Download muscle power point - bhshecurriculumwork2011

Bones
•
•
a type of connective
tissue made up of cells
suspended in a matrix
the collagenous matrix
in bone just happens
to be heavily
impregnated with
minerals.
Functions of Bone
•
As a lever. The bones of the upper and lower limbs pull
and push, with the help of muscles.
•
As a calcium store. 97% of the body's calcium is stored
in bone. It is easily available and turns over fast.
Bone and its marrow

The cavities produced in unstressed areas
(like the holes in the tubes of a bicycle
frame) are used for marrow, or in some
places (mastoid) just for air storage.
Marrow sits in the interconnecting cavities
between these plates or rods of bone.
Dead or Alive?
•
The main misconception about bones is
that they are made up of dead tissue. This
is not true, they have cells, nerves, blood
vessels and pain receptors. Bone
constituents, organic and inorganic matrix
and cells all turn over at a fairly rapid rate.
How strong is bone?
•
In tensile strength bone is rather like cast
iron, although around 1/3 of the weight, in
bending stress it behaves like steel,
although only half as strong and in
compression it can withstand the forces
exerted by a running man ( approximately
equivalent to a dead weight of 594
pounds).
Classification of Bones
•
The skeleton is made up of many bones
which change in proportion between man
and his close relatives but are easily
recognizable. The easiest way to classify
bones is by shape.
Classification of Muscles
•
•
•
•
•
•
•
Some muscles (skeletal muscles) do not contract until stimulated by
neurons
Other muscles (smooth & cardiac) will contract without nervous
stimulation but their contraction can be influenced by the nervous
system.
Characteristics of muscle:
excitability - responds to stimuli (e.g., nervous impulses)
contractility - able to shorten in length
extensibility - stretches when pulled
elasticity - tends to return to original shape & length after contraction
or extension
Long Bones
•
Typical of limbs, and a good place to start.
They consist of a central, usually hollow,
tubular region, the diaphysis linked to
specialized ends (epiphysis) by a junctional
region (metaphysis). Look at the shaft first.
Tubular, a bit like a bicycle frame tube.
Inside a long bone
Parts of a Long Bone
diaphysis,
shaft
The long, relatively straight main body of the bone; region of primary ossification.
epiphyses
The end regions of the bone; regions of secondary ossification.
epiphyseal plate
The thin sheet of bone marking the fusion of epiphyses to the diaphysis (adults only).
head
The proximal articular end of the bone.
neck
The region of bone between the head and the shaft.
Short Bones
•
Found in the wrist and ankle, carpals and
tarsals respectively. They have no shaft, as
they do not increase dramatically in size in
one dimension during growth, and tend to
be cuboidal in shape.
Flat Bones
•
In the cranium or the scapula are
sandwiches of spongy bone between two
layers of compact bone
Irregular bones
•
Any bones which don't fit these arbitrary
categories (bones of the face, vertebrae) are
referred to as irregular.
Sesamoid Bones
•
Interesting because they occur in tendon,
especially where a tendon turns a corner,
and is thus exposed to friction.
Terminology
process
articulation
articular process
eminence
tuberosity
tubercle
trochanter
spine
suture
malleolus
condyle
epicondyle
line, ridge
crest
facet
foramen
fossa
canal
meatus
sinus
A relatively large projection or prominent bump.
The region where adjacent bones contact each other—a joint.
A projection that contacts an adjacent bone.
A relatively small projection or bump.
A projection or bump with a roughened surface.
A projection or bump with a roughened surface, generally smaller than a tuberosity.
One of two specific tuberosities located on the femur.
A relatively long, thin projection or bump.
Articulation between cranial bones.
One of two specific protuberances of bones in the ankle.
A large, rounded articular process.
A projection near to a condyle but not part of the joint.
A long, thin projection, often with a rough surface.
A prominent ridge.
A small, smooth articular surface.
An opening through a bone.
A broad, shallow depressed area.
A long, tunnel-like foramen, usually a passage for notable nerves or blood vessels.
A short canal.
A cavity within a cranial bone.
Connecting bones to muscles
What it looks like
Functions of muscle:
•
motion
•
maintenance of posture
•
heat production
Skeletal
•
attached to bones & moves
skeleton
•
also called striated muscle
(because of its appearance
under the microscope, as
shown in the photo to the left)
•
voluntary muscle
Breaking it down
Physiologically
In the (H) Zone
Types of muscle contractions
•
•
Isotonic- tension or force generated by the
muscle is greater than the load and the muscle
shortens
Isometric- load is greater than the tension or
force generated by the muscle and the muscle
does not shorten
Twitch:
•
The response if a skeletal muscle to a
single simulation.
Latent Period
•
•
•
no change in length
time during which impulse is traveling
along sarcolemma
chemical reaction is is happening to spur
the contraction
Contraction Period
• Tension increases
Relaxation Period
•
Muscle relaxes
•
Return to original length