Connective Tissue Flashcards
Connective tissue is derived from which embryonic layer?
A) Ectoderm
B) Mesoderm
C) Endoderm
D) Any of the above
B) Mesoderm, which is the middle layer gives rise to mesenchyme which the differentiates into bone, cartilage, connective tissue, muscle tissue and adipose tissue. (bccAM)
The ectoderm is the outer layer which gives rise to the epidermis and the nervous system. The endoderm gives rise to mucous membranes lining the digestive and respiratory tracts. Remember endoderm sounds like andhar like inside.
What are the three basic components of connective tissue?
- Specialised cells (e.g. fibroblast, osteocyte…)
- Protein fibres (e.g. collagen, elastin, reticulin…)
- Ground substance - fills the space between cells
Remember, GPS to connect
What is mesenchyme?
Undifferentiated embryological tissue that differentiates into ABCC - Adipose, Bone, Cartilage and Connective tissue.
ABCC as you learn this as a child.
What 2 components of the connective tissue form the matrix?
The ground substance and fibres.
Remember the matrix is a Fun Game
What are the different types of connective tissue proper?
- Loose connective tissue: areolar, adipose and reticular (RAA you’re loose uno)
- Dense connective tissue: regular, irregular and elastic
What type of connective tissue is hyaline, fibrocartilage and elastic?
Cartilage
Does all of the mesenchyme develop into differentiated tissue during the embryological period, or does anything persist beyond this period?
Some persists, e.g. fibroblasts around blood vessels for repair; umbilical cord
Proper connective tissue can be categorised into 6 sub-types. What are they?
- Loose
- Dense Regular
- Dense Irregular
- Elastic
- Reticular
- Adipose
Loose Connective Tissue
Binding and packing Flexible - strength in all directions e.g. skin to underlying muscle, surrounds blood vessels and nerves
Dense Regular Connective Tissue
Densely packed collagen fibres parallel to the direction of a force. Not a good blood supply e.g. tendons and ligaments as it can withstand a lot of stress.
What type of tissue are tendons and ligaments? (be specific)
Dense regular connective tissue
Dense Irregular Connective Tissue
Densely packed collagen fibres. Strength in all directions e.g. dermis of the skin, submucosa of GI tract. Much richer blood supply.
Elastic Connective Tissue
Elastic fibres that can stretch 1.5x and return to their shape Elastic fibres are irregularly arranged and yellow e.g. walls of large arteries; portions of larynx, trachea, and bronchial tubes
Reticular Connective Tissue
Network of woven reticular fibres in a jelly-like matrix most made of ground substance e.g. Forms framework of organs such as liver and spleen
Adipose Connective Tissue
Cells store fat droplets and swell Acts as a food reserve, protects organs, insulates e.g. hypodermis of skin, surface of heart, breast, surrounds joints
What cell type is found in cartilage? What is their role?
Chondrocyte which is present in small spaces called lacunae.
They are the only cells located in cartilage. They produce and maintain the cartilage matrix.
What are the three types of cartilage?
- Hyaline
- Elastic
- Fibrocartilage
Where is fibrocartilage found?
Pads (meniscus) within the knee joint; between pubic bones of the pelvis; spinal discs as this is the strongest type of cartilage and it absorbs shock and resists compression. Prevents bone to bone contact (knee prevents connection of femur and fibula/tibia for limited movement).
Where is elastic cartilage found?
Found in the ear; epiglottis; auditory canal; cuneiform cartilages of the larynx
What are the functions of elastic cartilage?
Provides support but tolerates distortion without damage and returns to original shape like the ear.
Where is hyaline cartilage found?
Between tips of ribs and bones of sternum; covering bone surfaces at synovial joints; supporting larynx (voice box), trachea, and bronchi; forming part of nasal septum
What are the functions of hyaline cartilage?
Provides stiff but somewhat flexible support; reduces friction between bony surfaces
What gives bone its hardness/rigidity?
Calcium phosphate
What are the two types of bone?
- Compact/dense outer layer
- Spongy or cancellous porous, vascular inner layer
What are the three cellular components of vascular connective tissue?
Vascular connective tissue = blood - Erythrocytes - Leukocytes - Thrombocytes (platelets)
What type of cells are these? and describe them.
Adipose cells,
The way you can tell is because each cell contains fat droplets that push the nucleus to the edge.
There are 2 types:
Brown = found in infants and newborns
White = They insulate organs and act as cushions.
Why is the inner layer of bones spongy?
It has pores which allow for marrow and blood cells.
What type of bone forms osteons?
Compact bone. Osteons are like rings and surround a central canal that houses blood vessels plus nerves.
What allows flexibility in bones?
Collagen fibres
Cartilage is vascular, avascular?
avascular
Is blood vascular or avascular?
It is richly supplied with blood vessels (vascular)
