Chapter 1

Development and Structure of Cells and Tissues

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development and Structure of Cells and Tissues: Learning Objectives

After reading this chapter, the student will be able to: Describe the cell and how it divides. Discuss the origin of tissue, the ovarian cycle, and

development of the embryonic disk. Describe the various tissues of the human body

and some of the adverse factors (environmental stress, hereditary, and dietary factors) that may affect these tissues development.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

Development and Structure of Cells and Tissues

Cell structure and function Cell division Origin of human tissue Development of human tissues

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 3

Structure of Cells

Nucleus Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA)

Cytoplasm

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 4

Cell Structure and Function

Absorption Assimilation Respiration Irritability Conductivity Growth Reproduction Excretion

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 5

Cell Nucleus

6Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Contains structures necessary for adsorption and for creation of cell products

Cytosol Contains organelles and solutes Uses raw materials to produce energy Functions in waste product excretion

Endoplasmic reticulum (ER) Membrane-bound cavities in the cytoplasm Contains newly acquired and synthesized protein

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 7

Cell Cytoplasm

Ribosomes: Particles that translate genetic codes for proteins and activate mechanisms for their production

8Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Endoplasmic reticulum (ER): An ultrastructural organelle consisting of membrane-bound cavities in the cytoplasm of the cell

ER function: Transports substances in the cytoplasm

Golgi apparatus or Golgi complex are critical for post-translational modifications that help sort, condense, package, and deliver proteins arriving from the ER.

9Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Golgi apparatus is composed of cisternae or saccules, small vesicles, and large vacuoles.

10Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Lysosomes are small, membrane-bound bodies that contain a variety of acid hydrolases, which function in breaking down substances both inside and outside the cell. Present in all cells except red blood cells Prominent in macrophages and leukocytes

Peroxisomes are another intracellular organelle important for breaking down fatty acids.

11Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Mitochondria are membrane-bound organelles that lie free in the cytoplasm and are present in all cells.

Functions: Generate energy Major source of

adenosine triphosphate (ATP)

Store and release ionic calcium

12Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Microtubules: Small tubular structures composed of protein tubulin

Functions: Structural elements Force-generating elements Relate to cilia Relate to centrioles Maintain cell shape

Centrioles: Either of two short cylinders appearing near the nucleus that migrate to opposite poles of the cell during cell division

13Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Plasma membrane or plasmalemma: Cell membrane that envelops the entire cell and provides a selective barrier that regulates transport of substances into and out of the cell

14Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Cytoplasm

Genetic mechanisms help a cell develop and maintain a high degree of order.

Basic genetic processes: RNA and protein synthesis DNA repair Replication and genetic recombination

15Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Division

Cell cycle: A series of discrete steps by which the cell component divides

Interphase Prophase Metaphase Anaphase Telophase

16Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Division: Mitosis of Somatic Cell

17Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Division: Meiosis

Meiosis: The process of reduction of the number of chromosomes to half the normal number in the germ cells to allow fusion of the male and female germ cells

18Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Division: Apoptosis

Apoptosis: Programmed cell death. All cells have a limited lifetime.

19Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cell Division: Adult Stem Cells

20Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Origin of Human Tissue

Induction: The process in which an undifferentiated cell is instructed by specific organizers to produce a morphogenic effect

Differentiation: The process by which cells acquire individual cellular characteristics from an undifferentiated state—that is, specialization

Growth factors: Chemical substances that induce cells to initiate specific cellular processes, including DNA synthesis

21Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Three Periods of Growth: Proliferative, Embryonic, and Fetal

22Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Ovarian Cycle, Fertilization, Implantation, and Development of the Embryonic Disk

23Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Ovarian Cycle, Fertilization, Implantation, and Development of the Embryonic Disk

24Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Ovarian Cycle, Fertilization, Implantation, and Development of the Embryonic Disk

25Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Ovarian Cycle, Fertilization, Implantation, and Development of the Embryonic Disk

26Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Formation of the Neural Tube

27Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Gastrointestinal Tract

28Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Ectoderm, Mesoderm, and Endoderm

29Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Epithelial Tissue

30Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Epithelial Tissue

31Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Nervous System

32Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Nervous System

33Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cranial Nerves

34Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Connective Tissue

35Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Blood

Erythrocytes: Red blood cells Function: Carry oxygen from lungs by hemoglobin;

also carry carbon dioxide from cells of the tissues to the lungs by both hemoglobin and plasma

Leukocyes: White blood cells Function: Defend the body against bacteria and

other invasive organisms and foreign substances Plasma: Blood platelets suspended in a liquid

36Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Blood

Granulocytes Neutrophils (polymorphonuclear leukocytes) Eosinophils Basophils

Granulocytes and agranulocytes Lymphocytes Monocytes

37Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Lymphatic System

Lymphatic system: A protective mechanism in the immunologic defense of the body. It destroys bacteria, viruses, and invasive microorganisms.

Cells are all formed in the bone marrow: B cells T cells NK cells Macrophages

38Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cartilage and Bone

39Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cartilage and Bone

40Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cartilage and Bone

41Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Muscle

42Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cardiovascular System

43Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cardiovascular System

44Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cardiovascular System

45Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Human Tissues: Cardiovascular System

46Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Developmental Abnormalities

Defects may be environmental or hereditary. The 3rd through 8th weeks of embryonic

development are the most critical time in development, because this is the period of differentiation.

47Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Developmental Abnormalities: Hereditary

Genetic abnormalities Dominant Recessive

Chromosomal abnormalities

48Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Questions for Discussion

Which dental environmental factors might have a different role during the first trimester and the last trimester?

Discuss dietary considerations for the pregnant patient during the first trimester.

49Copyright © 2014 by Mosby, an imprint of Elsevier Inc.