1. Ch 36 Skeletal, Muscular, and Integumentary Systems

2. I. The Skeletal System
A. Purpose
1. structural support
a. hydrostatic
1) soft bodied invertebrates
b. exoskeleton
1) arthropods
c. endoskeleton
1) mammals

3. 2. protects internal organs
3. provides for movement
4. stores mineral reserves
5. provides a site for blood cell formation (only in some bones)

4. B. The Skeleton
bones in adult humans
2. Axial skeleton
a. skull
b. vertebral column
c. rib cage
3. Appendicular skeleton
a. arms
b. legs
c. pelvis
d. shoulder/pectoral girdle

5. C. Structure of Bones
1. solid network of living cells and protein fibers that are surrounded by deposits of calcium salts
2. osteocytes – mature bone cells
3. Ca and P – maintain levels in blood to support metabolic activities
4. compact bone
a. resists mechanical shock
b. Haversian canals
1) contains blood vessels

6. The Structure of Bone Spongy bone Haversian canal Compact bone
Periosteum
Bone marrow
Haversian canal
Osteocyte
Artery
Vein

7. 5. Periosteum
a. protective covering
6. spongy bone
a. add strength w/o lots of mass
b. red marrow
1) site of blood formation
c. yellow marrow
1) fatty area providing
protection
2) converts to red marrow if
needed

8. D. Development of Bone
1. cartilage
a. includes network of protein fibers
including collagen and elastin
b. embryo starts with cartilage then
later turns to bone
c. does not contain blood vessels
d. relies on diffusion to obtain
nutrients

9. 2. ossification
a. cartilage is replaced by bone
3. long bones have growth plates at both ends until early 20’s or late teens

10. E. Types of Joints
1. Immovable Joints or Fibrous
a. fixed
b. ie – bones in skull
2. Slightly Movable or Cartilaginous
a. between tibia and fibula
b. between vertebrae
3. Freely Movable or Synovial Joints
a. Ball-and-Socket (shoulder)
b. Hinge (knee)
c. Pivot (elbow)
d. Saddle (hand/fingers)

11. Freely Movable Joints and Their Movements
Ball-and-Socket Joint
Pivot Joint
Clavicle
Ball-and-socket joint
Scapula
Humerus
Humerus
Radius
Pivot joint
Ulna
Hinge Joint
Saddle Joint
Femur
Patella
Hinge joint
Tibia
Fibula
Metacarpals
Carpals
Saddle joint

12. Figure 36-5 Knee Joint Muscle Tendon Femur Patella Bursa Ligament
Synovial fluid
Cartilage
Fat
Fibula
Tibia
Figure 36-5 Knee Joint

13. F. Structure of Joints
1. ligament
a. holds bones together
2. Bursa
a. small sacs of synovial fluid
b. acts as tiny shock absorbers

14. II. Muscular System
A. Types of Muscle Tissue
1. Skeletal

15. 2. Smooth

16. 3. Cardiac

17. Figure 36-7 Skeletal Muscle Structure
Section 36-2

18. B. Muscle Contraction – Sliding-Filament Model
1. muscle contracts when the thin filament in the muscle fiber slides over the thick filament decreasing distance between the Z lines

19. 2. sarcomeres
a. myosin
1) thick filaments of protein
b. actin
1) protein making up most of
the thin filament
c. Z lines
1) separate sarcomeres
2) anchor sarcomeres
3. requires lots of ATP
a. produced by cellular respiration
b. requires Phosphorus

21. Cycle Diagram Myosin forms cross-bridge with actin1
Myosin forms cross-bridge with actin 5
Myosin returns to original shape 2
Cross-bridge changes shape 4 3
Cross-bridge releases actin
Actin pulled

22. C. Control of Muscle Contraction
1. CNS via motor neurons control muscle contractions
2. difference in electrical charge across plasma membrane
3. Neuromuscular junction
a. the point of contact between a
motor neuron and a skeletal
muscle cell
b. acetylcholine (ACo)
1) the neurotransmitter in the
vesicles of motor neurons

23. c. impulse causes Ca2+ ions to be
released
d. Ca affects regulatory proteins
which cause actin and myosin
to interact
e. ACo release stops
f. enzyme destroys excess ACo
g. Ca2+ pumped back in to cell
h. contraction ends

24. 4. Phosphorus taken from ATP or from creatine phosphate
a. ATP comes from glucose in blood
or glycogen breakdown in cells
5. strong vs. weak contraction
a. brain stimulates many or only a
few muscle cells

28. D. How Muscles and Bones Interact
1. Tendons
a. connect muscles and bones
b. cause bones to work like levers
2. most skeletal muscles work in opposing pairs
3. the weight of an object’s pull and gravity also pull on muscles

29. Figure 36-11 Opposing Muscle Pairs
Section 36-2
Movement
Movement
Biceps (contracted)
Biceps (relaxed)
Triceps (relaxed)
Triceps (relaxed)

30. III. Integumentary System
A. Purpose
1. serves as barrier against infection and injury
2. helps to regulate body temp
3. removes waste from body
4. protects against UV radiation
B. Skin

31. Figure 36-13 The Structure of Skin
Section 36-3

32. B. Skin
1. epidermis
a. outer layer
b. dead cells on outside
c. inner layer – rapid cell division
d. tough, flexible, waterproof
e. melanocytes produce melanin

33. 2. dermis
a. inner layer
b. contains collagen fibers, blood
vessels, nerve endings, glands,
sensory receptors, smooth muscles,
hair follicles
c. glands
1) sweat glands
a) cools body, rids waste
2) sebaceous glands
a) oil secretion
(waterproof)

34. 3. under dermis is layer of fat and loose connective tissue

35. End