B2L1+L2: Anatomical/Directional terms + intro to locomotor apparatus

Median (midsagittal) Plane

divides body equally into equal left and right halves

Sagittal Plane

divide body into UN-equal halves

What is the transverse plane?

A plane that is perpendicular to the axis of the trunk, head, and limbs.

What body segments does the transverse plane divide?

Cranial/caudal or rostral/caudal.

How does the transverse plane divide limbs?

Into proximal and distal.

Dorsal Plane

divides body into dorsal and ventral parts

Dorsal

in the direction toward the back

Ventral

in the direction toward the belly

Medial

Toward the midline of the body

Lateral

Away from the midline of the body

Cranial

toward the head

Caudal

toward the tail

Rostral

toward the nose

Internal

Located within the body

External

Located outside the body

Superficial

near the surface of the body

Deep

Away from the body surface; more internal

Proximal

Nearer to the trunk of the body

Distal

Farther from the trunk of the body

Axial

directed toward the longitudinal central axis of the limb

Abaxial

directed away from the longitudinal central axis of the limb

Flexion

decreasing angle between limb segments

Extension

increasing angle between limb segments

Abduction

moving away from median plane

Adduction

moving towards median plane

Circumduction

movement circumscribing a cone shape

Rotation

rolling pin movement on the axis of limb

Supination

Pronation

Brachium

supported by humerus

Antebrachium

supported by radius and ulna

Crus

Manus

Front paw = Carpus + Metacarpus + Digits

Flat bone

scapula

Long bone

humerus, radius, ulna

Short bones

carpal bones

Sesamoids

special type of short bones within tendons

Diaphysis

bone shaft

Medullary cavity

contains yellow marrow

Epiphysis

end regions of bone

Physeal growth plate

located between epiphyses and diaphysis in young animals, comprised of cartilage cells

Wolf's law

form follows function

- bones get remodeled in response to stress placed upon them

Non-articular prominences

attachment sites for muscles, passages of vessels and nerves

Ex: spine of scapula

Articular promiences

make up joints

Ex: glenoid cavity

What type of connective tissue unites the articular surfaces of bones in fibrous joints?

Strong connective tissue

What is the term for the fusion of bones in fibrous joints?

Synostosis

What is the movement capability of bones in fibrous joints?

Almost no movement, or none at all

Cartilaginous joints

cartilage unites articular surfaces of bones >> limited movement

Synovial joints

joint cavity between articular surfaces of bones filled with synovial fluid >> most movable

Articular surfaces

- protected by articular cartilage

- enclosed within a fluid-filled joint cavity

Joint capsule is composed of three parts

- synovial layer

- fibrous layer

- joint cavity

Synovial layer

- produces synovial fluid

- highly vascularized and innervated

Fibrous layer

provides strenght and resistance

Joint cavity

for lubrication and nutrition of the articular cartilages

Accessory structures of synovial joints

- ligaments

- meniscus

Ligaments

bands of tough fibrous connective tissue

Meniscus

fibrocartilages located within a synovial cavity, allow articular surfaces to fit together

2 articulating bones

- simple

Ex: glenohumeral (shoulder) joint

More than 2 articulating bones

- compound

Ex: humeroradioulnar (elbow) joint, carpal joint

Congruent joint

articular surfaces fit well together

Ex: elbow joint

incongruent joint

articular surfaces do not fit well together

Ex: knee joint

Hinge joint

- least versatile

- flexion and extension only

Ex: elbow

Spheroidal (ball &socket) joint

- most versatile

- all rand of movements

Ex: shoulder joint, hip joint

Tendon of origin

- proximal attachment

- relatively fixed point, less movement here than at the insertion end

Muscle head or belly

the part that contracts

Tendon of insertion

- distal attachment

- relatively more motile, more movement at the insertion end that at the origin end of the muscle

Aponeurosis

a flat, sheet-like tendon, allows muscle to have a broader attachment

Synovial burse

synovial fluid-filled "balloon" protecting a tendon from a bony surface

Synovial tendon sheath

synovial fluid-filled "sleeve" completely surrounding a tendon, easing its gliding between a retinaculum and bone

Retinaculum

fibrous band holding down tendon(s) to a bone

Ligaments

attach bone to bone

Tendons

attach muscle to bone

Fasciae

fibrous layers enveloping and isolating muscle groups and individual muscles

Superficial fascia

loose connective tissue attaching skin to underlying mm

Deep fascia

leaf of dense connective tissue from which some muscles may originate or insert, separates muscle groups/layers into fascial planes

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