The most credible source of evidence is:

A.Anecdotal

B.Endorsement or testimonial

C.Marketing Claims

D.Expert Opinion

E.Scientific

In one experiment, a scientist removes a single muscle fiber from a rat to test the effects of lactic acid on muscle contraction. Which research term best describes this approach?

A. Reductionist

B. Epidemiological

C.Translational

D.Applied

Indicator of a strong discipline or profession

Societies are often accompanied by journals

Generalizing from an insufficient amount of evidence

'My grandfarther smoked like a chimney and died health in a car crash at age 99'

Motivation is to sell a product or service

Often based on internal reports that are biased and not peer reviewed

Testiomonials: Sales-pitches attributed to ordinary citizens

Endorsements: Pitches by celebrities

The most important type of evidence

Appears in scientific journals that are peer reviewed

Observation

Formulate hypothesis

Design experiment

Results may contribute to an existing/new theory

Results often suggest new experiments

Basic science applied to a problem

Scientific study and research that seeks to solve practical problems

Pharmacogenomics: branch of pharmacology which deal w/ the influence of genetic variation on drug response

Seeks the reason for a change in a physiological system or the reason why it operates as it does

Determining whether strength gains during a training were due to factors in the muscle or in the nervous system

Systematic and well-controlled experimentation on fundamental parts of a system

(Ex. myosin heads in muscle cells)

Helps formulate a better understanding of the whole

Describes characteristics about the system, population or phenomenon being studied

Ex. scientist wants to know more about the muscle arrangements in the foot (muscle architecture), so the scientist studies the feet of cadavers and reports the emipirical data

Compares two groups

Ex. Waling stride lengths of older adults vs. older adults with knee osteoarthritis

An experimental condition is applied

Ex. Changes in strength due to a training program

Report changes over substantial time (years to decades)

Ex. Long term Changes in blood pressue

Objective: to identify the common factors and characteristics that contributed to CVD (Cardiovascular Disease)

Over 5,000 Men and Women studied

Every two years, came for a detailed medical review

All practical decisions made should:

1. Be based on research studies

2. That research studies are selected and interpreted according to some specific norms

The study of the patterns, causes and effects of health and disease conditions in defined populations

Epidemiology is used to explain/support the importance of our research problems

#1 Epidemiologist=Dr. John Snow (1854 Cholera outbreak in London)

Scientific research that facilitates the translation of findings from basic science to practical applications that enhance human well-being

"Bench-to-bedside'

Author-submits final manuscript draft (describes an experiment) to the most appropriate journal

Editor-selects 2/3 experts in the same/related field to evaluate the manuscript

Editor-Evaluates the review/determines: accept as is (rare), revise and resubmit, reject

Accepted manuscript-published in a peer-reviewed journal (deemed acceptable by members of the scientific community)

1. Inherent adaptations suchs as those related to development, aging and pathophysiological conditions

2.Adaptations to the external environment such as those occuring w/ exercise, microgravity, hypoxia, hypo- and hyperbaria and hyop- and hyperthermic conditions

Horizontal: across organ systems

Vertical: from molecule to cell to organ

Neuron

Responds to acute challenges of the body

Important in: disease condition (MS) and sport performance (controlling movement)

Provides movement

Primary component: muscle fiber

Muscle=the most metabolically active organ in the body

Types: smooth, cardiac, skeletal

Structural framework

Protects underlying organs/tissues

Provides a lever system for movement

Serves as a storage area for minerals

Minerals and cells bone

Osteoporosis: serious diseases that affets bone

Transport: oxygen, nutrients, hormones, electrolytes

Removes: waste products from the body

Elimination of waste products

Regulation of fluid volume, electrolyt composition and pH

Moving air into and out of the lungs

Regulation of acid-base balance

Regulation of physiologic function and systems of the body

Secrete hormones to blood stream via endocrine glands

Insulin secreted by pancrease regulates carbs and fat metabolism

J curve

[image]

Erect standing position

Feet slightly separated

Arms hanging relaxed at the sides

Palms of the hands facing forward

Body split between posterior (dorsal) and anterior (ventral)

AKA front and back

Split down the middle (left and right)

Lateral

Medial

Cut in half at the waist

Superior (cephalic) and inferior (caudal)

