BELLWORK

CHAPTER 4: TISSUES

4.3 & 4.4: Muscular and Nervous Tissue

MUSCULAR TISSUE

Tissue consist of elongated cells called muscle fibers Muscle fibers are specialized to generate force

Muscle Tissue Provides motion Maintains posture Generates heat

Types of Muscle Tissue Skeletal Cardiac Smooth

MUSCULAR TISSUE

Skeletal Muscle Attached to the skeleton Can be controlled voluntarily Cells have a striated look to

them Skeletal muscle cells are long,

cylindrical, and have many nuclei

Causes gross body movements

MUSCULAR TISSUE

Cardiac Muscle Found ONLY in the heart Function is to pump

blood to the rest of the body

Is under involuntary control

Cells have striated appearance

Only ONE nucleus per cell

MUSCULAR TISSUE (VIDEO)

Smooth Muscle Found in walls of hollow organs

(stomach, bladder, uterus) Controlled involuntary Can contract (making organs

smaller) or enlarge (making organ dilate) to move substances along

No striations Smooth muscle cells have a

single nucleus, and are spindle shaped

Peristalsis: moving food via contractions

NERVOUS TISSUE (VIDEO)

Found in the brain, spinal cord and nerves

Mostly consist of 2 types of cells Neurons: nerve cells that are

sensitive to stimuli Convert stimuli into nerve impulses

(action potentials) and send the impulses to other neurons, muscles fibers or glands

Neuroglia Don’t conduct nerve impulses

TISSUE REPAIR

Tissues repair themselves in 2 major ways. Regeneration: the replacement of destroyed tissue

by the same kind of cells. Fibrosis: involves repair by dense connective tissue

forming scar tissue. The type of repair chosen depends on the type of tissue

damaged and the severity of the injury. Clean cuts heal much more easily and quickly than rips or

tears

CHECK FOR UNDERSTANDING 1

1. Three types of muscle tissues

2. Has no striations, controlled involuntarily and found in the walls of hallow organs

3. Replacement of damaged tissue by the same type of cells

4. Has striations and is only found in the heart

5. Found in the brain, nerves and spinal cord

6. Responsible for gross body movements

CHECK FOR UNDERSTANDING 1

1. Three types of muscle tissues

2. Has no striations, controlled involuntarily and found in the walls of hallow organs

3. Replacement of damaged tissue by the same type of cells

4. Has striations and is only found in the heart

5. Found in the brain, nerves and spinal cord

6. Responsible for gross body movements

1.Skeletal, smooth, cardiac

2. Smooth

3. Regeneration

4. Cardiac

5. Nervous tissue

6. Skeletal