Do Histo Part 2 Lab Manual and Post Review Slides Togatherfinish Studying

Lab two: Microscopy and the Study of Tissues

1. Introduction to histology (Function ane)

Tissues are composed of similar types of cells that piece of work in a coordinated fashion to perform a common task, and the study of the tissue level of biological organization is histology. Four basic types of tissues are constitute in animals.

Epithelium is a type of tissue whose chief function is to encompass and protect trunk surfaces but tin can also form ducts and glands or exist specialized for secretion, excretion, absorption and lubrication.

Epithelial tissues are classified co-ordinate to the number of cell layers that make upward the tissue and the shape of the cells. Simple epithelium is composed of a single layer of cells while stratified epithelium contains several layers.

Epithelial sells can be apartment (squamous = "scale-like"), cube-shaped (cuboidal) or alpine (columnar). So, to correctly identify the blazon of tissue requires three words (e.g., simple columnar epithelium, stratified, squamous epithelium, etc.

2. Introduction to histology (Part 2)

Connective tissue performs such diverse functions equally binding, support, protection, insulation and ship. Despite their diversity, all connective tissues are comprised of living cells embedded in a non-living cellular matrix consisting of extracellular fibers or some type of ground substance. Thus, what distinguishes the dissimilar connective tissues is the type of matrix. Examples of connective tissue would include os, cartilage, tendons, ligaments, loose connective tissue, adipose (fatty) tissue, and fifty-fifty blood (although some authorities would classify blood equally a vascular tissue).

Muscle tissue is specialized for contraction. In that location are three kinds of muscle tissue:

1. Smoothen muscle (designed for slow, sustained, involuntary contractions) is made upward of spindle-shaped cells with one nucleus per cell.
2. Skeletal, or striated muscle, which is associated with voluntary contractions, contains cylindrical cells with many nuclei per jail cell arranged in bundles.
3. Cardiac (middle) muscle is striated like skeletal muscle, just each cell contains only one nucleus.

iii. Introduction to histology (Part iii)

Nervous tissue is specialized for the reception of stimuli and conduction of nerve impulses. The tissue is composed of nerve cells (neurons), each of which is fabricated up of a cell body and cell processes that carry impulses toward (dendrites) or away from (axons) the prison cell body.   In the following pages of this lab unit, you volition accept an opportunity to examine a few (of the many) types of animal tissue.

In terms of understanding the workings of the multicellular animal body, however, y'all should realize that tissues are but one of many connected levels of biological system. Tissues rarely work alone but instead, they are grouped into organs.  Organs are combined to course organ systems (e.grand., the circulatory system, nervous system, skeletal system, muscular system, excretory system, reproductive organisation, etc.) that part as an integrated unit of measurement chosen an organism.

In subsequent units of the Zoo Lab website, you lot will be introduced to the diversity of animal life that results from the interaction of all of these key components.

4. Elementary squamous epithelium (frog skin)

This slide shows a thin section of frog skin. The outermost portion of this skin is equanimous of a unmarried layer of irregularly-shaped, flat (squamous) cells, which gives the tissue its name. Notation: You are viewing this tissue section from the top! This slide shows a sparse section of frog skin. The outermost portion of this skin is composed of a single layer of irregularly-shaped, apartment (squamous) cells, which gives the tissue its name. Note: Y'all are viewing this tissue section from the top!

v. Simple cuboidal epithelium (cross section of the kidney)

The red and blue arrows signal to unproblematic cuboidal epithelial tissue

This is a slide of a sparse section taken from the mammalian kidney showing the many tubular ducts that make up much of this organ. The walls of these ducts (pointed to by the ruby-red arrows) are comprised of simple cuboidal epithelial cells, which are usually half dozen-sided in shape simply may appear square from a side view. Notation also the sparse wall of uncomplicated cuboidal epithelium (pointed to by the blue arrow) that forms the acme border of this department.