Left lower extremity=hip flexion, knee flexion

Right lower extremity=hip extension, knee extension

Right upper extremity=elbow flexion

Basic bone cells

Located in the matrix of the bone

Bone-forming cells

Osteocytes can become osteoblasts and vice versa

Bone-eroding cells

Remodelling of the bone involves erosion and deposition of bone tissue

Full remodelling= 3 month process

Cancellous

Trabecular

Very springy

Each osteocyte is close to a nutrient supply because the bony tissue is surounded by blood vessels and associated material

Cortical/dense bone

Bone cells too dar from nutrient supply because now the blood vessels are surounded by bony tissue

Also caled osteon

Canals are longitudinaly arranged

Carry blood vessels and are surrounded by layer of bone (lamellae)

Where is most of the calcium within a bone located?

Elite athletes have this

Relationship between strength and mass

Bones in our body are very efficient and are able to withstand large forces and are relatively light

Large surface area spreads forces

More spongy bone in big ends=more flexible

Thing layer of compact bone covers spongy

At the knee

Flexible connective tissue

Reduces friction between bones and allows them to glide

Absorbes shock

Thousands of repeating units of thick and thin filaments moving

Structural and functional unit of a muscle

Structural and function unit of the neuromuscular system

Consists of nerve and muscle fibers

Little overlap between thick and thin protein

1. attachment of the myosin to the active site of the actin filament

2.pivoting of the myosin head to pull the actin toward it

3. release of the myosin head from the actin

4. reactivation of the myosin

Muscle fiber velocity >0

Positive velocity=the shortening

A contraction that permits the muscle to shorten

Ex. Raising a weight during a bicep curl

Greatest forces produced in this type!

Force is less than resistance of environment

Muscle fiber velocity is <0

Negative velocity=lengthening

During normal activity, muscles are active while lengthing

Ex. walking, or setting an object down

The muscle is controling the movement produced by gravity working on the weight

Muscle fiber velocity=0

When the muscle is activated, but instead of being allowed to lengthen or shorten, it is held at a constant length

Ex. pushing a car that is stuck, aka exerting force against a stationary object

Ex. Carrying an object infront of you (the weight of the object would be pulling down, but your hands and arms would be opposing the motion with equal force going upwards. Since your arms are neither raising or lowering, your biceps with be isometrically contracting)

Muscles that cross two joints

Ex. hamstring muscle group at the back of the thigh

Muscles that cross more than one joints

Ex. Muscles in the forearm that bend the fingers

Large ends and high surface area

Cartilage on bone ends

Synovical fluid: contains constituents of blood, substances secreted by the synovial mebrane (lubrication, protection and nutrition) 

Caused by repetitive pouding activities of physical training 

Overuse injuries that occur when muscles transfer the overload of strain to the bone (most commonly in lower leg and cause a tiny crack)

Also: occurs more commonly for people in the military

Property of a fluid that offers resistance to flow

High viscosity: oil

Low viscosity: water

Decrease in visosity with increase in age

Quiz ?: In one experiment, a scientist removes a single muscle fiber from a rat to test the effects of lactic acid on muscle contraction. Which research term best describes this approach?

A. Reductionist

B. Epidemiological

C. Translational

D. Applied

Quiz ?:  Select the answer that best represents horizontal integration

A. Reductionist, applied, translational

b. Skeletal, cardiovascular, immune

C. Myosin molecule, muscle cell, muscle

D. Discipline groups, parent disciplines, subdisciplines

Quiz ?: Select the physiological systems that benefit from the right amount of physical activity

a. Digestive system

B. Muscular system

C. Nervous system

D. Immune system

Quiz ?: In the study of the bone health and skeletal system, which of the following represents the perspective of horizontal integration?

A. Osteocyte, bone, joint

B. Osteocyte, osteoclast, osteoblast

C. Skeletal system, circulatory system, endocrine system

Quiz ?: What structures facilitate the delivery of nutrients through out bone tissue?

A. Sarcomeres

B. Osteocytes

C. Haversian Canals

Quiz ?: When walking, the forward and backward movement of the legs occurs in which plane?

A. Frontal

B. Sagittal

C. Transverse

D. Third

Quiz ?: What conditions might occur with poor bone health?

