Membranes

1. Membranes • Book definition= Flat sheets of flexible connective tissue found covering parts of the body or lining body cavities. • This definition is not quite accurate because there are epithelial cells found in membranes as well that secrete substances.

2. Membranes • Mucous membranes: line body cavities exposed to the outside world. • Nasal and oral cavities • Reproductive and urinary tracts • Function to help keep exposed tissues from drying out and trap foreign particles

3. Membranes • Serous membranes: line body cavities that are not exposed to the outside world. • Ventral and dorsal cavities • Produce serous fluid (watery liquid) for lubrication • Function to surround and protect internal organs and hold them in place. • Serous fluid is found between the parietal and visceral layers.

4. Membranes • Synovial membranes: line the cavities of freely movable joints. • Secrete synovial fluid • Function to protect and lubricate a moveable joint.

5. Muscle Tissue • Muscle tissue is responsible for movement of the body or the movement of materials through the body. • Gross movement- Movement of the body such as running and walking • Transport movement- Movement of materials throughout the body such as food through the digestive tract.

7. Skeletal Muscle • Skeletal muscle is named for its location. It is attached to bones of the skeleton. • Made of long cells called muscle fibers that attach to bones by connective tissue (tendon). Do you remember what kind of connective tissue? • Muscle fibers in skeletal muscle are multinucleated. • The muscle fibers are cylindrically shaped. • Proteins within cells are organized creating striations (alternating light and dark bands).

8. Skeletal Muscle

9. Smooth Muscle • Smooth muscle lines hollow internal structures such as blood vessels, airways to the lungs, the stomach, intestines, and bladder. • It constricts blood vessels, physically breaks down and moves food and moves fluid through the body. • Smooth muscle tissue is not striated. • The cells of smooth muscle have 1 nucleus. • The cells are long with tapered ends.

10. Smooth Muscle

11. Cardiac Muscle • Cardiac muscle makes up the wall of the heart. • Cardiac tissue is striated. • Cardiac muscle fibers are y-branched and have 1 nucleus. • Cardiac muscle fibers are attached end to end by thickened membranes called intercalated disks.

12. Cardiac Muscle intercalated disk nucleus striations

14. Skeletal Tissue

17. Smooth Muscle Tissue

18. Cardiac Muscle Tissue

20. Nervous Tissue • Nervous tissue is specially designed to generate and transmit electric impulses. • Neurons: The functional cell of the nervous system. • Sensitive to stimuli • Consist of a central body with extensions coming off of it. • Neuroglial cells: Cells that are used to support neurons. • Smaller and more numerous than neurons. • Cannot transmit electrical impulses.

21. Neuron structure

23. Nervous Tissue