or mucas
- removed from body by shredding skin, coughing or flushing bodily fluids (urine/ tears)
what are macrophages
a type of phagocyte located in tissues
consumes microbes and dead cells within tissues (phagocytosis)
what are neutrophils
Type of phagocyte that exits the blood to enter tissues during an acute phase response
RAPID responders to infection/ stress
the most abundant immune cells in blood (45-75%)
what are natural killer cells
Destroy virus infected cells and cancerous cells
Produce proteins, such as cytokines and perforin to kill infected/ transformed cells
Found in blood (1-6%)
where are complement proteins made
in the liver
what are complement proteins part of
innate/ non specific immune system
what do complement proteins do
circulate as inactive proteins in the blood
when activated they attach to the surface of microbes (bacteria) or dead cells
They tag the surface and signal via chemical gradients to recruit phagocytes to the site and destroy microbes/ dead cells
what are T cells
a type of lymphocyte produced in the thymus that conducts cell mediated immunity
Release proteins that can kill eg virus infected cells
20-40% in blood
what are B cells
A type of lymphocyte that can trigger the making and release of antibodies
can differentiate into plasma cells to produce antibodies
antibodies trap infected cell and trigger other immune cells to destroy them
what’s special about T and B cells
They have the ability to create memory cells
what are helper T cells (CD4+)
- Can activate B cells to produce plasma cells
- Co-ordinate immune responses by recruiting other immune cells to site of damage/ infection
- Regulatory T cells have a role in supressing the activity of immune system (prevent autoimmune illness)
60-70% of T cells
What are cytotoxic T cells (CD8+)
Highly efficient, specific killers that can recognise antigens on the surface of damaged or infected cells or tumours
30-40% of T cells
where are B cells made
produced in bone marrow
What is the function of plasma cells in immunity
Secrete antibodies (immunoglobulins) that bind to a non-self protein (antigen) or an infected cell
in terms of excise and immunity describe the shape of the graph
TICK SHAPE
Low exercise makes infection risk average
Moderate exercise makes infection risk below average - this is good
High exercise makes infection risk above average - this is bad
how can we measure immune function
-Self reported illness
(upper respiratory tract infections - URTI)
-Cellular level
-Release of ‘stress’ molecules from immune cells
What are altered cells
cells becoming cancerous
describe innate immunity when there is exercise induced muscle damage
Exercise induced muscle tissue elicits a strong innate Immune response involving neutrophils, monocytes and macrophages
these cells release proteins that initiate mediate and terminate muscle repair by modulating processes such as
- migration (to sites where the body may encounter damage)
- muscle fibre breakdown and regeneration
- antimicrobial defence
what happens to lymphocytes after exercise
Exercise increases blood pressure, stress and induces adrenaline and proteins (cytokines) that mobilise lymphocytes into blood
what are the factors affecting susceptibility to infection in athletes
- increased exposure to pathogens
- exercise induced immune suppression
- inadequate diet
- mental stress
- lack of sleep
what are the roles of the respiratory system
-PULMONARY RESPIRATION
ventilation
exchange of o2 and co2 in lungs
-CELLULAR RESPIRATION
o2 utilisation and co2 production by tissues
what is the purpose of respiratory system during exercise
- Gas exchange between environment and body
- Regulation of acid-base balance during exercise
describe the movement of oxygen down the partial pressure gradient
- from the alveoli into pulmonary capillaries in the lungs
- from tissue capillaries into tissues in the periphery
describe the movement of carbon dioxide down the partial pressure gradient
- from tissue into tissue capillaries in the periphery
- from the pulmonary capillaries into alveoli in the lungs
what is the function of the pleural cavity
- Holding the lungs inflated without any physical attachments
- Lubrication for the constant movement of the lungs
What is Ficks law of diffusion
The rate of gas diffusion is proportional to the tissue area
rate of diffusion = (tissue area/ tissue thickness) x diffusion coefficient of gas x difference in partial pressure
when does inspiration occur
when the volume of the lung increases
when does expiration occur
when the volume of the lung decreases
inspiration during exercise recruits which muscles
external intercostals and scalene muscles
what does airflow depend on
- pressure differences between 2 ends of the airway
- resistance of airways
what is the pulmonary ventilation equation
pulmonary ventialtion = volume of gas moved per breath x frequency of breathing
what is tidal volume
amount of air inhaled or exhaled in one breath during quiet breathing
what is total lung capacity