A. Stress fractures

B. Anemia-due to lack or red blood cells

C. A higher rate of upper respiratory tract infections

D. All of the Above

Quiz ?: Which of the following prevent or reduce damage due to bone on bone contact?

A. Cartilage

B. Tendons

C. Synovial fluid

D. Large bone surfaces at joints

Quiz ?: What cell type breaks down bone?

A. Osteoclast

B. Osteocyte

C. Osteopore

D. Osteoblast

True

Have a role in movement because they lay cross joints and thus initite and control movement

Also have multiple nucleus' and is striated

Actin (thin filament) and myosin (thick filament)

Myosin heads pull actin filaments

Voluntary muscle contraction=controlled by the Central Nervous System

Each skeletal muscle fiber is controlled by a neuron at a single nueromuscular junction midway along the fiber's length (neuromuscular junction)

Controlled in sets stimulated by an electrical impulse (action potentional from a neuron)

Part of the nerve cell that allows one cell to communicate to another

Involved the pre-synaptic nerve terminal and the post-synaptic membrane

1. In the neuromuscular junction, a chemical is released (Acetylcholine) from the end of the nerve fiber, which causes a rapid change in the voltage in the muscle

2. The electrical signal travels over the surface of, and along the muscle fibers

3.The electrical signal causes the release of calcium ions into the cytoplasm of the muscle fiber (links excitation and contraction of the muscle)

4. Calcium ions expose active sites on the actin myofilaments by removing troponin-tropomyosin our of the way to which the myosin filaments immediately attach to the actin

5.Causes a cross-bridge (the attachment) where each myosin filament pulls the actin filaments that ovelap with it at either end toward its center (producing the cross-bridge cycling)

6. When the calcium from the previous step is taken away, the process stops and the contractile proteins relax

Quiz ?: What is the significance of the observation that muscle cells have more than one nucleus?

A. A large fiber can potentially split and there will be a nucleus to control function in both new cells

Quiz ?: The type of muscular contraction in which there is no change in muscle length

A. Eccentric

B. Isokinetic

C. Isometric

D. Concentric

Quiz ?: Select the type of muscular contraction in which the velocity of muscle shortening or lengthening is constant

A. Concentric

B. Isometric

C. Eccentric

D. Isokinetic

Increased muscle mass

Increased bone density and strength

Thicker, stiffer ligaments (evidence that endurance training increases ligament thickness more than spring training)

Thicker and stronger tendons

Gains in bone, ligaments and tendons=generally slower than muscle

Associated with addition of bone like walking and running

Not always good in other activities like swimming and cycling

Weight lifters=highest bone density

Study-

34 rats; 17 exercised, 17 ccontrol

One month exercsie program

Duration=2 hrs a day (1 hr treadmill, 1 hr swimming)

Frequency=5 days per week

Basically concluded that overworking your muscles and bones in exercise can not be good for growing adults or animals, it results in poorer bone strength

In this experiment, there was only 24 hours of recovery, which is not enough if someone is overtrained

Forced exercise compared to voluntary exercise=stressful, stress hormones are released (reduce bone growth)

Refers to the amount of matter in an object

Grams (g)

Kilograms (kg)

Pounds (lb)

Refers to the amount of space (in three dimensions) occupied by an object

Cubic centimeters (cm3)

Cubic meters (m3)

Liters (L)

An objects mass per unit volume

M/V

g/cm3

kg/m3

g/L

A force

It is an object's mass times gravitational acceleration

Calculated=mass in kg x -9.81m/s2

180lb=82kg

Used to determine an objects volume (L or mL)

Volume (forearm and hand)-Volume (and)=Volume (forearm)

Used to estimate the % body fat

Based on different densities of lean and non-lean tissues

Weight (kg), Heigh (m)

Weight/Height squared

For pounds and inches

Same thing, except multiply by conversion factor of 703

Obese=above 30

Overweigh=25-30

Normal=18.5-25

Underweight=less than 18.5

The incidence of ill health (obesity)

Morbidity rate (the # of individuals in por health during a given period of time)

The incidence of death

Mortality rate (the number of deaths during a given time period)

Diseases or conditions that are more likely to occur with obesity but are not necessarily caused by obesity

Ex. with obesity you can have diabetes, hypertension, high cholesterol, sleep apnea

Quiz ?: You apply 40N of force on the side of a dorm refridgerator and it slides 4 meters. Which of the following is a true statement?

