Post Cranial Skeleton Flashcards
What is the axial skeleton in fish composed of?
chondrocranium, splanchnocranium, dermatocranium, vertebrae, ribs, caudal complex
what is the appendicular skeleton composed of in fish?
girdles, fins, and medial fins
what is the axial skeleton composed of in tetrapods?
skull, vertrebral column, ribs, sternum
what is the appendicular skeleton composed of in tetrapods?
pectoral and pelvic girdles, limbs
How many true ribs are present in humans?
7 true ribs
how many false ribs in humans? how many floating?
5 false, 2 floating
what are the 3 parts of the sternum?
manubrium, sternal body, xiphoid process
vertebrae typically consist of a _____ and a ______ arch that protects the spinal cord
centrum (vertebral body), neural
what do the spinous and transverse processes provide?
muscle attachment
T/F: Vertebrae may have superior and inferior processes and facets that form zygapophyseal joints (articulate adjacent vertebrae)
true
the notochord is restricted to _________ of intervertebral disc in humans
nucleus pulposus
What is amphicoelous?
concave anterior and posterior articulating surfaces (chondrichthyans, actinopterygians)
what is procoelous?
concave anterior and convex posterior articulating surfaces (amphibians, snakes)
what is opisthoceolous?
convex anterior and concave posterior articulating surfaces (crocidilians, cervical of ungulates)
what is acoelous?
flat articulating surfaces (mammals, dinosaurs)
what is heterocoelous?
saddle shaped articulating surfaces (neck of birds)
What function does the neural arch serve in fish?
protects spinal cord and provides area for muscle attachment
what function does the centrum serve in fish?
vertebral body surrounding compressed notochord
ribs protect ____ and provide ______ attachement
viscera, muscle
Ventral ribs form ____ arch in ______ region to protect vasculature
hemal, caudal
sharks centra are ______
amphicoelous
T/F: in sharks the neural arch consists of paired dorsal plates (intercalary)
true
what do hemal arches consist of?
paired ventral plates
T/F: bowfin and perch have ventral and dorsal ribs
true
what is aspidospondyly?
notochord surrounded by intercentrum and pleurocentrum
what are some features of spines?
hard and pointed, unsegmented, unbranched
what are some features of lepidotrichia?
soft, segmented, branched
What is a heterocercal tail?
upper lobe larger than lower, vertebral column extends into upper lobe, generates upwards forward force
what is a homocercal tail?
symmetrical upper and lower lobes, vertebral column ends at base, produces forward thrust
lateral undulation of vertebral column in fishes assists in _______
locomotion
what is aspidospondyly?
all bony elements remain separate (primitive condition)
What is holospondyly?
all bony elements fused into a single structure (formed by enlargment of pleurocentrum
intercentrum became prominent in the ________ lineage (gave rise to extant amphibians
temnospondyl
pleurocentrum became prominent in the _______ lineage (gave rise to amniotes
anthracosaur
T/F: intercentrum does not contribute to centrum in amniotes and is homologous with the head of the rib
true
_____ and ______ articulate adjacent vertebrae
pre and post-zygapophyses
what is the urostle?
splint like extension of vertebral column posterior to sacral vertebrae adapted for salatorial motion
what is the gastralium?
dermal ribs constricted to ventral wall used for muscle attachment and bone support
T/F: In lizards and crocodiles, dermal ribs articulate with vertebrae
false
plastron consists of _____ plates and ______ elements
dermal, clavicle
What forms carapace?
throacic vertebrae and ribs fused with dermal plates and epidermal plates/scutes
T/F: turtles have 8 double jointed vertebrae that permit extensive range of motion
true
How do pleurodires retract the head?
bending neck horizontally
how do cryptodires retract the head?
bending neck in vertical S-shape
What is the structure and function of the pygostyle?
fusion of several caudal vertebrae, supports tail feathers
T/F: uncinate processes strengthen ribcage
True
What is the structure and function of the synsacrum?
fusion of some thoracic, all lumbar, sacral, and some caudal vertebrae, extensive rigid structure provides stability during flight
carinate birds have enlarged ________ to support flight muscles
sternal keel
T/F: ratite birds lack distincitve keel
true
How many fused sacral vertebrae make up the sacrum in humans?
5
the atlas articuates with the ____
skull (nodding motion)
the axis pivots around the ______ process and allows for _______ of head
odontoid, rotation
thoracic vertebrae articulate with the _______
ribs
Lumbar vertebrae are
robust, lower back vertebrae
How is the axial skeleton connected to the pectoral girdle in humans?
articulation between manubrium of the sternum and clavicle
How is the axial skeleton connected to the pelvic girdle in humans?
articulation between the sacrum and illium
Derived ostracoderms had _________ fins, lacked ____ fins
pectoral, pelvic
lampreys and hagfish lack _____________ fins
both pectoral and pelvic
placoderms had _________ fins
pectoral and pelvic
Acanthodians had _________ fins precceded by spines
bothe pectoral and pelvic
T/F: in sharks, pectoral girle has no connection with the skull or vertebral column
true
In sharks, the basal pterygiophores articulate with ____
scapular portion of the pectoral girdle
T/F: in sharks, pelvic girdle has no connection to vertebral column
true
The clasper is an extension of the ______
metapterygium
In bony fishes, the sacpulacoracoid supports the __________
basal and radial pterygiophores and lepidotrichia (endochondral bones)
In bony fishes, the girdles are attached to the back of the skull via the _____
cleithrum, postcleithrum, supracleithrum, posttemporal bones, and clavicle
T/F: interclavicle first forms in rhipidistian fishes and connects both clavicles in some tetrapods
true
the metapterygial axis gives rise to
bones of sarcopterygian fin and tetrapod limb
In tetrapods, there is a significant loss of ________ bone attaching pectoral girdle to skull (e.g., posttemporal, postcleithrum, supracleithrum etc.)
dermal
T/F: the coracoid process of therian mammals is not homologous with the coracoid bone of other vertebrates
true
The cleithrum is lost in _______
amniotes
cleithrum clavicle and interclavicle are reduced in _____ and lost in extant ________
forgs, salamanders
in ______, the clavicle and interclavicle are incorporated into plastron
turtles
In _______ clavicle and interclavicle fuse forming furcula
birds
in eutherians (true mammals) ______ is lost, but retain ______
interclavicle, clavicle
tetrapod limb is characterized by _______(muscular limb with functional joints and digits)
chiridium
T/F: pre-axial is important when it comes to developmetn
false
WHich developmental region do carpal bones belong to?
autopodium
which developmental region does the forearm belong to?
zeugopodium
the __________ axis is important for the fin to limb transition
metapterygial
what is pentadactylous?
5 digit pattern
polyphalangy
increased number of phalanges in each digit
polydactyly
increased number of digitd (more than 5) very rare
plantigrade
walking on soles of feet
digitgrade
walking with ankle and heel off ground (walking on toes)
unguligrade
walking on ends of digits and hooves
what is sprawling posture?
most primitive, upper limbs horizontal, body may or may to drag on ground. laterally undulate with steps
what is erect posture?
mammals, dinosaurs, birds, limbs beneath body avoids carriers constraint, alows prolonged activity
what is carriers constraint?
lung compression of flexed side during lateral undulation
Flight evolved independently 3 times in ______, _______, and ________
birds, bats, pterosaurs
Pterosaurs wings composed of ______
elongated 4th digit with skin membrane
Birds wings composed of _______-
fusion of carpals with metacarpals (carpometacarpus) and fusion of digits (feathered)
Bat wings composed of _______
1st digit forming hook, 2-5th digit elongated covered in skin membrane
