?
Blastomere: In humans, blastomere formation begins
immediately following fertilization and continues
through the first week of embryonic development. About
30 hours after fertilization, the egg divides into two cells.
These mitotic divisions continue and result in a grouping
of cells called blastomeres. During this process, the total
size of the embryo (also called a “zygote”) does not
increase, so each division results in smaller and smaller
cells. When the zygote contains 12 to 32 blastomeres it
is referred to as a “morula.”
?
Egg: An ovum (plural ova) is a haploid female
reproductive cell or gamete. The word is derived from
Latin, meaning egg or egg cell. Both animals and
embryophytes have ova. The term ovule is used for the
young ovum of an animal. In some plants, such as algae,
it is also called oosphere. In higher animals, ova are
produced by female gonads (sexual glands) called
ovaries and all of them are present at birth in mammals,
and mature via oogenesis.
?
Embryonic Stem Cells: ES cells are stem cells derived
from the inner cell mass of an early stage embryo known
as a blastocyst. Human embryos reach the blastocyst
stage 4-5 days after fertilisation, at which time they
consist of about 30 cells. Embryonic stem cells are
pluripotent, meaning they can develop into each of the
more than 220 cell types of the adult body when given
the sufficient and necessary stimulation for a specific
cell type. Because of their plasticity and potentially
unlimited capacity for self-renewal, ES cell therapies
have been proposed for regenerative medicine and tissue
replacement after injury or disease.
?
Erythrocytes: Red blood cells known as RBCs or
erythrocytes are the most common type of blood cells
and the vertebrate body’s principal means of delivering
oxygen from the lungs or gills to body tissues via the
blood. Erythrocytes consist mainly of Haemoglobin, a
complex molecule containing heme groups whose iron
atoms temporarily link to oxygen molecules in the lungs
or gills and release them throughout the body. Oxygen
can easily diffuse through the red blood cell’s cell
membrane. Hemoglobin also carries some of the waste
product carbon dioxide back from the tissues. A related
compound, myoglobin, acts to store oxygen in muscle
cells. The colour of erythrocytes is due to the heme group
of Haemoglobin.
?
Fibroblast: A fibroblast is a type of cell that synthesizes
and maintains the extracellular matrix of many animal
tissues. Fibroblasts provide a structural framework for
many tissues, and play a critical role in wound healing.
They are the most common cells of connective tissue in
animals. Fibroblasts secrete the precursors of all the
components of the extracellular matrix, primarily the
ground substance and a variety of fibres.
?
Hepatocytes: It makes up 70-80% of the cytoplasmic
mass of the liver. These cells are involved in protein
synthesis, protein storage and transformation of
carbohydrates, synthesis of cholesterol, bile salts and
phospholipids, and detoxification, modification and
excretion of exogenous and endogenous substances. The
hepatocyte also initiates the formation and secretion of
bile. The hepatocyte is a cell in the body that
manufactures albumin, fibrinogen, and the prothrombin
group of clotting factors. It is the main site for the
synthesis of lipoproteins, ceruloplasmin, transferrin,
complement and glycoproteins. The liver forms fatty
acids from carbohydrates and synthesizes triglycerides
from fatty acids and glycerol. Hepatocytes also
synthesize
apoproteins
with
which
they then assemble and export lipoproteins (VLDL,
HDL). Hepatocytes have the ability to metabolize,
detoxify, and inactivate exogenous compounds such as
drugs and insecticides, and endogenous compounds
such as steroids.
?
Myoblast: A myoblast is a type of stem cell that exists
in muscles. Skeletal muscle cells are called muscle fibres
and are made when myoblasts fuse together; muscle
fibres therefore have multiple nuclei.
Myoblasts that do not form muscle fibres differentiate
into satellite cells. These satellite cells remain adjacent to a
muscle fiber, separated only by its cell membrane and by
the endomycium (the connective tissue of collagen
surrounding the muscle fibre).
?