6. Simple columnar epithelium (cantankerous department of the small intestine)

1. Smooth muscle (long. layer)
2. Smoothen muscle (circ. layer)
3. Simple columnar epithelium
4. Goblet cell
5. Lumen of the intestine

This slide is a cross section from the small intestine. Projecting into the intestinal lumen (space) are numerous finger-like projections called villi, which role to slow the passage of nutrient and increase the surface area for the assimilation of nutrients. The lining of these villi is a tissue layer called the mucosa, which is fabricated up of elementary columnar epithelial cells. Interspersed among these columnar cells are goblet cells that secrete mucus into the lumen of the intestine. During routine histological preparation, the fungus is lost, leaving a articulate or lightly stained cytoplasm. Below a thin, outer covering of the intestine called the serosa is a thick layer of smooth muscle cells called the muscularis externa. The muscularis externa is divided into an outer longitudinal muscle layer with cells that run along the axis of the intestine and an inner, circular muscle layer whose fibers encircle the organ. Peristaltic contraction of these two muscle layers keeps food moving through the digestive tract.

one- Smooth muscle (long. layer) & 2 - Smooth muscle (circ. layer)

1. Longitudinal muscle layer
2. Round muscle layer
3. Columnar epithelial cells

three - Simple columnar epithelium & 2 - Goblet prison cell

1. Goblet prison cell
2. Columnar epithelial cells
3. Epithelial prison cell nucleus
4. Lumen of the intestine

7. Stratified squamous epithelium (cross section of the esophagus)

1. Stratified squamous epithelium
2. Lumen of the esophagus
3. Connective tissue

This slide shows a cross department of the esophagus, the commencement portion of the digestive tract that leads to the tummy. Note that the organ is lined with a many layers of cells referred to collectively as stratified squamous epithelium. By convention, stratified epithelial tissues are named past the shape of their outermost cells. Thus, although the deeper and basal layers are composed of cuboidal and sometimes even columnar cells, those cells at the surface are squamous (flat) in shape, giving the tissue its name.

i - Stratified squamous epithelium

1. Stratified epithelial layer
2. Outer squamous cells
3. Lumen of the esophagus

8. Loose connective tissue (spread film of fascia)

1. Collagen fiber
2. Elastin fiber

This slide shows a sparse department of loose connective tissue (sometimes called areolar tissue). This type of tissue is used extensively throughout the trunk for fastening downwardly the skin, membranes, blood vessels and fretfulness as well as binding muscles and other tissues together. Information technology often fills in the spaces between epithelial, musculus and nervous tissue, forming what is known as the stroma of an organ, while the term parenchyma refers to the functional components of an organ. The tissue consists of an extensive network of fibers secreted past cells called fibroblasts. The most numerous of these fibers are the thicker, lightly staining (pink) collagen fibers (1). Thinner, nighttime-staining rubberband fibers (2) composed of the protein elastin can also be seen in the section. south is a slide of a thin department taken from the mammalian kidney showing the many tubular ducts that make upward much of this organ. The walls of these ducts (pointed to by the red arrows) are comprised of uncomplicated cuboidal epithelial cells, which are commonly six-sided in shape but may announced square from a side view. Notation also the sparse wall of simple cuboidal epithelium (pointed to by the blue pointer) that forms the height edge of this section.

ix. Hyaline cartilage (cross section of the trachea)

1. Lumen of the trachea
2. Pseudostratified (ciliated)columnar epithelium
3. Hyaline cartilage (100x)
4. Adipose tissue

This slide showing a cross section of the mammalian trachea (wind pipe) contains examples of several dissimilar kinds of tissues. Supporting the trachea is a ring of connective tissue chosen hyaline cartilage. The chondrocytes (cartilage cells) that secrete this supporting matrix are located in spaces called lacunae.

3 - Hyaline cartilage (100x)

1. Hyaline cartilage (400x)
2. Adipose tissue

1 - Hyaline Cartilage (400x)

1. Lacuna
2. Chondrocyte (cartilage cell)
3. Perichondrium

ten. Pseudostratified columnar epithelium (cantankerous section of the trachea)

1. Lumen of the trachea
2. Pseudostratified columnar epithelium (close-up view)
3. Hyaline cartilage
4. Adipose tissue

This slide showing a cross department of the mammalian trachea (wind pipage) contains examples of several different kinds of tissues. The lining of the trachea consists of a type of tissue called pseudostratified (ciliated) columnar epithelium. This single layer of ciliated cells appears stratified considering the cells vary in their thickness and considering their nuclei are located at dissimilar levels.

two - Pseudostratified columnar epithelium (close-up view)

