Chapter 4 – Human Physiology Flashcards
Bioenergetics
Describes the various processes of energy/macronutrient use within the body and relates to the function of various energy systems for fuel provision during exercise.
Enzymes
Protein-based components produced by cells that function to catalyze a biochemical reaction.
Creatine phosphate
An inorganic compound found in skeletal muscle tissue capable of storing and providing high-energy phosphate elements to fuel muscular contractions; along with ATP, it comprises an immediate substrate of the phosphagen system.
Creatine kinase
An enzyme which can catalyze creatine phosphate into creatine and a free phosphate ion to liberate immediate energy within the phosphagen energy system.
Glucose
A simple sugar molecule that provides the primary source of metabolized fuel for the glycolytic energy system.
Glycogen
Storage form of carbohydrates in the body which is broken down to fuel mechanical work: primary storage sites include skeletal muscles and the liver.
Glycolysis
Metabolic process involving the breakdown of sugars (glucose) through a series of reactions to provide energy (ATP) during anaerobic work.
Ischemic
A low oxygen state usually due to obstruction of arterial blood supply or inadequate blood flow leading to tissue hypoxia.
Lactic acid
Energy substrate produced as an end product of glycolysis that can be used by various tissues of the body as fuel to continue ongoing work.
Pyruvate
An energy substrate that results as an end-product of sugar metabolism during glycolysis in the presence of oxygen.
Gluconeogenesis
The creation of new glucose in the liver from other organic molecules, such as pyruvate, lactate, glycerol, and amino acids.
Cori cycle
Name given to the process of lactate and pyruvate recycling in the liver to produce new glucose.
Cytosol
The cytoplasmic fluid which surrounds all organelles within a cell.
Deaminate
The process by which the liver breaks down a protein by removing an amino group for use as potential fuel; glutamate is also deaminated in the kidneys.
Aerobic system
Metabolic pathway wherein the mitochondrion utilizes fats, pyruvate from carbohydrates, and amino acids from protein to produce ATP in the presence of oxygen.
Metabolic equivalent
A measurement of energy use expressed as multiples of the resting `metabolic rate.
1 MET
an oxygen uptake rate of 3.5 ml of O2 per kg of body weight per min of work
Anaerobic system
One of two major metabolic pathways, the ATP-PC phosphagen system or anaerobic glycolysis, that produces energy without the presence of oxygen. Anaerobic systems provide the energy for high power, high intensity activities.
Steady state
A condition within the human body which indicates that the current level of oxygen utilization matches demand, signified by a leveling off or steady heart rate.
Oxygen deficit
The difference between total oxygen consumed during the transition to steady state and the actual amount of oxygen required by the working tissues.
Excess post-exercise oxygen consumption
A measurable increase in the rate of oxygen consumption following strenuous activity due to a deficit created by the work.
Krebs cycle
A series of enzymatic reactions that occur in the mitochondria involving aerobic metabolism of acetyl compounds which produce ATP for cellular energy.
Oxidative phosphorylation
The formation of ATP energy created by the aerobic breakdown of various substrates, especially the organic compounds involved in the Krebs cycle.
Lipids
Various classes of organic compounds composed of fatty acids or their derivatives; dietary sources include oils, fats, waxes, and cholesterol, while endogenous sources include free fatty acids, triglycerides, lipoproteins, and phospholipids
FatMax
The highest intensity of work that can be performed where fat is the primary fuel for energy.
Fat-burning zone
Lower-intensity training where the predominant fuel source is fat, as aerobic pathways can maintain the workload.
Triglycerides
Consist of a glycerol and three fatty acids bound together in a single large molecule.
Adipose tissue
The storage form of fat tissue in the human body, which can be broken down for the liberation of necessary energy.
Lipase
A specific enzyme capable of breaking down lipid molecules in
the body.
Free fatty acids
Liberated lipid molecules found in blood plasma that represent around 10 percent of fat in the body.
Lipolysis
The breakdown of triglycerides from fat storage in the body for potential liberation into circulation to serve energy needs.
Albumin
A blood protein produced in the liver that functions as a transporter for various molecules including FFA, hormones, and calcium.
