Activity 1: Tissue Types
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1-1: List the four types of tissue found in the human body and give an example of each.
1. Epithelial example: Skin
2. Connective example: Tendons
3. Muscle example: Muscles of heart
4. Nervous example: Brain
Activity 2: Epithelial tissue
2-1: What are the characteristics of epithelial tissue? Polarity, Specialized contacts, Supported of connective tissue, Avascular but innervated, Regeneration
2-2: What is the function of epithelial tissue? protection, absorption, filtration, secretion, excretion, sensory reception
2-3: Where is epithelial tissue found? Outer layer of skin, lines the open cavities of the cardiovascular, digestive, and respiratory system, also covers the walls and organs of the closed ventral body cavity
2-4: This is a cross section of the esophagus. Number 1 represents the lumen
of the esophagus. Identify the tissue types indicated by 2 and 3.
2. Stratified squamous epithel
3. Dense irregular connective tissue
2-5: Below is a picture of intestinal villi. Identify the tissue type at 1 and the cell type at 3.
1. Simple columnar epithelium
3. Goblet cells
2-6: Below is a photo of the trachea. Identify the cell modifications at 1, and the tissue types at 2 and 3.
2. Pseudostratified epithelial layer
3. Pseudostratified columnar epithelium
2-7: Identify the tissue type at 1 below: Simple columnar epithelium
2-8: The picture below shows kidney tubules. Identify the tissue type at 1 and 3:
1. Outer wall composed of simple cuboidal epithelium
3. Nucleus of a simple cuboidal epithelial cell
2-9: The picture below shows a cross-section of a lung. The areas labeled 2 are alveoli, the air sacs of the lungs. What type tissue is 1? Simple squamous epithelium
2-10: Identify the tissue or cell types or component below.
1. (tissue type) Epithelium
2. (tissue type) Lamina Propia
4. Mucin in globlet cell
5. Cilliated cells of pseudostratified epithelium
Activity 3: Connective tissue
3-1: What are the characteristics of connective tissue? Common origin, Degrees of vascularity, Extracelluar matrix
3-2: What are the functions of connective tissue? binding and support, protection, insulation, transportation of substances within the body
3-3: Where would you find connective tissue? everywhere in the body, mostly in the primary tissue
3-4: The slide below is a section of the small intestine. In this tissue, the collagen fibers are interwoven and irregularly arranged (i.e. they run in more than one direction), which provides great structural strength. The tissue is well suited for areas where tension is exerted from many different directions, such as the dermis of the skin, submucosa of the gastrointestinal tract and fibrous capsules of organs and joints. It also forms fascia, the tough, white material that surrounds muscles.
What classification of connective tissue is the area marked by 1? Dense irregular
3-5: The tissue below is a loose connective tissue comprised of a semi-fluid ground substance containing several kinds of loosely-arranged fibers and cells. This is the most widespread type of connective tissue. It is found in every microscopic section of the body, fastening down the skin, membranes, vessels and nerves as well as binding muscles and other parts together. There are two types of fibers, the most numerous of which are thicker, lightly-staining collagenous fibers that crisscross the matrix in a random fashion. Thinner, more darkly stained elastic fibers composed of the protein elastin can also be seen. The principal type of cells seen are lightly-staining fibroblasts that secrete the matrix materials.
1. Fibroblast nuclei
2. Collagen Fiber
3. Elastic Fibers
3-6: This slide shows a section of a tendon with regularly arranged closely packed collagen fibers running in the same direction. This results in a flexible tissue with great resistance to pulling forces. With its enormous tensile strength, this tissue forms cord like tendons, which join muscles to bones, sheet-like aponeuroses, which attach muscles to muscles or muscles to bones, and ligaments, which bind bones together at joints. What classification of connective tissue is this? Dense regular
The nuclei of the cells that secrete the collagen fibers are indicated by the number 1. What type cells are these? Collagen Fibers
3-7: The cells of the connective tissue pictured below in a cross section from the trachea are specialized for fat storage and do not form ground substance or fibers. On prepared slides, this type tissue appears somewhat like a fish net with white spaces connected together in a network. The cytoplasm and nucleus have been pushed to one side by a single, large, fat-filled vacuole that occupies the center of the cell.
