Chapter 2: Basic Exercise Science Flashcards
human movement system
the combination and interrelation of the nervous, muscular, and skeletal systems (kinetic chain)
nervous system
a conglomeration of billions of cells specifically designed to provide a communication network within the human body
sensory function
the ability of the nervous system to sense changes in either the internal or external environment
integrative function
the ability of the nervous system to analyze and interpret sensory information to allow for proper decision making, which produces the appropriate response
motor function
the neuromuscular response to the sensory information
proprioception
the cumulative sensory input to the central nervous system from all mechanoreceptors that sense body position and limb movement
neuron
the functional unit of the nervous system
sensory (afferent) neurons
transmit nerve impulse from effector sites (such as muscles and organs) via receptors to the brain and spinal cord
interneurons
transmit nerve impulses from one neuron to another
motor (efferent) neurons
transmit nerve impulses from the brain and spinal cord to effector sites
central nervous system
- the portion of the nervous system that consists of the brain and spinal cord
- primary function is to coordinate the activity of all parts of the body
peripheral nervous system
- cranial and spinal nerves that spread throughout the body
- connects the CNS to the rest of the body and the external environment
mechanoreceptors
sensory receptors responsible for sensing distortion in body tissues
muscle spindles
- receptors sensitive to change in length of the muscle and the rate of that change
- run parallel to the muscle fibers
- help regulate the contraction of muscles via the stretch reflex mechanism
Golgi tendon organs
- receptors sensitive to change in tension of the muscle and the rate of that change
- located at the point where skeletal muscle fibers insert into the tendons of skeletal muscle
- activation of the Golgi tendon organ will cause the muscle to relax, which prevents the muscle from excessive stress or possibility of injury
joint receptors
- receptors surrounding a joint that respond to pressure, acceleration, and deceleration of the joint
- act to signal extreme joint positions and thus help to prevent injury
- act to initiate a reflexive inhibitory response in the surrounding muscles if their is too much stress placed on that joint
skeletal system
- the body’s framework, composed of bones and joints
- proves the shape and form for our bodies, in a addition to supporting, protecting, allowing bodily movement, producing blood for the body, and storing minerals
bones
provide a resting ground for muscles and protection of vital organs
joints
junctions of bones, muscles, and connective tissues at which movement occurs- also known as articulation
axial skeleton
portion of the skeletal system that consists of the skull, ribcage, and vertebral column
appendicular skeleton
portion of the skeletal system that includes the upper and lower extremities
remodeling
the process of resorption and formation of bone
osteoclasts
a type of bone cell that removes bone tissue
osteoblasts
a type of cell that is responsible for bone formation
epiphysis
the end of long bones, which is mainly composed of cancellous bone, and house much of the red marrow involved in red blood cell production. they are also one of the primary sites for bone growth.
diaphysis
the shaft portion of a long bone
epiphyseal plate
the region of the long bone connecting the diaphysis to the epiphysis. it is a layer of subdividing cartilaginous cells in which growth in length of the diaphysis occurs.
