Connective tissues Flashcards
Differences between CT and epithelia
CT not found on body surfaces
CT is highly vascular (except cartilage)
Similarities between CT and epithelia
Presence of nerves (except cartilage)
What is CT made up of
ECM and cells
What is ECM made up of
Ground substance and fibres
What is ground substance made up of
Water
Proteins
Polysaccharides
Features of a glycosaminoglycan
Long and unbranched polysaccharide
Repeating disaccharide units
Highly polar and attract water
Examples of sulphated GAG’s
Dermatan sulphate
Heparin sulphate
Keratan sukphate
Chondroitin sukphate
Example of non-sulphated GAG
Hyaluronic acid
What are proteoglycans made up of
Protein and GAG
General function of GAG’s
Trap water, making ground substance more jelly-like
Purpose of hyaluronic acid
Viscous slippery substance binds cells together, lubricates joints and maintains shape of eyeball
Does not bind to protein
What produces hyaluronidase and why
Sperm, WBC and some bacteria
Makes ground fluid more watery so they can move more easily
Function of chondroitin sulphate
Support and provide adhesive features of cartilae, bone, skin, and blood vessels
Location of keratan sulphate
Bone, cartilage, cornea of eye
Location of dermatan sulphate
Found in skin, tendons, blood vessels, heart valves
Abnormal Periorbital ECM and thyroid disease (Exopthalmos) causes
Autoimmune over-activation of thyroid
Abnormal Periorbital ECM and thyroid disease (Exopthalmos) symptoms
Goitre
Bulging eyes
3 different protein fibres of ECM
Collagen
Reticular fibres
Elastic fibres
Features of collagen
Strong and flexible
Abundant
Parallel bundles
Features of Reticular fibres
Composed of collagen covered with a glycoprotein in fine bundles that form networks
Made by fibroblasts
Strength and support
Part of basement membrane
Where are reticular fibres found
Adipose tissue, nerve fibres, smooth muscle tissues
Features of elastic fibres
Thinner than collagen
Fibrous network
Consist of elastin surrounded by fibrillin to give strength and stability
Can stretch by 150%
Where are elastic fibres found
Skin, blood vessels, lungs
Cause and symptoms of Marfan syndrome
Dominant mutation of chromosome 15 in gene coding for fibrillin
Sufferers are often tall, long-limbed, and have chest deformity
Have weak artery walls and heart valves
Connective tissue cell types
Fibroblasts Adipocytes Macrophages Plasma cells Mast cells Leukocytes
Function and location of fibroblasts
Widely distributed and migratory
Secrete fibres and ground substance
Function and location of adipocytes
Found under skin and around organs
Store triglycerides
Function and location of macrophages
Fixed dust cells (lungs) kupffer cells (liver) and langerhan cells (skin)
Wandering in CT to sites of infection/inflammation
Function and location of plasma cells
Produce antibodies
Gut, lungs, salivary glands, lymph nodes, spleen
Function and location of mast cells
Produce histamines
Found alongside blood vessels
Function and location and leukocytes
WBC
Migrate from blood
Two types of connective tissue
Embryonic
Mature
Function of mesenchyme tissue
Gives rise to all other CT
Structure of mesenchyme tissue
Consists of mesenchymal cells in a semi-fluid ground substance of reticular fibres
Function of mucous tissue
Support umbilical cord
Structure of mucous tissue
Widely scattered fibroblasts in jelly ground substance
3 fibres in loose areolar tissue
Collagen
Reticular
Elastic
Location and function of loose areolar tissue
Widely distributed packing material
Strength, elasticity, support
Structure and types of loose adipose tissue
Mainly adipocytes (central triglyceride drop) White adipose: energy storage Brown adipose (mainly in children): heat production
Structure of reticular connective tissue
Fine interlacing network of reticular fibres and cells
Location of reticular CT
Stroma (framework) of spleen, liver, lymph nodes
Function of reticular CT
Binds smooth muscle cells
Filters and removes worn-out blood cells
Structure and location of dense regular CT
Regularly arranged collagen
Shiny white colour
Tendons, ligaments, appeneuroses
Structure and function of dense irregular CT
Irregularly arranged collagen
Occurs in sheets
Tensile strength in many directions
Structure and function of elastic CT
Predominantly elastic fibres with fibroblasts between
Yellowish colour
Allows stretching of various organs
Structure and function of hyaline cartilage
Fibres not obvious
Resilient gel
Relatively weak
Flexibility and movement
What are chrondocytes
Mature cartilage cells
Structure and function of fibrocartilage
Chrondocytes among thick collagen bundles in ECM
Support and join structures
Strongest cartilage
Structure and function of elastic cartilage
Chrondocytes in threadlike network of elastic fibres
Found in epiglottis
Provides strength and elasticity
2 types of bone tissue
Osseous
Compact
Structure and function of compact bone
Composed of osteons
Covers outer layers of bone
Store Ca and P
Structure and function spongy bone
Porous
Lies under compact bone
No osteons
Yellow and red marrow
What are osteogenic cells
Mesenchymal stem cells that develop, starts to lay
down collagen; become trapped and become
osteoblasts
What are osteoblasts
Bone forming cells. They lay down collagen,
and cause mineralization process to start
What are osteocytes
Mature bone cells derived from osteoblasts trapped within the extracellular matrix. Many gap junctions
What are the function of osteocytes
They maintain bone tissue through exchange of nutrients and waste products
Features and function of osteoclasts
Large
Multinucleated
Formed from fusion of monocytes
Break down bone
4 parts of osteons
Canaliculi
Lacunae
Lamellae
Central haversian canal
How are osteons arranged
Along axis of stress
Structure of lamellae
Concentric rings of mineral salts (e.g Ca2(PO4)3 or Ca(OH)2 which combine to give hydroxyapatite) for hardness and collagen
What are lacunae
Small spaces between lamellae that contain osteocytes
What are canaliculi
Minute canals that radiate from lacunae and provide routes for oxygen, nutrients and waste.
What is the central Haversian canal
Blood
Lymph
Nerves
Function of osteoclasts
Reabsorb dead bone
Remodel new bone
Function of osteoblasts
Lay down new bone
Function of chondroblasts
Lay down hyaline cartilage callus
Contents of blood
Plasma
Formed elements
What are formed elements
Euthrocytes Neutrophils/monocytes Basophils/mast cells Eosinophils Lymphocytes Platelets