1. Ciliated border
2. Epithelial layer

11. Adipose tissue (cross section of the trachea)

1. Lumen of the trachea
2. Pseudostratified columnar epithelium (close-up view)
3. Hyaline cartilage
4. Adipose tissue (100x)

This slide showing a cross department of the mammalian trachea (wind pipe) contains examples of several unlike kinds of tissues. In addition to the pseudostratified columnar epithelium lining the trachea and hyaline cartilage, also seen on this slide is an all-encompassing expanse of adipose tissue, which is specialized for fatty storage. On prepared slides, the fat has been removed from the cells giving the tissue the appearance of fish internet.

iv - Adipose tissue (100x)

1. Hyaline cartilage
2. Adipose tissue (400x)

2 - Adipose tissue (400x)

1. Adipose (fat) cells
2. Cell nucleus

12. Compact bone (cross section of dried bone)

This slide contains a department of dried compact os. Note that the os matrix is deposited in concentric layers called lamellae. The basic unit of structure in meaty os is the osteon. In each osteon, the lamellae are bundled around a fundamental Haversian canal that houses nerves and blood vessels in living os. The osteocytes (bone cells) are located in spaces called lacunae, which are continued by slender branching tubules called canaliculi. These "little canals" radiate out from the lacunae to grade an extensive network connecting bone cells to each other and to the blood supply.

Close-Up View of an Haversian Organization

1. Haversian canal
2. Lacunae

13. Shine muscle (separated fibers)

This is a slide of a bundle of polish muscle tissue that has been teased apart to reveal the private cells. Each of these spindle shaped musculus cells has a single, elongated nucleus. In most animals, smoothen muscle tissue is arranged in circular and longitudinal layers that act antagonistically to shorten or lengthen and tuck or aggrandize the body or organ. For an case of such an arrangement, come across the two smoothen muscle layers on a cross department of mammalian gut.

14. Skeletal muscle (cross section of the tongue)

1. Stratified squamous epithelium
2. Duct composed of simple cuboidal epithelium
3. Skeletal musculus
4. Adipose tissue
5. Dense irregular connective tissue

Close-Up View of the Natural language

1. Adipose tissue
2. Skeletal musculus (longitudinal view)
3. Uncomplicated cuboidal epithelium

xv. Cardiac muscle (sectioned to show intercalated disks)

This slide contains a section of cardiac muscle, which is striated like skeletal muscle just adapted for involuntary, rhythmic contractions similar smooth muscle. Although the myofibrils are transversely striated, each cell has just one centrally located nucleus. Note the faintly stained transverse bands, which are called intercalated disks, (indicated by the blue arrows) that marker the boundaries between the ends of the cells. These specialized junctional zones are unique to cardiac musculus.

16. Nervous tissue (multipolar neuron)

1. Nerve prison cell body
2. Nerve cell procedure

This slide contains a smear taken from the spinal string. Note the large, bluish-staining multipolar motor neuron. Coming off the neuron are jail cell processes called axons and dendrites that conduct nervus impulses away from and toward the nerve cell body respectively. Although these processes can easily be seen on the slide, it is not always possible to distinguish between the axon and dendrites.

17. Dense regular connective tissue (tendon)

This slide contains a longitudinal department of a tendon, which is composed of dense regular connective tissue. Note the regularly arranged bundles of closely packed collagen fibers running in the same direction, which results in flexible tissue with not bad resistance to pulling forces.

18. Simple squamous epithelium model

Because it is made up a unmarried layer of scale-like cells, simple squamous epithelium is well suited for rapid improvidence and filtration. These cells await hexagonal in surface view but when viewed from the side (as shown in the image of the model above), they appear flat with bulges where nuclei are located. Simple squamous epithelium forms the inside walls of blood vessels (endothelium), the wall of Bowman's capsule of the kidney, the lining of the body cavity and viscera (parietal and visceral peritoneum) and the walls of the air sacs (alveoli) and respiratory ducts of the lung.

Surface view

xix. Simple cuboidal epithelium model

Uncomplicated cuboidal epithelial cells are commonly half-dozen-sided (cube shaped), but they appear square in side view (as shown on the above image of the model) and polygonal or hexagonal when viewed from the superlative. Their spherical nuclei stain darkly and often requite the layer an appearance of a string of beads. This blazon of tissue is adapted for secretion and absorption. It can be found in such areas as the kidney tubules, the covering of the ovary and equally a component of the ducts of many glands.

