4 types of CT joints
- Bony
- Fibrous
- Cartilaginous
- Synovial - most freely moveable
3 types of fibrous joints and examples
- Sutures -serrate (coronal suture), lap or squamous (squamousal suture) , plane or butt (L/R palatine processes of maxilla)
- Gomphoses - tooth to socket
- Syndesmoses - 2 bones bound my ligament like radius to ulna, interosseus membrane composed of tough fibrous CT
2 types of cartilaginous joints and examples
- Synchondroses - hyaline cartilage - ribs to sternum by costal cartilage, epiphyseal plates of long bones
- Symphyses - fibrocartilage - pubic symphysis/intervertebral discs (slight movement, absorbs shock)
In the TMJ, what is the articular disc made of?
Dense fibrous CT
In the TMJ, what is the surface covering of the joint made of?
Fibrous tissue (NOT FIBROCARTILAGE)
Difference between tendon sheaths and bursae?
Tendon sheaths - tubes of synovial membrane that wraps tendons
Bursae AKA articular capsule- sac like extension of a joint capsule, allows to slide easily, extends between or around nearby tendons - REDUCE FRICTION
3 main classes of joints by motion and examples
- Synarthroses - immovable - cranial sutures
- Amphiarthrosis - slightly movable - symphysis pubis or vertebrae (can be connected by discs of fibrocartilage)
- Diarthrosis - fully movable - shoulder
What makes up synovial fluid?
albumin, and hyaluronic acid - secreted by synovial membrane
What type of joint is the radial-ulna joint?
ellipsoidal
What type of joint is the metacarpal bone?
saddle
What type of joint is the atlas axis joint?
Pivot
What type of joint is the elbow or knee?
Hinge
What type of joint is the carpal bones>
Gliding
Articular cartilage (MENISCUS) is made up of hyaline cartilage except in 2 locations, what are they and what cartilage is it made up of?
TMJ and knee - fibrocartilage
What type of joint is the TMJ?
Anterior cavity - Gliding (articular eminence)
Inferior cavity - Hinge (condyle)
The spheno-occipital synchondrosis in the midline of the cranial base of a newborn consists of what?
Synchondroses - Hyaline cartilage
What are 5 distinguishing features of synovial joints?
- Articular cartilage - hyaline or fibrocartilage - no innervation
- Synovial cavity
- Articular capsule - double layered - outer layer fibrous CT, inner layer thin vascular synovial membrane
- Synovial fluid - provides nutrition
- Supporting ligaments
What joint component envelops the proximal humerus and facilitates gliding of the proximal humerus under the coracoacromial arch? Its a large synovial membrane which is adherent to the undersuface of the coracoacromial ligament, acromion and deltoid laterally and the floor is adherent to the rotator cuff and greater tuberosity
Subacromial bursa
Which joint allows you to shake your head yes?
Altanto-occipital joint - synovial articulation between the superior articulating facets of the atlas and the occipital condyles of the skull
Which joint allows you to shake your head no?
Atlanto-axial joint ( max rotation around vertical axis)
Synovial articulation between inferior & articulating facets of the atlas and the superior articulating facets of the axis
CNS nervous tissue is derived from where compared to PNS nervous tissue?
CNS - neural tube ectoderm
PNS - Neural crest ectoderm
4 parts of neurons that conduct electrical impulses
- Perikaryon (cell body) - contain Nissl bodies
- Axon - away from cell body - only 1 per cell body
- Dendrites - towards the cell body - variable number
- Cytoskeleton
What are 2 types of cells found in the PNS?
- Schwann cells - myelination
2. Satellite cells - support/surround nerve ganglia
What are 5 types of cells found in the CNS?
- Astrocytes - scaffolding of BBB
- Oligodendrocytes - myelination
- Microglia - phagosytosis
- Ependymal cells - epi of ventricles, brain, spinal cord
- Choroidal cells - secrete CSF