periosteum
a dense membrane composed of fibrous connective tissue that closely wraps (invests) all bone, except that of the articulating surfaces in joints, which are covered by a synovial membrane
medullar cavity
the central cavity of bone shafts where marrow is stored
articular (hyaline) cartilage
cartilage that covers the articular surfaces of bones
depressions
flattened or indented portions of bone, which can be muscle attachment sites
processes
projections protruding from the bone where muscles, tendons, and ligaments can attach
vertebral column
a series of irregularly shaped bones called vertebrae that houses the spinal cord
arthrokinematics
joint motion
synovial joints
- joints that are held together by a joint capsule and ligaments and are most associated with movement in the body
- comprise approximately 80% of all the joints in the body and have the greatest capacity for motion
nonsynovial joints
- joints that do not have a joint cavity, connective tissue, or cartilage
- exhibit little or no movement
ligament
primary connective tissue that connects bones together and provides static and dynamic stability, input to the nervous system (proprioception), guidance, and the limitation of improper joint movement
muscular system
series of muscles that moves the skeleton
epimysium
a layer of connective tissue that is underneath the fascia and surrounds the muscle
perimysium
the connective tissue that surrounds fascicles
endomysium
the deepest layer of connective tissue that surrounds individual muscle fibers
tendons
connective tissues that attach muscle to bone and provide an anchor for muscles to produce force
sarcomere
the functional unit of muscle that produces muscular contract and consists of repeating sections of actin and myosin
neural activation
the contraction of a muscle generated by neural stimulation
motor unit
a motor neuron and all of the muscle fibers it innervates
neurotransmitters
chemical messengers that cross the neuromuscular junction (synapse) to transmit electrical impulses from the nerve to the muscle
3 main parts of a neuron
the cell body, axon, and dendrites
cell body (or soma)
contains a nucleus and other organelles, including lysosomes, mitochondria, and a Golgi complex
axon
- a cylindrical projection from the cell body that transmits nervous impulses to other neurons or effector sites (muscles, organs)
- provides communication from the brain and spinal cord to other parts of the body
dendrites
gather information from other structures and transmit it back to the neuron
the peripheral nervous system consists of…
12 cranial nerves, 31 pairs of spinal nerves (which branch out from the brain and spinal cord), and sensory receptors
2 main functions of peripheral nerves
- provide a connection for the nervous system to activate different effector sites, such as muscles (motor function)
- relay information from the effector sites back to the brain via sensory receptors (sensory function), thus providing a constant update on the relation between the body and the environment
subdivisions of the PNS
somatic and autonomic nervous systems
somatic nervous system
- consists of nerves that serve the outer areas of the body and skeletal muscle
- voluntary control of movement
autonomic nervous system
supplies neural input to the involuntary systems of the body (e.g., heart, digestive systems, and endocrine glands)
subdivisions of the autonomic system
sympathetic and parasympathetic nervous systems
sympathetic nervous system
during exercise, increases levels of activation in preparation for activity
parasympathetic
during exercises, decreases levels of activation during rest and recovery
4 types of sensory receptors
- mechanoreceptors (touch and pressure)
- nociceptors (pain)
- chemoreceptors (smell and taste)
- photoreceptors (vision)
stretch reflex
- a normal response by the body to a stretch stimulus in the muscle
- when a muscle spindle is stretched, an impulse is immediately sent to the spinal cord, and a response to contract the muscle is received within 1-2 ms
- the rapid neural response is designed as a protective mechanism to prevent overstretching and potential muscle damage
joint receptor examples
- Ruffuni endings
- Pacinian corpuscles
growth, maturation and functionality of the skeletal system are greatly affected by….
- posture
- physical activity
- nutrition status
subdivisions of the skeletal system
axial and appendicular skeletal systems
of bones in the axial skeleton
approximately 80
of bones in the in the appendicular skeletal system
approximately 126
pelvic girdle
often considered a component of either the axial or appendicular system and is actually a link between the two systems
of bones in the skeletal system
206
of bones used in voluntary movement
177
the bones in the human body form more than ___ joints
300
2 vital functions of bones
- leverage- act and perform as levers when acted on by muscles
- support- posture, which is necessary for the efficient distribution of forces acting on the body
during resorption….
old bone tissue is broken down and removed by special cells called osteoclasts
during bone formation…
new bone tissue is laid down to replace the old by special cells called osteoblasts
for most people, bone formation continues at a faster pace than removal until bone mass peaks usually by the time individuals reach their ___
thirties
remodeling tends to follow….
