1. Unit 13 (ch 26) Movement
What’s another word for movement?
Which two systems work together to allow support & movement? Muscular & skeletal system
What’s another word for movement? locomotion
Which two systems work together to allow support & movement?

2. 2 Types of Skeletal Systems
Exoskeletons
Endoskeletons
What’s the difference?
Difference Exoskeleton  cover body Endoskeleton  inside body

3. Skeletal Systems: Exoskeletons
Found in arthropods – “jointed legs”
made of chitin & protein
Advantages?
Disadvantages?
What must an arthropod do to its exoskeleton in order to grow?
Chitin is a carbohydrate
Advantages? Tough & rigid  Protection + support + locomotion (movement) waxy outer surface  Helps prevent water loss
Disadvantages? Limits size (b/c of weight) & growth (exoskeleton does not grow) What must do to exoskeleton in order to grow?  molt

4. Skeletal Systems: Endoskeletons
Found in vertebrates
Similarities to exoskeleton?
Differences from exoskeleton?
Advantages?
Disadvantages?
Similarities to exoskeleton? Protection (skull, ribs, breast bone, vertebrae) of organs, support (thigh bones = femur), and locomotion (attachment for muscles)
Differences from exoskeleton? Lies inside soft tissue not on outside, subdivided into different parts (bones), which are specialized for certain functions & types of movement, does not limit space/does not need to molt, makes blood cells
Advantages? Protect internal organs, size & growth not as limited as w/ exoskeleton, bones are stronger than exoskeleton so size limit is bigger
Disadvantages? Little external protection
206 bone in adult human

5. Development of Bones Cartilage
Tough, flexible tissue, no minerals, less dense than bone
Where found?
Where found? Most of skeleton in vertebrate fetus, ends of bones in adult (to provide for smooth joint surface), trachea to prevent collapse
Density = mass/volume (higher density = more mass per unit volume, so more compact)

6. Development of Bones
Even though hard & made of minerals bone IS a living tissue that grows
Ossification
Ossification = replacement of cartilage w/ bone by activity of osteoblasts & addition of minerals such as calcium compounds (taken from blood) Occurs in most bones Not completed until ~25 years old
Some cartilage remains at ends to provide smooth joint surfaces

7. Structure of Bone 3 types of bone cells osteoblasts osteocytes
osteoclasts
Osteoblasts – cells that form new bone through ossification – replacement of cartilage or membrane by bone – take calcium from blood
Osteocytes -- are mature osteoblasts found in most formed bone tissue
Ostoeclasts break down bone

8. Structure of Bone 2 types of bone tissue compact bone spongy bone
Osteoblasts – cells that form new bone through ossification – replacement of cartilage or membrane by bone – take calcium from blood
Osteocytes -- are mature osteoblasts found in most formed bone tissue
Ostoeclasts break down bone
Periosteum – touch outer membrane, supplies nerves and blood vessels to Haversian canal, contains cells needed for growth & repair, point of attachment for muscle
2 types of bone tissue compact bone  shafts of long bones, hard & compact, made of alternating layers of collagen (protein) & minerals & contains many tiny channels called Haversian canals which carry blood vessels & nerves that supply osteocytes in the bone tissue, marrow in central hollows of many bones (red marrow in flat bones & ends of long bones produces red blood cells, some white blood cells, & platelets, & yellow marrow in hollow interior of long bones stores fat), marrow also functions in formation of bone cells
spongy bone  ends of long bones, under a layer of compact bone, composed of a system of cavities & intersecting plates
Interactive Bone Diagram 8

9. Joints in Vertebrates Point(s) where bones connect
Ends of bones covered with cartilage
Fluid-filled bags between cartilage & bone
Why?
Ends of bones covered with cartilage provide smooth joint surfaces Fluid-filled bags between cartilage & bone (= bursa) Why? Cushion to prevent bones from rubbing against each other

