Theme 1 Anatomy - Skeletal system

Question 1

what are the two parts of the skeletal system?

Answer 1

axial and appendicular

Question 2

what is the axial skeleton?

Answer 2

skull, vertebrae, sternum and hyoid bone

Question 3

what is the appendicular skeleton?

Answer 3

limb bones, pectoral bones and pelvic girdle

Question 4

name four functions of the skeleton

Answer 4

protection of organs, movement, production of red blood cells, metabolic reservoir for calcium and mineral salts,

Question 5

what germ layer does the skeletal system arise from and at what week?

Answer 5

from mesoderm from week 4 onwards

Question 6

which bones ossify last and at what age is this?

Answer 6

clavicle, humerus, femur at 20-30 years and carpals at 18 years

Question 7

which type of mesoderm forms the appendicular skeleton?

Answer 7

lateral plate mesoderm

Question 8

what are the two types of ossification?

Answer 8

intramembranous and endochondral

Question 9

what is intramembranous ossification and where does it occur?

Answer 9

direct mineralisation of connective tissue and occurs in the skull, mandible and clavicle

Question 10

what produces the radial pattern of bone in the skull?

Answer 10

direct mineralisation where the capillary networks are - bone grows outward from the primary ossification centre

Question 11

what happens to the connective tissue that does not become bone in intramembranous ossification?

Answer 11

is penetrated by blood cells and undifferentiated mesenchyme and gives rise to bone marrow

Question 12

how much remodelling is there in intramembranous ossification (skull)?

Answer 12

not very much - a little to increase the thickness of the skull

Question 13

what type of ossification starts with a cartilage template which is replaced by bone in an ordered fashion?

Answer 13

endochondral ossification

Question 14

where does primary ossification occur?

Answer 14

the bone collar on the diaphysis

Question 15

where does secondary ossification occur and what does it make?

Answer 15

the epiphysis and makes spongey bone

Question 16

how do bones grow in length during development?

Answer 16

cartilage cells are stacked on top of each other at the growth plate and bone is laid down behind them

Question 17

what structure can look like a fracture on X ray in children?

Answer 17

the epiphyseal growth plate

Question 18

does cartilage become bone or is it replaced by bone?

Answer 18

hyaline cartilage acts as a template and is replaced by bone

Question 19

what processes allows bone to grow both radially as well as in length and which hormone controls this?

Answer 19

partial reabsorption by parathyroid hormone

Question 20

what structure is abolished when bone becomes mature from immature?

Answer 20

the epiphyseal plate

Question 21

what three dietary elements regulate bone development and maintenance?

Answer 21

calcium, phosphorus and vitamins

Question 22

what is the function of vitamin D and what does deficiency cause?

Answer 22

it is essential for calcium absorption and deficiency causes rickets due to lack of calcium

Question 23

what three hormones control bone growth and where are they produced?

Answer 23

parathyroid hormone produced in the parathyroid glands, calcitonin produced by the thyroid gland and growth hormone produced by the pituitary gland

Question 24

what is the function of parathyroid hormone?

Answer 24

increases absorption of bone and therefore increases the amount of calcium circulating in the blood

Question 25

what does too much parathyroid hormone lead to?

Answer 25

osteopenia - edges of the bone being eaten away

Question 26

what does calcitonin do?

Answer 26

works in opposition to PTH and reduces amount of calcium circulating in the blood

Question 27

what does too much or too little growth hormone cause?

Answer 27

too little before puberty causes dwarfish, too much after puberty causes acromegaly (elongation of mandible and maxilla)

Question 28

how does cartilage get its nutrients?

Answer 28

from diffusion as its avascular

Question 29

what are the two types of bone?

Answer 29

compact (outside) and spongey (in the middle)

Question 30

what is the thin membrane covering bone?

Answer 30

periosteum or perichondrium if connective tissue

Question 31

what is the role of the periosteum

Answer 31

helps get blood vessels into the bone through the nutrient foramen

Question 32

what are the four cell types that make up bone?

Answer 32

osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts

Question 33

what is the role of osteoprogenitor cells?

Answer 33

can turn into any form of cell

Question 34

what is the role of osteoblasts?

Answer 34

building cells - lay down organic matrix around them and trap themselves

Question 35

what is the role of osteocytes?

Answer 35

trapped osteoblasts become osteocytes - maintain the organic matrix and sit in their own lacunae

Question 36

what is the role of osteoclasts?

Answer 36

eat and destroy bone under the influence of parathyroid hormone

Question 37

what is the name of the concentric later of inorganic matrix laid down by osteoblasts in compact bone?

Answer 37

lamella

Question 38

which way does the Haversian canal run and what is its role?

Answer 38

runs vertically and transports blood and nerve supply to bone

Question 39

what are canaliculi?

Answer 39

radiate out of lacunae and help with nutrient transport to the osteocyte

Question 40

what is another name for spongey bone

Answer 40

cancellous bone

Question 41

what are spaces in spongey bone filled with?

Answer 41

bone marrow therefore are highly vascularised

Question 42

give two examples of flat bones

Answer 42

scapula and skull

Question 43

give three examples of irregular bones and how can they be described?

Answer 43

vertebrae and sacrum - developed over time for a specific function

Question 44

give an example of a sesamoid bone and how can it be characterised?

Answer 44

patella - completely surrounded by tendons

Question 45

why does the mastoid process have a bump on it?

Answer 45

flat at birth then pressure from the sternocleidomastoid bone makes it produce a bump in order to strengthen

Question 46

what are the three types of joints?

Answer 46

synovial, fibrous and cartilaginous

Question 47

what is a synovial joint and where is it found?

Answer 47

has a joint capsule and a synovial cavity to allow movement - knee joint

Question 48

what is a fibrous joint and where is its found?

Answer 48

connected by collagen and doesn't allow movement - sutures of skull

Question 49

what is a cartilaginous joint and where is it found?

Answer 49

connected by cartilage - some but not much movement - intervertebral disks

Question 50

what do the menisci in the knee joint do?

Answer 50

shock absorb and stabilise the knee

Question 51

what two things stables the knee?

Answer 51

menisci and ligaments (ACL and PCL)