Histology

Question 1

skeletal muscle cells are striated/nonstriated, branched/unbranched

Answer 1

striated and unbranched

Question 2

skeletal muscle cells are multinucleated- what does this form

Answer 2

syncytium

Question 3

define syncytium

Answer 3

cell containing multiple nuclei

Question 4

where in a skeletal muscle cell are the nuclei found?

Answer 4

periphery of the fibre, just under the cell membrane

Question 5

what is the cell membrane in a muscle cell called?

Answer 5

sarcolemma

Question 6

muscle fibres are grouped into bundles- what are these bundles called?

Answer 6

fascicles

Question 7

the connective tissue surrounding the entire muscle is called what?

Answer 7

the epimysium

Question 8

the connective tissue surrounding a single fascicle is called what?

Answer 8

the perimysium

Question 9

the connective tissue surrounding a single muscle fibre is called what?

Answer 9

endomysium

Question 10

each muscle fibre contains many myofibrils which are made up of what?

Answer 10

sarcomeres placed end-to-end

Question 11

what other structures are contained within muscle?

Answer 11

blood vessels connective tissue nerves lymphatics

Question 12

by definition where do sarcomeres begin/end?

Answer 12

Z lines

Question 13

when does the axon of a motor neurone branch?

Answer 13

as it nears its termination

Question 14

what is the name given to the special synapse at the end of each branch of a motor neurons axon?

Answer 14

neuromuscular junction

Question 15

the fibres in a motor unit are bunched/scattered?

Answer 15

scattered

Question 16

list some features of cartilage

Answer 16

semi-rigid and deformable permeable avascular

Question 17

what are the cells found in cartilage called?

Answer 17

chondrocytes

Question 18

what is the name given to immature chondrocytes?

Answer 18

chondroblasts

Question 19

where exactly are chondrocytes found?

Answer 19

space within the extracellular matrix termed a lacuna

Question 20

what is the function of chondrocytes?

Answer 20

secrete and maintin the extracellular matrix around them

Question 21

what are the three types of cartilage?

Answer 21

hyaline

elastic

fibrocartilage

Question 22

what is the most common type of cartilage?

Answer 22

hyaline

Question 23

describe the appearance of hyaline cartilage

Answer 23

blue-white in colour

translucent

Question 24

describe the appearance of elastic cartilage

Answer 24

light yellow in colour

quite flexible (addition of elastic fibres)

Question 25

describe fibrocatilage

Answer 25

appears white hybrid between tendon and hyaline cartilage bands of densely packed **type I** collagen with rows of chondrocytes

Question 26

what are the components of the ECM in hyaline cartllage?

Answer 26

75% water 25% organic material- **type II collagen** and **proteoglycan**

Question 27

what is the difference between type I and type II collagen

Answer 27

**type I** - thicker (75nm) - aggregates into linear bundles **type II** - finer (15-45nm) - forsm 3D meshwork

Question 28

list some of the sites hyaline cartilage can be found in?

Answer 28

articular surfaces tracheal rings costal cartilage epiphyseal growth plates precursor in fetus to many bones

Question 29

list the functions of **bone**

Answer 29

support levers for movement protection calcium store haemopoesis

Question 30

what is the compostiion of bone?

Answer 30

**65%** bioapatite(calcium phosphate) **23%** collagen **10%** water **2%** non collagen protiens

Question 31

name the two types of bone visible to the naked eye?

Answer 31

**cortical bone** (outer shell) **cancellous/trabeciullar bone** (epiphyses)

Question 32

what process does bone undergo throughout life?

Answer 32

remodelling

Question 33

what is the main difference between cortical and trabecular bone?

Answer 33

the presence of spaces- **marrow cavities**

Question 34

define lamellar

Answer 34

made up of **layers**

Question 35

what is the name given to the circular layers foudn in compact bone?

Answer 35

circumferential lamellae

Question 36

what is an osteon?

Answer 36

unit of lamellar bone layed down in circles

Question 37

what is the name given to the canal in the centre of an osteon?

Answer 37

**haversion canal** e.g. blood vessel

Question 38

what is the name given to the canal type that runs across the bone?

Answer 38

**V****olkmanns canal**

Question 39

how does trabecullar bone differ from comapct bone?

Answer 39

both are lamellar however trabecullar doesnt have **blood vessels**

Question 40

what is the name of the livign cells within bone?

Answer 40

osteocytes

Question 41

name the following

Answer 41

**A-** osteocytes in lucunae **B-** haversion canal **C****-** volkmanns canal **D-** osteons

Question 42

what are **cement lines?**

Answer 42

the lines often visible surroundign the osteon - not seen in oroginal developmetn onyl in those that have formed durign remodelling

Question 43

which bone cells are loacted on the surface and serve as a pool of reserve osteoblasts?

Answer 43

**osteoprogenitor cells**

Question 44

what are osteoblasts

Answer 44

cells found on surface of **developing** bone- they have plentiful RER and prominent mitochondria

Question 45

which bone cells are trapped within the bone matrix?

Answer 45

osteocytes

Question 46

what are osteoclasts

Answer 46

large multinucleated cells found on the surface of bone

Question 47

which bone cells are bone **forming**

Answer 47

osteoblasts

Question 48

which boen cells are responsible for bone **resorption?**

Answer 48

osteoclasts

Question 49

desctibe the process of remodelling in bone

Answer 49

1. **osteoclasts** congreagte and 'drill' down into the bone formign a tunnel 2. a blood vessel will grow into the tunnel 3. **osteoblasts** line the tunnel laying down lamellar bone 4. process contnues until only the space known as **haversian canal** is left

Question 50

what do osteoblasts secrete?

Answer 50

collagen glycoaminoglycans (GAGs) proteoglycans

Question 51

what is teh collective term fo rthe secretions of an osteoblast?

Answer 51

**osteoid**- this becomes mineralised over time

Question 52

the mineral of bone is made up principally of what?

Answer 52

calcium phosphate crystals (particularly hydroxyapatite)

Question 53

osteoblasts will fuse to form what?

Answer 53

a single giant cell

Question 54

why can the matrix that will become bone only be added at the surface?

Answer 54

becasue bone is a solid matrix

Question 55

in developing bone how are the collagen fibres arranged? what is the name given to this pattern of bone?

Answer 55

arranged in random, haphazard fashion- this is called **woven** bone