10. Joints in Vertebrates What holds bones to other bones?
What holds bones to other bones? Muscles & connective tissue called ligaments (made of collagen & some elastic fibers)

11. Joints in Vertebrates major types movable fixed ball & socket hinge
Classification of Joints Animation
major types
movable
ball & socket
hinge
pivot
gliding
fixed
Ends of bones covered with cartilage provide smooth joint surfaces Fluid-filled bags between cartilage & bone (= bursa) Why?
Most are movable What holds them together? Muscles & connective tissue called ligaments (made of collagen & some elastic fibers
Fixed
joint
Gliding joint
Gliding joint

12. Movable Joints in Vertebrates
1) Ball & Socket
examples
most mobility
Which directions?
Examples  shoulder (end of humerus = rounded knob, shoulder/scapula = depression) & hip (end of femur = rounded knob, pelvis = depression)
most mobility How can it move? Rotate, move front–back, move side-side

13. Movable Joints in Vertebrates
2) Hinge Joint
examples
limited mobility
Which directions?
Examples Elbow, knee, fingers, toes
Limited mobility Which directions? movement in only 1 direction (like a door  opened or closed)

14. Movable Joints in Vertebrates
3) Pivot Joint
examples
limited mobility
Which directions?
Examples where skull connects to spine, where ulna & radius (lower arm) connect near elbow
limited mobility Which directions? The end of one bone rotates (pivots) on another

15. Movable Joints in Vertebrates
4) Gliding Joint
examples
limited mobility
Which directions?
Examples vertebrae, wrist, ankle
limited mobility Which directions? back and forth motion, side to side

16. Fixed Joints in Vertebrates
not connected by ligaments
examples
mobility?
another name?
Examples individual bones of skull
mobility? Fixed joints in the skull create flexibility during birth b/c not fused yet (“soft spots”), in adults fused together (not connected by ligaments), connecetd by fibrous connective tissue
Also known as immovable joints or sutures

17. Ligament Injuries Sprains Common symptoms 1st degree 2nd degree
3rd degree
Common symptoms
Sprains 1st - 3rd degree 1st = ligaments stretched, 2nd = ligament partially torn, 3rd = ligament completely torn
Why? b/c hinge joint
Example The anterior cruciate ligament, also called the ACL, is one of the four major ligaments of the knee. The ACL prevents excessive motion of the knee joint--patients who sustain an injury to their ACL may complain of symptoms of the knee "giving out.“
How does this affect a person? Impede movement b/c ligaments attach bones across movable joints

18. Ligament Injuries Common in knee
especially if hit from side
Why?
Ex. Anterior Cruciate Ligament (ACL)
How do ligament injuries affect a person?
Sprains 1st - 3rd degree 1st = ligaments stretched, 2nd = ligament partially torn, 3rd = ligament completely torn
Why? b/c hinge joint
Example The anterior cruciate ligament, also called the ACL, is one of the four major ligaments of the knee. The ACL prevents excessive motion of the knee joint--patients who sustain an injury to their ACL may complain of symptoms of the knee "giving out.“
How does this affect a person? Impede movement b/c ligaments attach bones across movable joints 18

19. Muscles in Vertebrates
>600 muscles human body
made of long, excitable cells capable of contraction
attached to skeleton
contract  pull on skeleton
movement
as contract pull on skeletal system results in movement

20. Muscles in Vertebrates
What holds muscles to bones?
Attachment to 2 sites necessary for movement
What holds muscles to bones? connective tissue called tendons
Attachment to 2 sites is necessary for movement (during contraction one end of the muscle the bone to which it is attached do not move = point of origin) (other end of the muscle & the bone to which it is attached move when the muscle contracts = point of insertion)

21. Tendons Which is the thickest & strongest tendon in the human body?
The Achilles tendon is the thickest and strongest tendon in the human body

22. Tendon Injuries tendonitis rupture
How does that affect a person?
Tendonitis soreness of tendon due to small tears
Rupture (totally torn tendon) tendon completely tears apart
Torn tendons are a common injury How does that affect a person? It would preclude (stop) movement b/c tendons attach muscles to bones 22