A. The mass of the refridgerator is 40N

B. 160 Joules of work was done

C. 10 Watts of power were applied to the refridgerator

D. 1600 Joules of power was applied to the refridgerator

1. Convert mass to force

m x a=N

2. Calculate Work

N x displacement (m)=Joules

3.Calculate Power

Work/time=Watts

A. 1471.5 Watts

1. 100kg x 9.81m/s2=981

2. 981 x 30m=29,430

3. 29,430/20s=1,471.5

B. 700 Newtons

F=ma

F=70kg x 9.81m/s2

F=686N ~ 700N

Quiz ?: As part of your training, you do hill repeats at White Clay Creek State Park. Last week you ran your hill 5 times. This week you ran it 8 times. Which statement is true

A. This week you did more work

B. This week you applied more power

Velocity=m/s

so, 1m/2s=.5m/s

C

Convert kg to N

Calculate work

Calculate power

A. 18.4 Watts

9kg x 9.81m/s2=88.29

88.29 x 50m=4,414.5

4,414.5/240s=18.4 Watts

To understand the human body

To prevent injuries

To optimize performance and efficiency

Physiological enegy systems 

Aerobic power and anaerobic power

May be a bad thing

More prone to back injuries

Temporal and spatial components of movement

Describes motion of points, bodies and systems of the body

Position of displacement

Velocity=displacement/time

Acceleration=velocity/time

Forces during movement, forces that cause movement

Ex. external forces (head injury), internal forces (muscle forces, bone on bone, shearing forces) 

Not traumatic, occur over time

Can be caused by overpronation and underpronation (angles of the rearfoot) of the foot [this is an example of kinematics, because position, velocity/acceleration is being discused]

Allows analysis of details of movement, or shows the movement characterists that are not otherwise visible

An injury that is caused by a non repetitive action

AKA contact injury

[This is an exampl that describes the force that caused the injury, so the focus is kinetics]

A body at rest or in motion will continue in that state unless acted upon by a force

F=ma

When biomechanists measure the forces acting on the body during running or walking

Ex. The amount of force of the body onto the earth, and the amount of force of the earth onto the body

Length of one stride (2 steps)

Calculation for it=stride frequence-# of strides/sec

Measures ground reaction forces

Analysis of kinetics

Location where body mass is in balance

COM changes with body position

Pfluid=pgh

p=m/V=fluid density

g=acceleration of gravity

h=depth of fluid

Closed

Fluid is blood

Pumped by heart

Heart fills passively (when it relaxes it fills)

Open

Fluid is air

Pumped by diaphragm and other resp. muscles

Lungs fill actively (diaphragm creates negative pressure and lungs fill, relaxation=exhale)

 Blood volume=5 liters in human

Dehydration can reduce blood volume

In closed system, this can result in lower blood pressure

Lose more water than you take in

Causes weakness, dizziness and fatigue

Force is up and down

Long fibers

Large range of motion

Fast shortening

Fibers are arranged diagonally

More fibers per area

More cross sectional area

Less large range of motion

Slower shortening

Very fast production

For power, weight lighting, short springs, jumping and throwing

Fast production

For longer sprints, middle distance team sports, ball games (soccer, basketball, rugby)

Slow production rate

For endurance events, team sports, ball games (soccer, field hockey, Australian rules football)

Fat, carbs and protein

Don't provide energy directly

All converted to ATP (which provides the energy)

ATP

Stored in muscle and ready to use

Converted to energy w/o oxygen (Anaerobic)

Breaking chemical bond in ATP releases energy

ATP->ADP + P + heat + energy

What provides short term energy?