maximum amount of air in the lungs at the end of a maximum inspiration
what is FEV
Forced expiratory volume
what does chronic obstructive pulmonary disease do to vital capacity
decreases vital capacity
what is daltons law
the total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert individually
what is the PO2 like at the lung
High PO2
Formation of oxyhemoglobin
what is the PO2 like at the tissues
Low PO2
Release of O2 to tissues
what is a leftward shift in the oxygen dissociation curve
improved affinity
what is a rightward shift in the oxygen dissociation curve
reduced affinity
what is myoglobin
an oxygen binding protein in skeletal muscle with a much higher affinity for oxygen compared to Hb
It shuttles oxygen from cell membrane to mitochondria
give a benefit of myoglobin
-It binds to o2 at very low po2
what are the 3 ways co2 is transported in blood
- dissolved in plasma (10%)
- bound to Hb (20%)
- Bicarbonate (70%)
increased ventilation does what to co2
results in co2 exhalation
decreased ventilation does what to co2
results in build ups of co2
describe ventilation in the 4 phases of steady state exercise
phase 1
intense and abrupt increase in ventilation
phase 2
slow and gradual increase in ventilation
phase 3
steady state ventilation
phase 4
huge decay in ventilation when exercise stops
what happens to ventilation at OBLA
ventilation rate increases again to correct pH via respiratory compensation
where is the respiratory control centre located
In the medulla oblongata
what are the 2 inputs into the respiratory control centre
-Humoral chemoreceptors
central and peripheral chemoreceptors
-Neural input
Muscle spindles, muscle mechanoreceptors, Golgi tendon organs, joint pressure receptors
does endurance training effect ventilation
YES
after endurance training ventilation is 20-30% lower at the same work rate
where does the info come from that stimulates ventilation
higher brain centres
central command
what does spinal cord injury do to BP
talk about sympathetic and parasympathetic
Spinal cord injury = sympathetic nervous system innervation is prevented
so if BP drops, HR must increase to rectify it however because SNS is inhibited can only use PNS and therefore HR can only get to 100
Unable to increase HR sufficiently
Rate of evaporative heat transfer is proportional to
- Surface area exposed to the environment
- Temp
- Relative humidity of ambient air
- Wind
what is overload
Training effect occurs when a physiological system is exercised at a level beyond which it is normally
(exercise induced adaptation/ hormesis)
what is specificity
Training effect is specific to
- Muscle fibres recruited during exercise
- Energy system involved (aerobic vs anaerobic)
- Velocity of contraction
- Type of contraction (eccentric, concentric, isometric)
what is reversibility
Gains are lost when training stops
what does heritability refer to
genetics
does genetics play a big role in vo2 max
genetics determines approx 50% of vo2 max in sedentary adults
also affects training response
can vo2 max improve with training
YES
average improvement is 15-20%
what is eccentric hypertrophy
heart chamber size and wall thickness increased
how does endurance training increase stroke volume
decreased afterload
increased contractility
what does endurance training do to stroke volume
increase stroke volume
what happens to vagal tone after training
vagal tone increased
what are the training induced increases in arteriovenous o2 difference
increased muscle blood flow
increased extraction and utilisation o2 from the blood (increased mitochondrial number/ volume)
increased capillary supply/ density and oxygen delivery in trained muscle
during Submaximal exercise describe the blood flow at trained muscles
blood flow in trained muscles is lower because the arteriovenous difference is greater (greater oxygen extraction)
during maximal exercise describe the blood flow at trained muscles
blood flow in trained muscles is higher and the arteriovenous difference is greater (greater oxygen extraction)
what is the effect of endurance training on performance and homeostasis
- Ability to perform prolonged, submaximal exercise is dependent on the ability to maintain homeostasis
- allows an easier transition from rest to steady state
What does Endurance exercise training do to muscle fibres
- Shift in muscle fibre type (fast to slow) and increased number of capillaries
- Increased mitochondrial volume
- Training induced changes in fuel utilization
- Increased antioxidant capacity
- Improved acid-base regulation
what happens to heart rate recovery (HRR) post endurance training
HRR is faster
what type of signalling pathways interact to promote exercise induced adaptations
primary and secondary signalling pathways
what does detraining cause
rapid decrease in vo2 max
decreased SVmax
Decreased mitochondria/ oxidative capacity of muscle
describe the mitochondria adaption to training
muscle mitochondria adapt rapidly to training
double within 5 weeks
describe the mitochondria adaption to de-training
lost rapidly!!
