INTRO TO ENDOSKELETON Flashcards
Provides body shape
Supports its weight
* Serves as levers that together with muscles produces movement
* Protects soft parts
nerves, blood vessels, and other viscera
SKELETON
formed from or within the integument
DERMIS
bone
epidermis to keratin
EXOSKELETON
deep within the body from mesoderm and other sources
Includes:
fibrous connective tissue, bone, and cartilage
ENDOSKELETON
(within the integument)
Exoskeleton
(deep, within the body)
Endoskeleton
Exoskeleton types
Keratinized exoskeleton (from epidermis)
Bony exoskeleton (from dermis)
Endoskeleton types
Bony exoskeleton
Cartilaginous Endoskeleton
Notochord
Skull
Cranial
vertebral column, limbs, girdles, and associated structures, such as ribs and shells.
Postcranial skeleton
Parts of the Endoskeleton
Notochord
Derivatives of Notochord
Derivatives of Notochord
❑ Skull
❑ Vertebral Column
❑ First endoskeleton of the chordates
❑ Principal endoskeleton of the lower chordates
Notochord
Parts of the Endoskeleton
AXIAL
APPENDICULAR
AXIAL
- SKULL
- VISCERAL SKELETON
- VERTEBRAL COLUMN
- RIBS
- STERNUM
APPENDICULAR
- PECTORAL GIRDLE
- PELVIC GIRDLE
- APPENDAGES
The Skeletogenous Regions
MYOTOMES
Myoseptum or Myocomma
a transverse partition or plate of mesenchyme
Myoseptum or Myocomma
Consist of those portions of th epimeres remaining after the formation of mesenchyme
Grow down between the skin and the digestive tract
MYOTOMES
All of the endoskeleton proper is first composed of
cartilage
The endoskeleton of elasmobranchs, for example, is composed entirely of
cartilage
In most vertebrates, the cartilage is replaced by the development of
bone
Not all of their bones arise in this manner, but some of them develop directly from the
mesenchyme
is located on the anterior or head portion of the shark.
chondrocranium
This process involves the replacement of hyaline cartilage with bone. It begins when mesoderm-derived mesenchymal cells differentiate into chondrocytes.
Endochondral Ossification
This process involves the direct conversion of mesenchyme to the bone.
Intramembranous Ossification
females are observed to be larger
than males in sharks
true
lateral projection that is anterior to the orbit
Antorbital process
a thick projecting shelf that forms the dorsal wall of the orbit
Supraorbital crest
capsule that encloses the auditory organs
Otic capsule
can be found below the chondrocraium
mandibular arch
mandibular arch
It is a semicircular arch that tapers anteriorly if viewed laterally
Palatoquadrate
mandibular arch
More planar and slender opposed to the Palatoquadrate
Laterally, one can distinguish a triangular outline
Meckel’s cartilage:
Splanchnocranium
Support for the tongue
Basihyal
is known for its segmented hoops placed on one behind the other. It is lightweight.
Splanchnocranium
sharks
It is a U-shaped structure consisting of two curved rods known as the suprascapular cartilages that extend dorsally
At the intersection of the head, trunk and forelimbs
Pectoral girdle
sharks
display a rigid and somewhat semi-circular or U-shaped in appearance, up until the claspers.
The pelvic girdle and pelvic fin may be found along the the posterior side of the vertebral column of the shark, just before the cloaca.
Pelvic Girdle
Parts of the typical vertebra of the shark
- Centrum
- Notochord
- Spinal cord
- Vertebral canal (neural canal)
- Dorsal intercalary plates
- Hemal canal
- Hemal arch
- Ventral intercalary plates
- Notochord
- Basapophyses
- Ribs
may be found on the most posterior end of a shark’s skeletal structure
Caudal Vertebrae
a shark is divided into two major morphological regions
a. Trunk (dorsals) - cranial to the anus
b. Tail (caudals) - caudal to the anus
a shark’s centrum is __________, where the anterior and posterior ends display concavities.
amphicoelous
Sharks display __________ with the presence of two centra and two sets of neural and hemal arches at the caudal region of the vertebra.
caudal diplospondyly
basic components of the shark’s visceral skeleton
mandibular arch
hyoid apparatus
gill arches
mandibular arch parts (sharks)
palatoquadrate and meckel’s cartilage
hyoid apparatus 2 sections
hyoid arch
gill arches
hyoid arch parts
hyomandibular
ceratohyal
basihyal
heart-shaped” and is larger than the cervical but smaller than the lumbar vertebrae in size. (chicken)
Thoracic Vertebrae
Creates the structure for the neck. It is connected at the base of the skull and extends into the thoracic vertebrae
form an S-shaped structure
(chicken)
Cervical vertebrae
This portion is composed of 4 to 5 free caudal vertebrae, along with transverse processes and a flattened bone (sometimes triangular) called pygostyle Together they form the caudal vertebrae curving upwards. (chicken)
caudal vertebrae
formed through the fusion of 3 to 4 caudal vertebrae. (chicken)
pygostyle
It is a fusiform structure, which is formed by the fusion of thoracic, lumbas, sacral and caudal vertebrae.(chicken)
Synsacrum
It is a blade-shaped bone and is one of the three bone that made up the hip bone.(chicken)
Ilium
head of the humerus of a chicken is
ellipsoid
of the chicken wing contains only one cone-shaped phalanx, while the other two consist of two phalanges.
1st digit (Alula)
different processes projecting from the vertebrae
Odontoid Process
Prezygapophyses and
Postzygapophyses
Hypapophyses
Pleurapophyses
Uncinate processes
Diapophyses
Parapophyses
Transverse Processes
Xiphisternal Process
Olecranon Process
Pectineal processes
have smooth sternum since it lacks a keel. Since they have an absent of keel, they are unable to fly; most commonly described as running birds. Additionally their clavicles are small or does not exist.
Pygostyle is not present.
have their coracoid and sternum fused.
Ratite
have a keel present, enabling them to fly since this is where their wing muscles anchor, prolonging their duration on air. Clavicles are present and well-developed with frequent use. Pygostyle is present.Their sternum and coracoid are connected with ligaments
Carinate
Shape: Ring-like structure with lateral masses.
Size: Small and compact, approximately 2-3
centimeters in diameter
Atlas (C1 Vertebra):
Shape: Features an upward peg-like projection called
the odontoid process.
Size: Larger than the atlas, with an additional 1-2
centimeters in height due to the odontoid process
Axis (C2 Vertebra):
The cranial part of the sacrum articulates cranially with the lumbar spine and with the pelvic girdle. The caudal part of the
sacral vertebrae
term primarily used in the context of amphibian anatomy, particularly in frogs and some salamanders. It is a bony or cartilaginous structure at the posterior end of the vertebral column, serving as the fused extension of the vertebral column in the tail region.
Urostyle
is a structure found in the human skeleton, also known as the tailbone.ygostyl. It is located at the base of the vertebral column, below the sacrum.
Coccyx
a structure found in the anatomy of certain birds, especially those belonging to the group called Neornithes (modern birds) It is located at the posterior end of the vertebral column, just before the tail feathers (rectrices).
Pygostyle
are free-floating and are only attached through muscles. This adaptation allows the cat to squeeze itself into tight spaces, to extend their stride, and to lengthen their bodies. This is advantageous for cats who are solitary hunters that rely on stealth, explosive power, and flexibility (cat)
pectoral girdle
odd-toed
Perissodactyla
Any of various hoofed mammals, having an even number of toes on each foot
artiodactyl
