ch1 HEMATOPOIESIS Flashcards
Homogenous, continuous, aqueous solution in the cytoplasmic matrix
Cytosol
Macromolecular complexes composed of small and large subunit of rRNA and many accessory ribosomal proteins. Ribosomes are found free in the cytoplasm or on the surface of rough endoplasmic reticulum Ribosomes serves as the site of protein synthesis
Ribosomes
- Synthesizes phospholipids and steroids
- Detoxifies drugs
- Stores calcium
Smooth endoplasmic reticulum
Synthesizes most membrane-bound proteins
Rough endoplasmic reticulum
Term used for the non-mitosis stages of the cell cycle, that is, G1, S, and G2.
Interphase
Two identical daughter cells are produced, each of which receives one entire set of the DNA that was replicated during the S phase
Mitosis – M phase
Duration of Mitosis
1 hour
- Also known as: Gap 1 phase
- Cell grows rapidly and performs its cellular functions
- Period of cell growth and synthesis of components necessary for replication.
Interphase – G1 phase
- Also known as: Synthesis phase
- DNA is replicated
- An exact copy of each chromosome is produced and they pair together as sister chromatids.
- The centrosome is also duplicated during the S stage.
Interphase – S phase
- Also known as: Gap 2 phase
Period when the cell produces materials essential for cell division - Tetraploid DNA is checked for proper replication and damage
Interphase – G2 phase
Duration of G1 Phase
11 hours
Duration of S Phase
8 hours
Duration of G2 Phase
4 hours
G0 Phase is also known as
Resting Phase
- Cells are not active in cell cycle
- Some cells may enter this phase after G1 phase
- Normally do not re-enter the cell cycle and remain alive performing their function until apoptosis occurs
G0 Phase
- Occur at the end of G1 phase
- Before DNA replication in S phase
- At the end of G2 phase before M phase
Checkpoint
Present in small numbers in the bone marrow (<1% cells in the bone marrow)
Stem Cells
- These cells are present in the first few hours after an ovum is fertilized.
- Can develop into any human cell type, including development from embryo into fetus.
- The most versatile type of stem cell.
- Give rise to all cell lineage
- Gives rise to CFU-S and CFU-L
- Can develop into any human cell type, including development from embryo into fetus.
Totipotent hematopoietic stem cell (THSC)
- These cells are capable of giving rise to multiple lineages of blood cells
- Example: CFU-S and CFU-L
Pluripotential or Multipotential stem cell
The identification and origin of stem cells can be determined by immunophenotypic analysis using
Flow Cytometry
Characteristic of stem cell
- Capable of self-renewal
- Give rise to differentiated progeny
- Able to reconstitute the hematopoietic system of a lethally irradiated host
Fate of Hematopoietic Stem Cell (HSC)
- Self-renewal
- Differentiation
- Apoptosis
- Glycoprotein
- Encoded on Chromosome 1q
- Stem cell marker
Stem Cells
Is a continuous, regulated process of blood cell production that includes cell renewal, proliferation, differentiation, and maturation.
Hematopoiesis
Is a collective term used to describe the process involved in the production of blood cells from human stem cells (HSCs) with subsequent cellular differentiation and development
Hematopoiesis
These processes result in the formation, development, and specialization of all of the functional blood cells that are released from the bone marrow to the circulation.
Hematopoiesis
In healthy adults, hematopoiesis is restricted primarily to the
Bone Marrow
Hematopoiesis occurs in the following parts of the body:
Bone marrow, liver, spleen, lymph nodes, and thymus
In fetus, hematopoiesis takes place at various intervals in the
Liver, spleen, thymus, bone marrow, and lymph nodes
Major locations of Hematopoiesis
Yolk sac, aorta-gonad-mesonephros (AGM) region, fetal liver, bone marrow, and thymus.
