Ppt

1. Musculoskeletal System

2. Introduction
 The Musculoskeletal
system is made up of
two different systems.
 It is important to know
how each system
works.

3. Three Types of Muscles
 The three types of muscles tissues are:
– Smooth
– Skeletal
– Cardiac

4. Smooth Muscle
 smooth (or visceral) muscle-
– forms the muscle layers in the walls of the
digestive tract, bladder, various ducts, arteries and
veins, and other internal organs.
– Smooth- muscle cells are elongated and thin, have
only one nucleus, and form sheets rather than
bundles of muscles.
– Smooth muscle is controlled by the
autonomic nervous system (ANS).

5. Smooth Muscle

6. Skeletal Muscle
 skeletal (or voluntary/striated) muscle, is the most abundant
tissue in the human body, it produces movement.
 Each skeletal-muscle fiber is roughly cylindrical, contains many
nuclei, and is crossed by alternating light and dark bands called
striations.
 Fibers bind together, via connective tissue, into bundles; and
these bundles, in turn, bind together to form muscles.
 Thus, skeletal muscles are composite structures composed of
many muscle fibers, nerves, blood vessels, and connective
tissue.
 Skeletal muscles are controlled by the somatic nervous system
(SNS).

7. Skeletal Muscle

8. Cardiac Muscle
 cardiac (or heart) muscle, a cross between
the smooth and striated muscles, makes up
the heart tissue.
 Like smooth muscle, it is controlled by the
autonomic nervous system (ANS).

9. Cardiac Muscle

10. Muscle Function
 There are two important
proteins involved in
muscle function.
– Actin
– Myosin
 They overlap at an area
called the sarcomere.
 Video1
 Video2

11. Muscle Function

12. Skeletal System
 Its 206 bones form a rigid
framework to which the
softer tissues and organs
of the body are attached.
 Vital organs are protected
by the skeletal system.
 They also function to
move, support, produce
red and white blood cells
and store minerals.

13. The parts of the skeleton
 The human skeleton is
divided into two
distinct parts:
– Axial
– Appendicular

14. Axial Skeleton
 The axial skeleton consists of bones that
form the axis of the body and support and
protect the organs of the head, neck, and
trunk.
The Skull
The Sternum
The Ribs
The Vertebral Column

15. Appendicular Skeleton
 The appendicular skeleton is composed
of bones that anchor the appendages to
the axial skeleton.
– The Upper Extremities
– The Lower Extremities
– The Shoulder Girdle
– The Pelvic Girdle--(the sacrum and coccyx are
considered part of the vertebral column)

16. Sacrum

17. Composition of bones
 Bone is not a uniformly
solid material, but rather
has some spaces
between its hard
elements.
 Two types of bone
tissue
– Compact
– Spongy

18. Compact Bone
 The hard outer layer of bones is composed of
compact bone tissue, so-called due to its
minimal gaps and spaces.
 This tissue gives bones their smooth, white,
and solid appearance, and accounts for 80%
of the total bone mass of an adult skeleton.

19. Spongy Bone
 Filling the interior of the organ is the trabecular bone
tissue (an open cell porous network also called
cancellous or spongy bone) which is composed of a
network of rod- and plate-like elements that make the
overall organ lighter and allowing room for blood
vessels and marrow.
 Trabecular bone accounts for the remaining 20% of
total bone mass, but has nearly ten times the surface
area of compact bone.

20. Bone Cells
 Osteoblasts: are mononucleate bone-forming
cells. Osteoblasts also manufacture
hormones, to act on the bone itself.
 Osteocytes originate from osteoblasts. Their
functions include formation of bone, matrix
maintenance and calcium homeostasis.
 Osteoclasts are the cells responsible for
bone resorption (remodeling of bone to
reduce its volume).

21. Five different types of bones
 Long (femur)
 Short (carpus)
 Flat (sternum)
 Irregular (vertebrae)
 Sesamoid (embedded in
tendon)

22. Disorders
 Bone fracture
 Osteomyelitis
 Osteoporosis
 Osteosarcoma
 Osteogenesis
imperfecta
 Arthritis

23. How do they work together?
 The musculoskeletal system consists of the skeletal system
-- bones and joints and the skeletal muscle system. These
two systems work together to provide basic functions that are
essential to life, including:
 Protection
 Support
 Blood cell formation
 Mineral homeostasis
 Storage: stores fat and minerals.
 Leverage

24. Tissues involved
 There are 5 basic tissues comprising the
musculoskeletal system:
– bones,
– ligaments (attaching bone to bone)
– cartilage (protective gel-like substance lining the
joints and intervertebral discs),
– skeletal muscles
– tendons (attaching muscle to bone).

25. How do our muscles and bones work
together to cause locomotion?
 Joint: where two bones
meet
 2 types:
– Structural
– Functional

26. Structural Joints
 Fibrous
 Cartilaginous
 Synovial

27. If you have a weak stomach look away
now!!

28. Functional Joints
 Functional joints are
classified by the range
of movement they
provide
– synarthroses
– amphiarthroses
– diarthrosis

29. Moveable joints
 Ball and socket
 Hinge
 Pivot
 Gliding
 Saddle
 Condyloid

30. Categories of moveable joints

32. How do muscles work to move joints?
 Flexor Vs Abductor
– Flexor contracts
– Abductor extends

33. Homeostasis and muscles
 Feedback loop
– Cold weather
– Reflex
 Muscles help you
respond to changes in
your environment by
enabling you to move.