Ch 32 Skeletal, Muscular, and Integumentary Systems

1
Ch 32Skeletal, 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
• 1. 206 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
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 20s 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
Hinge Joint
Saddle Joint
12
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

20
(No Transcript)
21
Cycle Diagram
1
Myosin forms cross-bridge with actin
5
Cross-bridge changes shape
Myosin returns to original shape
2
3
4
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

25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
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 objects 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