Bones 1 - structure of the skeleton

Question 1

Skeletal system

Answer 1

bones, cartilage, ligaments, tendons and connective tissue that support and connect

Question 2

How many bones in the body?

Answer 2

206
80 - axial, head, thoracic and vertebral column - longitudinal axis
126 - limbs and girdles

Question 3

Functions of the skeleton

Answer 3

• Support - structural framework for attatchment of muscles and ligaments

*Storage - of energy in the form OF Adipose tissue and Calcium salts for minerals

• Blood cell production in the bone marrow. Red bone marrow makes RBCs when young, when we grow older it turns to yellow marrow (not all) i.e adipose tissue
• Protection of delicate organs and muscles
• Leverage but pulling in bones and the ability to change the magnitude and direction of skeletal muscle movements

Question 4

6 types of bones

Answer 4

*Flat bones - thin, flat, roughly parallel, extensive surface for muscle attatchment, - protect underlying soft tissues and organs
- spongy in the centre and think layer of compact around

• Irregular - Complex bones with projections, notches, flat, ridges
• Lots of foramina

*Long - elongated, has metaphysis, diaphysis and epiphysis
- Cancellous bone found in the epiphysis, compact in the diaphysis, medullary cavity has bone marrow, compression on medial and tension on lateral side

• Short - square or rounded, carpals and tarsals
• Cancellous bones to absorb force from everywhere and stabilise
• Sesamoid - small, flat, sesame shaped, develops in the inside of tendons
• Sutural - Small, flat irregularly shaped bones in between the bones of the skull

Question 5

Axial skeleton bones

Answer 5

Skull - 8 cranial, 4 facial
Associated - 6 auditory ossicles, 1 Hyoid attatched by membranes connected to temporal bone. Total 29

Thoracic cage - 24 ribs, 1 sternum

24 vertebrae, 1 sacrum + 1 coccyx

Provides framework and protection, surface for muscle attatchment, adjusts position of head and trunk, provides an area of attatchemnt for limbs, stabilize this area

Joints of this skeleton have very limited movement but are very reinforced with ligaments

Question 6

Facial bones (14)

Answer 6

2 Palatine
2 Maxillary
1 Mandibular
2 Nasal
2 Inferior nasal conchae
2 Zygomatic
2 Lacrimal
1 Vomer

Question 7

Skull (8)

Answer 7

1 Frontal - coronal suture
2 Parietal - Sagittal suture
I occipital - Lamboid suture
2 Temporal - Squamous suture
1 Ethmoid
1 Sphenoid

Suture held by DCFT and

Question 8

Vertebrae

Answer 8

7 - C
12 - T
5 - L

Intervertebral discs made of fibrocartilage

Question 9

Ribs

Answer 9

1-7 are vertebrosternal (T)
8-10 Vertebrochondral (F)
11 and 12 are floating ribs (F)

Sternum is Jugular notch, manubrium, sternum and xiphoid process

Question 10

Two types of bone tissue

Answer 10

Chemically same, structurally different

*Compact - dense and strong, osteons run in one direction, takes force from one direction and transmits in one direction
* Cancellous/trabecular - spongy, network to take forces from all directions and absorb it and transmit it down long ends i.e diaphysis of long bones. More SA so the bone marrow runs in between

Question 11

Why is our upper limb different from our lower?

Answer 11

They have more articulation for more movement but the lower and more stability as we are bipedal.

Question 12

Hand bones and foot bones

Answer 12

Hand (27) - 14 phalanges, 5 metacarpals and 8 carpals

Foot (26) - 14 phalanges, 5 metatarsals and 7 tarsals

Question 13

Pectoral girdle

Answer 13

The clavicle and the scapula
- Clavicle connects the to the scapula for stability
- The scapula are not connected but it provides an extensive surface for muscle attatchment + attatched to the humerus

Question 14

Pelvic girdle

Answer 14

Pelvis + sacrum

Question 15

Pelvic bones

Answer 15

Ilium, Ramus (Ischium and pubic) and the pubic symphysis, women have a less pubic angle for childbirth