SC 121 Unit 4 Assignment

SC121 Unit 4 Assignment

PART 1

1. Why are cells are important to the body

The cells are the basic living, structural, and functional unit of the body. They carry out a multitude of functions that help each system contribute homeostasis of the entire bod. All cells share structures and functions that support their intense activity. The Human body is composed of trillions of cells. They can provide structure to the body, take in nutrients from food that is consumed, convert those nutrients into energy and carry out specialized functions. There are two types of cells which are prokaryotic (bacteria) and eukaryotic (animal, fungi, plant, and protoctista)

2. Which organelle do you think would kill you the fastest if you lost it? Explain your answer.

Mitochondrion.

Mitochondrion is referred to as the powerhouse of the cell. Mitochondria generate most the ATP (Adenosine Triphosphate) through aerobic respiration (oxygen requiring). Some organs and tissues have a large number of mitochondria. These can be found in muscles, liver, and kidneys. Through aerobic respiration it takes the nutrients in the cell, break it down and turns it into energy. The energy is then used by the cell to carry out all the necessarily functions. This can include what the body needs to stay warm, to moving (exercise), and even thinking. Example includes if you was to regularly exercise it can lead to a increase in the number of mitochondria found in the cell which allows for the muscles cells to function more efficiently. Without ATP the cell would immediately die because it would be incapable of performing all biochemical processes that are required to sustain life.

3. How is cell shape related to function? Give at least 3 examples and explain.

Human sperm cells – these allow them to swim long distances to reach and egg for fertilization. They use flagella, which is there log whip-like tails, also by being very small carrying little more than the DNA for a potential zygote.

Intestinal Lining- Cells that are located within the intestine are covered by many cilia. It increases the surface area so the more nutrient are absorbed from the food the is passing through.

Nerve Cells – The4ese cells contain long spindles that are known as axons. These axons have to be long because they relay electrical impulses throughout the body (from the head to the lower extremities)

4. Choose one organelle or cellular component and research a disorder that affects it. Then, answer the following:

What is the name of the disorder? Tay-Sachs Disease

Which part of the cell is affected? Lysosomes

What are the consequences of this disorder? Tay- Sachs disease most often affects children of a eastern European Jewish descent. It is a inherited condition which is classified by the absence of a single lysosomal enzyme called Hex A. Children with Tay-Sachs disease experience seizures and muscled rigidity. They will eventually become blind, demented, and uncoordinated and will typically die by 5 years old.

PART 2

Question #1

Name of tissue: Skeletal Muscle tissue

Two characteristics used for identification: I recognized this type of tissue because of it long, cylindrical, and striations.

Question #2

Name of epithelium: Stratified Cuboidal Epithelium

Discuss the classifications of epithelial tissue based on:

Cell layers

Stratified Cuboidal Epithelium has two or more layers of cells. The cells are in apical layer.

Simple squamous epithelium – a single layer of flat cells that resemble a tiled floor.

Simple Cuboidal Epithelium – singe layer of cube shaped cells

Nonciliated simple columnar epithelium- a single layer of Nonciliated column like cells with oval nuclei near base of cells. It contains columnar epithelial cells with microvilli at apical surface and goblet cells.

Ciliated Simple Columnar Epithelium – a single layer of ciliated column like cells with oval nuclei towards the base of the cells.

Nonciliated Pseudostratified Columnar Epithelium- Appears to have several layers because the nuclei of each of the cells are at different levels.

Ciliated Pseudostratified Columnar Epithelium- Several layers because the cell nuclei are at different levels.

Stratified Squamous Epithelium- two or more layers of cells that is in apical and several layers deep are squamous.

Stratified Columnar Epithelium – Basal layers and only apical layer gas columnar cells.

Transitional Epithelium (Urothelium) – has a variable appearance multiple layers and elasticity make it ideal for lining hollow structures.

Shape

Stratified Cuboidal Epithelium is cube-shaped.

Simple squamous epithelium – oval or spherical in shape

Simple Cuboidal Epithelium – cube shaped

Nonciliated simple columnar epithelium- column like cells

Ciliated Simple Columnar Epithelium- Column like cells

Nonciliated Pseudostratified Columnar Epithelium- Column like cells

Ciliated Pseudostratified Columnar Epithelium – Column like cells

Stratified Squamous Epithelium – the can very from cuboidal to columnar

Stratified Columnar Epithelium – basal layer consists of shortened irregular shaped cells, but the apical layer has columnar cells

Transitional Epithelium (Urothelium)- Apical layer cells tend to be large and rounded. Whereas the tissue in a relaxed or unstretched state will look like stratified cuboidal epithelium. Once the tissue is stretched the cells become flatter.

How did this knowledge help you to identify the epithelium?

Question #3

Structure name: Neuron of the spinal cord (Nervous tissue)

Identify each label:

A – Dendrite

B –Nucleus in cell body

C – Axon

Direction of the nerve impulse: BAC

Question #4

Name the tissue: Areolar Connective Tissue- one of most widely distributed connective tissues.

List of all fibers present and function of each fiber

Collagen – Very strong and resist pulling or stretching but they are not stiff which allows for the tissue’s flexibility.

Elastic- smaller in diameter than collagen fibers that branch and join to create a fibrous network within the connective tissue.

Reticular- consisting of collagen arranged in bundles with a coating of glycoprotein to provide support in the walls of the blood vessels to create a network around the cells in some tissues.

List 5 types of cells present and function for each cell

Fibroblasts – large flat cells with branching processes. Usually present in general connective tissues, both are numerous.

Macrophages- are phagocytes that develop form monocytes which are a type of white blood cells.

Plasma Cells- located in many places in the body, most plasma cells do reside in the connective tissue.

Adipocytes- are fat cells that store triglycerides. Found deep to the skin and around the organs such as kidneys or heart.

Mast Cells – Involved in the inflammatory response, the bodys reaction to injury or infection and can also ingest, bind to, and kill bacteria.

References

Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy & physiology. Hoboken, NJ: Wiley.