loss of 50% of the training gain within 1 week
majority of adaptation lost in 2 weeks
how long does it take to regain mitochondrial adaptations
requires 3-4 weeks of retraining to regain mitochondrial adaptations
what body adaptations does anaerobic sprint training have
- increase peak anaerobic power by 3-28%
- improves muscle buffering capacity (increasing intracellular buffers and H+ ion transporters)
- hypertrophy of type2 muscle fibres
- elevates enzymes involved in both the ATP-PC system and glycolysis
what is muscular strength
maximal force that a muscle group can generate
1rep max
what is muscular endurance
ability to make repeated contractions against a Submaximal load
what is high resistance/ low resistance strength training and what do they result in
-High resistance training (6-10reps till fatigue)
Results in strength increases
-Low resistance training (35-40reps till fatigue)
Results in increases in muscular endurance
is resistance training beneficial for older people
YES - will reduce sarcopenia as resistance training promotes hypertrophy
but the gains won’t be as big as they would for a young person doing resistance training
how does resistance training increase muscle strength
changes in the nervous system and muscle fibre size/function
Resistance training
what changes in nervous system are there
- Increased neural drive
- Increased number of motor units recruited
- Increased firing rate of motor units
- Increased motor unit synchronisation
- Improved neural transmission across neuromuscular junction
Resistance training
what changes in muscle fibre are there
-Increased muscle fibre specific tension in type 1 fibres (due to calcium sensitivity, meaning greater cross burgess formation)
what is hyperplasia
increased number of muscle fibres
what does resistance training do to both protein synthesis and breakdown
increases both protein synthesis and protein breakdown
what are the key reasons that resistance training increases protein synthesis
- mRNA increases
- Ribosome number increases
- activation of protein kinase mechanistic target of rapamycin (mTOR) accelerates protein synthesis
what 2 molecules stimulate mTOR
phosphatidic acid (PA)
Ras homolog enriched in brain (Rheb)
what does the protein kinase mTOR do
accelerates protein synthesis following resistance training
does resistance training have any effect on insulin-like growth factor1 (IGF-1) and growth hormone?
YES
resistance training results in small increases in both growth hormone and IGF-1
what does resistance training do to satellite cells
activates satellite cells to divide and fuse with adjacent muscle fibres to increase myonuclei
increased myonuclei helps protein synthesis
how much of differences in muscle mass between individuals are due to genetics
80% of the differences in muscle mass variation between individuals is due to genetics
what does strength and endurance training together do to gains
both training methods together impair strength gains
for best gains- just do strength training
what is associated with central fatigue
central nervous system
what is associated with peripheral fatigue
neural factors
mechanical factors
energetics of contraction
what is central fatigue characterised by
reduced motor units activated
reduced motor unit firing frequency
why does radical production cause fatigue during prolonged exercise
- exercise promotes radical production
- radicals are capable of damaging muscle proteins
- damage of contractile proteins (actin and myosin) = less cross bridge formation
what is hyponatremia
when the sodium conc in your blood are abnormally low
Does gender influence a training programme
YES
exercise prescriptions should be individualised depending on gender
does fitness level alter training improvements
YES
improvements are always higher in those with a lower initial fitness
what is more defined by genetics anaerobic capacity or aerobic capacity
anaerobic
more dependant on fast type2x fibres that are determined during early years development
what 3 things contribute to aerobic performance
a high vo2 max
superior exercise economy/ efficiency
a high lactate threshold and critical power
what are low responders
possess a relatively low untrained vo2 max
exhibit limited exercise training response, vo2 max improves by 5% or less
what are high responders
possess a high untrained vo2 max
individuals with ideal genetic makeup required for a champion
vo2max can increase by 50% with training
why should you warm up
- increase HR
- Increases CO
- increase blood flow
- Increases muscle temp & enzyme activity
- delivers oxygen to muscle
- minimise risk of injury