Neurons: They are electrically excitable cells in the
nervous system that function to process and transmit
information. In vertebrate animals, neurons are the core
components of the brain, spinal cord and peripheral
nerves. Neurons are typically composed of a soma, or
cell body, a dendritic tree and an axon. Neurons
communicate via chemical and electrical synapses, in a
process known as synaptic transmission. Human brain
has about 100 billion (1011) neurons.
?
Oocyte: An oocyte or ovocyte is a female gametocyte or
germ cell involved in reproduction. The formation of an
oocyte, called oogenesis, is a form of gametogenesis whose
male counterpart is spermatocytogenesis. Oogenesis results
in the formation of both primary oocytes before birth, and
of secondary oocytes after it as part of ovulation. The
oocyte divides in meiosis II into one ootid and the second
polar body. The ootid then differentiates into an ovum.
The secondary oocyte is the largest cell in the body, and
in humans is just visible to the naked eye. Oocytes are
rich in cytoplasm which contains yolk granules to nourish
thecell early in development. The only normal type of
secondary oocyte has sex chromosomes 23,X (where sperm
can be 23,X or 23,Y).
?
Osteoblast: An osteoblast is a mononucleate cell that is
responsible for bone formation. Osteoblasts produce
osteoid, which is composed mainly of Type I collagen.
Osteoblasts are also responsible for mineralization of
the osteoid matrix. Bone is a dynamic tissue that is
constantly being reshaped by osteoblasts, which build
bone, and osteoclasts, which resorb bone. Osteoblasts
that become trapped in the bone matrix become osteocytes. They cease to generate osteoid and
mineralized matrix, and instead act in a paracrine
manner on active osteoblasts. They are believed to act
in a mechanosensory manner.
?
Osteoclast: An osteoclast is a type of bone cell that
removes bone tissue by removing the bone’s mineralized
matrix. This process is known as bone resorption.
Osteoclasts and osteoblasts are instrumental in
controlling the amount of bone tissue. Osteoblasts form
bone; osteoclasts resorb bone. Osteoclasts are formed by
the fusion of cells of the monocyte-macrophage cell line.
Osteoclasts are characterized by high expression of
tartrate resistant acid phosphatase (TRAP) and cathepsin K.
Blastomere: In humans, blastomere formation begins
immediately following fertilization and continues
through the first week of embryonic development. About
30 hours after fertilization, the egg divides into two cells.
These mitotic divisions continue and result in a grouping
of cells called blastomeres. During this process, the total
size of the embryo (also called a “zygote”) does not
increase, so each division results in smaller and smaller
cells. When the zygote contains 12 to 32 blastomeres it
is referred to as a “morula.”
?
Egg: An ovum (plural ova) is a haploid female
reproductive cell or gamete. The word is derived from
Latin, meaning egg or egg cell. Both animals and
embryophytes have ova. The term ovule is used for the
young ovum of an animal. In some plants, such as algae,
it is also called oosphere. In higher animals, ova are
produced by female gonads (sexual glands) called
ovaries and all of them are present at birth in mammals,
and mature via oogenesis.
?
Embryonic Stem Cells: ES cells are stem cells derived
from the inner cell mass of an early stage embryo known
as a blastocyst. Human embryos reach the blastocyst
stage 4-5 days after fertilisation, at which time they
consist of about 30 cells. Embryonic stem cells are
pluripotent, meaning they can develop into each of the
more than 220 cell types of the adult body when given
the sufficient and necessary stimulation for a specific
cell type. Because of their plasticity and potentially
unlimited capacity for self-renewal, ES cell therapies
have been proposed for regenerative medicine and tissue
replacement after injury or disease.
?
Erythrocytes: Red blood cells known as RBCs or
erythrocytes are the most common type of blood cells
and the vertebrate body’s principal means of delivering
oxygen from the lungs or gills to body tissues via the
blood. Erythrocytes consist mainly of Haemoglobin, a
complex molecule containing heme groups whose iron
atoms temporarily link to oxygen molecules in the lungs
or gills and release them throughout the body. Oxygen
can easily diffuse through the red blood cell’s cell
membrane. Hemoglobin also carries some of the waste
product carbon dioxide back from the tissues. A related
compound, myoglobin, acts to store oxygen in muscle
cells. The colour of erythrocytes is due to the heme group
of Haemoglobin.
