lecture 3 - skeleton structure Flashcards
How do bones aid in body movement?
They act as levers
What do bones store, and how?
Minerals and trace elements in bone matrix
Where do bones form red blood cells?
In the red bone marrow, within the medullary cavity
What are the two types of bone?
Compact and cancellous
What is compact bone?
Bone which is strong and has densely packed crystals that transmit force in one direction
What bones are light and spongy?
Cancellous bones
Why are cancellous bones shock absorbing?
They have multidirectional sruts which allow force to be absorbed from joint surfaces that experience stress from multiple directions.
What are the four classes of bone?
Long, short, flat, irregular
What is the shape of long bones?
Longer than they are wide
What are the parts of a long bone? (2)
Diaphysis and two epiphyses
What is the diaphysis and what type of bone is it mostly constructed from?
The long, slender part of a long bone, mainly made of compact bone.
What are epiphyses?
The larger rounded parts at the top and/or bottom of long bones, that are wider than the diaphysis.
What are the two epiphyses of a long bone, and how are they named?
Proximal and distal, named for their relativity to the attachment of the limb to the trunk.
What is the cavity inside of a bone called?
Medullary cavity
What is the shape of short bones?
Approximately equal length and width
What type of bone is the rib?
Flat bone
What type of bone are short bones mostly made up of?
Cancellous bone
What is the flat part of flat bones often used for?
Muscle attachment
What are the key roles of flat bones? (2)
Protection and muscle attachment
What is the structure of the flat bones of the cranium?
Outer layer of compact bone filled with layers of spongey cancellous bone
What are flat bones predominantly made up of?
Compact bone
What do irregular bones often contain?
A foramen
What is a foramen?
A boney hole/arch through which nerves or blood vessels pass.
What are the divisions of the skeleton?
Axial and Appendicular
What are the bones of the axial skeleton?
Skull, ribs, sternum, vertebral column/spine, sacrum, coccyx
What is the primary role of the axial skeleton?
To protect vital organs
What are the two functions of the cranium?
To protect the brain and provide surface area for muscle attachment
What are the two types of bones of the skull?
Facial bones and the cranium
What joins the bones of the skull together?
Sutures
What is the function of the vertebral column in terms of stability?
Keeps the trunk upright and supports the head
How many vertebrae are in the vertebral column?
24
What are the divisions of the vertebral column?
Cervical, thoracic, lumbar, sacrum and coccyx
How many vertebrae are in the cervical division of the vertebral column?
7
How many vertebrae are in the thoracic division of the vertebral column?
12
How many vertebrae are in the lumbar division of the vertebral column?
5
What are the bottom parts of the vertebral column called?
sacrum and coccyx
What is the role of the rib cage?
To protect the heart and lungs
What are the bones of the upper limb (excluding hand)
Humerus, radius, ulna, scapula, clavicle
What are the bones of the hand?
Carpals, metacarpals, phalanges
What bones make up the lower limb (excluding the foot)?
Femur, patella, tibia, fibula
What is the proximal bone of the lower limb?
Femur
What is the proximal bone of the upper limb?
Humerus
How many distal bones are in the limb (excluding hand/foot)
two
What are the distal bones of the upper limb?
Radius and ulna
What are the distal bones of the lower limb?
Tibia and fibula
Why are the lower limbs more stable and strong, while the upper limbs are precise and mobile?
The lower limbs are used for walking (humans are bipedal)
What rotating motions allow the upper limb forearm and hand to be mobile?
Pronation and supination.
What characteristics of the bones of the arms allow for mobility?
Greater surface area where bones can slide past one another.
What feature of the distal lower limb bones creates stability in the ankle?
The cup shaped distal end of the tibia/fibula, that the talus bone sits within. Fibrous inferior tibiofibular joint
What are the types of bone in the hand/wrist?
Carpals, metacarpals, phalanges
What type of bones are carpals?
Short bones
How many carpals are there?
8
How many metacarpals/metatarsals are in the hand/foot?
5
What type of bone are metacarpals/metatarsals and phalanges?
long bones
How many phalanges are in the hand/foot?
14
What type of bone are tarsals?
short bones
How many tarsals are found in the foot/ankle?
