Introduction to Rheumatology (23) Flashcards
What are the 4 types of tissue?
- nervous tissue
- epithelial tissue
- muscle tissue
- connective tissue
What are the 4 subtypes of connective tissue and what unites them?
bone, cartilage, blood, and proper
- all come from mesoderm
What are the different functions of connective tissue?
- binds together, supports and strengthens body tissues
- protects and insulates internal organs
- compartmentalises structures e.g. skeletal muscle
- major transport system within body
- site of stored energy reserves
- main site of immune responses
What are the components that make up the structure of connective tissue?
- cells
- and extracellular matrix (largest component: ground substance + fibres)
What is ground substance?
- component of connective tissue
- between cells and fibres
- structurally supports cells and binds them together
- jelly-like, made of starch, proteins and water
What are the 3 types of connective tissue matrix fibres?
- collagen: strong, resists forces, flexible
- elastic: more flexible, branch to form network, made of elastin, smaller diameter
- reticular: made of collagen w/glycoprotein coat, smaller diameter
What are the different types of cells in connective tissue?
- fibroblasts: large flat cells w/ branches, migrate through connective tissue secreting fibres and ground substance
- macrophages: develop from WBCs, surround and engulf material by phagocytosis
- mast cells: produce histamine–> dilates blood vessels
- adipocytes: store triglycerides
What is the most abundant protein in the body?
collagen
What is the main function of connective tissue matrix fibres (collagen, reticular and elastic)?
provide strength and support to connective tissue
What are the 2 categories of proper connective tissue?
loose connective tissue: more ground substance
dense connective tissue: more collagen (more tightly packed)
What are the types of loose (proper) connective tissue?
- areolar: most common form, lots of ground substance, lines organs
- adipose: composed of adipocytes, energy reserve
- reticular: composed of reticular fibres, mesh structural support e.g. spleen
What are the types of dense (proper) connective tissue?
- regular: tight collagen fibres, tendons and ligaments
- irregular: skin dermis, irregular formation of collagen
- elastic: in vertebrae, composed of elastic fibres
What are general features of cartilage?
- avascular and no nerve supply
- strengthens and supports connective tissue
- resists compression
- cushions and supports body structures
- collagen fibres, sometimes elastic fibres
- chondroblasts in growing cartilage–> mature into chondrocytes
What are the features of hyaline cartilage?
- weakest, but most abundant of 3 types of cartilage
- in synovial joints
- gel-like ground substance
- found at end of long bones to cushion joints and at epiphyseal plates
What are the features of fibrocartilage?
- has thick collagen fibres in matrix
- strongest of 3 types
- found in intervertebral discs bc good shock absorber
- chondrocytes scattered in matrix
What are the features of elastic cartilage?
- strength, elasticity and maintains shape of certain structures e.g. external ear
- similar to hyaline, but more elastic fibres in extracellular matrix
- chondrocytes in a threadlike network of elastic fibres
What are the general features of blood (connective tissue)?
- no fibres
- plasma
- erythrocytes: transport oxygen
- leukocytes: immune function
- platelets: blood clotting
What is rheumatoid arthritis?
- autoimmune disorder
- inflammatory
- warm, swollen and painful joints
- genetic and environmental factors
What is arthritis?
- disorder that affects the joints
- 2 types: rheumatoid and osteoarthritis
What are the joint changes in rheumatoid arthritis?
- swollen, inflamed synovial membrane
- bone erosion
- cartilage wears away
- reduced joint space
What are some key pathophysiological mechanisms involved in developing rheumatoid arthritis?
- cytokines: TNF-alpha, IL-1, IL-6 and IL-17–> inflammation
- proteinase enzymes (MMPs) and NO–> cartilage destruction
- osteoblasts- RANKL–> bone destruction
What are 3 key symptoms that people present with rheumatoid arthritis?
- joint pain, stiffness and swelling for >6wks
- morning stiffness
- symmetrical and polyarticular (>3 joints)
(N.B. mainly affects small joints e.g. fingers and wrists)
What are the key differences between rheumatoid vs osteoarthritis?
- inflammatory vs degenerative
- autoantibodies (RF/rheumatoid factor and anti-CCP) vs no antibodies
- symmetrical vs asymmetrical
- morning stiffness vs no
- 30-50yrs vs >50 yrs
- rapid vs slow
- AM stiffness in rheumatoid, not osteo
- small joints vs large, weight bearing joints
How do we investigate rheumatoid arthritis?
- blood tests
- inflammatory markers
- x-rays
- ultrasounds
How do we manage rheumatoid arthritis?
- MDT
- patient education
- physiotherapy
- mild pain killers and/or steroids
- longterm: disease modifying anti-rheumatic drugs (DMARDs) e.g. methotrexate, leflunomide, sulfasalazine, hydroxychloroquine
^effectively immunosuppressants
What are some extraarticular manifestations of rheumatoid arthritis?
- fibrosis of lungs
- fluid in lungs
- dry eyes
- kidney damage
- nodules at elbows or hands
What is lupus/SLE?
- connective tissue disorder, so v. variable symptoms
- autoimmune condition w/ inflammation
- arthritis, skin rash, joint pain, photosensitivity etc.
What is vasculitis?
a group of disorders that destroy blood vessels by inflammation
What are the key X-ray changes found in rheumatoid arthritis?
- loss of joint space
- juxta-articular bone erosions
- soft tissue swelling
- osteopenia (weak)
- subluxations
