Skulls-mammals Flashcards
Process
Sticks out. Usually forms muscle attachment
Condyle
Convex part of joint. Ball
Fossa
Indentation. Socket
Foramen
Holes through which nerves/ vessels pass
Skull
Entire framework of the head
Mandible
Lower jaw
Cranium
Skull without lower jaw
Neurocranium
Encases brain
Calvaria
(Skull cap) top of neurocranium
Basicranium
Bottom of neurocranium
Splanchocranium/ viscerocranium
Facial skeleton
How many bones are joined at sutures
22
How many cranial bones are there
8
How many air sinuses does the sphenoid bone contain
2
What does the sphenoid bone contain
A body and a lesser, greater, medial and lateral wing
Where is the ethmoid bone located
Roof of nasal cavity
What is the ethmoid bone part of
Nasal septum
What does the frontal bone form
Forehead and part of cranium
Roof of orbit
What’s within the frontal bone
Contains the frontal sinus
What’s different about the front sinus
It’s unique like a finger print
Occipital bone is where
Rear and majority of base skull
Spinal cord is encircled by what
Foramen magnum
What does the skull rest upon
The atlas at the occipital condyles
Nuchal ligament
Runs from base of external occipital protuberance to the spinous process of the 7th cervical vertebrae (last neck bone)
How many parietal bones are there
2
The parietal bones are bordered by what sutures
Coronal, sagittal, lamboid, squamous
What suture joins the two parietal bones
Sagittal
How many temporal bones are there
2
What do the temporal bones form
The lateral wall and part of floor of cranial cavity
Name the ossicles in the middle ear
Malleus, stapes, incus
Are facial bones in contact with meninges
No
How many maxillae bones are there
2
What does the maxilla form
Upper jaw
2/3 of hard palate
How many zygomatic bones are there
2
What do the zygomatic bones form
Cheek bone and lateral orbital wall
What does the zygomatic bone contain
Frontal process, temporal process, infraorbital margin and zygomaticofacial foramen
How many palatine bones are there
2
What shape is the palatine bones
L- shaped
What are the palatine bones part of
Nasal wall and orbital floor
What is another name for the inferior nasal concha
Inferior turbinate (crista conchalis)
Is the inferior nasal concha bones part of ethmoid or maxilla?
No
What does “turbinate” refer to
“Scroll” curled up in itself
How many turbinates do humans have
3
What do the 2 nasal bones support
Nasal cartilage
What does the vomer consist of
1/2 of nasal septum
Can the mandible move
No
What does the mandible hold
Lower teeth
What do the 2 lacrimal bones form
Part of the medial wall of each orbit
Tears collect where and drain where
Collect in sac and drain into nasal cavity
As brain size increases what happens
Face rotates downwards
Where does the nose direct air to
Onto the olfactory area
Size of chimpanzee skull
305-485 cubic centimetres
Size of Africanus skull
420-500 cubic centimetres
Size of homo habilis skull
590-700 cubic centimetres
Size of a robustus skull
500-530 cubic centimetres
Size of homo erectus skull
815-1,959 cubic centimetres
Size of homo sapien skull
1,040- 1,595 cubic centimetres
As brain grows what 2 things then happen
Ethmoid area grows = shit smell
Face rotates down, therefore nose stuck out
What distinguishes modern humans to their nearest ancestors
Noses and chins
What animals have nostrils but no nose/chin
High primates
As you go back in time what happens to the foramen magnum
It gets further away from face
Do non-Africans have DNA markers?
Yes
Afarensis evolves to what…
Habilis–> erectus –> sapiens
As animals stand up what happens to their spine
Spine rotates downwards
What is the biggest family
Mustelindae (bear)
Do carnivores have a small or large sagittal crest
Large
Why do sheep have large head muscles
From pulling side to side
Carnivores have forward facing orbits which results in what
Binocular vision which means better depth perception
The TMJ in a carnivore is what and why
Tight as it needs a powerful bite but is unsuitable for grinding
Artiodactyla can be described as what
Even toed
Cloven- Hooved mammals
Do Artiodactyla have a sagittal crest
No
What way do the orbits face in Artiodactyla and what does this help
Laterally
Excellent peripheral vision
Artiodactyla have poor what
Binocular vision
Do Artiodactyla have a loose tmj or a tight tmj
Loose which allows sideways grinding
Most Artiodactyls lack what type of tooth and what animal is the exception
Canine, pigs
Artiodactyla have a narrow nuchal crest, how does this help their head
It holds their head up but is weak sideways
Rodentia orbits face what way
Laterally
TMJ in rodentia is loose or tight
Loose
Do rodentia have a sagittal crest?
No
The temporalis and masseter are prominent muscles located where
Lateral surface of the skull
Where does the temporalis pass
Passes medial to the zygomatic arch to insert on the cork lid process of the mandible
What shape is the temporalis
Fan shaped
What is the action of the temporalis
Elevate mandible/ close jaw
What is the insertion of the temporalis
Coronoid process and anterior surface of Ramus of mandible
What is the origin of the temporalis
Inferior temporal line
What is the origin of the masseter
Zygomatic process of maximally and lower border of zygomatic arch
What is the insertion of the masseter
Ramus of Mandible
What is the action of the masseter
Elevate mandible and occlude teeth