- increase performance
why do we do a cool down
return blood ‘pooled’ in muscles to central circulation
what are 3 training methods to improve aerobic power
- Interval training
- long, slow distance
- High intensity continuous exercise
what does training aerobic power improve
vo2 max
lactate threshold
running economy
what are the 4 laboratory tests used to quantify endurance exercise potential
- lactate threshold
- ventilatory threshold
- critical power
- exercise economy
What is HIIT
- repeated high intensity exercise bouts separated by brief recovery periods
- expressed as a ratio of work:rest
- intensity part normally between 85-100% of HRmax
- rest interval = light activity eg walking
what are the training outcomes of HIIT
- improved vo2 max
- improved running economy
- improved lactate threshold
- increases mitochondrial volume
what is long slow distance training
- low intensity exercise 50-65% vo2max, OR 60-70% of HRmax
- training duration greater than event of competition duration
what are long slow distance training improvements dependant on
based on volume of training
what is high intensity continuous exercise
- at or above lactate threshold
- 80-100% of vo2max
- monitor intensity using HR
-a good method of increasing vo2 max and lactate threshold
when are injuries most likely to occur
as a result of over training
- short term, high intensity exercise
- prolonged, low intensity exercise
what is the 10% rule
to increase exercise intensity or duration <10% per week
what are other injury risk factors apart from training
- strength and flexibility imbalance
- footwear problems
- poor running surface
- disease (arthritis)
what systems can you train to improve anaerobic power
ATP-PC system
glycolytic system
for anaerobic power how do you train the ATP-PC system
-short (5-10s) high intensity work intervals eg 30m sprints
with 30-60s rest intervals
little lactic acid is produced so recovery is rapid
for anaerobic power how do you train the glycolytic system
short 20-60s high intensity work intervals
may deplete muscle glycogen levels
should alternate hard and light training days
what are the 3 types of strength training exercises
isometric or static
dynamic or isotonic
isokinetic
what is isometric or static strength
application of force without joint movement
what is dynamic or isotonic strength
includes variable resistance exercises
what is isokinetic strength
exertion of a force at constant speed
define strength
the ability to exert force in order to overcome resistance
define power
ability to exert force with respect to time (eg rate at which force can be applied)
what is progressive overload
periodically increasing resistance to continue to overload the muscle
how often a week should you train for strength
2-4 days per week to incorporate rest days
how many sets should you do for maximal strength training gains
2-9 sets result in greater strength gains and hypertrophy
what should be specific about you strength training
you should use muscles that you will use in competition
do untrained males have greater absolute strength than untrained females
YES
upper body 50% stronger
lower body 30% stronger
describe long term hypertrophy between men and women
men exhibit greater hypertrophy long term as a result of strength training
what are the nutritional suggestions when training
low muscle glycogen
-promotes mitochondria formation & protein synthesis
high protein
-increases protein synthesis post training
antioxidant supplements
-may prevent damage and fatigue from free radical production
what are DOMS
- appears 24-48hrs after strenuous exercise
- occurs due to microscopic tears in muscle fibres or connective tissue
what causes more damage eccentric exercise or concentric exercise
ECCENTRIC = more damage
what is the common treatment for DOMS
rest
ice
compression
elevate
maybe anti-inflammatory drugs
what are the 3 types of stretching
static stretching
dynamic stretching
proprioreceptive neuromuscular facilitation (PNF)
what is static stretching
continuously holding a stretch position
hold for 10-60s, repeat 3-5 times
less muscle spindle activity
what is dynamic stretching
ballistic stretching movements
moving
what is PNF stretching
a static stretch followed by isometric contraction of muscle being stretched - requires a training partner
stimulates Golgi tendon organ
what is tapering
the short term reduction in training load prior to competition
allows muscles to resynthesise glycogen and heal from training induced damage
benefits strength and endurance events
what are the 3 cycles in training periodisation
macrocycle
mesocycle
microcycle
what is the macrocycle
