22 Questions
What is a characteristic feature of mast cells under the light microscope?
Rounded to oval cells with central nucleus and many basophilic granules
What is the function of heparin secreted by mast cells?
Anticoagulation
What type of adipocytes are found in brown adipose tissue?
Multi-locular adipocytes
What is the site of mast cells?
Loose connective tissue around blood vessels and under epithelium of the gastrointestinal tract and respiratory system
What is the function of unilocular adipocytes?
Supportive and heat insulation
What is the morphology of unilocular adipocytes under the light microscope?
Large oval cells filled with a single large droplet of fat
Which type of cells are essential components of connective tissue?
Mesenchymal cells
What is the function of fibroblasts in connective tissue?
Formation of connective tissue fibers and ground substances
What is the origin of macrophages?
Monocytes
What is the characteristic shape of fibroblasts in the light microscope?
Elongated and branched
What is the function of macrophages in inflammation?
All of the above
What is the characteristic feature of macrophages in the electron microscope?
All of the above
What is the name of macrophages in the liver?
Kuffer cells
What is the shape of plasma cells in the light microscope?
Oval
What is the primary function of connective tissue?
To maintain the shape of the body and connect cells and organs
What is the origin of connective tissue?
Mesoderm
What is the characteristic of mesenchymal cells?
They have many thin cytoplasmic processes and an oval nucleus
What type of tissue develops from mesenchymal cells?
All types of connective tissue cells, blood cells, endothelial cells, and muscle cells
What is the role of connective tissue in exchanging nutrients and metabolites?
It acts as a medium for exchanging nutrients and metabolites
What is the characteristic of resident cells in connective tissue?
They are long-lived and essential components of connective tissue
What is the function of adipose tissue, cartilage, bone, blood, and lymphoid tissue?
They have special functions in addition to providing support and structure
What are the two categories of connective tissue cells?
Resident and migratory cells
Study Notes
Connective Tissue (C.T.)
- Definition: Connective tissue connects, supports, and maintains the form of the body, and is derived from mesenchyme (an embryonic tissue).
Origin of C.T.
- Mesenchyme develops mainly from the middle layer of the embryo, the mesoderm.
- Mesenchymal cells are elongated, have many thin cytoplasmic processes, oval nucleus, and fine chromatin, and migrate from their site of origin to the developing organs.
Functions of C.T
- Provides and maintains the shape of the body.
- Connects, binds, and supports cells and organs.
- Acts as an exchange medium for nutrients and metabolites.
- Performs special functions for adipose tissue, cartilage, bone, blood, and lymphoid tissue.
Structure of C.T
- Consists of cells and extracellular matrix.
Connective Tissue Cells
- Can be classified into two distinct categories: Resident (fixed, intrinsic) cells and Wandering (free, migrant) cells.
Resident (fixed, intrinsic) cells
- Examples include:
- Mesenchymal cells
- Fibroblasts
- Fat cells
- Reticular cells
- Pigment cells
Wandering (free, migrant) cells
- Examples include:
- Plasma cells
- Mast cells
- Macrophages
- Leukocytes
Fibroblasts
- Site: all types of CT
- Light Microscopy (LM):
- Elongated branched cells with many long processes
- Spindle-shaped in side view
- Function:
- Formation of CT fiber and ground substances
- Healing and repair of CT after injury
Macrophages
- Origin: Monocytes
- Sites: Distributed throughout the body
- Light Microscopy (LM): Special stains trypan blue or India ink
- Electron Microscopy (EM):
- Irregular surface with protrusions and indentations
- Kidney-shaped nucleus
- Well-developed Golgi complex
- Prominent rough endoplasmic reticulum
- Many lysosomes
- Functions:
- Phagocytosis
- Production of cytokines, chemotactic factors that participate in inflammation (defense)
- Antigen processing and presentation
- May fuse to form multinuclear giant cells
Plasma Cells
- Site: Lymphatic tissue
- Light Microscopy (LM):
- Oval cell
- Eccentric nucleus
- Deeply basophilic cytoplasm (excess rER) showing negative Golgi image
- Function: Antibody production
Mast Cells
- Site: Loose CT around BV, under epithelium of GIT and respiratory system
- Light Microscopy (LM):
- Rounded to oval cells
- Central nucleus
- Many basophilic granules filling cytoplasm stained metachromatically with Toluidine blue
- Function: Secretion of:
- Heparin
- Histamine
- Eosinophil chemotactic factor
Adipose (Fat) Cells
- There are two types: Uni-locular adipocyte and Multi-locular adipocyte
- Both originate from mesenchymal precursors called lipoblasts
Uni-locular Adipocytes
- Site: White adipose CT
- Light Microscopy (LM):
- Large oval cell filled with a single large droplet of fat
- Fat occupies most of the cell volume, compressing cytoplasm into a thin rim and pushing the nucleus to one side, resulting in a signet ring appearance
- Function: Supportive and heat insulation
Multi-locular Adipocytes
- Site: Brown adipose CT
- Light Microscopy (LM):
- Small rounded cells with many small fat droplets and central rounded nucleus
- Numerous mitochondria
- Function: Heat generation
This lecture covers the definition, structure, and function of connective tissue, as well as its types and cells. Learn about the role of connective tissue in the human body.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