Lipoproteins
Protein-based compounds that transport various forms of lipids, such as cholesterol, in the bloodstream.
Beta oxidation
The process by which fats are oxidized, or broken down, in the mitochondria to produce acetyl CoA.
Electron transport chain
A group of compounds which expedite a series of oxidation-reduction reactions for eventual aerobic production of ATP within the mitochondria.
Acetyl CoA
Compound that functions as a coenzyme in various biological reactions and is formed as an intermediate for the metabolism of carbohydrates, fats, or proteins in the mitochondria.
Amino acids
Organic molecules consisting of hydrogen, carbon, oxygen, and nitrogen that combine to form the basic elements of proteins.
Branched chain amino acids
These serve as a potential fuel source during long-duration exercise bouts, have a nitrogen-sparing effect, and can bypass the liver and become available for uptake by muscle directly from circulation.
the three BCAAs
Includes leucine, isoleucine and valine
Transamination
A reversible process involved in both anabolism and catabolism by which excess amino acids are diverted toward energy production as an amino group is transferred from one molecule to another.
Oxaloacetate
An intermediate of the Krebs cycle that binds with acetyl-CoA to form
citrate; it helps facilitate aerobic energy production.
Central fatigue
Occurs with insufficient or systemic depletion of CHOs, resulting in reduced motor unit recruitment and firing rate.
General peripheral fatigue
Occurs with a lack of energy in working tissues due to low pre-exercise stores or localized depletion of anaerobic energy store.
Acute peripheral fatigue
Occurs when cells experience dysfunction due to a metabolic reduction in pH.
Rest period
The period of rest in between sets or structured periods of activity within a single exercise bout
Recovery period
The period of time in between separate exercise bouts so adaptations may occur.
Glucagon
Hormone released from the pancreas to promote the breakdown of glycogen to glucose in the liver to aid in blood sugar homeostasis.
Cellular permeability
The ability of nutrients and other substances to pass through the cellular wall: the greater the permeability, the greater the transfer of nutrients and other compounds.
Delayed onset muscle
soreness
Muscle soreness expedited by an inflammatory response to cellular damage, ischemia, and tonic spasms which presents 24-72 hours following an intense bout of exercise.
Graded exercise test
An exercise test which uses progressive stages to measure/estimate maximal oxygen consumption capacity.
Cardiac output
The total volume of blood available for use by all bodily tissues, dictated by heart rate and stroke volume.
A-V O2 difference
The difference in oxygen saturation when comparing the arteries and veins.
Stroke volume
The volume of blood expelled (to body tissues) per contraction from the left ventricle during each heartbeat.
Atria
The two upper chambers in the heart that receive blood from the veins and push it into the ventricles
Ventricles
The two lower chambers of the heart. The right ventricle receives blood from the right atrium and pumps it into the lungs via the pulmonary artery, and the left ventricle receives blood from the left atrium and pumps the blood to the rest of the body via the aorta.
Diastole
The heart’s relaxation phase in which the atrial chambers fill with blood.
Systole
The contraction phase of the heart ventricles by which blood is pumped out to the body
Alveoli
The tiny, thin-walled, capillary-rich sacs found in the lungs where the exchange of oxygen and carbon dioxide takes place.
Hemoglobin
A protein found in red blood cells that helps to transport oxygen to tissues.
Red Blood Cells
The most common type of blood cell and the primary means of delivering oxygen to the tissues: also called erythrocytes.
Aorta
The main artery of the body, supplying oxygenated blood from the left ventricle to the circulatory system.
Myocardium
The muscular tissue of the heart that is specialized to allow for continuous contractions
Capillaries
The smallest vascular structures with the thinnest walls, which allow for oxygen and nutrient transport as well as waste product removal from muscles, organs, and other tissues.
Angiogenesis
The development of new blood vessels as an adaptation-specific response to aerobic training, resulting in greater capillary density and improved oxygen-extraction capacity.
Baroreceptors
Specialized receptors that detect changes in blood pressure and blood flow in order to inform the CNS to either decrease or increase blood pressure or heart rate.