the entire season/ year
what is the mesocycle
2-6 weeks
targets specific training goals
what is the microcycle
7 days
a focus block of training
eg prep for match day or comp
what training is suggested in the off season
- weight training
- running
- skill practice
- other sport participation
what training is suggested in preseason
- weight training
- running
- skill practice
- learning strategies
what training is suggested during the season
a maintenance programme
what happens to thermoregulation in women during the menstrual cycle
thermoregulation = impaired during menstrual cycle
what are some concerns with female athletes
- exercise during menstrual cycle
- eating disorders
- bone mineral density
- exercise during pregnancy
what is athletic amenorrhea
stopping of your period
due to modified release of hormones from hypothalamus
how common is athletic amenorrhea
12-69% of female athletes
what causes athletic amenorrhea
- overtraining
- increased psychological stress (more catecholamines)
- low energy availability , and increased energy expenditure
what is dysmenorrhea
painful menstruation due to prostaglandins
may limit training due to discomfort
what is anorexia nervosa
extreme steps to reduce body weight
what are some techniques used for anorexia
starvation
excessive exercise
laxative use
how to help someone with anorexia
nutritional guidance
psychological counselling
what is bulimia
pattern of big eating followed by vomiting
what are the effects of bulimia
damage to teeth and oesophagus due to vomiting of stomach acids
how do you treat bulimia
professional support
what is osteoporosis
loss of bone mineral content
what are the main causes of osteoporosis
estrogen deficiency due to amenorrhea
inadequate calcium intake due to easting disorders
what is the female athlete triad
low energy availability, menstrual dysfunction, low bone mineral density
now known as RED-S (relative energy efficiency in sport)
describe exercise during pregnancy
is good as long as…
- body temp is monitored to prevent hyperthermia
- maintain adequate hydration
- reduce training intensity as due date approaches
describe knee injury occurrence between men and women
women 3.5x more likely to do their ACL than men
why are women more likely to injure their ACL than men
- fluctuation in hormones during menstrual cycle compromises ACL strength and proprioreceptor feedback
- sex differences in knee anatomy (looser joint in women)
is musculoskeletal skeletal training good in children
yes may optimise growth in children
does musculoskeletal training in children have any risks
damage concerns to articular cartilage, growth plates and muscle tendons
can people with type 1 diabetes train vigorously
yes if they are free from diabetic or medical complications
what safety measurements do type 1 diabetics need to carry out with exercise
NEED TO AVOID HYPOGLYCAEMIA
How do diabetics avoid hypoglycaemia
combination of exercise, diet and insulin -through pumps to keep optimal blood glucose control
have available carbohydrate snack or drink available during exercise
where should the insulin injection site be in type1 diabetics
away from working muscle to prevent increased rate of uptake and hypoglycaemia
can asthmatic people exercise
Yes apart from scuba diving
- aerobic training can decrease airway inflammation and improve asthmatic symptoms
- have to control exercise induced bronchospasm
- requires inhaler to be present during exercise
what is epilepsy
loss of consciousness, muscle tremor and sensory disturbances
characterised by seizures
-stress can be a major cause of seizures
what increases the risk of seizures during exercise
- physical fatigue
- hyperventilation
- hypoxia
- hyperthermia
- hypoglycaemia
- electrolyte imbalance
- emotional stress
what happens to endurance performance after age 60
endurance perfomance declines
what are the training guidelines for masters athletes
medical clearance needs to be obtained
be aware of overtraining
training programme individualised
rest days in between challenging workouts
what is neurogenic bladder in para athletes
predisposed to UTIs
UTIs can cause pain, fever, increased muscle spasticity and autonomic dysreflexia
what is neurogenic bowel in para athletes
difficulty with bowel evacuation may have a negative impact on athletes prep for comp
regular and time consuming bowel programme
what is autonomic dysreflexia
serious medical problem that can happen if you’ve injured your spinal cord in your upper back
It makes your blood pressure dangerously high and, coupled with very low heartbeats, can lead to a stroke, seizure, or cardiac arrest.
