Connective tissues are composed of cells and an extracellular matrix. There are four main types of connective tissues - loose connective tissue, dense connective tissue, cartilage, and blood. Loose connective tissue has loosely arranged cells and fibers in a semi-fluid ground substance. Dense connective tissue has compactly packed fibers and cells. Cartilage is a solid but flexible tissue found in joints, nose and ears. Bone is a hard tissue providing structure and protection, containing osteocytes in lacunae. Blood is a fluid connective tissue that transports substances throughout the body.
detail notes on connective tissue..
Connective tissue (CT) is one of the four basic types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesoderm. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central nervous system, the three outer membranes (the meninges) that envelop the brain and spinal cord are composed of connective tissue.
All connective tissue consists of three main components: fibers (elastic and collagenous fibers), ground substance and cells. Not all authorities include blood or lymph as connective tissue because they lack the fiber component. All are immersed in the body water.
Every organism is composed of several different types of human body tissue. The human body tissue is another way of describing how our cells are grouped together in a highly organized manner according to specific structure and function. These groupings of cells form tissues, which then make up organs and various parts of the body.
detail notes on connective tissue..
Connective tissue (CT) is one of the four basic types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesoderm. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central nervous system, the three outer membranes (the meninges) that envelop the brain and spinal cord are composed of connective tissue.
All connective tissue consists of three main components: fibers (elastic and collagenous fibers), ground substance and cells. Not all authorities include blood or lymph as connective tissue because they lack the fiber component. All are immersed in the body water.
Every organism is composed of several different types of human body tissue. The human body tissue is another way of describing how our cells are grouped together in a highly organized manner according to specific structure and function. These groupings of cells form tissues, which then make up organs and various parts of the body.
Under the microscopeCORE273 Summer2019What is Biology.docxouldparis
Under the microscope
CORE273 Summer2019
What is Biology?
Biology is a word derived from the Greek words bios, meaning “life”, and logos meaning “study”.
Therefore biology is defined as the science and study of life and living organisms.
An “organism” is a living entity consisting of one cell (bacteria) or several cells (plants, animals, fungi).
https://www.ntnu.edu/biology/about-us/what-is-biology
2
Characteristics of Living things
Made of different molecules than non-living things.
Carbon atoms form bonds with other atomic elements.
Molecules result: carbohydrates, proteins, lipids, nucleic acids.
Require energy and raw materials.
Intake of above molecules offers energy and building blocks of cells.
Have a metabolism.
Breaks down/builds up molecules into/from atoms (respectively).
Living things will grow, reproduce, and evolve.
Characteristics of Living things
Respond to their environment and maintain homeostasis.
Necessary to maintain a relatively constant internal environment.
Systems present in any organism must respond to internal/external stimuli.
Make adjustments to compensate for stress on other systems.
Negative Feedback Loops
Controlled Variable is the factor being monitored.
Sensors keep “tabs” on if these factors are at their “set points”.
Control Center gathers information and determines appropriate actions.
Effectors are activated by control center to carry out necessary response.
Characteristics of Living things
All living things are composed of cells and cell products.
A single cell is the smallest unit exhibiting all characteristics of life.
Often divided by internal structural organization:
Prokaryotic cells lack a membrane bound “nucleus” and have few “organelles” (i.e.; bacteria)
Eukaryotic cells do have a membrane bound nucleus and many organelles with different functions (i.e.; plants, animals, fungi)
Inside our human Cells
Nucleus is the “brain”; directs activities via DNA.
DNA molecules contain our genetic information.
Organelles are “little organs”
Ribosomes: produce proteins.
Rough endoplasmic reticulum: produces proteins via ribosomes that are on membrane.
Smooth endoplasmic reticulum: produces primarily lipids; no ribosomes.
Golgi apparatus: refines, ships, and packages products from both endoplasmic reticula.
Mitochondria: “powerhouse”. Produces energy in the form of ATP molecules.
Cells of the body
While the internal structure remains fairly similar between cells of the body, cells can differ in external structure.
The form (shape/size) of a cell will greatly influence it’s overall function.
Neurons are long and thin for fast communication between cells.
Muscle cells have special segments that shorten to allow the tissue to contract.
Tissues of the body
Groups of similar cells come together to form tissues.
There are four primary types of tissues:
Epithelial: covers body cavities, lines organs, and surfaces.
Glandular epithelium secretes products.
Connective: supports and connects.
Loose, d ...
5. (diff cell + matrix/ grnd sub)
Connective tissues are most abundant
and widely distributed in the body of
complex animals.
Why they are named as connective
tissues?
It is because of their special function of linking and
supporting Other tissues/organs of the body.
6. In all connective tissues except blood, the cells
secrete fibers of structural protein called
1.Collagen(White, tensile, thick)
2. Elastin (elastic, thin, yellow)
These fibers provide strength, elasticity and
lexibility to the tissue. These cells also secrete
modified polysaccharides,
which accumulate between cells and fibers
nd act as matrix (ground substance).
7.
8.
9. Loose Connective
Tissue
Loose Connective Tissue: Loose connective tissue has cell and
fibers loosely arranged in a semi-fluid ground substance,
for example, areolar tissue present beneath the skin.
Often it serves as a support framework for epithelium.
It contains fibroblasts (cells that produce and secrete fibers),
macrophages and mast cells. Adipose tissue is another type of
loose connective tissue located mainly beneath the skin.
The cells of this tissue are specialised to store fats.
the excess of nutrients which are not used immediately
are converted into fats and are stored in this tissue.
10.
11. Dense
Connective
Tissue
Dense Connective Tissue: Fibers and fibroblasts are compactly
packed in the dense connective tissues. Orientation of fibers show a
regular or irregular pattern and are called dense regular and dense
irregular tissues. In the dense regular connective tissues, the
collagen fibers are present in rows between many parallel bundles
of fibers. Tendons, which attach skeletal muscles to bones and
ligaments which attach one bone to another are examples of this
tissue. Dense irregular connective tissue has fibroblasts and many
fibers (mostly collagen) that are oriented differently. This tissue is
present in the skin.
12.
13. Specialised Connective
Tissue
Specialised Connective Tissue: Cartilage,
bones and blood are various types of specialized
connective tissues.
1.Cartilage : The intercellular material of
cartilage is solid and pliable and resists compression.
Cells of this tissue (chondrocytes) are enclosed in
small cavities within the matrix secreted by them.
Most of the cartilages in vertebrate embryos are
replaced by bones in adults. Cartilage is present in the
tip of nose, outer ear joints, between adjacent bones
of the vertebral column, limbs and hands in adults.
14. 2.Bones : Bones have a hard and non-pliable ground
substance rich in calcium salts and collagen fibers which
give bone its strength. It is the main tissue that provides
structural frame to the body. Bones support and protect
softer tissues and organs. The bone cells (osteocytes) are
present in the spaces called lacunae. Limb bones, such as
the long bones of the legs, serve weight-bearing functions.
They also interact with skeletal muscles attached to them
to bring about movements. The bone marrow in some
bones is the site of production of blood cells.
15. 3.Blood: Blood is a fluid connective tissue containing plasma,
red blood cells (RBC), white blood cells (WBC) and platelets. It is
the main circulating fluid that helps in the transport of various
substances.