What does ECM and ECF stand for?
ECM stands for Extra-Cellular Matrix and ECF stands for Extra-Cellular Fluid
What is ECF and what does it contain?
The extra-cellular fluid is what covers the cells of a tissue. It contains blood plasma, transcellular fluid and interstitial fluid.
What is ECM and what does it contain?
- Extra-cellular matrix is a collection of macromolecules secreted from Connective tissue cells.
- A complex network connected to cell’s integrated proteins.
- Provides mechanical and biochemical support to tissues (allows for diffusion of chemical messengers).
- It contains a basement membrane and interstitial matrix.
- Most ECM has significant vasculature (cartilage is avascular, tendons have limited vasculature),
- Receives information from nervous system (except cartilage).
What is interstitial fluid and what is the interstitial matrix?
The interstitial matrix is the formation between cells in tissues that supports them structurally. Made up of fibronectins, proteoglycans and collagens.
Interstitial fluid the liquid surrounding cells in tissue that isn’t the blood, but a filtrate of blood plasma.
What is the basement membrane?
Sits between cells and the interstitial matrix. It’s a thin layer of extracellular matrix that provides support for cells and acts as a platform for complex signalling.
What is transcellular fluid?
The smallest constituent of extracellular fluid, it’s the fluid that’s contained in epithelial-lined spaces.
Name the 4 principle tissues.
- Muscle tissue
- Epithelial Tissue
- Connective Tissue
- Neural Tissue
What is Muscle Tissue?
Contractile tissue which produces movement.
Smooth muscle tissue is found in organs and internal spaces, it contracts slower than rough muscle tissue and is involuntary.
Rough muscle tissue is the opposite, it contract faster and is attached to the skeleton and tendons to allow movement, voluntary.
What is Epithelial Tissue?
It covers exposed surfaces of the body, hollow organs, lines body cavities and makes up majority of tissue in glands.
Produces and secretes glandular secretions (glandular epithelium)
Some epithelium has motor function to move substances along it’s surface (ciliated epithelial cells)
What is Connective Tissue?
Connects many other different tissues in the body. Tissue provides structural support as well as being used for energy storage in the case of fat. Used for storage of vitamins and many other vital compounds.
What is Neural/Nervous Tissue
Used for information processing and transfer. Can process and respond to stimuli and in turn send signals to other nerves in parts of the body, this produces responses to such stimuli.
What is the original stem cell from which connective tissues derive?
Mesenchymal stem cells. These are pluripotent.
Mesenchyme is used interchangeably with connective tissue.
What are the levels of stem cells in humans.
Totipotent embryonic stem cells.
Pluripotent embryonic stem cells. (Endoderm line, Mesoderm line, Ectoderm line
Multipotent stem cells.
Endoderm line differentiates into lung and pancreas cells and more
Mesoderm line differentiates into heart muscle, red blood cells + more
Ectoderm line differentiates into skin, neurons and more
What are the transitory forms for the four principle tissues?
Osteoblasts, differentiate into Osteocytes
Transitory Chondrocytes, differentiate into Chondrocytes
Transitory Fibroblasts differentiates into Fibroblasts
Pre-Adipocytes different into Adipocytes
How do osteoblasts differ from osteocytes?
Osteoblasts are the cells that generate calcified bone, once trapped inside the mineral matrix of bone they develop into osteocytes and form dendrites that extend out into spaces in the bone matrix.
What is an osteocyte?
The terminally differentiated cells present in the bone. It is responsible for regulating the connective tissue in bone.
What are transitional chondrocytes and transitional fibroblasts?
Transitional chondrocytes are cells that have not fully differentiated into chondrocytes and fibroblasts yet.
What are chondrocytes?
Cartilage is produced by chondrocytes sent to a joint, cartilage is the buffer that prevents two bones in a joint from making contact and damaging each other.
What are Fibroblasts?
Fibroblasts are the cells that lay down networks of the protein known as collagen. And collagen is used in many structures of the body such as bones, muscles, skin and tendons. Fibroblasts are some of the first cells dispatched to injury site when hurt, and will lay down lots of collagen, this results in scars.
What are pre-adipocytes?
Precursor cells to adipocytes, which will terminally differentiate into adipocytes.
What are adipocytes?
These cells are found in many places in the body that have a high energy demand. An example is bone marrow, as it produces so many new blood cells and is very energy intensive. That is why bone marrow is so fatty.
What are four functions of connective tissue?
- Energy storage and isnulation with adipocytes
- Support and containment for structures, e.g. organs, bone, ligaments.
- Immune response, certain cells found in loose connective tissue.
- Transport system, collagen fibres for transport of materials.
What are the three main groups of connective tissue?
- Supportive connective tissue
- Connective tissue proper
What are the sub-types of supportive connective tissue?
What connective tissues are in these sub-types?
What are the two sub-types of Fluid connective tissues?
What specific connective tissues/constituents are part of these types?
- Red blood cells
- White blood cells
- Plasma (makes it a matrix therefore connective tissue)
- Lymph (waste water recycled)
What are the sub-types of connective tissue proper?
What specific tissues are part of these sub-types?
- Regular elastic
- Irregular elastic
What are the constituents of a connective tissue?
- Connective tissue fibres (ECM)
- Ground substance (ECM)
What is ground substance?
- This is the amorphous gel like substance, made up of all the components of ECF excluding collagen and elastin.
- Mostly made up of water, but with proteinaceous substances in it (glycoproteins, proteoglycans, glycosaminoglycans)
- Contains hyaluronic acid (lubricant and shock absorber in joints)