02 Skeleton Flashcards
The skeleton is subdivided into two divisions, what are these?
The axial skeleton and the appendicular skeleton
What makes up the axial skeleton?
The vertebral column and thoracic cage - longitudinal axis of the body
What makes up the appendicular skeleton?
The bones of the limbs and girls. So limbs, pectoral girdle and pelvic girdle.
The vertebral column fulfils a number of functions, list three.
- Protects the spinal cord 2. Transmits weight from the skull to the pelvis 3. Provides attachment points for ribs and muscles of back and neck
The vertebral column is divided into five distinct regions, what are these?
- Cervical vertebrae 2. Thoracic vertebrae 3. Lumbar vertebrae 4. Sacrum 5. Coccyx
How many vertebra make up the cervical region of the vertebral column?
7
How many vertebra make up the thoracic region of the vertebral column?
12
How many vertebra make up the lumbar region of the vertebral column?
5
List a way in which you can easily remember how many vertebrae make up each of the different regions of the vertebral column.
7 - breakfast, 12 - lunch, 5 - tea/dinner if you’re fat
How many vertebrae make up the sacrum?
five fused vertebrae
How many vertebrae make up the coccyx
Four - sometimes 3, sometimes 5
Why do the individual vertebrae become larger moving downwards?
Because they bear the weight of those above them, duh
What does concave mean?
The word concave means curving in or hollowed inward,
What does convex mean?
Convex means curving out or extending outward
Describe how the s shape of the vertebral column comes about by concave/convex structures of different regions
- Cervical region - concave 2. Thoracic region - convex 3. Lumbar region - concave 4. Sacrum - convex
What are the two atypical highly specialised cervical vertebrae called?
c1 - atlas c2 - axis
What does the atlas allow?
The nodding movement of the head
What does the atlas lack in structure?
The body and spinous processes
What structure of the atlas houses the occipital condyles of the skull?
The superior articular facets
What is the missing body of the atlas called and where is it found?
The odontoid process (dens) found on c2 axis - fuses with the axis during development
What does the axis allow the head to do?
Rotate laterally
How would you describe the body of a typical cervical vertebrae?
An oval body
How would you describe the spinous processes on the cervical vertebrae from c3-c7?
Short and bifid except for c7 which is not bifid
How would you describe the foramen of the cervical vertebrae from c3-c7?
Large, triangular vertebral foramen
What is special about the transverse processes on the typical cervical vertebraes?
They have a transverse foramen which allows the passage of vertebral arteries to the brain
The non bifid spinous process of c7 can be seen
through the skin
What is c7 also known as?
The vertebra prominens
How would you describe the body of the thoracic vertebrae?
Heart shaped
What are the two demifacets (superior and inferior costal facets) on each side of the thoracic vertebrae for?
They articulate with the heads of the ribs
How would you describe the foramen of the thoracic vertebrae?
Circular
How would you describe the spinous processes of the thoracic vertebrae?
Long, downward pointing spinous processes
What are the transverse costal facets on the transverse processes for?
To articulate with the tubercles of the ribs except t11 and t12
The lumbar vertebrae bear the greatest load, this is reflected by the more
robust size
How would you describe the bodies of the lumbar vertebrae?
Large, kidney shaped bodies
How would you describe the spinous processes of the lumbar vertebrae?
Short, flat spinous processes
How would you describe the vertebral foramen of the lumbar vertebrae?
Triangular
How is the sacrum formed?
By the fusion of s1-s5
What three structures does the sacrum articulate with?
With l5, coccyx and iliac bone of pelvis
What marks the sites of vertebral fusion in the sacrum?
Transverse ridges
What marks the site of fusion of spinous processes in the sacrum?
Median sacral crest
Where is the body’s centre of gravity?
It lies about 1cm posterior to sacral promontory
What does the coccyx articulate with?
The sacrum
What is the function of the coccyx?
Provides slight support for pelvic organs, otherwise largely without function
What does the thoracic cage consist of? 4 parts
- Thoracic vertebrae 2. Ribs 3. Sternum 4. Costal cartilages
Describe the structure of the thoracic cage
Roughly cone shaped, wider at bottom
List three functions of the thoracic cage
- Protects the heart and lungs 2. Supports shoulder girdle and upper limbs 3. Provides attachment for muscles of neck, back, chest and shoulders
How many ribs are there and how are they attached to the thoracic vertebrae?
12 pairs - all attached posteriorly
What does vertebrochondral mean in terms of ribs?
pertaining to a vertebra and a costal cartilage.
Which ribs are true ribs and why?
