1. Principles of Cell Biology Chapter 14: Tissues

2. Chapter Summary: The Big Picture (1)
Chapter foci:
Tissues form macroscopic equivalents of individual cells.
Explore how biology merges into anatomy and physiology by introducing 4 major tissue types

3. Chapter Summary: The Big Picture (2)
Section topics:
Epithelial tissues form protective, semi-permeable barriers between compartments
Nervous tissues store and transmit information as electrical charge
Muscle tissues convert chemical signals into mechanical force
Connective tissues provide mechanical strength and cushioning to the animal body

4. Epithelial tissues form protective, semi-permeable barriers between compartments
Key Concepts:
Epithelial tissues share important properties with cellular membranes: they possess structural polarity and protect the material they enclose, forming a semi-permeable barrier.
Epithelial cells contain specialized structures that help them form strong bonds to each other and the extracellular matrix.
Epithelial tissues are specialized to perform specific functions, including protection, secretion, transport, and absorption. .

5. Epithelial cells have structural polarity
Figure 14.02: Epithelial tissues are macroscopic analogs of cellular membranes.

6. Figure 14.03: Examples of different types of epithelial tissues.
Epithelial tissues are classified according to cellular structure and function
Figure 14.03: Examples of different types of epithelial tissues.

7. Some epithelial tissues are optimized for protection: the epidermis
Figure 14.04: Structural organization of skin.

8. Figure 14.05: The gastrointestinal system.
Some epithelial tissues are optimized for absorption: the gastrointestinal system
Figure 14.05: The gastrointestinal system.
Figure 14.06: Cross-section of the stomach. Note the deep folds (gastric pits). The protective mucous layer is stained dark purple in this image.

9. Some epithelial tissues are optimized for transport: the kidney
Figure 14.07: Summary of kidney function. The nephron collects wastes filtered from the blood in Bowman's capsule and converts it into urine for excretion.
Figure 14.08: Kidney epithelial cells use transport proteins (pumps, carriers, and channels) to move material into and out of the bloodstream.

10. Nervous tissues store and transmit information as electrical charge
Key Concepts:
Nervous tissues are composed of neurons and supportive cells called glial cells.
Neurons transmit information in the form of an electrical current that is passed between neurons. The network of interconnected neurons in an organism is functionally analogous to the signaling network in a single cell.
The electrical current is conducted through individual neurons by a coordinated transport of ions across the plasma membrane - an action potential.

11. Nervous tissues are the macroscopic equivalent of the information transfer network

12. Nervous tissues are composed of at least 2 different cell types
2 types of cells:
Neurons - store and transmit electrical information
Glial cells - provide support to the neurons but do not actually manipulate the information

13. Neurons transmit signals via action potentials
Figure 14.10: Summary of action potential generation in a neuron.

14. Figure 14.11: Structural organization of nerve cells.
Glial cells support neurons and increase the speed of action potential transmission
Figure 14.11: Structural organization of nerve cells.

15. Figure 14.11: Structural organization of nerve cells.
Glial cells support neurons and increase the speed of action potential transmission
Myelin sheath
Schwann cells
Oligodendrocytes
Sphinganine
Figure 14.12: Glial cells wrap neurons with myelin. Some glial cells wrap a portion of one axon, others wrap many. The gaps between wraps are called Nodes of Ranvier.
Figure 14.11: Structural organization of nerve cells.

16. The synapse is a customized junction to facilitate cell–cell communication
Figure 14.14: A model of how myelin-associated glycoprotein (MAG) and Nogo-66 receptor participate in suppression of neurite outgrown in neurons.

17. Muscle tissues convert chemical signals into mechanical force
Key Concepts (1):
Muscles are effectors targeted by the nervous system and composed primarily of muscle tissue.
Muscle tissues are classified into three types: skeletal, cardiac, and smooth muscle. Collectively, muscle and bone tissues form the functional analog of the cytoskeleton in tissues.
Skeletal muscle cells are multinucleated, terminally-differentiated cells composed of parallel actin and myosin bundles called sarcomeres. They are stimulated to contract by the electrical current passing from neurons to the muscle cells.

18. Muscle tissues convert chemical signals into mechanical force
Key Concepts (2):
4) Cardiac muscles are structurally similar to skeletal muscle cells, except they contract autonomously and are found only in the heart.
5) Smooth muscles lack sarcomeres, and are capable of contracting in several directions. This enables them to line tubes such as blood vessels and airways and control their diameter. Smooth muscle cells are also capable of sustaining contractions much longer than skeletal or cardiac muscle cells.

19. Figure 14.15: Transmission of information at a chemical synapse.
Each type of muscle tissue is specialized for a different type of motion
Figure 14.15: Transmission of information at a chemical synapse.
This material is definitely on the third exam

20. Skeletal muscle cells are multinucleated, highly-specialized cells
Figure 14.17: Structural organization of skeletal muscle.
Sarcomeres are combined to form muscle fibrils
Action potentials stimulate skeletal muscle contraction

21. Skeletal muscle cells are multinucleated, highly-specialized cells
Figure 14.16: Three classes of muscle tissue: skeletal (top),
smooth (middle) and cardiac (bottom). Note that both skeletal and cardiac muscle form large, multinucleated cells called fibers.

22. Skeletal muscle contraction is driven by the crossbridge cycle
Figure 14.18: How an action potential triggers skeletal muscle contraction.

23. 3D model of Sarcomere

24. Sarcoplasmic Reticulum Stores Ca+2

25. Troponin and Tropomyosin Control Skeletal Muscle Contraction

26. Better drawing of Troponin/Tropomyosin

27. Figure 14.19: The crossbridge cycle for skeletal muscle contraction.

28. Cardiac muscle is responsible for pumping blood
Figure 14.20: Structural organization of mammalian heart. Note that blood flow changes direction in the left and right ventricles.

29. Figure 14.21: Transmission of action potentials in cardiac muscle.

30. Smooth muscle cells generate force in three dimensions
Figure 14.23: Smooth muscle forms a contracile layer around all but the smallest blood vessels.

31. Smooth Muscle Contracts in All Directions

32. Smooth muscle cells generate force in three dimensions
Figure 14.22: Summary of signaling mechanisms controlling smooth muscle cell contraction. Note that all converge on myosin II regulatory light chain phosphorylation.

33. Connective tissues provide mechanical strength and cushioning to the animal body
Key Concepts:
The term “connective tissue” refers to a wide variety of tissues that collectively fill spaces between epithelial, nervous, and muscle tissues. In most cases, connective tissue is characterized by the type and organization of the ECM it contains. It is analogous to the ECM surrounding individual cells.
Most connective tissues are classified into five types. Each type is populated by different cells that secrete and organize the ECM.

34. Common property of connective tissues
“glue” that holds cells and tissues together
Contains well organized ECM to:
Form stable bonds between neighboring cells
Govern the location and behavior of the cells
Provide a means for intercellular communication

35. 5 types of connective tissue
Loose connective
Dense connective
Elastic
Reticular
Adipose