what are the symptoms of autonomic dysreflexia
pounding headache, blurred vision, facial flushing, nasal congestion or stuffiness
what is cerebal palsy catagory in paralympics
- disorders of speech, hearing and vision can affect communication
- increased muscle tone, decreased joint range of motion, higher likelihood of overuse injuries
what is the amputee catagory in Paralympics
the damaged limb and prosthetic device combine so the limb is still able to be used
overuse injuries = common due to contralateral limb compensating
when is it beneficial to use altitude training
- Long events that depend on oxygen delivery are worsened as there’s less oxygen available
what is it about altitude training that provides benefits for SPRINTERS
- The lower air density at altitude offers less resistance to high-speed movement, and sprint performances are either not affected or are improved
What is boyles law
gas volume is inversely proportional to its pressure
what happens to atmospheric pressure at altitude
atmospheric pressure decreases at higher altitudes
what is normoxia
normal PO2 (sea level)
what is hypoxia
low PO2 (altitude)
what is hyperoxia
high PO2
What is polycythemia
an abnormally increased concentration of haemoglobin in the blood, either through reduction of plasma volume or increase in RBC
What does higher o2 in blood mean for extraction
higher extraction as less reliance on central delivery
what are the long term adjustments to altitude hypoxia
- hyperventilation
- HR increased
- SV increased
- decreased plasma volume
- increased capilarisation
- increased oxidative enzyme activity
- loss of body weight and lean body mass
what are some downsides to altitude training
blood viscosity
loss of training intensity
reduced muscle mass
what is the perfect solution for altitude training
live high altitude
train low altitude
in tents (hypoxicators)
what are important factors to consider when talking about performance/ training (not about the athlete)
heat
humidity
altitude
nutrition
how does regular physical activity relate to health outcomes
- lower rates of mortality
- Lower risk of CVD
- improved weight management
- lower risk of cancer
- decreased fall risk
- improved brain health
- improved bone health
what are the physical activity guidelines for adults
-move more, sit less each day
150-300mins of moderate intensity exercise weekly
75-150mins of vigorous exercise weekly
at least 2 times a week
what do you need to think about when considering medicine with exercise
- does the drug work
- how much change in effect comes from a change in dose
- is it efficient
- does the affect very between individuals
- is there a side affect
what does FITT stand for
and what are the 2 add ons
frequency
intensity
time
type
can add volume and progression
in reference to the dose response for exercise
what is an acute response
occur with 1 or several bouts of exercise but do not improve further
in reference to the dose response for exercise
what is a rapid response
benefits occur early and plateau
in reference to the dose response for exercise
what is linear
gains are made continuously over time
in reference to the dose response for exercise
what is delayed
gains only occur after weeks of training
what is MVPA
moderate to vigorous physical activity
what type of responders is HIIT good for
low responders
what is LPA
light physical activity
called background physical activity because it describes activities of daily living
can be qualified by step count
what is considered a sedentary step count
less than 5,000
what is considered an active step count
7,500-9,000
what is MPA
moderate physical activitiy
what are the guidelines for cardiorespiratory fitness
dynamic larger muscle activities (walking, jogging, swimming cycling, rowing, dancing
3-5 sessions per week
20-60min sessions
intensity = 40-89% HRmax
what are some risk factors of chronic disease
- age
- gender
- race
- social economic factors
- smoking
- alcohol
- poor diet
- physical inactivity
what is the name of the model used to establish cause of chronic disease
epidemiological model
what is atherosclerosis
- thickening of the inner lining of arteries
- leads to heart attack or stroke or death
what are some risk factors of CHD
- age
- family history
- cigarette smoking
- sedentary lifestyle
- obesity
- hypertension
- dyslipidemia
what is dyslipidemia
Dyslipidemia is the imbalance of lipids such as cholesterol, low-density lipoprotein cholesterol, (LDL-C), triglycerides, and high-density lipoprotein (HDL).