Ribs 1-7 are true (or vertebrochondral) attaching directly to sternum via individual costal cartilages
Which ribs are false and why?
Ribs 8-10 are false (still vertebrochondral) ribs attached indirectly to the sternum
Which ribs are vertebral or floating ribs and why?
Ribs 11-12 are vertebral or floating ribs without anterior attachments
Which three bones fuse together to form the sternum?
The manubrium (handle), the body and the xiphoid process (sword shaped process)
What eight bones make up the carpals of the hands?
scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate and hamate
What are the phalanges that make up the hand?
Distal phalanges, intermediate phalanges, proximal phalanges, metacarpals and carpals
What does the pectoral girdle consist of?
The clavicle and the scapula
Describe the shape of the clavicle
S shaped
What is the function of the clavicle?
Braces shoulder keeping upper limb away from the midline
The clavicle may thicken in people accustomed to
heavy labour
The most frequently broken bone in the body is the
clavicle causes the shoulder to drop
Describe the structure of the scapula
Triangular with superior, medial and lateral borders
What ribs does the scapula overlie?
ribs 3-7
What are the three key parts of the scapula?
- Acromion 2. Caracoid process 3. Glenoid cavity
What does the acromion articulate with?
The clavicle
What does the caracoid process do?
Attachment for biceps brachii and other muscles of the arm
What does the glenoid cavity articulate with?
With the head of the humerus
What seven bones make up the tarsals of the foot?
- medial/intermediate/lateral cuneiform bones 2. talus 3. calcaneus 4. cuboid 5. navicular
Which bones make up the pelvic girdle?
the ilium, pubis and ischium
What is pubic symphysis?
A cartilaginous joint uniting left and right pubis
Why is the pubic symphysis used in forensic anthropology to estimate the age of skeletons?
It wears at a more or less predictable rate
What is the difference in the pelvis of males and females?
The iliac crest and general breadth. the size of pelvis opening
What is the difference between shoulder breadth in males and females?
Males have a greater shoulder breadth
What is the difference between the ribcage in males and females?
Ribcage barreled in males, flatter in females
What is the difference between the male and female jaw?
Squarer jaw in males
What is the difference between male and female brow ridges?
Heavier brow ridges in males
What is the difference between the mastoid process in males?
More robust
What is the difference between male and female occipital protubuerance?
More prominent external occipital protuberance in males
What is the difference between the temporal line in males and females?
Extended in males - this is where the temporalis muscle attaches by the way
What is the supraorbital notch or foramen?
Above the eyes allows passage of supraorbital nerve, supraorbital vein and supraorbital artery
What is a myth related to the supraorbital notch or foramen?
Sometimes claimed that females have a notch and males a foramen, this is incorrect and quite often skulls have both
The shape of the pelvic inlet differs between males and females in which way?
Round in females, quite narrow in males
The shape of the pelvic outlet differs in male and females how?
Females sacrum and coccyx is pushed outwards
Point to the cranial, the axial and appendicular skeleton on yourself
There
Point to the clavicle
Point to the scapula
Point to the sternum
Point to the humerus
Point to the ulna
Point to the radius
Point to the sacrum
Point to the carpals
Point to the metacarpals
Point to the phalanges
Point to the femur
Point to the patella
Point to the tibia
Point to the fibula
Point to the tarsals
Point to the metatarsals
Point to the phalanges on the foot
Point to the concave and convex sections of your spine
What bone is this?
That is the c1
What bone is this?
That is c2
What bone is this and explain one special feature?
c7 - prominent non bifid spinous process
What vertebra is this? and why?
thoracic , heart shaped body, circular vertebral foramen, long downward pointing spinous process, transverse costal facets on transverse proceses to articulate with tubercles of ribs except t11 and t12
WHat bone is this?
t3
What bone is this?
t11
What bone is this?
l2
Point to the manubrium, the body and the xiphoid process of the thoracic cage
Point to the distal phalanges, the intermediate phalanges, the proximal phalanges, the metacarpals and the carpals
Point to the trapezium
Point to the trapezoid
Point to the capitate
Point to the head of the capitate
Position 4
Point to the hamate
Point to the hook of hamate
position 6
Point to the scaphoid
Point to the lunate
Point to the triquetral
Point to the pisiform
What is this shown?
Clavicle
What is this shown?
The scapula
What does the A, the Cp and the Gc stand for?
acronim articulates with the clavicle
coracoid process attachment for biceps brachii and other muscles of arm
glenoid cavity articulates with head of humerus
Point to the tarsals
Point to the talus
Point to the calcaneus
Point to the cuboid
Point to the navicular
Point to the ilium, the pubis and the ischium and the pubic symphysis