Blood pressure
A measure of the force or lateral pressure exerted by the circulating blood against the arterial walls
Vasodilation
The dilation or widening of a vascular structure, which decreases blood pressure and allows for increased blood flow and the potential for improved oxygen and nutrient delivery.
Vasoconstriction
The constriction or narrowing of a vascular structure due to contraction of the muscular wall, which increases blood pressure and reduces blood flow
Total peripheral resistance
The resistance to blood flow experienced within peripheral vasculature which can be modulated by various internal/external factors
Mean arterial pressure
The average arterial pressure during one cardiac cycle.
Hypertension
High blood pressure: a condition that has a negative impact on the cardiovascular system due to excessive pressure exerted upon arterial walls that causes damage over time.
Blood viscosity
A measure of the thickness and stickiness of blood caused by variable quantities of various blood constituents.
Orthostatic hypotension
A state of low blood pressure commonly caused by rapid changes in position from lying or seated to standing.
Arteries
The large, muscular-walled blood vessel structures that transport oxygenated blood away from the heart to the tissues.
Arterioles
The smaller, thinner-walled arteries that serve as the connecting structures to capillaries.
Interstitial spaces
Fluid-filled spaces between tissues that allow for the transfer of oxygen, nutrients, waste products, hormones, neurotransmitters, and other compounds.
Endothelium
A thin layer of flat epithelial cells that line blood vessels. These cells allow for the diffusion of oxygen and waste products.
Veins
Any of the blood vessels that are part of the circulatory system and transport deoxygenated blood back to the heart/ lungs
Autonomic nervous system
A component of the nervous system responsible for bodily functions that are not consciously controlled, such as breathing, heart function, and digestive processes.
Diabetes
A group of metabolic diseases (type 1 and 2) that involve insulin and glucose mismanagement
Arteriosclerosis
A thickening and hardening of the arterial walls from chronic conditions such as high blood pressure, old age, or negative behaviors, such as smoking.
Atherosclerosis
Refers to the deposit and buildup of fats, cholesterol, and other substances (known as plaque) in and on arterial walls, which can restrict blood flow and lead to heart attack or stroke.
Coronary artery disease
A disease of the coronary arteries often due to atherosclerosis; it leads to an obstruction of coronary circulation, potentially resulting in a dangerous cardiovascular event.
Varicose veins
Veins that have become enlarged and twisted; as one ages, vascular structures lose elasticity
Deep vein thrombosis
Deep vein blood clots that can cause serious circulation blockage and potential death from pulmonary embolism.
Hematocrit
The percentage of blood that consists of red blood cells; the most commonly used erythrocyte test.
Plasma
The clear, liquid portion of blood that contains salts, glucose, amino acids, vitamins, urea, proteins and fats.
White blood cells
A group of immunological cells in the bloodstream which serve various protective functions, such as protection from invasive pathogens.
Platelets
Tiny cells responsible for blood coagulation (blood clotting) and the repair of damaged blood vessels.
Valsalva maneuver
A strain against a closed airway, combined with muscle tightening.
Diastolic blood pressure
The pressure within arteries in between heart beats when the ventricles are relaxed and filling with blood.
Systolic blood pressure
The pressure within arteries during heart beats via contraction of the left ventricle.
Rate pressure product
An estimate of myocardial oxygen demand and cardiovascular disease risk; it is calculated as systolic blood pressure x heart rate.
Myocardial infarction
The medical term for heart attack; it refers to the process by which one or more regions of the heart experience severe or prolonged ischemia due to a blockage of a coronary artery, resulting in the death of the affected cardiac tissue.
Lactate threshold
Reflects the maximal intensity at which steady state can be maintained: the intensity at which lactate accumulation begins to exceed lactate removal.
Eustress
A positive, desirable form of stress that influences physiological or psychological health
Distress
A negative form of stress that influences physiological or psychological health
Hypothalamus
A region of the forebrain that coordinates the autonomic nervous system and governs the endocrine system via the pituitary gland.
Pancreas
A relatively large gland that secretes digestive enzymes into the small intestines for macronutrient breakdown.