the lines of stress placed on the bone
long bone characteristics
- long, cylindrical shaft and irregular or widened ends
- composed predominantly of compact bone tissue to ensure strength and stiffness
- also have spongy bone tissue for shock absorption
long bone examples
humerus, clavucle, radius, ulna, metacarpals, phalanges, femur, tibia, fibula, metatarsals, phalanges
short bone characteristics
- similar in length and width and appear somewhat cubical in shape
- consist of predominantly spongy bone tissue to maximize shock absorption
short bone examples
carpals of hand, tarsals of feet
flat bone characteristics
- thin, protective
- comprising two layers of compact bone tissue surrounding a layer of spongy bone tissue
- involved in protection of internal structures and also provide broad attachmenet sites for muscles
flat bone examples
sternum, scapulae, ribs, ilium, and cranial bones
irregular bone charactersitics
unique shape and function
irregular bone example
vertebrae, pelvic vones, and certain facial bones
sesamoid bone charactersitics
=small often round bones embedded in a joint capsule or found in locations where a tendon passes over a joint
- develop within particular tendons at a site of considerable friction or tension
- serve to improve leverage and protect the joint from damage
sesamoid bone example
patella
fossa
type of bone depression
example of a fossa
the supraspinous or infraspinous fossa located on the scapulae (shoulder blades)
sulcus
- type of bone depression
- a groove in a bone that allows soft tissue (i.e., tendons) to pass through
example of a sulcus
- the intertubercular sulcus located between the greater and lesser tubercles of the humerus (upper arm bone)
- commonly known as the groove for the bicep tendon
examples of processes
- spinous process found on the vertebrae
- the acromion and coracoid processes found on the scapulae
condyles
- processes
- located on the inner and outer portions at the bottom of the femur (thigh bone) and top of the tibia (shin bone) to form the knee joint
epicondyles
- processes
- located on the inner and outer portions of the humerus to help form the elbow joint
tubercles
- processes
- located at the top of the humerus at the glenohumeral (shoulder) joint
trochanters
- processses
- located at the top of the femur and are attachment sites for the hip musculature
how many different categories of the vertebral column
5
cervical vertebrae
- cervical spine, C1-C7
- form a flexible framework
- provide support and motion for the head
thoracic vertebrae
- thoracic spine, T1-T12
- located in the upper and middle back
- move with the ribs to form the rear anchor of the rib cage
- larger than cervical vertebrae
- increase in size from top to bottom
lumbar vertebrae
- lumbar spine, L1-L5
- these bones are the largest in the spinal column
- support most of the body’s weight
- attached to many of the back muscles
- often a location of pain for individuals because these vertebrae carry the most amount of body weight and are subject to the largest forces and stresses along the spine
sacrum
- a triangular bone located just below the lumbar vertebrae
- consists of 4 or 5 sacral vertebrae in a child, which become fused into a single bone during adulthood
coccyx or tailbone
- bottom of the spinal column
- 3-5 bones that are fused together in an adult
- many muscles connect to the coccyx
intervertebral discs
- located in between the vertebrae
- made of fibrous cartilage that act as shock absorbers and allow the back to move
functions of the vertebral column
- allowing humans to stand upright and maintain their balance
- helps support the head and arms while permitting freedom of movement
- provides attachment for many muscles, the ribs, and some of the organs and protects the spinal cord, which controls most bodily functions
neutral spine
- the optimal arrangement of curves
- represents a position in which the vertebrae and associated structures are under the least amount of load
3 major curvatures of the adult human spine
- a posterior cervical curvature
