Tissue and Skin Lab PDF

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Tissue and Skin PRE-LAB QUESTIONS 1. What is a tissue? – A tissue is a group of cells bunched together that perform with one another to carry out specific tasks

2. What is the function of epithelial tissue? – The functions of epithelial tissue include protection, secretion, and absorption

3. What is the function of connective tissue?- Connective tissue has many functions including binding and supporting, protecting, insulating, storing reserve fuel, and transporting substances

4. What is the function of muscular tissue? – Muscular tissue is the only tissue able to form contractions, allowing it move body parts.

5. What is the function of nervous tissue? Nervous tissue’s function is to control and coordinate bodily activities.

6. Describe sebaceous glands, sudoriferous glands, and hairs with regard to skin function. – The sebaceous glands are responsible for playing a role as a protective barrier. The level of sebum secreted in these glands determines a person’s skin texture. The sudoriferous glands are in charge of sweat secretion meaning it can cool the skin down which is a big role in temperature regulation in the body. Lastly, hair on our bodies has been derived from evolution. Our ancestors had hair that was more fur-like which provided heat in extreme cold weather conditions.

7. What is the function of melanin? – The main function of melanin to provide protection from the suns UV rays of light. It also influences skin and hair color.

8. List the similarities and differences among the layers of the epidermis. – The layers of the epidermis include the stratum corneum, the stratum granulosum, the stratum lucidum, the stratum spinosum, and the stratum basale. Each of these is similar because all five layers make up the epidermis. They are also all working together to perform specific tasks. However, the functions each of the layers perform differ from one another. The corneum provides structural strength, the granulosum produces keratohyalin ©eScience Labs, 2016

Tissue and Skin granules, the spinosum produces keratin fibers, the lucidum disperses the keratohyalin and keratin, and the basale produces cells.

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Tissue and Skin EXPERIMENT 1: MICROSCOPIC SLIDE EXAMINATION OF TISSUE Tissue Identification Epithelial Tissue

A) Epithelial Tissue Type Simple squamous

B) Epithelial Tissue Type Simple cuboidal

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Tissue and Skin Connective Tissue

C) Connective Tissue Type Adipose

D) Connective Tissue Type Reticular

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Tissue and Skin

E) Connective Tissue Type Elastic cartilage

Muscular Tissue

F) Muscular Tissue Type Cardiac

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Tissue and Skin

G) Muscular Tissue Type Skeletal

Additional Tissue Type

H) Unidentified Tissue Type Nervous tissue

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Tissue and Skin Post-Lab Questions 1. What structural characteristics did you observe for each type of tissue? Be specific. – Epithelial tissue contains many cells that are tightly packed together. The connective tissues were the most abundant in comparison to the other tissues. It also contained three main components, cells, fibers, and ground substance. The skeletal muscle appears banded due to the appearance that involves light and dark bands that are visible due to the usage of a microscope. The nervous tissue was the unidentified special tissue which consisted of neurons and the supporting cells known as neuroglia

9. What is the difference between simple, stratified, and pseudostratified epithelial tissue. – The main difference between simple, stratified and pseudostratified epithelial tissue is that simple tissue is only one layer thick and all types of stratified tissue contain multiple layers.

10. Describe the cell shape of squamous, cuboidal, and columnar epithelial cells. – Squamous cells are very flat and thin, cuboidal cells are shaped like cubes, and columnar epithelial cells are tall and rectangular shaped, like columns.

11. Does the number of cell layers or the cell shape play a role in the function of epithelial tissue? Provide three examples. – Yes, the number of cell layers or the cell shape plays a role in the function of epithelial tissue. For instance, squamous cells have a flat, thin shape allowing them to carry out functions like diffusion. Cuboidal cells are found in the digestive tract and their main functions involve absorption and secretion.

12. List and describe the different types of connective tissue. What similarities and differences did you notice when viewing the slides? - The five different types of connective tissue include bone, cartilage, blood, dense connective, and loose connective tissues. Organic matrix is materially like connective tissue due to the collagen and elastic fibers. Cartilage connective tissue is much less rigid than bone, but still provides support. Blood is a connective tissue containing plasma. Dense connective tissue that contains fibers as its main matrix element. These fibers consist of type collagen. Loose connective tissue is the most common type found in vertebrates.

13. What are three components of the extracellular matrix in connective tissue? – The three components of the extracellular matrix in connective tissue include highly viscous ©eScience Labs, 2016

Tissue and Skin proteoglycans, insoluble collagen fibers, and soluble multiadhesive extracellular matrix proteins.

14. What are the three types of cartilage? What are their similarities and differences? – The three types of cartilage are hyaline cartilage, fibrocartilage, and elastic cartilage. Hyaline cartilage is the most abundant type found in the ribs, nose, larynx, trachea. Fibrocartilage is in layers found in invertebral discs, joint capsules, and ligaments. Lastly, elastic cartilage is found in the external ear, epiglottis, and larynx.

15. What are the three types of muscular tissue? For each, describe the cell shape, the type of control (voluntary or involuntary), and the presence or absence of striations. The three types of muscular tissue are cardiac, smooth, and skeletal. Cardiac muscular tissue is striated and is under involuntary control. Smooth muscular tissue is spindle shaped and in under involuntary control. Skeletal muscular tissue is striated and under voluntary control.

16. Looking at the nervous tissue slides, list the visible cell processes (e.g., axons). For each process, state its function. Every single neuron contains an axon which generates nerve impulses away from the cell. These axons contain branches called axon collaterals. Dendrites carry impulses toward the cellbody.