7
Where are the upper limbs attached to the axial skeleton?
the pectoral girdle
What bones make up the pectoral girdle?
Clavicle and Scapular
What does the clavicle connect?
The scapula to the sternum
What connects the lower limbs to the axial skeleton?
The pelvic girdle
What are the two key components of the pelvis?
The sacrum and the hip bones
What is the primary function of the pelvis?
To bear the load of the body by transferring/channeling the weight from the vertebral column into the lower limbs towards the ground. Support organs such as reproductive organs
What are the three parts of the hip/pelvic bone?
ilium, pubis, ischium.
What are the two differences between the male and female pelvis?
Female has a more circular and open pelvic cavity, and a more open angled pubic arch
What is the name for the large cavity in the pelvis?
Pelvic inlet
What is the name for the large rounded depression in the wing of the hip bone?
Iliac fossa
What joint connects the two hip bones anteriorly with a cartilaginous joint?
Pubic symphysis
What is the rounded bone that extends from the ischium at the bottom of the pelvis?
Ischial tuberosity
What is the name for the lower and back parts of the hip bone?
Ischium
Where is the pubis located?
The most forward facing bone, above the ischium. Forms the cup-shaped structure of the pelvic girdle
What is the largest part of the hip bones?
Ilium
Where is the ilium located?
At the uppermost part of the hipbones, forming the ‘wings’ of the hipbones.
Where is the coccyx located?
At the inferior end of the sacrum
What two bones make up the pubis?
Superior ramus and inferior ramus
What is the anterior superior iliac spine?
A bony projection that forms a ‘ridge’ on the anterior edge of the ilium.
What are the rounded prominences at the distal end of the femur?
Femoral condyles
How many phalanges are in the thumb?
2
What structure of the distal end of the humerus articulates at the elbow joint?
Condyle
What are the wide bony projections of the humerus that are medial and lateral to the condyle?
Epicondyles
What part of the humerus does the ulna attach to?
The anterior part of the ulna articulates with the trochlear part of the condyle of the humerus. The posterior olecranon of the ulna articulates with the olecranon fossa.
Which forearm bone articulates with the carpals?
Radius
What type of joint is the proximal radioulnar joint?
Pivot joint
How are the carpals arranged?
In two rows
What are the parts of a metacarpal?
base, shaft, head
Are the heads of a metacarpal/metatarsal distal or proximal?
Distal
Which region of the metacarpals do the carpals articulate with?
Base
What type of joint is the distal radioulnar joint?
Pivot joint
How many ribs make up the rib cage?
24 (12 on each side)
What are the articulations of the ribs of the thorax/rib cage?
The vertebral column (posteriorly), the sternum (anteriorly)
How many ribs on each side are connected with the sternum?
10 (20 in total)
How do ribs attach to the sternum?
With costal cartilage
What is the structure of the sacrum?
5 fused vertebrae that sit at the base of the spine, and at the posterior of the pelvis
What bones does the scapula articulate with?
Humerus, clavicle
What are the four key bones of the cranium?
Frontal, parietal, occipital and temporal
What is the most anterior cranial bone?
Frontal bone
What cranium bones articulates with the frontal bone?
Parietal bones
What is the posterior/inferior bone of the cranium?
Occipital bone
What key component of the cranium is made up of two bones (one on either side)
Temporal bones
Which bone of the cranium is the only one that is able to move?
Mandible (jaw bone)
What is the lateral bone of the leg?
The fibula
How does the radius and humerus articulate at the elbow joint?
The anterior of the radius articulates with the capitulum of the humerus (part of the condyles)
How many bones are found in each upper limb?
32
How many bones are found in each lower limb?
30
Which bone crosses which in pronation?
Radius crosses ulna anteriorly, so that the palm faces backwards and the distal end of the ulna becomes lateral to the distal radius
How many of each of the 4 main cranial bones are there in the skull?
1 frontal bone, 2 parietal bones, 1 occipital bone, 2 temporal bones
Going down the vertebral column, in each region, does the vertebral foramen get smaller or larger?
Smaller - the spinal cord becomes smaller as nerves branch out to the peripheral nervous system
Why does the medullary cavity not reduce the strength of the diaphysis?
The centre of the bone is not subjected to tension or compression, as force is channeled down the compact bone of the diaphysis