- an anterior thoracic curvature
- a posterior lumbar curvature
posterior cervical curvature
a posterior concavity of the cervical spine
anterior thoracic curvature
a posterior convexity of the thoracic spine
posterior lumbar curvature
a posterior concavity of the lumbar spine
joints
- formed by one bone that articulates with another bone
- can be categorized by both their structure and their function
3 major joint motion types
- roll
- slide
- spin
true or false: motions usually occur as an isolated, true motion
FALSE
rolling movement
one joint rolls across the surface of another, much like the tire of a bicycle rolls on the street
sliding movement
one joint’s surface slides across another much like the tire of a bicycle skidding across the street
spinning movement
one joint surface rotates on another much like twisting the lid off of a jar
example of a rolling movement
the femoral condyles moving (rolling) over the tibial condyles during a squat
example of a sliding movement
the tibial condyles moving (sliding) across the femoral condyles during a knee extension
example of a spinning movement
the head of the radius (a bone in the forearm) rotating on the end of the humerus during pronation and supination of the forearm
synovial joint characteristics
- synovial capsule (collagenous structure) surrounding the entire joint
- synovial membrane (inner layer of the capsule)
- hyaline cartilage (pads the ends of the articulating bones)
- produce synovial fluid
synovial fluid
- resembles egg whites and works much like engine oil
- secreted within the joint capsule from the synovial membrane and is essential for lubricating the joint surfaces to reduce excessive wear and to nourish the cartilage cells that line the joint
types of synovial joints
- gliding (plane)
- condyloid (condylar or ellipsoidal)
- hinge
- saddle
- pivot
- ball-and-socket
gliding (plane) joint
- a nonaxial joint that has the simplest movement of all joints
- moves either back and forth or side to side
example of a gliding (plane) joint
the joint between the navicular bone and the second and third cuneiform bones in the foot or the carpals of the hand and in the facet (spine) joints
condyloid (condylar or ellipsoidal) joints
- the condyle of one bone fits into the elliptical cavity of another bone to form the joint
- movement predominantly occurs in one plane (flexion and extension in the sagittal plane) with minimal movement in the others (rotation in the transverse plane; adduction and abduction in the frontal plane)
examples of condyloid joints
seen in the wrist between the radius and carpals and in the joints of the fingers (metacarpophalangeal)
hinge joint
a uniaxial joint allowing movement predominantly in only one plane of motion, the sagittal plane
examples of hinge joints
the elbow, interphalangeal (toe), and ankle
saddle joint
- one bone looks like a saddle with the articulating bone straddling it like a rider
- allows movement predominantly in two planes of motion (flexion and extension in the sagittal plane; adduction and abduction in the frontal plane) with some rotation to produce circumduction (circular motion)
example of saddle joint
carpometacarpal joint in the thumb
pivot joints
allow movement in predominantly one plane of motion (rotation, pronation, and supination in the transverse plane)
examples of pivot joints
the atlantoaxial joint at the base of the skull (top of spine) and the proximal radioulnar joint at the elbow
ball and socket joints
- the most mobile of the joints
- allow movement in all three planes
examples of ball and socket joints
the shoulder and hip
examples of nonsynovial joints
seen in the sutures of the skull, the distal joint of the tibia and fibula, and the symphysis pubis (pubic bones)
functions of joints
- allow for motion and thus movement
- provide stability, allowing for movement to take place without unwanted movement
kinetic chain of movement
all joints in the human body are linked together, which implies that movement of one joint directly affects the motion of others
what are ligaments made of?
