1. Chapter 32 Skeletal, Muscular, and Integumentary Systems
The HUMAN BODY
Chapter 32
Skeletal, Muscular, and Integumentary Systems

2. Chapter 32.1 Skeletal System
Objectives
List the structures and functions of the skeletal system
Describe the structure of a typical bone
List and describe the different kinds of joints

3. SKELETAL SYSTEM Functions: Provides shape and support Allows movement
Protects tissues and organs
Stores certain minerals
Produces blood cells
Skeletal system has 5 important functions – must know ALL 5
Shape and support – like the internal wood frame supports a house; body would collapse without a skeleton
Allows movement – bones provide a system of levers on which muscles act to produce movement (levers = rigid rods that move about a fixed point)
Protect tissues and organs – for example, skull protects the brain and rib cage protects the heart and lungs
Store certain minerals – contain reserves of minerals, mainly calcium
Produce blood cells – blood cells produced in soft marrow tissue that fills internal cavities of some bones

4. Skeleton Components Made up of approximately 206 bones
Bones held together by ligaments
Bones attached to muscle by tendons
Ask students to name common bones in body (repeat several times) – refer to page 923 of book:
Cranium (bones of head), vertebrae, pelvis, sternum, ribs, scapula (back shoulder blade), clavicle (front)
Arm: humerus, radius (thumb side), ulna (back), carpals, metacarpals, phalanges
Leg: femur (longest bone in body), tibia (big), fibula (small), patella (kneecap), calcaneus (heel), tarsals, metatarsals, phalanges
Use doc camera and have students label bones on worksheet
Ligaments hold bone to bone
eg., in your knee, the ligaments hold the bones (femur, patella, tibia, fibula) together (for example, ACL)
Tendons hold muscle to bone
eg. Achilles tendon attaches calf muscle to your heel bone (calcaneus)

5. Skeleton- Bones
Cartilage- strong, connective tissue that supports the body; softer, more flexible than bone
Ossification- process of bone formation, cartilage replaced by bone
Cushions bones & Reduces friction
Cartilage = strong connective tissue
Skeleton of embryo made almost entirely of cartilage
Ossification begins before birth (up to 7 months before birth)
cartilage is gradually replaced by bone
many long bones (like ones in arms and legs) have growth plates on ends
growth of cartilage at ends of bones causes bones to lengthen
cartilage is slowly replaced by bone
during late adolescence/early adulthood, cartilage in growth plates is entirely replaced with bone and person “stops growing”
Adults still have some cartilage (in tip of nose, external ears, where ribs attach to sternum – to allow rib cage to move when breathing)

6. Skeleton- Bones
Bones: solid network of living cells and protein fibers that are surrounded by deposits of calcium
Contains marrow:
Yellow marrow- mainly made of fat cells
Red marrow- produces blood cells
Structure of typical bone:
- surrounded by tough outer layer of connective tissue = periosteum
- thick layer of compact bone – dense bone, but contains Haversian canals that contain blood vessels and nerves
- inside the compact bone layer – spongy bone (not soft and spongy, but quite strong); found in ends of long bones (like femur) and middle of short flat bones
- within bones are cavities that contain a soft tissue called bone marrow
- yellow marrow made of fat cells
- red marrow produces RBC, some WBC, and platelets
Using doc camera, have students label diagram of bone

7. Skeletal Joints Joints- any place where two bones come together
Joint types:
Movable
Pivot, ball-and-socket, hinge, saddle
Semi-movable
Vertebrae
Immovable
Cranium, sacrum
Joints allow bones to move without damaging each other
Cartilage covers the surfaces of joints to protect bones as they move against each other
Movable: prevent movement in one or more directions; grouped according to shapes of bones
pivot joint – allow one bone to rotate around another (eg., ulna and radius of forearm)
ball-and-socket – permit movement in many directions / allow most movement (eg., arm into shoulder; leg into hip)
hinge – back and forth movement (eg., knee)
saddle – allow one bone to slide in two directions (eg., thumb)
gliding – allow two bone plates to glide against one another (eg., joints in your ankles and wrists - holding your forearm steady while your hand points upward and then waving side-to-side with your hand is an example of this joint's functioning.)
Semi-movable: allow a little bit of restricted movement
eg., vertebrae
Immovable: allow no movement at all; bones are interlocked or fused together
eg., bones of the skull and sacrum (tailbone)

8. Skeletal System Disorders
Arthritis: inflammation of joint
Osteoporosis: loss of calcium in bones leads to weakening of bones
Skeletal System Disorders
Arthritis = inflammation of the joint
rheumatoid arthritis results when immune system attacks the joints
osteoarthritis results when cartilage protecting joints wears down and bones begin to rub against each other, causing inflammation
Osteoporosis = loss of calcium in bones leads to weakening of the bones that can cause fractures
to prevent – good nutrition, including plenty of calcium in diet, and weight bearing exercise (which helps to build up bones)