Viewed from the top

20. Simple columnar epithelium model

Unproblematic columnar epithelium is composed of alpine (columnar) cells that are closely packed together. Viewed from the surface they appear hexagonal but when viewed from the side (every bit shown on the epitome of the model in a higher place), they appear every bit a row of rectangles with the elongated nuclei frequently located at the same level, ordinarily in the lower role of the cell. Simple columnar epithelial cells may exist specialized for secretion (such as the goblet cells that secrete a protective layer of fungus in the small intestine), for absorption or for protection from abrasion. Columnar epithelial cells line a big part of the digestive tract, oviducts and many glands.

Viewed from the surface

21. Pseudostratified columnar epithelium model

The image to the left shows a model of pseudostratified columnar epithelium. This blazon of tissue consists of a unmarried layer of cells resting on a noncellular basement membrane that secures the epithelium. The tissue appears stratified (occurring in several layers) because the cells are not all the same elevation and because their nuclei (shown as black oval structures) are located at different levels. Pseudostratified ciliated columnar epithelium lines the trachea (windpipe) and larger respiratory passage ways.

22. Skeletal (striated) musculus model

Skeletal musculus is the nearly abundant type of musculus tissue constitute in the vertebrate body, making upwards at least 40% of its mass. Although it is oft activated past reflexes that function in automatically in response to an outside stimulus, skeletal musculus is as well called voluntary muscle because it is the only blazon subject area to witting control. Considering skeletal muscle fibers have obvious bands called striations that can be observed under a microscope, it is also called striated musculus. Note that skeletal muscle cells are multinucleate, that is, each cell has more than one nucleus.

23. Smooth muscle model

Smooth muscle is the simplest of the 3 kinds of muscle. It is found where slow, sustained, involuntary contractions are needed such as in the digestive tract, reproductive system and other internal organs. Shine muscle cells are long and spindle shaped with a single, centrally located nucleus. Polish muscle is often arranged in two layers that run perpendicular to ane another, a round layer whose fibers appear in cross department every bit shown on the model in a higher place and a longitudinal layer whose fibers announced similar the ends of a cut cable when viewed on-end.

24. Cardiac muscle model

Cardiac musculus is striated like skeletal muscle but adapted for involuntary, rhythmic contractions like smooth muscle. The myofibrils are transversely striated, but each jail cell has only ane centrally located nucleus. Note the dark blue transverse bands on the model called intercalated disks that mark the boundaries between the ends of the muscle cells. These specialized junctional zones are unique to cardiac muscle.

25. Meaty os model

This model shows a cross section of meaty os. Observe that the matrix of the bone is deposited in concentric layers that are chosen lamellae (5). The basic unit of structure in this type of os is the Haversian system, or osteon. In each of these osteons, the lamellae are arranged around a central Haversian culvert (1) housing nerves (4) and blood vessels (2, 3) in living bone. Osteocytes or bone cells, (6) are located in spaces called lacunae (7) that are continued by slender branching tubules called canaliculi (8). These "little canals" radiate out from the lacunae to form an extensive network, assuasive bone cells to communicate with one some other and to commutation metabolites.

26. Multipolar neuron model

The image above is that of a greatly enlarged multipolar neuron, the nearly common type of neuron found in humans. Notice that the cell body (i) contains the nucleus (ii) with its conspicuous darkly staining nucleolus (3). Branching from the cell body are cytoplasmic extensions called nervus jail cell processes. In motor neurons (which bear nerve impulses toward muscle cells), these processes consist of a single, long axon (iv) and many of shorter dendrites (5).

4 - Axon

Annotation in this magnified view of an axon that it is surrounded by specialized cells called Schwann cells (one) whose plasma membranes class a covering of the axon called the neurilemma (2), which is shown in dark-brown on the model. These Schwann cells secrete a fatty myelin sheath (3), which is shown in yellow on the model, that protects and insulates nerve fibers from one another and increases the speed of transmission of nervus impulses. Adjacent Schwann cells along an axon do non touch on 1 another, leaving gaps in the sheath chosen nodes of Ranvier at regular intervals (4).

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Source: https://www.uwlax.edu/biology/zoo-lab/lab-2--microscopy-and-the-study-of-tissues/

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