primarily made up of a protein called collagen with varying amounts of a second protein called elastin
collagen
- a protein that makes up ligaments
- situated in a more parallel fashion to the forces that are typically placed on the ligament
- provide the ligament with the anility to withstand tension (tensile strength)
elastin
- a protein that makes up ligaments
- gives a ligament some flexibility or elastic recoil to withstand the bending and twisting it may have to endure
true or false: ligaments have good vascularity (blood supply)
FALSE
-ligaments do not heal or repair very well and may be slower to adapt to stresses placed on the body, such as stress caused by exercise
examples of weight-bearing exercises
resistance training, walking, body weight squats, push-ups, jogging, climbing stairs, dancing
examples of exercises that are not weight-bearing
swimming, bicycling
best kind of exercise to strengthen bones
weight-bearing exercises
true or false: individuals who exercise regularly generally achieve greater peak bone mass (maximal bone density and strength) than those who do not
TRUE
3 major muscle types
- skeletal
- cardiac
- smooth
fascia
outer layer of connective tissue on bundles of muscle fivers
role of connective tissues in movement
allow the forces generated by the muscle to be transmitted from the contractile components of the muscle to the bones, creating muscle
true or false: tendons have poor vascularity (blood supply)
TRUE
-leaves them susceptible to slower repair and adaptation
sarcolemma
plasma membrane that encases muscle fibers
myofibrils
structures in muscle fibers that contain myofilaments that are the actual contractile components of muscle tissue
2 types of myofilaments
- actin
2. myosin
actin
thin string like filaments
myosin
thick filaments
2 protein structures that are important to muscle contraction
- tropomyosin
2. troponin
tropomyosin
located on the actin filament and blocks myosin binding sites located on the actin filament, keeping myosin from attaching to actin when the muscle is in a relaxed state
troponin
located on the actin filament, plats a role in muscle contraction by proving binding sites for both calcium and tropomyosin when a muscle needs to contract
neuromuscular junction
- the point at which the motor neuron meets an individual muscle fiber
- a specialized synapse that allows motor neurons originating from the CNS to communicated with muscle fibers
when are neurotransmitters released?
when electrical impulses (action potentials) reach the end of the axon (axon terminal)
what is the neurotransmitter used by the neuromuscular system?
acetylcholine (ACh)
sliding filament theory
describes how thick and thin filaments within the sarcomere slide past one another, shortening the entire length of the sarcomere and thus shortening muscle and producing force
excitation-contraction coupling
- the process of neural simulation creating a muscle contraction
- involves a series of steps that start with the initiation of a neural message (neural activation) and end up with a muscle contraction
steps in the sliding filament theory
- a sarcomere shortens as a result of the Z lines moving closer together
- the Z lines converge as the result of myosin heads attaching to the actin filament and asynchronously pulling (power strokes) the actin filament across the myosin, resulting in shortening of the muscle fiber
a single motor unit consists of….
one motor neuron (nerve) and the muscle fibers it innervates
true or false: motor units can vary the amount of force they generate
FALSE
-either they contract maximally or not at all- hence the “all or nothing” law
the overall strength of a skeletal muscle contraction depends on…
- the size of the motor unit recruited (i.e. how many muscle fibers are contained within the unit)
- the number of motor units that are activated at a given time
true or false: the size of motor units making up a a particular muscle will relate directly to the function of that muscle
TRUE
Type I (slow-twitch) muscle fiber characteristics
- more capillaries, mitochondria, and myoglobin
- increased oxygen delivery
- smaller in size (diameter)
- less force produced
- slow to fatigue
- longer-term contractions (stabilization)
- slow twitch
- red fibers
- important for muscles that need to produce the long-term contractions necessary for stabilization and postural control
Type II (fast-twitch) muscle fiber characteristics
- fewer capillaries, mitochondria, and myoglobin
- decreased oxygen delivery
- larger in size
- more force produced
- quick to fatigue
- short-term contractions (force and power)
- fast twitch
- white fibers
- important for muscles producing movements requiring force and power such as performing a sprint
Type IIa muscle fibers
- higher oxidative capacity and fatigue more slowly than type IIx
- intermediate fast-twitch fibers
-they can use both aerobic and anaerobic metabolism almost equally to create energy
Type IIx muscle fibers
- low oxidative capacity (ability to use oxygen)
- fatigue quickly
4 muscle types (as movers)
- agonist
- synergist
- stabilizer
- antagonist
agonist function
- prime mover
- the muscles that are most responsible for a aprticular movement
synergist function
assist prime movers during movmenet
stabilizer function
stabilize or support the body while prime mover and synergist work
antagonist
oppose prime mover (perform the opposite action)
agonist in hip extension
gluteus maximus
synergist in hip extension
hamstring complex and the erector spinae
stabilizer in hip extension
transversus abdominis, internal oblique, and multifidus (deep muscles in the low back) stabilize the low back, pelvis, and hips (lumbo-pelvic-hip complex)
antagonist in hip extension
the psoas (a deep hip flexor)
agonist in chest press
pectoralis major
agonist in overhead press
deltoid
agonist in row
latissimus dorsi
agonist in squat
gluteus maximus, quadriceps
synergist in chest press
anterior deltoid, triceps
synergist in overhead press
triceps
synergist in row
posterior deltoid, biceps
synergist in squat
hamstring complex
stabilizer in chest press
rotator cuff
stabilizer in overhead press
rotator cuff
stabilizer in row
rotator cuff
stabilizer in squat
transversus abdominis
antagonist in chest press
posterior deltoid
antagonist in overhead press
latissimus dorsi
antagonist in row
pectoralis major
antagonist in squat
psoas
endocrine system
- a system of glands that secrete hormones into the bloodstream to regulate a variety of bodily functions, including the control of mood, growth and development, tissue function, and metabolism
- consists of host organs (known as glands), chemical messengers (hormones), and target (receptor) cells
what happens when a hormone is secreted from a gland?