Steroid hormones
Organic, cholesterol-based hormone compounds that serve various functions related, but not limited to, sexual development, reproduction, tissue synthesis, inflammation regulation, and metabolism: examples include cortisol, aldosterone, estrogen, progesterone, and testosterone.
Polypeptide hormones
A chain of amino acids synthesized on the ribosomes of the endoplasmic reticulum of endocrine cells
Anabolic hormones
Compounds involved in stimulating protein synthesis and tissue growth.
Growth hormone
Promotes cell division and proliferation by facilitating protein synthesis.
Testosterone
An anabolic hormone produced in the gonadal glands of both men and
women.
Insulin-like growth factor 1
Considered to be a central signaling hormone released from the liver that initiates muscle growth following resistance training.
Myostatin
A protein found primarily in skeletal muscle that functions to restrain the growth of muscular tissue
Androgenic hormone
A generic term used to describe any natural or synthetic steroid-based hormone that controls the development and maintenance of masculine characteristics.
Estrogen
A steroid hormone that promotes the development and maintenance of female secondary characteristics
Aromatization
Chemical reaction process by which excess testosterone is converted to estrogen in order to maintain a homeostatic environment.
Gynecomastia
An overdevelopment of the mammary glands among males (male breast tissue) due to hormonal imbalance.
Atrophy
The wasting away of an organ, muscle, or other bodily tissue.
Insulin
A hormone produced by the pancreas that serves various functions including blood glucose control and tissue growth.
Hyperglycemia
An abnormally high blood glucose level.
Hypoglycemia
A low blood sugar level that occurs when glucose concentrations drop below a critical concentration in the blood.
Catecholamines
Potent neurotransmitters that help the body respond to stress or elicit “fight-or-flight” reactions.
Thyroid
A gland which serves as the primary regulator for growth and development via the rate of metabolism within the body.
Hypothyroidism
An abnormally low activity of the thyroid gland which results in “slow metabolism” and usually weight gain.
Adrenal cortex
The outer portion of the adrenal glands that secretes steroidal hormones such as cortisol and aldosterone.
Cortisol
Regulates numerous metabolic and cardiovascular functions and helps to manage blood pressure
Adrenal medulla
The inner portion of the adrenal glands that converts the amino acid tyrosine into the catecholamines for release into the bloodstream.
Epinephrine
A catecholamine hormone, also known as adrenaline, that is secreted by the adrenal glands during conditions of stress to increase blood circulation, ventilation, and carbohydrate metabolism to prepare skeletal muscles for exertion.
Norepinephrine
A catecholamine hormone secreted from the adrenal glands in response to stress by increasing blood pressure and blood glucose levels.
Fight-or-flight response
An acute increase in adrenal hormone activity which expedites enhancements in cardiac output, blood flow, and energy metabolism to rapidly deal with a perceived stress.
Nitrogen balance
A comparison of nitrogen input and nitrogen output.
Proteolytic enzymes
Function to break down protein compounds and eventually amino acids for energy use or protein recycling.
Growth Hormone function
Stimulates IGF, protein synthesis, growth and metabolism
Thyroxine function
Stimulates metabolic rate, regulates cell growth and activity
Cortisol function
Promotes use of fatty acids and protein catabolism; conserves sugar; maintains blood glucose level
Aldosterone function
Promotes sodium, potassium metabolism and water retention
Epinephrine function
Increases cardiac output; increases glycogen catabolism and fatty acid release
Norepinephrine function
Has properties of epinephrine and constricts blood vessels
Insulin function
Promotes glucose uptake by the cell, stores glycogen; aids in protein synthesis
Glucagon function
Releases sugar from the liver into circulation
Insulin-like Growth Factors function
Increases protein synthesis
Estrogen function
Stimulates bone remodeling activity; female sex hormone
Testosterone function
Stimulates growth; increases protein anabolism; reduces body fat; male sex hormone
Afferent stimuli
Sensory information carried inward toward the brain and spinal cord from sensory and motor nerves throughout the body, as opposed to efferent stimuli, which carry information from the brain to the peripheral nerves.
