1. Developmental processes - proliferation, migration, differentiation, growth, death.

2.Growth 2 kinds:

1.Growth in the Context of cell development: increase in cytoplasmic and organelle volume (G1 phase and G2 phase of cell cycle), as well as increase in genetic material (S phase) following the replication during the M phase. 2. Growth in the context of cell division: refered to as proliferation, where a cell, known as the "mother cell", grows and divides to two daughter cells.

Migration

1.Migration= movement of cells to the target tissue. 2.It is a central process in the development and maintenance of multicellular organisms that includes activities like embryonic: development (for example: a.migration of sperm to oocyte), b.wound healing and c.immune response (migration of leukocytes to area of infection) or d.cancer metastasis. (Metastasis means that cancer spreads to a different body part from where it started.) 3.Cells migrate in response to specific external signals, including A. chemical signals (chemotaxis) like sugars or peptides, or B.mechanical signals (mechanotaxis) due to pressure, shear stress in fluids, C.and others.

1.Proliferation 2.Migration 3.Differentiation 4.Growth 5.Death

1.Proliferation= increase in cell number caused by cell growth and division by mitosis. - Non-proliferative cells -In these cases, the fully differentiated cells do not proliferate themselves - Proliferative cells proliferative divide continuously throughout life. 2.Migration= movement of cells to the target tissue 3. Differentiation= the process where a cell changes from one cell type to another. 4.Growth= A.Growth in the Context of cell development. B.Growth in the context of cell division 5.Death= a biological cell ceasing to carry out its functions. A.Programmed cell death (PCD) = apoptosis or autophagy-cell death mediated by an intracellular program, usually during an organism's life-cycle. B.Necrosis-non-physiological process that occurs as a result of infection or injury.

Death Definition Other causes of death

Death= a biological cell ceasing to carry out its functions Reasons of death: A. This may be the natural process of old cells dying and being replaced by new ones, or B. as result of disease, injury, or the death of the organism of which the cells are a part of. Other causes of cell death: 1.Programmed cell death (PCD) = apoptosis 2.Necrosis

Proliferation

Definition of proliferation : increase in cell number caused by cell growth and division by mitosis. A.Non-proliferative cells B.Proliferative cells -

Differentiation

Differentiation=the process where a cell changes from one cell type to another. Most commonly the cell changes to a more specialized type. Differentiation continues throughout life as adult stem cells divide and create fully differentiated daughter cells. During differentiation the cell will change a.size b.shape c.membrane potential d.metabolic activity, e. responsiveness to signals - to fit its functionality. With a few exceptions, cellular differentiation never involves a change in the DNA sequence itself, but rather changes in transcription and translation of specific genes, or the inhibition of others. Pluripotency is the ability to give rise to all differentiated cell types of ectoderm, endoderm and mesoderm. Pluripotent embryonic stem cells have this ability.

During differentiation-what will happened?

During differentiation the cell will change a.size b.shape c.membrane potential d.metabolic activity, e. responsiveness to signals - to fit its functionality.

Topic 1-opening -what early development is characterized by?

Early development is characterized by the rapid proliferation of embryonic cells, which then differentiate to create specialized types of cells that make up the--> tissues and organs of the body. They can migrate to different locations where they are needed.

1.Growth in the Context of cell development:

Increase in cytoplasmic and organelle volume (G1 phase and G2 phase of cell cycle), as well as increase in genetic material (S phase) following the replication during the M phase.

A.Non-proliferative cells

Non-proliferative cells 1.cardiac muscle cells, blood cells, and others. Some differentiated tissues like skin and the epithelial cells lining the digestive tract have short life spans and must be replaced by continuous cell proliferation. In these cases, the fully differentiated cells do not proliferate themselves. Instead, they are replaced via the proliferation of stem cells. Stem cells divide to produce daughter cells that can either differentiate or remain as stem cells, thereby serving as a source for the production of differentiated cells throughout life. This process can be: 1.symmetric (two daughter cells that will remain stem cells) or 2.assymetric (one cell will remain a stem cell and the other will differentiate)

Other types of stem cells can be predefined to differentiate into a specific lineage:

Other types of stem cells can be predefined to differentiate into a specific lineage: hematopoeitic stem cells for example can differentiate into all cells of the bone marrow including white and red blood cells.

Pluripotency

Pluripotency is the ability to give rise to all differentiated cell types of ectoderm, endoderm and mesoderm. Pluripotent embryonic stem cells have this ability.

B.Proliferative cells

Proliferative cells - proliferatives divide continuously throughout life. -fibroblasts, -smooth muscle cells, -the endothelial cells of blood vessels, -the epithelial cells of most organs, such as the liver, pancreas, kidney, lung, prostate, skin and breast. As cells differentiate most cells in adult animals are arrested in the G0 stage of the cell cycle. A few types of differentiated cells are nonproliferative, but most cells are able to resume proliferation as required to replace cells that have been lost as a result of injury or cell death. Cell proliferation is carefully balanced to maintain a constant number of cells in adult tissues and organs.

Programmed cell death (PCD) = apoptosis

cell death mediated by an intracellular program, usually during an organism's life-cycle. For example, the embryonic differentiation of fingers and toes occurs because cells between the fingers die, allowing the digits are separate.

Necrosis:

non-physiological process that occurs as a result of infection or injury. It is cell death caused by external factors, and occurs in several different forms.

2. Growth in the context of cell division:

refered to as proliferation, where a cell, known as the "mother cell", grows and divides to two daughter cells.