Skeletal System 2 - Appendicular Flashcards
- Consists of the bones within the pectoral and pelvic girdles
- The attached limbs
appendicular skeleton
- bones of the shoulder
- anterior
- supports the arms and hands
pectoral girdle
- bones of the pelvis
- posterior
- supports the legs and feet
pelvic girdle
three replacement bones and a series of dermal bones
early fishes
three replacement bones of early fishes
- coracoid
- scapula
- suprascapula
series of dermal bones of early fishes
- clavicle
- cleithrum
- supracleithrum
- posttemporal
reduction in number and size of replacement bones
later bony fishes (ganoid fish)
reductio in number of dermal bones
tetrapods
- reduced coracoid & scapula (replacement bone) but large cleithrum& supracleithrum (dermal bone)
- posttemporal bone (dermal) connects the supracleithrum to the skull.
bony fishes
what is reduced in bony fishes
- coracoid
- scapula
what is large in bony fishes
- cleithrum
- supracleithrum
connects the supracleithrum to the skull of bony fishes
posttemporal bone (dermal)
no dermal bone
cartilganious fishes
early ones had pectoral girdle similar to those of early bony fishes, but lost posttemporal & acquired interclavicle (which still occurs in several amniotes)
tetrapods
what is lost in tetrapods
posttemporal
what is acquired in tetrapods
interclavicle
one or both typically brace scapula against sternum (as in birds; below)
- clavicle
- coracoid
present in all tetrapods with even vestiges of anterior limbs, e.g., turtles & birds & mammals
scapula
Bones of the pectoral girdle
- clavicle
- scapula
- head of humerus
- humerus
- head of radius
- radius
- ulna
- carpals
- metacarpals
- phalanges
- brace posterior paired appendages
- no dermal components (unlike pectoral girdle)
pelvic girdles
pelvic girdle consists of 2 cartilaginous or bony plates (ischiopubic plates) that articulate with the pelvic fins
Fishes
what does the pelvic girdle in fishes contain
2 cartilaginous or bony plates (ischiopubic plates)
- pair of cartilaginous plates form in embryos & each ossifies at 2 centers to form: pubis & ischium.
- An additional blastema gives rise to the ilium.
Tetrapods
what is formed from 2 centers in tetrapods
- pubis
- ischium
gives rise to the ilium in tetrapods
blastema
- ilia elongated & extend from sacral vertebra to urostyle
- joint between ilium & sacral vertebra (sacroiliac) is freely moveable (& moves when a frog or toad jumps)
forgs and toads
ilium and sacral vertebrae
sacroiliac
- ilium & ischium expanded to accommodate musculature needed for bipedal locomotion
- girdle is braced against lumbar & sacral vertebrae
- pubic bones are typically reduced (long but thin); the limited pubic symphysis provides a larger outlet for eggs
birds
provides a larger outlet for eggs
limited pubic symphysis
ilium, ischium, and pubis unite to form the innominate bone (the 2 innominates = pelvic girdle)
mammals
what is united to form the innominate bone
- ilium
- ischium
- pubis
2 innominate bones = ?
pelvic girdle
Bones of the pelvic girdle
- coxal bone
- head of femur
- neck of femur
- femur
- patella
- tibia
- fibula
- tarsals
- metatarsals
- phalanges
degree of pubic arch in males
50-60 degrees
degree of pubic arch in female
80-90 degrees
- reproductive hormone produced by your ovaries and the placenta
- loosens and relaxes your muscles, joints and ligaments during pregnancy to help your body stretch
Relaxin
parts of the pelvic girdle
- ilium
- sacrum
- pubic symphysis
- coccyx
- pubis
- ischium
what do all jawed fish have (except eels)
pectoral and pelvic fins
fins are used for what
steering (rudders)
types of fins
- lobed fins
- fin fold fins
- ray fin
found in sarcopterygians
lobed fins
- found in cartilaginous fish
- consist of 1 to 5 basal cartilages plus several rows of radials
fin fold fins
tendency to lose proximal components of fin skeleton
ray fin
Limbs
- anterior limb
- posterior limb
5 segments of anterior limb
- brachium
- antebrachium
- carpus
- metacarpus
- digits
- upper arm
- consists of humerus
brachium
- forearm
- consists of radius and ulna
antebrachium
- wrist
- consists of carpals
carpus
- palm
- consists of metacarpals
metacarpus
consists of phalanges
digits
5 segments of posterior limb
- femur
- crus
- tarsus
- metatarsus
- digits
- thigh
- consists of femur
femur
- shank
- consists of tibia and fibula
crus
- ankle
- consists of tarsals
tarsus
- instep
- consists of metatarsals
metatarus
lack limbs
- caecilians (apodans)
- most snake
- snake-like lizards
vertebrates with forelimbs only
- manatee and dugongs
- dolphins
- cetaceans
- sirens (salamander)
upper arm
humerus
forearm
radius and ulna
or hand
manus
3 rows of carpal bones
- proximal row
- middle row
- distal row
proximal row
- radiale
- ulnare
- intermedium
- pisiform
middle row
3 central carpals (centralia)
distal row
5 distal sarpals numbered 1 to 5 starting on thumb
general formula starting at thumb
2,3,4,5,3
five toed
pentadactyl
Adaptive modifications of the Manus
- flight
- swimming
- terrestrial locomotion
- grasping
manus of birds
- loss of digits & bones
- fusion of some bones
manus of bats
- 5 digits
- elongated metacarpals (II-V)
- phalanges support the patagium
manus of pterosaurs
4th digit elongated to support patagium
4th digit elongated to support patagium
pterosaurs
increase in number and size of phalanges
swimming
Terrestrial locomotion
- plantigrade
- digitigrade
- unguligrade
- flat-footed
- all bones of manus and/or pes on the ground
- amphibians, most reptiles & some mammals (insectivores, monkeys, apes, humans, & bears)
plantigrade
- 1st digit is reduced or lost
- manus & pes are elevated
- rabbits, rodents, & many carnivores
digitigrade
- reduced number of digits
- walk on tips of remaining digits
- claws become hooves
unguligrade
- opposable thumb
- saddle joint at base of thumb where it meets palm
- thumb at wider angle from index finger
- strong thumb muscles
Grasping
joint at base of thumb
saddle joint
bones are comparable to those of forelimbs except that a patella(‘kneecap’) develops in birds & mammals
posterior limbs
animals that forms a patella
- birds
- mammals
feeling internal structure through the skin with fingers
Palpation
run your fingers over the surface of your head
cranial bones
roughened area just behind the ear
mastoid process
grasp your auricle and insert your small finger into the canal
external auditory meatus
run your hand anteriorly from your ear toward your eye
zygomatic arch
spread your fingers on the skin of your face and feel it bunch and stretch as you smile.
muscle of facial expression
place a finger directly in front of the external auditory meatus, and open and close your mouth several times
temporomandibular joint
along the entire length from the sternum to the shoulder (interclavicular joint – sternum-clavicle junction; acromion – high point of the shoulder, anterior end of the scapular spine).
Clavicle
sternum-clavicle junction
interclavicular joint
high point of the shoulder, anterior end of the scapular spine
acromion
feel the medial projection at the distal end of the humerus.
Medial epicondyle of the humerus
flexing and extending it – as you palpate its dorsal aspect to feel the olecranon process of the ulna moving in and out of the olecranon fossa on the backside of the humerus
Elbow
clench your fist
Metacarpophalangeal joints or knuckles
rest your hands on your hips
Iliac crests
palpate the medial protrusion of your ankle
Medial malleolus of the distal tibia
feel the bulge of your lateral ankle
Lateral malleolus of the fibula