Glycolysis

Goal is to make ATP from Glucose

Most glucose stored as glycogen in the muscle

Glycogen converted to glucose is first step in glycogenolysis

Anaerobic, provides a yield of 2 ATP and byproducts that enter the Krebs cycle in the mitochondria

Creatine Phosphate (PCr)

Stored in muscle

Breaking bonds in PCr provides energy to reassemble ATP from ADP and available phosphate

PCr + ADP <-> ATP + creatine

The arrow indicates the use of creatine kinase: an enzyme that speeds up a chemical reaction

Lactate

Used as a fuel

Lactate + Hydrogen ions= lactic acid

Bad= Causes a burning sensation

Muscle contraction impaired by hydrogen

Good=energy source for other metabolic pathways

Perferred fuel source for the heart, liver, kidneys and possibly slow twitch muscle fibers

Allows transport of glucose molecules across the muscle membrane (acts like a gate)

Movement of glucose from the blood into the cell depends on this

Insulin and Glut4 facilitate glucose uptake by cells of the blood

Oxidative Metabolism

2 Aerobic processes (both require oxygen and occur in the mitochondria aka power house of the cell)

1. Krebs cycle (yields 4 ATP per glucose)

2. Electron Transport Chain aka ETC (yields 32 ATP per glucose)

Where fat is stored

Largest storage form of energy in the body

Adipocytes=fat cells

Mostly subcutaneous (under skin) and some visceral (surrounding organs)

Fat cells

Composed of triglycerides which are converted to free fatty acids (FFA)

FFA enters Beta oxidative pathway (the highest ATP yield, but slowest)

Provide a lot of input to Krebs and ETC (about 640 ATP) for long term energy

Energy substrate for muscle

1. Oxygen

2. Blood glucose

Wastes

Carbon dioxide

Lactate

1. Deoxygenated blood returns from the body to the heart

2. Heart sends some blood to lungs to get rid of carbon dioxide and pick up oxygen

3. Oxygenated blood returns to the heart

4. Heart sends oxygenated blood to body to support systems

5. Oxygen dropped off at capillary beds in different tissues and organs

6. Deoxygenated blood returns to heart

Carries oxygenated blood

Ex. coronary artery supplies heart tissue with oxygen rich blood

2 atria, left and right (smaller)

2 ventricles, left and right (larger

Have valves that separate chambers and control direction of blood flow (no backwash)

Heart muscle

Heart has own blood supply/nervous system

Coronary Bypass Surgery: arteries or veins from elsewhere in the patient's body are grafted to the coronary arteries to bypass narrowings and improve blood supply

Angioplasty: technique to mechanically widen narrowed arteries

Stint: mesh tube that holds up narrowed artery

Limiting factor in exercise

Heart rate (resting heart rate, beats/min) x Stroke volume (volume pumped per beat, depends on left ventricle size and forcefullness of heart contraction aka systole)

Immediate

Ex. During a run, heart rate goes up

Short lasting

Ex. After the run, heart rate returns to its resting value

Long lasting

Ex. after 6 weeks of running a person's resting heart rate might be lower

Contraction of smooth muscle in arteriolar walls

Reduces flow to area

Thickening of the myocardium of the left ventricle wall

Occurs as a training response

Thickening

Makes it harder for blood to leave the heart

Plasma

3 Blood cells types

1. RBC=carries oxygen

2.WBC=part of immune system

3.Platelets=clotting

Lack of blood

Not enough RBCs (hematocrit=measurement of the amount of RBCs in blood)

Not enough hemoglobin (Hb)

Poor binding of oxygen to  Hb due to deformation of Hb binding site

Breath pure oxygen

Hyperbaric oxygen therapy (increases the removal of CO from the hemoglobin and increases O2 binding)

Indicates the maximal amout of oxygen they can use per minute

VO2 max is increased w/ training

VO2 max running and cycling protocal

Exercise at steady state

Higher intensity=more lactate being made than can be clear from muscle (the exercise intensity where this begins is your lactate threshold)

Subject is on stationary bike/treadmill

Exercises in successive 4-5 minute intervales increasing workload

Period finger stick to measure blood lactate

To assess anaerobic power

Timer pads are typically on the 8th and 12th steps

Tests anaerobic power

Mechanically braked bicycle

10 min warmup

Athlete pedals as fast as possible w/o any resistance

In 3 seconds a fixed resistance is applied to the flywheel and the athlete continues to pedal 'all out' for 30 seconds

Receptors

Motor Nerves

Sensory Nerves

Spinal Cord

Brain

Detects tension in muscle tendon organ

Inhibits motor neuron

Detect joint poisition

Most sensitive near the end of a joints range of motion

False

HR x SR

False

Systole