Lab 8: Locomotion, Cranial Kinesis, Joints

Aquatic locomtion

specialized to live in water

Terrestrial locomotion

locomotion on land

Cursorial locomotion

specialized for rapid running

Arboreal locomotion

locomotion through trees

Brachiation

locomotion by arm swings under branches of trees; a form of arboreal locomotion

Fossorial

specialized for digging or burrowing

Saltatorial locomotion

specialized for hopping and jumping

Aerial locomotion

specialized for flying

What adaptations aid in aquatic locomotion?

1. long and slender body

2. absence of a functional neck

3. reduction of projections not needed for propulsion/steering

4. pectoral girdle attached to skull

5. pelvic girdle not attached to vertebral column

Stride

full cycle of a limb movement at a particular gait

Speed is the product of ….

stride rate and stride length

What’s an adaptation that increases stride length?

1. increased limb length; ex. unguligrades have longer functional limbs

2. repositioning of the scapula

3. spinal flextion

Plantigrade

the heel is on the ground and strikes first each stride

Digitigrade

the digits bear the weight of the animal

Unguligrade

weight is borne by the tip of the digits

What are two adaptations that increase stride rate?

1. reduction in number of distal bones

2. having larger muscles restricted to the proximal limb

What are three adaptations that facilitate brachiation?

1. prominent clavicle firmly attached to sternum - functions to transfer the weight of the body to the arm

2. relatively long forelimbs

3. grasping hands - digits on manus form a hook

What adaptations aid in saltatorial locomotion?

1. extreme lengthening of the hindlimbs and distal segments

2. long tails to act as a prop or counterbalance

3. spinal modifications that concentrate weight in line with the hind legs

What adaptations aid in fossorial locomotion?

1. Large, robust limb bones with large muscles attached 

2. Elbow lengthened (large olecranon process) 

3. Broad shovel-like manus (see mole skeleton in lab). 

What adaptations aid in aerial locomotion?

1. wings that provide upward force

2. light weight

3. compact body

4. mechanisms to minimize muscle effort

5. high metabolism

What are skull fenestrae?

Large openings in the temporal region of the deramtocranium in amniotes that increase attachment area for muscles associated with the jaws.

What is cranial kinesis?

Movement between the upper jaw and braincase about a joint between them.

What are some examples of animals that display cranial kinesis?

1. fish

2. reptiles

3. birds

What are two names for the joint between the femur and the tibia?

1. stifle joint

2. knee joint

tendon

connects tissue to bone

ligament

connects bone to bone

cranial cruciate ligament

caudal cruciate ligament

articular cartilage (hyaline cartilage)

articular/joint capsule: incorporates the collateral ligaments, quadriceps tendon, and the patellar tendon

articular cartilage

synovial fluid: lubricates the joint to prevent friction

synovial membrane: secretes synovial fluid

meniscus (composed of fibrocartilage)

1. lateral collateral ligament (because the fibula is lateral to the tibia)

2. medial collateral ligament