results from diet, tobacco exposure, or genetic and can lead to cardiovascular disease with severe complications.
what is hypertension
raised blood pressure
130/80 or above
how to treat hypertension
physical activity
how to measure obesity
through BMI
what BMI is considered obsese
30+
what are statin drugs
lower LDL-C and CRP
can reduce the risk of cardiovascular disease and death
what is CRP
C reactive protein
protein made by liver
Sent into bloodstream in response to inflammation.
what is a mediterranean diet
fruits, vegetables, legumes, whole grains, olive oil
cause reductions in CRP and IL-6
what does LDL-C stand for
Low density lipoprotein cholesterol
what does IL-6 stand for and what does it do
Interleukin 6
interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine.
how to reduce inflammation
exercise
statin drugs
mediterranean diet
what is metabolic syndrome
medical term for a combination of diabetes, high blood pressure (hypertension) and obesity
when does someone get diagnosed with metabolic syndrome
when they have 3 or more of the risk factors
what are the risk factors for metabolic syndrome
- abdominal obesity
- waist circumference (>102 men, >88 women)
- hyperglycaemia
- low LDL cholesterol
- high BP
- inability to control blood sugar levels
what are the 2 major causes of metabolic syndrome
- low grade chronic inflammation
- increased oxidative stress
what is asthma caused by
- contraction of smooth muscle of airways
- swelling of mucosal cells
- hypersecretion of mucus
what are some common triggers for asthma
animal fur pollen cigarette smoke execrise viral infections dust
why does exercise cause asthma
respiratory tract cools and drys
increases osmolarity on surface of the cell which triggers the release of chemical mediators and airway narrowing
what does COPD stand for
Chronic obstructive pulmonary disease
what is COPD
The name given to a group of lung diseases
- chronic bronchitis
- emphysema
- bronchial asthma
can irreversibly create changes in the lung
how to treat COPD
breathing exercises
exercise training
how to test for COPD
FEV (forced expiratory volume in 1 second)
Graded exercise test
what are some warning signs/ symptoms of type 1 diabetes
frequent urination frequent thirst extreme hunger rapid weight loss, weakness, fatigue irritability, nausea and vomiting
what is a primary treatment of type 2 diabetes
exercise
helps reduce obesity
control blood glucose
reduces insulin resistance
what training is recommended for people with diabetes
aerobic and resistance
what is cancer caused by
uncontrolled division of abnormal cells
cancer cells invade normal tissues and alter physiological function
does physical activity reduce the risk of cancer
physical activity reduces the risk of certain types of cancer
what are some cancer treatments
chemotherapy radiation surgery hormone therapies immunotherapies
what can occur as a result of cancer treatment
muscle loss
bone mineral density loss
explain chemotherapy and exercise
physical activity recognised to benefit chemotherapy patients
what can physical activity do to terminal ill cancer patients
exercise can improve the quality and duration of life in terminally ill cancer patients
what needs to be considered for exercise prescription in cancer patients
tumour site
cancer stage
treatment type
other medical conditions
what is some suggested guidance for exercise in cancer patients
- 2 days a week
- aerobic (walking)
- every other day if possible
- 30 min sessions
what is CAD
Coronary artery disease
what should patients with heart failure be offered
be offered exercise based rehab
it increases quality of life and exercise tolerance and decreases hospitalisation
what are some common medicines for cardiac patients
Beta blockers
-decreased HR & BP
anti-arrhythmia medications
-controls dangerous heart rhythms
nitroglycerin
-relaxes smooth muscle in veins to reduce venous return
what does graded exercise testing normally monitor
ECG (HR and rhythm)
BP
ratings perceived exhaustion
when prescribing exercise what is one thing to consider
invisible issues
eg autonomic dysfunctions in neurological conditions
when would you stop HIIT training
elevated resting BP or hR
feeling unwell
angina (chest pain), dyspnea, dizziness
what happens to distribution of blood to brain during 30min moderate to vigorous intensity
no change