1. Cell membrane
2. Cell nucleus
3. Fat Vacuoles
3-8: The slide below shows a section of the trachea (windpipe). Rings of hyaline cartilage embedded within the walls of the trachea provide support and help to maintain an open airway. Hyaline cartilage is the most common form of cartilage in the body, making up part of the nose, connecting ribs to the sternum and covering the articulating surfaces of bones. When sectioned and stained, the matrix of hyaline cartilage takes on a light purple color. Cartilage-forming cells called chondroblasts produce this matrix, which consists of an amorphous ground substance heavily invested with collagen fibers. Chondrocytes (mature cartilage cells) can be seen singly or in groups within spaces in the matrix called lacunae. The surface of all cartilage (except for articular cartilage) is covered by a membrane of connective tissue fibers called the perichondrium. Although the perichondrium is well-vascularized, cartilage tissue proper is avascular, which means that oxygen and nutrients have to diffuse from blood vessels in the perichondrium to the chondrocytes within the cartilage proper.
1. Cartilage matrix
4. Adipose cells
(Hint for 4: see previous slide)
3-9: This image shows a dried section of compact bone. Like cartilage, bone cells (osteocytes) occupy spaces (lacunae) found within the dense matrix. A major difference, however, is that the matrix is calcified in bone, which endows bone with the property of hardness and the ability to resist compressive forces. This calcified matrix is deposited in layers called lamellae (singular = lamella) approximately 3-7 microns thick. The most common unit of structure in compact bone is the Haversian system or osteon. In each Haversian system, the lamellae are arranged concentrically around a central Haversian canal which houses nerves and blood vessels (unlike cartilage, bone is well supplied with blood vessels). The lacunae that house mature osteocytes in living bone appear as tapered, black spaces arranged around the concentric lamellae. Slender, branching tubules called canaliculi (“little canals”) radiate out from the lacunae to form an extensive network of passageways that connect the bone cells to each other and to the blood supply in the Haversian canal. Identify:
2. Haversian canal
3-10: What type connective tissue is pictured below? Blood
3-11: What is the matrix of this connective tissue? plasma, no fibers
3-12: What are the living cells of this connective tissue? Erythocytes, Leukocytes, Platelets
3-13: What is the function of this connective tissue? Carry O2, CO2, nutrients, wastes, and other substances
Activity 4: Muscle tissue
4-1: What are the characteristics of muscle tissue? Conductivity, Contractility, Extensibility, Elasticity
The image below shows a longitudinal view of a type of muscle. Note the multiple nuclei that lie at the periphery of the muscle fibers as well as the striations (thin lines) formed by the arrangement of the thick and thin myofilaments. It is the arrangement of these myofilaments that results in the A bands, I bands and Z lines that run perpendicular to the long axis of the myofibrils. 4-2: What type muscle tissue is this? Skeletal
4-3: Is this type muscle voluntary or involuntary? Voluntary
4-4: What is its function? locomotion, manipulation of the enviroment, facial expression, voluntary control
1. Muscle cell nuclei
2. Muscle fiber
Although the muscle below is striated, the striations are not so readily apparent as in the muscle above. These muscle cells are short, branched and interconnected. Each cell usually contains one centrally located nucleus. These muscle cells are joined end-to-end at specialized junctional zones called intercalated discs [pointed to by the blue arrows]. These discs allow force to be transmitted from one cell to another. Additionally, they contain gap junctions that allow an action potential in one cell to pass directly to an adjoining cell through these electrical synapses.
4-6: What type muscle tissue is this? Cardiac
4-7: Is it voluntary, or involuntary? involuntary
4-8: Where is it found? in the walls of the heart
4-9: This slide shows a longitudinal section of muscle that has been teased apart to reveal the individual muscle cells. Note the spindle shaped muscle fibers, each of which has a single, elongated nucleus. This type muscle is the simplest of the three types of muscle tissue. It is found where slow, sustained contractions are needed such as in the digestive tract, uterus and other internal organs. Involuntary in nature, its actions are under control of the autonomic nervous system.
What type muscle is this? Smooth
4-10: The picture below is a close-up view of a single cell from above.
Identify 1: Nuclei
4-11: This slide shows a cross section of the duodenum (a portion of the small intestine). Note that there are two relatively thick layers of smooth muscle cells that run perpendicular to one another, an outer (thinner) longitudinal layer and an inner (much thicker) circular layer of smooth muscle. Peristaltic contractions of these two opposing layers of muscle keep food moving through the gut.
1. Submucosal connective tissue
2. Circular smooth muscle layer
3. Longitudinal smooth muscle layer
Activity 5: Nervous tissue
5-1: Name the functional cell of nervous tissue. Neurons
5-2: The slide below shows a magnified view of a multipolar neuron from the spinal cord. Note the cell body with its prominent nucleus and nucleolus and the origin of cell processes called axons and dendrites. The numerous small, darkly stained dots are the nuclei of glial cells, primarily astrocytes.