Question 1
1. Which of the following statements is FALSE regarding the structure of epithelial tissue?
A. Epithelial tissue has a direct nerve supply.
B. Epithelial tissue draws its blood supply from the basement membrane.
C. Epithelial tissue is composed of a small cellular content with a large amount of matrix.
D. All of the above statements are true.
Tissues refer to groups of cells and the material surrounding them that work together to perform a particular function in the human body. The structure and features of any tissue depend on the nature of the extracellular matrix and the connection between the cells that make up the tissue. There are 4 major types of tissues in the human body:
Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue
Question 2
Consider the reaction: H2(g) + I2(g) 2 HI(g) Keq = ??? Into a 1.00 L vessel, 1.00 mol H2(g) and 1.00 mol I2(g) are placed at a high temperature. When the reaction mixture stops changing, it is found that 79.0% of the H2(g) has reacted. What is the equilibrium constant for this reaction at this temperature?
Question 3
Answer to question 1
1. The false statement regarding epithelial tissue is C. Epithelial tissue is composed of a small cellular content with a large amount of matrix
Epithelial tissues are those tissues that cover body surfaces such as the skin, line internal organs, body cavities and ducts, such as blood vessels and respiratory organs, and they form the secretory portion of glands in the body. The features of epithelial tissues include:
The cells within the epithelial tissues are arranged in either single or multiple layers
The cells have three surfaces, namely, the lateral, apical and basal surfaces.
There are numerous cellular junctions which provide a secure attachment to other neighboring cells
They are avascular tissues without blood vessels supplying them, so they get blood from the underlying basement membrane and vascular connective tissue.
The cells are tightly packed together and with little to no extracellular matrix between neighboring cells.
They have a high capacity for cell renewal by mitotic division
They have a wide array of functions which depend on where they are found in the human body, for example, in the skin, they provide protection, and in the lungs, they enable diffusion of gases.
Answer to question 2
Step 1
H2(g) + I2(g) = 2HI (g)
Initial : 1 M 1M 0
Step 2
H2(g) + I2(g) = 2HI (g)
Initial : 1 M 1M 0
Change: -x -x +2x
Equi: 1-x 1-x +2x
x = 0.79
K = [HI]2/[H2] [I2]
= (2x)2 /(1-x)2
= (2×0.79)2 /(1-0.79)2
= (1.58)2 /(0.21)2
= 56.6
Answer to question 3
Explanation: –
There are three principal shapes of epithelial cell: squamous, columnar, and cuboidal. These can be arranged in a single layer of cells as simple epithelium, either squamous, columnar, cuboidal, pseudo-stratified columnar or in layers of two or more cells deep as stratified (layered), either squamous, columnar or cuboidal. All glands are made up of epithelial cells. Functions of epithelial cells include secretion, selective absorption, protection, transcellular transport, and sensing.
** there is no thick vascular matrix in epithelial tissue