Transcript File

Musculoskeletal System
SPORTS MEDICINE 10 HCS1050

Human Body Facts – DID YOU KNOW?
 1. For every pound of fat gained, you add seven miles
of new blood vessels.
 New tissue needs blood supply, so your vascular system
expands to accommodate it. This also means your heart
must work harder to pump blood through the new
network, which may reduce oxygenation and nutrient
replenishment in other tissues. Lose a pound? Your body
will break down and reabsorb the unneeded blood
vessels from the previous tissue.
 2. Muscle tissue is three times more efficient at
burning calories than fat.
 This is why possessing more muscle should be a
training goal for most people. More muscle = more
calories burned = less fat = being more thin and fit
looking.
 3. You are taller in the morning than in the evening.
 When you crawl out of the sack in the morning you are
at your tallest. On average, you are approximately one
half inch taller when you wake in the morning, thanks to
excess fluid between within your spinal discs. While you
are sleeping, these fluids replenish. During the day your
body has to deal with the stress of standing, so the discs
become compressed and the fluid seeps out. This results
in you losing a small amount of extra height.
 4. Your stomach manufactures a new lining every three
days to avoid digesting itself.
 As a part of the digestive process, your stomach secretes
hydrochloric acid (HA). HA is a powerful corrosive
compound also used to treat various metals. The HA
your stomach secretes is also powerful, but mucous
lining the stomach wall keeps it within the digestive
system. As a result it breaks down the food you
consume, but not your own stomach.
 5. Your body produces enough heat in only thirty
minutes to boil 2L of water.
 Your body is the epitome of a study on the laws of
thermodynamics. You produce heat from all that is
going on - exercise, metabolizing food, maintaining
homeostasis – and as you sweat, exhale, excrete,
and urinate.
 6. Human bone is as strong as granite, relative to
supporting resistance.
 Would you believe a matchbox-size chunk of bone
can support 18,000 pounds? Compared to concrete,
human bone is four times greater in support
strength.
 7. Your skin is an organ.
 Just like the liver, heart, and kidneys, your outer covering
is an organ. An average man has enough skin on his body
to cover approximately twenty square feet. For an
average woman it is approximately seventeen square
feet. Approximately 12% of your weight is from your
skin. And, your skin replaces 45,000+ cells in only a few
seconds. It's constantly growing new skin and shedding
old skin.
 8. By the age of eighteen your brain stops growing.
 From that age forward it begins to lose more than 1,000
brain cells every day. Only two percent of your body
weight is occupied by your gray matter, but is uses up to
20% of your overall energy output (it needs
carbohydrates). Your brain works continuously and never
rests, even when you're asleep. Aside from producing
REM dreams, your brain works overtime to replenish its
ability to function normally during your daytime waking
hours.
 9. There are more than 600 individual skeletal
muscles and 206 bones in your body.
 If all 600+ muscles contracted and pulled in the
same direction, you could lift over twenty tons of
resistance. Additionally, the adult skeleton is
composed of 206 bones, but at birth an infant
skeleton contains approximately 350 bones. Over
time, some of the 350 bones fuse together and
eventually grow to the 206 adult figure.
 10. You need to consume 1L of water each day for four
months to equate to the amount of blood your heart
pumps in one hour.
 Additionally, over a lifetime, at your normal (resting)
heart rate you will have pumped enough blood to fill
thirteen oil super tankers. To further expound on this
fact, on average, your heart beats 40,000,000 times per
year. Doing the math, over your lifetime (both men and
women averaged), that results in 2,600,000,000
heartbeats (two billion, six hundred million). This does
not even factor in your increased heartbeats due to
higher levels of exercise.
What are our bodies made up of?
Types of Body Tissues
1)Nervous
2)Epithelial
3)Muscular
4)Connective
Regional and Directional Terms
 All of these directional terms are in
reference to anatomical position.
 Recall: Anatomical position is the standard
point of reference for the human body and
looks like:
 Standing erect and eyes forwards, chin
neutral.
 Standing with legs together and feet flat
on the floor, toes pointing forwards.
 Hands down at side and palms facing
forwards.
Regional and Directional Terms
Term
Region or Reference
Example
Anterior
Front
The navel is on the anterior side of the trunk
Posterior
Back
