Muscles And Locomotion

Front 1

Cartilage

Back 1

-Connective tissue that is softer and more flexible than bone.

-Chrondytes synthesize cartilage

Front 2

Bone

Back 2

Two types of bone:

1. Compact bone
2. Spongy bone

Front 3

Compact bone

Back 3

-Dense bone with no cavities.

-Made up of structural units called osteons

-Each osteon has a central channel known as a Haversian canal, surrounded by concentric circles of bony matrix called lamellae.

Front 4

Spongy bone

Back 4

-Less dense than compact bone.

-Consists of interconnecting lattic of bony spicules.

-The cavities are filled with either red or yellow marrow.

-Yellow marrow is inactive

-Red marrow is involved in blood cell formation.

Front 5

Osteocytes

Back 5

-Two types of cells found in bone:

1. Osteoblasts
2. Osteoclasts

Front 6

Osteoblasts

Back 6

-Synthesize and secrete organic constituents of bone matrix.

-Once they have been surrounded by their matrix, they turn into osteoclasts

Front 7

Osteoclasts

Back 7

-Large, multinucleated cells involved in bone resorption

Front 8

Bone formation

Back 8

Either through:

a) endochondral ossification

b) intramembranous ossification

Front 9

Endochondral ossification

Back 9

TYPE OF BONE FORMATION

-Exisiting cartilage is replaced by bone

Front 10

Intramembranous ossification

Back 10

TYPE OF BONE FORMATION

-Embryonic connective tissue is transformed into bone.

Front 11

Muscle organization

Back 11

1. Each muscle is made up of fibers

2. Each fiber has myofibrils embedded in them.

3. The myrofibrils are divided into sacromeres.

4. The myofibrils are enveloped by the sarcoplasmic reticulum (stores calcium).

5. The plasma of muscle fiber is called sarcoplasm.

6. Cell membrane is known as sarcolemma, which can make action potentials and is connected to a system of transverse tubules (T system).

7. The T system gives channels for ions to flow throughout the muscle.

Front 12

Structure of Sacromere

Back 12

1. Z lines - Define boundaries of a sacromere and anchor thin filaments.

2. M line - runs along center of sacromere

3. I band - contains only thin filaments

4. H zone - contains only thick filaments

5. A band - spans the entire length of thick filaments and overlapping portions of thin filaments. (During contraction, A band is not reduced in size, while H and I are)

Front 13

Contraction

Back 13

-When an action potential is generated, it goes along the sarcolemma and the T system into the muscle fiber.

-This causes sarcoplasmic reticulum to release calcium ions which initiates contraction of the sarcomere.

-Actin and myosin slide past each other, and the sarcomere contracts.

Front 14

5 major types of muscle contraction

Back 14

1. Isotonic

2. Concentric

3. Dynamic

4. Eccentric

5. Isometric

Front 15

Isotonic

Back 15

-Muscle shortens against a fixed load while tension on muscle is constant.

Front 16

Concentric

Back 16

-A type of dynamic contraction

-Muscle fiber shortens and the tension on muscle increases.

Front 17

Dynamic

Back 17

-Includes both concentric and eccentric

-Results in both change in length of muscle with change in tension on that muscle.

Front 18

Eccentric

Back 18

-Type of dynamic contraction

-Muscle fiber lengthens and tension on muscle increases.

Front 19

Isometric

Back 19

-Both ends of the muscle are fixed and no change in length occurs, but tension increases.

Front 20

Smooth muscle

Back 20

-Responsible for involuntary actions.

-Innervated by autonomic nervous sytem

-Nonstriated

-One nucleus per cell

-Smooth, continuous contractions

Front 21

Cardiac Muscle

Back 21

-Muscle tissue of the heart

-Striated (actin and myosin filaments arranged in sacromeres)

-One to two nuclei per cell

-Involuntary/autonomic nervous system

-Strong, forceful contractions

Front 22

Skeletal Muscle

Back 22

-Striated

-Multinucleated

-Voluntary/somatic nervous system

-Strong, forceful contractions