Muscular System Prepared by Mr. Shoup

Muscular System• There are nearly 650 skeletal muscles in the human body• Muscles control movement • Help to maintain posture• Circulate blood and move substances throughout the body.• Muscle makes up around half of the total human body

weight. • Muscle tissue is also around 15% denser than fat tissue

• The word muscle is derived from the Latin term musculus, meaning "little mouse".

This Latin term could be due to the shape of some muscles or because muscles contracting under the skin can look like a mouse moving under a rug.

It takes 17 muscles to smile and 43 to frown.

We are about 1 cm taller in the morning than in the evening.

The strongest muscle in the human body is the tongue. The tongue has 8 muscles, so it is technically not the strongest muscle in the body.

You use 200 muscles to take one step. Most of us take about 10,000 steps a day.

It takes twice as long to lose new muscle if you stop working out than it did to gain it.

If muscle strength is regarded as the ability to use force on something then the jaw muscle (masseter) is the strongest in the body.

The strongest muscles in relation to the job they have to do is the external muscles of the eye which are large and about 100 times stronger than they need to be in relation to the small size and weight of the eyeball.

Muscular System

• There are three types of muscles in the body

• Skeletal-Striated/Striped

• Smooth

• Cardiac

Skeletal Muscle• Skeletal muscles are attached to the skeleton-bones

• Have A and Z bands-light/dark bands Muscle fibers parallel• They work in pairs called antagonistic motion-as one muscle contracts

the other muscle group relaxes.

• Skeletal muscles are voluntary muscles - in other words we think about what movements we want to make and send messages via our nervous system to tell the appropriate muscle(s) to contract.

Examples: biceps, triceps deltoids, hamstrings and quadriceps.

• Provide us to run, walk, swim, etc.

• Muscle contractions can be short, single contractions or longer

contractions.

Smooth Muscle• Smooth muscles are involuntary muscles - we do not have to think about

contracting them because they are controlled automatically by the autonomic nervous system.

• Have no light or dark bands, muscle fibers are staggered, or feather like.

• Smooth muscles are found in our internal organs: in our digestive system the esophagus, stomach, intestines, our circulatory system blood vessels, glands, our urinary tract the bladder, our respiratory organs (diaphragm) and, in a female reproduction system the uterus

• It would be pretty inconvenient if we had to think about

digesting our food, telling blood vessels to contract or relax, if we

could do that.

• Smooth muscles can stretch and maintain tension over extended periods.

Cardiac Muscle• Cardiac-means heart, the muscle is found only in the

heart.

• Cardiac muscle is involuntary. We can not control!

• It can stretch, just like smooth muscle, and contract like skeletal muscle.

• It is a twitch muscle - it only does short single contractions. Beats 72-80 times per minute at resting.

SprainOverstretched or torn ligament

StrainOverstretched or torn muscle/tendon

Skeletal muscle can be further divided into two types, slow twitch and fast twitch.

• Slow Twitch (Type I) muscle contain proteins that give it a rich red color. (Red Muscle Fiber) Red color due to myoglobin

• This muscle carries more oxygen efficiently and using fats, proteins or carbs as energy slow twitch muscle fibers contract over a long period of time.

• Therefore type I muscle fiber works well for aerobic sports such as long distance jogging and cycling, jump roping, swimming longer distance, walking, ski machines, stair climbers, steppers, elliptical.

____________________________________________________• Fast Twitch (Type II) muscle is whiter in color (White Muscle Fiber) as

it has less myoglobin (a oxygen carrying protein). • Fast twitch fibers contract quickly and powerfully, however they

fatigue rapidly. • Therefore type II muscle fiber is useful for anaerobic exercise such as

sprinting or for strength sports like weightlifting, sprints

Aerobic• Oxygen, fats and glucose are used to produce adenosine

triphosphate-ATP=energy• Once glucose is used up, body will go to fats-stored energy

for energy.• Glucose, oxygen=ATP=Energy-produces lactic acid by

product of work. (Krebs Cycle) Lactic acid broken down into water and carbon dioxide.

• Cardiovascular Endurance• It burns calories very effectively and can increase basal

metabolic rate which aids in weight loss.• You perform it for 30 to 60 minutes, three to five days a

week

Aerobic health benefits• Strengthening muscles involved in respiration, to

facilitate the flow of air in and out of the lungs.• Strengthening the heart muscle, to improve its

pumping efficiency and reduce the resting heart rate.

• Toning muscles throughout the body, which can improve overall circulation and reduce blood pressure.

• Increase the total number of red blood cells in the body-transportation of oxygen.

Anaerobic Exercise

• Anaerobic means with oxygen. Limits oxygen and fat usage.• Think-Short and Fast• Process: Glucose process of glycolysis which produces

pyruvic acid plus Nicotinamide Adenine dinucleotide9(NAD)=lactic acid=muscle fatigue and soreness

• Rest time-muscles recovery, due to oxygen and the breakdown of lactic acid=replenish energy.

• Examples of anaerobic exercise-heavyweight lifting, sprinting, jumping, rowing short, quick push ups, sit ups.

• Around a few seconds to no more than minutes-3 minutes. Interval training

Anaerobic exercise benefits

• Higher calorie consumption• Increase body metabolism• Shorter, more effective workouts• This exercise is anabolic in nature, meaning

that it promotes lean tissue.

Find Target Heart Rate

• Subtract your age from 220 to find maximum heart rate 220-48=172 beats per minute.

• Then multiply your maximum heart rate by 65%. • 172 x 65%=111.8 beats per minute=low target

heart rate (Burns more fat)• High target heart rate 172 x 85%=146.2 beats per

minute. (Burns calories)• Target heart rate 111.8 to 146.2 beats per minute