Connective Tissue

Question 1

Connective tissue is derived from which embryonic layer?

A) Ectoderm

B) Mesoderm

C) Endoderm

D) Any of the above

Answer 1

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.

Question 2

What are the three basic components of connective tissue?

Answer 2

• Specialised cells (e.g. fibroblast, osteocyte…)
• Protein fibres (e.g. collagen, elastin, reticulin…)
• Ground substance - fills the space between cells

Remember, GPS to connect

Question 3

What is mesenchyme?

Answer 3

Undifferentiated embryological tissue that differentiates into ABCC - Adipose, Bone, Cartilage and Connective tissue.

ABCC as you learn this as a child.

Question 4

What 2 components of the connective tissue form the matrix?

Answer 4

The ground substance and fibres.

Remember the matrix is a Fun Game

Question 5

What are the different types of connective tissue proper?

Answer 5

• Loose connective tissue: areolar, adipose and reticular (RAA you’re loose uno)
• Dense connective tissue: regular, irregular and elastic

Question 6

What type of connective tissue is hyaline, fibrocartilage and elastic?

Answer 6

Cartilage

Question 7

Does all of the mesenchyme develop into differentiated tissue during the embryological period, or does anything persist beyond this period?

Answer 7

Some persists, e.g. fibroblasts around blood vessels for repair; umbilical cord

Question 8

Proper connective tissue can be categorised into 6 sub-types. What are they?

Answer 8

• Loose
• Dense Regular
• Dense Irregular
• Elastic
• Reticular
• Adipose

Question 9

Loose Connective Tissue

Answer 9

Binding and packing Flexible - strength in all directions e.g. skin to underlying muscle, surrounds blood vessels and nerves

Question 10

Dense Regular Connective Tissue

Answer 10

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.

Question 11

What type of tissue are tendons and ligaments? (be specific)

Answer 11

Dense regular connective tissue

Question 12

Dense Irregular Connective Tissue

Answer 12

Densely packed collagen fibres. Strength in all directions e.g. dermis of the skin, submucosa of GI tract. Much richer blood supply.

Question 13

Elastic Connective Tissue

Answer 13

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

Question 14

Reticular Connective Tissue

Answer 14

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

Question 15

Adipose Connective Tissue

Answer 15

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

Question 16

What cell type is found in cartilage? What is their role?

Answer 16

Chondrocyte which is present in small spaces called lacunae.

They are the only cells located in cartilage. They produce and maintain the cartilage matrix.

Question 17

What are the three types of cartilage?

Answer 17

• Hyaline
• Elastic
• Fibrocartilage

Question 18

Where is fibrocartilage found?

Answer 18

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).

Question 19

Where is elastic cartilage found?

Answer 19

Found in the ear; epiglottis; auditory canal; cuneiform cartilages of the larynx

Question 20

What are the functions of elastic cartilage?

Answer 20

Provides support but tolerates distortion without damage and returns to original shape like the ear.

Question 21

Where is hyaline cartilage found?

Answer 21

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

Question 22

What are the functions of hyaline cartilage?

Answer 22

Provides stiff but somewhat flexible support; reduces friction between bony surfaces

Question 23

What gives bone its hardness/rigidity?

Answer 23

Calcium phosphate

Question 24

What are the two types of bone?

Answer 24

• Compact/dense outer layer
• Spongy or cancellous porous, vascular inner layer

Question 25

What are the three cellular components of vascular connective tissue?

Answer 25

Vascular connective tissue = blood - Erythrocytes - Leukocytes - Thrombocytes (platelets)

Question 26

What type of cells are these? and describe them.

Answer 26

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.

Question 27

Why is the inner layer of bones spongy?

Answer 27

It has pores which allow for marrow and blood cells.

Question 28

What type of bone forms osteons?

Answer 28

Compact bone. Osteons are like rings and surround a central canal that houses blood vessels plus nerves.

Question 29

What allows flexibility in bones?

Answer 29

Collagen fibres

Question 30

Cartilage is vascular, avascular?

Answer 30

avascular

Question 31

Is blood vascular or avascular?

Answer 31

It is richly supplied with blood vessels (vascular)