- it travels through the bloodstream to target cells designed to receive its message
- the target cells have hormone-specific receptors ensuring that each hormone will communicate only with specific target cells
- along the way, special proteins bind to some hormones, acting as carriers that control the amount of hormone that is available to interact with and affect the target cells
what is the endocrine system responsible for?
-regulating multiply bodily functions to stabilize the body’s internal environment
hormones produced by the endocrine system virtually affect all forms of human function including….
triggering muscle contraction, stimulating protein and fat synthesis, activating enzyme systems, regulating growth and metabolism, and determining how the body will physically and emotionally respond to stress
primary endocrine glands
hypothalamus, pituitary, thyroid, and adrenal glands
pituitary gland
- “master” gland because it controls the functions of the other endocrine glands
- three different sections or lobes, the anterior, intermediate, and posterior loves, and each lobe secretes specific types of hormones
anterior lobe of pituitary gland
secretes growth hormone, prolactin (to stimulate milk production after giving birth), adrenocorticotropic hormone or ACTH (to stimulate the adrenal glands), thyroid-stimulating hormone or TSH (to stimulate the thyroid gland), follicle-stimulating hormone or FSH (to stimulate the ovaries and testes), and luteinizing hormone or LH (to simulate the ovaries or testes)
intermediate lobe of pituitary gland
secretes melanocyte-stimulating hormone (to control skin pigmentation)
posterior lobe of pituitary gland
secretes antidiuretic hormone or ADH (to increase absorption of water into the blood by the kidneys) and oxytocin (to contract the uterus during childbirth and stimulate milk production)
thyroid gland
produces hormones that regulate the rate of metabolism and affect the growth and rate of function of many other systems in the body
adrenal glands
- secrete hormones such as corticosteroids and catecholamines, including cortisol and adrenaline (epinephrine) in response to stress
- situated on top of each kidney
what is the body’s prime energy source during vigorous exercise?
carbohydrates (specifically glucose)
effects of too much glucose
damage the vascular system
effects of too little glucose
inhibit performance
control of blood glucose is regulated by the _________
pancreas
2 hormones that the pancreas produces
- insulin
2. glucagon
carbohydrates
the human body’s key source of energy
glucose
the principal fuel for the brain
insulin
helps regulate energy and glucose metabolism in the body
what happens after consuming a meal?
- glucose enters the blood at the small intestine, causing a rise in blood glucose levels
- as the blood is circulated through the pancreas, elevated levels of glucose trigger the release of insulin
- the circulating insulin binds with the receptors of its target cells, and the cell membrane becomes more permeable to glucose
- glucose the diffuses out of the bloodstream and into the cell
- the net result is a drop in blood glucose levels
- thus insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle
effect of glucagon
-opposite to that of insulin, as it functions to raise blood glucose levels by triggering the release of glycogen stores from the liver (glycogen is the stored form of glucose)
what happens hours after a meal?