9. Check-in Review bones of body What holds bone to bone?
Ligaments
What holds muscle to bone?
Tendons

10. Check-in What are the functions of the skeletal system?
Shape and support, allows movement, protects tissues and organs, mineral storage, produces blood cells
Process by which cartilage is replaced by bone
Ossification

11. Check-in Strong connective tissue more flexible than bone
Cartilage
Place where two bones come together
Joint
Disorder that causes inflammation of joints
Arthritis

12. Check-in Dense bone containing Haversian canals Outer layer of bone
Contains fat cells
Produces blood cells
Adds strength w/o mass
Yellow marrow
Compact bone
Periosteum
Spongy bone
Red marrow

13. Chapter 32.2 Muscular System
Objectives
Describe the structure and function of the three types of muscle tissue
Describe how muscles contract
Describe how muscle contractions produce movement

14. MUSCULAR SYSTEM
Muscles - bundles of fibers that work together to allow for movement and structure
More than 40% of mass of average human body is muscle
Muscles are bundles of fibers (kind of like Twizzlers)

15. Muscles- 3 Types Skeletal- Smooth- Cardiac-
Attaches to and moves bones; voluntary
Smooth-
Controls breathing, digestive system; involuntary
Cardiac-
Found only in heart; involuntary
Three types of muscle tissue, each specialized for specific function within body
Skeletal:
Attached to and moves bones
Voluntary
Striated (alternating light and dark bands)
Cells are large, have many nuclei, may be 1mm to 30 cm long; long and slender (often called muscle fibers)
A complete skeletal muscle has muscle fibers, connective tissues, blood vessels, and nerves
Consciously controlled by nervous system
Reacts quickly and tires quickly
Smooth:
Not under voluntary control
Cells are spindle-shaped (fat in middle and tapered at ends), have one nucleus, and are not striated
Move food through digestive system, control way blood flows through vessels, decrease size of pupils in bright light
Can function w/o nervous stimulation
Cardiac: Found only in heart
Features of both skeletal and smooth muscle
Striated, but smaller cells than skeletal
Cells have 1 nucleus (sometimes 2)
Usually not under direct control of CNS (connected to neighbors by gap junctions) - involuntary

16. Check-in What muscle type(s) is/are striated?
Skeletal and cardiac
What muscle type moves bones?
Skeletal
What muscle type is found in digestive system?
Smooth
What muscle type(s) is/are involuntary?
Smooth and cardiac

17. Muscle Action Muscles work in pairs- one contracts, the other relaxes
Biceps, Triceps
Flexor
Decrease angle between bones (eg. Biceps)
Extensor
Increase angle between bones (eg. Triceps)
Individual muscles can only pull in one direction
Muscles generally work in opposing pairs – when one contracts, the other relaxes
biceps contract – forearm moves towards the upper arm (flexor)
triceps contract – forearm moves away from upper arm (extensor)
controlled movement requires contraction by both muscles (they must contract in balance to hold a tennis racket or play a violin)

18. How do muscles contract?
Nerve tissue sends message to muscle to contract/relax
Electrochemical signal sent to muscle via nerve
Signal causes release of Calcium ions which react with protein (myosin and actin) in muscle cells
Muscles react by having their long filaments slide past each other
Muscle cells get closer- they contract
Muscle fibers are made up of myofibrils which are made up of filaments
Thick and thin filaments make the striations (thick = myosin and thin = actin) - SHOW NEXT SLIDE
Go through steps of muscle contraction
Electrochemical signal sent to muscle through nerve
Ca2+ ions released, which react with myosin and actin in muscle cells
Muscles respond by having long filaments slide past each other
head of mysin (thick fibers) binds with actin (thin) and then pulls actin toward center of sarcomere
mysin releases, binds again, and pulls
4. Muscles cells get closer

19. Muscle Contraction Video Clip
Sarcomere is the unit of muscle contraction; sarcomeres are separated from each other by Z lines
Muscle Contraction Video Clip

20. Check-in Type of muscle that decrease angle between bones.
Flexor
Muscle contraction begins with
Nerve impulse
Two proteins found in skeletal muscles
Actin and myosin

21. Chapter 32.3 Integumentary System
Objectives
State the functions of the integumentary system
Identify the structures of the integumentary system

22. Integumentary System Function:
Communication of pain, pressure, temperature
Protection of body:
Prevents dehydration
Regulates body temperature
Barrier for disease/infection
Covers and holds in organs
Removes waste products
Barrier for sun’s UV rays
Integumentary system = skin and its related structures (hair, nails, and a variety of glands)
Skin is the single largest organ of the body
Two main functions:
Skin contains several types of sensory receptors that allow it to transmit sensations such as pain, pressure, temp to nervous system
Most important function – protection of body
We will learn how the skin is specialized for each of these aspects of protection
Apple demonstration
Cut apple in half
Cover one half tightly with plastic wrap and leave the other unwrapped and open to environment
What do you think will happen to each during the period?
At end – show both pieces (How are they different?)
What role do you think the skin of the apple plays?
How is the skin of an apple like human skin?