?
Fibroblast: A fibroblast is a type of cell that synthesizes
and maintains the extracellular matrix of many animal
tissues. Fibroblasts provide a structural framework for
many tissues, and play a critical role in wound healing.
They are the most common cells of connective tissue in
animals. Fibroblasts secrete the precursors of all the
components of the extracellular matrix, primarily the
ground substance and a variety of fibres.
?
Hepatocytes: It makes up 70-80% of the cytoplasmic
mass of the liver. These cells are involved in protein
synthesis, protein storage and transformation of
carbohydrates, synthesis of cholesterol, bile salts and
phospholipids, and detoxification, modification and
excretion of exogenous and endogenous substances. The
hepatocyte also initiates the formation and secretion of
bile. The hepatocyte is a cell in the body that
manufactures albumin, fibrinogen, and the prothrombin
group of clotting factors. It is the main site for the
synthesis of lipoproteins, ceruloplasmin, transferrin,
complement and glycoproteins. The liver forms fatty
acids from carbohydrates and synthesizes triglycerides
from fatty acids and glycerol. Hepatocytes also
synthesize
apoproteins
with
which
they then assemble and export lipoproteins (VLDL,
HDL). Hepatocytes have the ability to metabolize,
detoxify, and inactivate exogenous compounds such as
drugs and insecticides, and endogenous compounds
such as steroids.
?
Myoblast: A myoblast is a type of stem cell that exists
in muscles. Skeletal muscle cells are called muscle fibres
and are made when myoblasts fuse together; muscle
fibres therefore have multiple nuclei.
Myoblasts that do not form muscle fibres differentiate
into satellite cells. These satellite cells remain adjacent to a
muscle fiber, separated only by its cell membrane and by
the endomycium (the connective tissue of collagen
surrounding the muscle fibre).
?
Neurons: They are electrically excitable cells in the
nervous system that function to process and transmit
information. In vertebrate animals, neurons are the core
components of the brain, spinal cord and peripheral
nerves. Neurons are typically composed of a soma, or
cell body, a dendritic tree and an axon. Neurons
communicate via chemical and electrical synapses, in a
process known as synaptic transmission. Human brain
has about 100 billion (1011) neurons.
?
Oocyte: An oocyte or ovocyte is a female gametocyte or
germ cell involved in reproduction. The formation of an
oocyte, called oogenesis, is a form of gametogenesis whose
male counterpart is spermatocytogenesis. Oogenesis results
in the formation of both primary oocytes before birth, and
of secondary oocytes after it as part of ovulation. The
oocyte divides in meiosis II into one ootid and the second
polar body. The ootid then differentiates into an ovum.
The secondary oocyte is the largest cell in the body, and
in humans is just visible to the naked eye. Oocytes are
rich in cytoplasm which contains yolk granules to nourish
thecell early in development. The only normal type of
secondary oocyte has sex chromosomes 23,X (where sperm
can be 23,X or 23,Y).
?
Osteoblast: An osteoblast is a mononucleate cell that is
responsible for bone formation. Osteoblasts produce
osteoid, which is composed mainly of Type I collagen.
Osteoblasts are also responsible for mineralization of
the osteoid matrix. Bone is a dynamic tissue that is
constantly being reshaped by osteoblasts, which build
bone, and osteoclasts, which resorb bone. Osteoblasts
that become trapped in the bone matrix become osteocytes. They cease to generate osteoid and
mineralized matrix, and instead act in a paracrine
manner on active osteoblasts. They are believed to act
in a mechanosensory manner.
?
Osteoclast: An osteoclast is a type of bone cell that
removes bone tissue by removing the bone’s mineralized
matrix. This process is known as bone resorption.
Osteoclasts and osteoblasts are instrumental in
controlling the amount of bone tissue. Osteoblasts form
bone; osteoclasts resorb bone. Osteoclasts are formed by
the fusion of cells of the monocyte-macrophage cell line.
Osteoclasts are characterized by high expression of
tartrate resistant acid phosphatase (TRAP) and cathepsin K.
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