Chapter 2.1 The study of cells Flashcards Preview

Human Anatomy > Chapter 2.1 The study of cells > Flashcards

Flashcards in Chapter 2.1 The study of cells Deck (33):
1

The structural and functional unit of all organisms, including humans

Cells

2

An adult human body contains about how many cells?

75 trillion cells

3

Most cells are composed of characteristic parts that work together to allow them to

Perform specific body functions

4

How many different type of cells are there in the human body

Approximately 200 different types of cells in the human body

5

Even though there are hundreds of different types of cells they all share certain common characteristics

*General "housekeeping functions"
*Must obtain nutrients and other materials essential for survival from its surrounding fluids
*Dispose of wastes they produce
*Shape and integrity is maintained by its internal contents and its surrounding membrane
*Most are capable of undergoing division to make more cells of the same type

6

The total of all the chemical reactions that occur in cells is called

Metabolism

7

If a cell didn't remove its wastes products what would happen?

The waste would build up in the cell and ultimately lead to the cells death

8

The study of cells is called

Cytology

9

What is the greatest obstacle in obtaining the nature of a cell

Their small size

10

Cells were discovered after what was invented?

Microscopes

11

What are required to see the smallest human body cell?

High-magnification microscopes

12

What is often used to measure cell size?

The dimensional unit, the micrometer (um)

13

One micrometer is equal to how many centimeters?

1/10,000 of a centimeter

14

A red blood cell has a diameter of about

7-8 um

15

One of the largest human cells, the oocyte, has a diameter of about

120 um

16

The use of the microscope is called

Microscopy

17

This has become a valuable asset in anatomic investigations

The microscope

18

What are the most commonly used microscopes

1) Light microscope (LM)
2) Transmission electron microscope (TEM)
3) Scanning electron microscope (SEM)

19

Because specimen samples have no inherent contrast, they cannot be seen clearly under the microscope unless

Contrast is added

20

Colored-dye stains are used in what type of microscope

Light microscopy

21

Heavy metal stain preparations are used in

Electron microscopy, which includes both TEM and SEM

22

This type of microscope produces a two-dimensional image for study by passing visible light through the specimen. Glass lenses focus and magnify the image as it is projected toward the eye.

The Light microscopy (LM)

23

Uses a beam of electrons to "illuminate" the specimen. Easily exceed the magnification obtained by light microscopy, they improve the resolution by more than a thousandfold. Directs an electron beam through a thin-cut section of the specimen. The resultant two-dimensional image is focused onto a screen for viewing or onto photogenic film to record the image. Can show a close up

Transmission electron microscope (TEM)

24

Detailed three-dimensional study of the surface of the specimen. The electron beam is moved across the surface of the specimen, and reflected electrons generate a surface-topography image captured on a television screen

Scanning electron microscope (SEM)

25

In what ways do cells vary?

Size and shape

26

What are the different cell shapes?

Flat, cylindrical, oval, or quite irregular

27

Often cells functions are reflected on what?

Their size or shape

28

What are the general function of cells?

1) Covering
2) Lining
3) Storage
4) Movement
5) Connection
6) Defense
7) Communication
8) Reproduction

29

Describe how cells are used for covering

Epithelial cells form a sheet to cover surfaces. For example, skin cells cover the external body surface

30

Describe how cells are used for lining

Epithelial cells line the internal surfaces of our organs, such as the small intestine

31

Describe how cells are used for storage

Some body cells, such as hepatocytes (liver cells) and adipocytes (fat cells), store nutrients or energy reserves for the body

32

Describe how cells are used for movement

Muscle cells are composed of contractile proteins that cause the muscle to shorten (contract), thereby allowing movement to occur. Skeletal muscle cells attach to the skeleton so that when these cells contract, they move the skeleton. In contrast, when the muscle cells in the heart wall contract, they are able to pump blood throughout the body

33

Describe how cells are used for connection

Multiple cell types are found in connective tissues, which help connect and support other tissues. For example, fibroblast cells produce protein fibers that are found in ligaments, the connective tissue that binds bone to bone