Mx2 Flashcards
What is cartilage and its function?
Cartilage is a resilient, avascular, connective tissue that consists of cells (chondrocytes) and a semisolid matrix
It provides support for some soft tissues in the body and forms a smooth sliding surface in moveable joints.
How are the types of cartilage distinguished?/
by the types of fibre embedded with the extracellular matrix of each type of cartilage
what constitutes the cartilage matrix that
gives the cartilage its resilience, firmness, flexibility and strength?
fibres, water and ground substance
What is the perichondrium?
the connective tissue that envelopes cartilage where it is not at a joint
Which type of cartilage forms most of the cartilaginous skeleton in the embryo and the fetus
hyaline cartilage
Where is hyaline cartilage present in childhood and adolescence?
epiphyseal growth plates, which are the sites of active bone growth - (its position can be seen in a long bone with unfused epiphysis and in radiographs of bone from a child)
Which areas can elastic cartilage be found?
external ear, Eustachian tube and epiglottis
Where is fibrocartilage found?
in areas of directional stress (e.g. intervertebral discs, pubic symphysis, articular discs associated with knee, in the temperomandibular and sternoclavicular joints) where resistance to compression, durability and tensile strength are needed
What happens when cartilage is damage or torn?
It is replaced by fibrous scar tissue laid down by fibroblasts. This may
prevent full restoration of cartilage function in the affected tissue.
Adult chondrocytes cannot undergo mitosis
What is periosteum?
a tough vascular fibrous connective tissue layer that surrounds bone
What is endosteum?
a thin cellular layer that lines the marrow cavity can be found internally in bone
What are the two forms in which bone exists?
Compact or dense (cortical)
Spongy (cancellous or medullary)
What do the central cavity of the long bones and spaces of the spongy bone contain?
bone marrow (red marrow, where active blood cell formation (haemopoiesis) occurs
and
yellow marrow which contains adipose (fat tissue) and where haemopoiesis does not occur
Where is compact bone found and what is its function?
Compact bone, which is found in shafts of long bones (e.g. femur) and flat bones (e.g. vault of the skull) provides primarily mechanical strength and protection of the underlying organs (e.g. brain in the case of the skull; heart and lungs in the case of the ribs and thoracic vertebrae
Where is spongy bone found and what is its function?
Spongy bone, which is found at the ends of long bones (e.g. humerus) and in the centre of flat bones and irregular bones (e.g. clavicle) provide space for the red marrow
what happens at the periosteum during the healing process?
proliferation of cell that form a soft cellular tissue mass that bridges the fracture site
Describe the healing process after a fracture
- Haematoma formation and local inflammatory response at the fracture site
- ingrowth of granulation tissue with formation of soft tissue callus
- formation of procallus composed of woven bone and cartilage with its characteristic fuisiform appearance and having 3 arbitrary components- external, intermediate and internal callus
- formation of osseous callus composed of lamellar bone following clearance of woven bone and cartilage
- remodelled bone ends; the external callus cleared away. intermediate callus converted into lamellar bone and internal callus developing bone marrow cavity
define neoplasia
A benign tumour of cartilage and bone are called a chondroma and osteoma respectively; malignant tumours are called chondrosarcoma and osteogenic sarcoma
What is Osteogenesis imperfecta?
a hereditary bone disease caused by a defect in collagen synthesis that results in the formation of an abnormal bone matrix; bones are thin and subject to multiple fractures (also known as ‘brittle bone disease’).
Give examples of surfaces of the ‘open’ cavities that are lined by moist mucous membranes
respiratory, digestive, reproductive and
urinary organs
State functions of skin
protection against microbial attack
prevention of fluid loss
temperature regulation
fine control of excretion, absorption
regeneration of skin tissues
sensation (fine touch and grip control)
Where do melanocytes reside?
at the junction between the epidermis and dermis (the basal layer –stratum basale).
How do melanocytes synthesis melanin?
Melanocytes synthesise melanin from tyrosine and package it into melanosomes that are transferred to the cytoplasm of keratinocytes