- hours after a meal, or as a result of a combination of normal metabolic processes and physical activity, the body will begin to exhibit lower blood glucose levels
- the drop in circulating blood glucose triggers the release of glucagon from the pancreas
- in contrast to insulin, glucagon has a much more specific effect, stimulating the liver to convert its glycogen stores back into glucose, which is then release into the bloodstream
what happens to glucose uptake as activity levels increase?
-as activity levels increase, glucose uptake by the body’s cells also increases
what happens to insulin levels during physical activity?
-insulin levels will drop during physical activity due to increase sensitivity of the cells to insulin
what happens to glucagon levels during physical activity?
-glucagon secretion by the pancreas increases, thus helping maintain a steady supply of blood glucose
the 2 catecholamines
- epinephrine (adrenaline)
2. norepinephrine
catecholamines
- hormones produced by the adrenal glands
- help prepare the body for activity; more specifically, they are part of the stress response known as the fight or flight response
- in preparation for activity, the hypothalamus trigger the adrenal glands to secrete more epinephrine
physiological effects of epinephrine
help sustain exercise activity by:
- increasing heart rate and stroke volume
- elevating blood glucose levels
- redistributing blood to working tissues
- opening up the airways
testosterone
- produced in the testes of the male and in small amount in the ovaries and adrenal glands of the female
- primarily responsible for the development of the male secondary sexual characteristics, such as facial and body hair and greater muscle mass
how much more testosterone do males produce than females?
up to 10 times more
estrogen
- produced primarily in the ovaries in the female, with small amounts produced in the adrenals in males
- women of reproductive age have significantly higher levels of estrogen than males, which gives rise to female secondary sexual characteristics such as breast development and regulation of the menstrual cycle
what role does testosterone play for both males and females?
- testosterone plays a fundamental role in the growth and repair of tissue
- raised levels of testosterone are indicative of an anabolic (tissue-building) training status
influence of estrogen
-has an influence on fat deposition around the hips, buttocks, and thighs
cortisol
- a catabolic hormone (associated with tissue breakdown)
- under times of stress, such as exercise, cortisol is secreted by the adrenal glands and serves to maintain energy supply through the breakdown of carbohydrates, fats, and protein
what can cause high levels of cortisol?
- overtraining
- excessive stress
- poor sleep
- inadequate nutrition
growth hormone
- released from the pituitary gland in the brain and is regulated by the hypothalamus
- primarily an anabolic hormone that is responsible for most of the growth and development during childhood up until puberty, when the primary sex hormones take over that control
- increases the development of bone, muscle tissue, and protein synthesis
- increases fat burning
- strengthens the immune system
factors that stimulate growth hormone
- estrogen
- testosterone
- deep sleep
- vigorous exercise
thyroid gland
- located at the base of the neck just below the thyroid cartilage
- sometimes called the Adam’s apple
- releases vital hormones that are primarily responsible for human metabolism
thyroid hormones
- responsible for human metabolism
- release is regulated by the pituitary gland
what are thyroid hormones responsible for?
- carbohydrate, protein, and fat metabolism
- basal metabolic rate
- protein synthesis
- sensitivity to epinephrine
- heart rate
- breathing rate
- body temperature
effects of low thyroid function
- low metabolism
- fatigue
- depression
- sensitivity to cold
- weight gain
the presence of cortisol in the blood stream is often taken to be indicative of what?
overtraining
role of cortisol in exercise
- maintaining energy levels during normal exercise activity
- may even facilitate recovery and repair during the post exercise period
result of extremely intense or prolonged bouts of endurance training
- lower testosterone levels and higher cortisol levels
- under these circumstances, catabolism (breakdown) is likely to outstrip anabolism (build up) and give rise to symptoms of overtraining