23. Muscles in Vertebrates
for locomotion
work in opposing pairs (or groups) b/c can only contract
examples
flexor & extensor
What does each do?
Example of each type?
for support of body
Examples biceps & triceps
Flexor & extensor What does each do? Flexor causes flexing/decrease of angle (bending) at a joint (ex. biceps) extensor causes the extension/increase of angle (straightening) of a joint (ex. triceps)
also important for support of body b/c both muscles of pair are always slightly contracted (“muscle tone”), keeps muscles ready for quick contractions
Animation of Muscles Working in Pairs
Muscles Contracting in Pairs

24. Muscles Types in Vertebrates
striated (a.k.a. skeletal)
smooth
cardiac
Skeletal muscles (striated) – voluntary, moves bones, long multinucleate cells “fibers”
Smooth muscles – involuntary, lines digestive and respiratory tracts and blood vessels, tapered distinct cells
Cardiac muscle – involuntary, only in heart, striated and branched

25. Skeletal muscles (striated) – voluntary, moves bones, long multinucleate cells “fibers”
Smooth muscles – involuntary, lines digestive and respiratory tracts and blood vessels, tapered distinct cells
Cardiac muscle – involuntary, only in heart, striated and branched

26. Muscles Types in Vertebrates
1) Striated (skeletal)
Appearance of cells?
Where typically found?
Function?
Voluntary or involuntary?
Appearance of cells? long multinucleate striated/striped cells “fibers”
Where typically found? Legs/arms
Function
Used for locomotion? Yes moves bones (locomotion)
Use for peristalsis? no
Involved in reflex arc? yes
Voluntary or involuntary? Voluntary
Contracts quickly or slowly? quickly
Stays contracted for a long or short period? short

27. Muscles Types in Vertebrates
2) Smooth
Appearance of cells?
Where typically found?
Function?
Voluntary or involuntary?
Appearance of cells? tapered distinct cells each w/ nucleus
Where typically found? lines digestive tract, respiratory tract, & blood vessels
Function
Used for locomotion? no
Use for peristalsis? Yes Regulate activity of organs or diameter or vessels
Involved in reflex arc? yes
Voluntary or involuntary? involuntary
Contracts quickly or slowly? slowly
Stays contracted for a long or short period? long

28. Muscles Types in Vertebrates
3) Cardiac
Appearance of cells?
Where typically found?
Function?
Voluntary or involuntary?
Appearance of cells? Striated & branched
Where typically found? Only in heart
Function contracts rhythmically to force blood out of heart chambers into arteries
Used for locomotion? no
Use for peristalsis? no
Involved in reflex arc? no
Voluntary or involuntary? involuntary
Contracts quickly or slowly? quick
Stays contracted for a long or short period? short

29. Voluntary or involuntary? Muscle Types in the Body
Striated (skeletal)
Cardiac
Smooth
Appearance of cells?
striated
striated & branched
smooth
Where typically found?
legs/arms
heart
digestive system, respiratory system, blood vessels
Function?
locomotion
pump blood from heart to arteries
peristalsis, regulate activity of organs or diameter or vessels
Voluntary or involuntary?
voluntary
involuntary
Muscle Types in the Body

30. Contraction of Vertebrate Muscles
Muscle fibers made of fibrils
made of protein filaments
called actin (thin) & myosin (thick)
Sliding Filament Hypothesis
muscle receives nerve impulse
actin & myosin slide over one another
muscle contracts
Nerve cell + muscle fiber = motor unit

31. Muscles in Arthropods
Muscles attached to inside of exoskeleton

32. Questions to Ponder More Review
How do skeletal & muscular systems show unity within diversity?
How does form follow function?
More Review
Joints of the Skeletal System Interactive Table
More Joints of the Skeletal System Interactive Table
Muscle & Connective Tissue Animation