23. Layers of the Skin Epidermis: outermost layer -Two layers: -Contains:
-Inner layer: living cells
-Outer layer: dead cells
-Contains:
-Keratin (waterproofing)
-Melanocytes (produces pigment)
Outer layer of skin
Has two layers: outer layer of dead cells and inner layer of living cells
Inner layer undergoes rapid cellular division (creating new cells) that push older cells upward towards surface
as cells move upward, they begin making keratin (tough fibrous protein) that serves as waterproofing  prevent dehydration
cells also flatten out and die
Outer layer forms tough, flexible, waterproof covering on surface of skin
shed or washed away at surprising rate (every 4-6 weeks the outer layer is replaced)
Epidermis also contains melanocytes that produce the dark-brown pigment melanin
this is what gives you a tan when you are in the sun
protects skin from damage by absorbing ultraviolet light from sun
too much sun results in burn and bad burns can lead to skin cancer (abnormal growth of skin cells)
protect yourself by wearing hat, sunglasses, protective clothing, sunscreen of at least SPF 15 when outside
Epidermis does NOT have any blood vessels – slight scratch not produce bleeding

24. Layers of Skin Dermis: middle layer Contains: -Hair follicles/roots
Irregular ridges between dermis and epidermis form fingerprints
Contains:
-Hair follicles/roots
-Sweat glands
-Sebaceous (oil) glands
-Arrector pili muscle
-Nerves
-Blood Vessels
Lies beneath the epidermis
Wavy ridges between the dermis and epidermis are what cause fingerprints
Two major kinds of glands
Sweat glands – when your body gets too hot, sweat glands produce sweat (water, salts, and other compounds); when sweat evaporates, it takes heat from your body; sweat also gets rid of wastes from blood along with water (excretory fcn)
Sebaceous (oil) glands – produce oily secretion called sebum which spreads out on surface of skin and helps keep epidermis and hair flexible and waterproof ; also acidic and can kill bacteria on surface of skin
Skin interacts with other body systems to maintain homeostasis by helping to regulate body temperature
on cold days, blood vessels narrow to help limit heat loss and conserve heat
on hot days, blood vessels widen to bring heat from body’s core to skin and increase heat loss
Also when cold, arrector pili muscle contracts, pulling the hair follicle upright and ejecting oil to help prevent evaporation (maintain heat); this is what goose bumps are

25. Layers of Skin Hypodermis (Subcutaneous Layer): Innermost layer
Contains:
Adipose (fat) cells: cushion,
insulation, anchors skin, etc.
Blood vessels: temp. regulation,
nutrients, etc.
Nerves: temp., pressure, pain
This layer – called hypodermis or subcutaneous layer – contains fat cells and loose connective tissue to help insulate the body
Pause here and have students label their skin diagram – use transparency to check for correctness of labeling

26. An inside look at the skin!

27. Derivatives of Skin Hair: Nails: Dead epidermal cells
Forms from bulb/root
Nails:
Sheets of keratinized cells
Forms from nail bed
Basic structure of hair and nails is keratin (tough fibrous protein that also forms outer skin layer)
Hair is made of dead epidermal cells
produced by cells at the base of the hair follicles (tubelike pockets of epidermal cells that extend into the dermis)
hair is actually large column of cells that have filled with keratin and died
sebaceous glands produce oils to help maintain the condition of each hair
function of hair: protect skin from UV rays (on head); provide insulation from cold; hairs in nose, ears, eyelashes prevent dirt and other particles from entering body
Nails grow from an area of rapidly dividing cells known as the nail root (near tips of fingers and toes)
during division, cells of nail root fill with keratin and produce tough, platelike nail that covers and protects tips of fingers/toes
nails grow avg. of 3 mm per month (fingernails grow faster than toenails)

28. Fingerprints Fingerprint Identification
Read introduction and show pictures of different types of fingerprint patterns
Fingerprints increase the sensory perception of fingertips and help in gripping rough surfaces as well as smooth wet surfaces
Have students complete the fingerprint activity

29. Check-in Describe the two layers of the epidermis
Inner layer of living cells and
Outer layer of dead cells
Cell that produces pigment (found in epidermis)
Melanocyte
Protein that waterproofs skin and forms hair and nails
Keratin

30. Check-in
Describe what the structures of the dermis do when you are hot.
Sweat glands produce sweat
Blood vessels widen to bring more heat to surface of skin
This part of the hypodermis cushions, insulates and helps to anchor skin
Adipose cells

31. Check-in Why do we have hair?
Protect head from UV rays, insulation, prevent dirt from entering body
Communicate pain, pressure, temperature to brain
Nerves