The scapula is posterior to the rib cage
Ventral
The belly side (equivalent: anterior)
The navel is on the ventral surface
Dorsal
The back side (equivalent: posterior)
The scapula is on the dorsal side of the body
Cranial
Toward the head
The cranial border of the pelvis is superior to thigh
Cephalic
Same as cranial
Superior
Above, at a higher level
The head is superior to the chest
Inferior
Below, at a lower level
The chest is inferior to the head
Medial
Toward the midline of body
The nose is medial to the eyes
Lateral
Away from the midline of the body
The ears are lateral to the nose
Proximal
Toward an attached base/center of body
The thigh is proximal to the foot
Distal
Away from an attached base/center of body
The foot is distal to the thigh
Superficial
At, near, or relatively close to body surface
The skin is superficial to the muscles below
Deep
Toward the interior of body, away from
surface
The bone of the thigh is deep to the surrounding
muscles
Practice
 Stand up and turn  1) Head
to a partner.
Please use the
regional and
directional terms
we just learned to
describe the
relative body
positions of the
following body
parts:
 7) Nose
 2) Hand
 8) Ears
 3) Belly Button
 9) Eyes
 4) Knee
 10) Elbow
 5) Foot
 6) Spinal Cord
Directional Planes
Sagittal – separates
body into left and right
halves
Frontal/Coronal –
separates body into
front (anterior) and
back (posterior) halves
Transverse – separates
body into upper
(superior) and lower
(inferior) halves
Superficial Musculature
(More detail to come later)
Major Bones of the Body
(More detail to come later)
Muscular System
There are three types of muscular tissue:
 Skeletal Muscle – moves the body by pulling on
bones of the skeleton making it possible to walk,
dance, play an instrument. Voluntary. Make up
30-40% of your body weight.
 Cardiac Muscle – pushes blood through the heart,
arteries, veins, and blood vessels of the circulatory
system. Involuntary.
 Smooth Muscle – pushes fluids and solids along
the digestive tract and performs varied functions
in other organs and systems. Involuntary.
Muscular System
 All three muscle types include the same four basic properties:
 Excitability: the ability to respond to stimulation. For
example, the muscular system responds to stimulation
from the nervous system and some smooth muscles
respond to circulating hormones
 Contractility: the ability to shorten actively and exert a
pull or tension on connective tissues and bones
 Extensibility: the ability to continue to contract over a
range of resting lengths.
 Elasticity: the ability of muscle to rebound towards it
original length after a contraction
5 Functions of the Muscular System
 Produce Skeletal Movement
 Maintain Posture and Body Position
 Support Soft Tissues
 Regulate Entering and Exiting of Material
 Maintain Body Temperature
Muscle Terminology
 Origins and Insertions
 An origin is where a muscle originates from
or is anchored at. An insertion is where a
muscle inserts or connects itself to.
 Typically the origin remains stationary and
the insertion moves with muscle
contractions, or the origin is proximal to the
insertion.
Muscle Terminology
 Actions
 Prime Movers or Agonists – a muscle whose contraction
is chiefly responsible for producing a particular
movement. Example: biceps brachii is an example of an
agonist producing flexion at the elbow.
 Synergists – when these contract, they assist the prime
movers in their action. May provide additional pull or
else stabilize the point of origin.
 Antagonists – oppose the movement of the agonists. For
example: if the agonist produces flexion (biceps), the
antagonist will produce extension (triceps)
How are muscles named?
1) Location to a nearby bone
Example: Quadriceps Femoris
(on the femur)
2) Location related to body
position, insertion, and/or
origin
Example: Tibialis Anterior
3) Size
Example: Gluteus Maximus vs.
Gluteus Minimus
How are muscles named?
4) Shape
Example: Deltoid
5) Direction of Fibers
Example: Transverse Abdominis
6) Number of heads
Example: Biceps Brachii (2) vs Triceps
Brachii (3)
7) Action
Example: Flexor Digitorum
(flexion of digits/fingers)
Associated Soft Tissues and Organs
Related to Skeletal Muscle

There are many soft tissues and other organs that
keep our muscles in place, and moving smoothly.

1) Tendons – attaches a muscle to a bone

2) Fascia - connective tissue fibers that form sheets
or bands beneath the skin to attach, stabilize,
enclose, and separate muscles and other internal
organs

3) Cartilage - a flexible connective tissue found in
many parts of the body. It can bend a bit, but resists
stretching. Its main function is to connect bones
together, and some types can help shock absorption.

4) Ligaments – attaches bone to other bone

5) Skin – protection, heat regulation