17. What is the difference between multipolar, bipolar, and unipolar neurons? Multipolar neurons have several processes extending from the cell body, but bipolar neurons have two processes. Unipolar neurons only have one process.

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Tissue and Skin EXPERIMENT 2: MICROSCOPIC SLIDE EXAMINATION OF SKIN Post-Lab Questions 1. Identify the indicated components in the slide below.

A Epidermis Layer

B Sweat Gland Duct

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Tissue and Skin C Dermal Papillae

D Dermis Layer

18. Indicate whether the statement pertains to the epidermis or dermis.

a. This layer consists of the papillary layer and the reticular layer. Dermis

b. Composed of keratinized, squamous epithelium. Epidermis

c. Langerhans cells and Merkel cells reside in this layer. Epidermis

d. Composed of dense, irregular connective tissue. Dermis

e. The fingerprint pattern, unique to each individual, is created in this layer. Dermis

f.

Outermost layer of skin. Epidermis

g. This layer has laminated granules and keratohyalin granules within the stratum granulosum. Epidermis

h. The dense supply of blood allows this layer to play a part in body temperature regulation. Epidermis

19. List the five layers of the epidermis, from most internal to most external, and describe their functions. – Stratum basale: The lowest layer of the skin, forms a basement membrane. Cells are constantly dividing to produce new ones. Stratum spinosum: Layer where cells divide rapidly. Stratum granulosum: Abundance of granules present, upper layer of this boundary is where cells start to die. Stratum lucidum: visible only in thick skin. Stratum corneum: 20 to 30 cells thick, durable.

20. List the two layers of the dermis, from internal to external, and describe their function. The most internal layer of the dermis is the reticular. The reticular is composed of dense ©eScience Labs, 2016

Tissue and Skin irregular connective issue featuring densely packed collagen fibers. It’s the primary location of dermal elastic fibers. The papillary is the uppermost layer and is composed of fine and loosely arranged collagen fibers.

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Tissue and Skin EXPERIMENT 3: SWEAT GLAND DISTRIBUTION Data Tables Table 2: Sweat Gland Distribution Body Region

Sweat Glands/cm2

Right Anterior Forearm

1

Right Palm

2

Right Anterior Thigh

0

Right Anterior Foot

0

Post-Lab Questions 1. What area of your body had the greatest density of sweat glands? What area had the lowest? Why do you think that is? – The greatest density of sweat glands was in the right palm and the lowest was the right foot. This is because there is a greater number of sweat glands located in the palms.

21. What is the purpose of sweat glands? The purpose of the sweat glands is to regulate body temperature.

22. If you were to perform this test on a friend, do you believe the results would be similar or different to yours? Why or why not? – I believe the results would be similar for the mosr part. Some limitations could include the weather or how much the individual sweats.

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Tissue and Skin EXPERIMENT 4: SKIN RECEPTORS Data Tables Table 3: Two-Point Discrimination Test Results Body Region

Left-Side Caliper Measurement

Right-Side Caliper Measurement

Scalp

3

0.5

Forehead

2.5

1.5

Lips

1

1

Front of Neck

1.5

1

Back of Neck

2.5

2.5

Shoulder

3.5

0.5

Upper Arm

3

3.5

Elbow

3

2.5

Forearm

3

1.5

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Tissue and Skin Body Region

Left-Side Caliper Measurement

Right-Side Caliper Measurement

Wrist

1.5

1.5

Back of Hand

1

1.5

Palm of Hand

1

1.5

Tip of Thumb

0.5

0.5

Tip of Index Finger

0.5

0.5

Tip of Middle Finger

0.5

0.5

Tip of Ring Finger

1

0.5

Tip of Pinkie

1

1

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Tissue and Skin Post-Lab Questions 1. Which region was the most sensitive to this test? Which was least sensitive? The most sensitive regions to this test were the hands and face, but the least sensitive regions were the shoulder and elbow.

23. Can you think an advantage to having more touch receptors in the area that you found to be most sensitive? – Fingers and hands are constantly being used for tasks we complete every single day. However, our face needs to protect more features, which is why there is a higher concentration of nerve endings.

24. Was there a difference between the measurements on the left and right sides of the body? Why or why not? – There was a difference between the right and left sides of the body. This could be due to imbalances in the body.

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Tissue and Skin EXPERIMENT 5: INTRODUCTION TO THE FETAL PIG Data Tables Table 4: External Observation of the Fetal Pig Area

Observations

Skin

Wrinkly, smooth, hairy

Head Region

Hairy, long ears, rough snout, closed eyes

Neck Region

Wrinkly, folded

Trunk Region

Very small bumps, hairy, umbilical cord

Tail Region (including sex of pig)

Female

Post-Lab Questions 1. What was the sex of your pig? Describe the criteria you used to determine this. My pig was a female, I was able to determine this due to the umbilical cord and the tail of the pig.

25. Which features of the fetal pig are not present in an adult pig? Umbilical arteries are features of the fetal pig that are not present in an adult pig.

26. Compare and contrast the external anatomy of the fetal pig versus a human. The fetal pig contains many feautures that us humans contain in our bodies. For instance, pigs ©eScience Labs, 2016

Tissue and Skin and humans both have shoulders, elbows, hips, wrists, knees, ankles, and more. However, the fetal pig contains a tail, which humans do not have.

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