Histology

Question 1

What is pseudostratified columnar epithelia?

Answer 1

Single layer of cells of differing heights

Question 2

What is transitional epithelia?

Answer 2

Where the basal cells are cuboidal or columnar and the apical cells are squamous or dome-like

Question 3

What is mesothelium?

Answer 3

Simple squamous epithelia which lines closed body cavities

Question 4

What are exocrine glands?

Answer 4

Ducted glands which secrete substances onto epithelium

Question 5

What are endocrine glands?

Answer 5

Duct-less glands which secrete substances directly into the blood

Question 6

What is a serosa?

Answer 6

Complex tissue which lines closed body cavities and consists of epithelia and underlying connective tissue

Question 7

How many microns are there in a millimeter?

Answer 7

1,000

Question 8

What are all connective tissue cells derived from?

Answer 8

Mesenchymal cell

Question 9

Name the 5 types of connective tissue

Answer 9

Fibrocollagenous, cartilage, blood, bone, fat (adipose)

Question 10

How is fibrocollagenous tissue classified?

Answer 10

By quantity of collagen fibres, type of collagen fibre, and organisation of collagen fibres

Question 11

Describe loose/areolar fibrocollagenous connective tissue

Answer 11

Relatively little type I collagen (in random directions), some type III collagen, some elastic fibres, has fibroblasts, mast cells, macrophages and some white blood cells

Question 12

Describe dense irregular fibrocollagenous connective tissue

Answer 12

Abundance of collagen type I (in random directions), some elastic fibres, fibroblast is main cell, provides ability to withstand tension in many directions

Question 13

Describe dense regular fibrocollagenous connective tissue

Answer 13

Abundance of collagen type I (in one direction only), few elastic fibres, mainly fibroblasts, found in tendons and most ligaments, withstands great tensile strength if force applied in one direction

Question 14

Describe reticular fibrocollagenous connective tissue

Answer 14

Fine meshwork of collagen type III, loose ground substance, soft internal skeleton formed by fibres (stroma), mainly found in lymphoid organs

Question 15

Describe white adipose connective tissue

Answer 15

Main adult fat store, insulates, shock absorber, made of unilocular adipocytes (lipids fuses into one big droplet)

Question 16

Describe brown adipose connective tissue

Answer 16

Involved in thermoregulation in neonates, multilocular adipocytes, organised into lobules by fibrocollagenous septa

Question 17

Describe the extracellular matrix of cartilage

Answer 17

Sulphated GAGs, rich in proteoglycans and hyaluronic acid and type II colalgen

Question 18

What are the different types of cartilage?

Answer 18

Hyaline, elastic and fibrocartilage

Question 19

Where do chondrocytes lie?

Answer 19

In lacunae (lake)

Question 20

Describe fibrocartilage and where it is found?

Answer 20

Contains both type I (stronger) and type II collagen fibres and is found in IV discs, pubic symphysis, and knee menisci

Question 21

What is the perichondrium?

Answer 21

A specialised layer of condensed, highly vascular fibrocollagenous tissue with chondroblasts embedded (for repair)

Question 22

What are muscle cells derived from?

Answer 22

Mesoderm

Question 23

What is the basement membrane of muscle cells called?

Answer 23

External lamina

Question 24

Why does muscle stain bright pink?

Answer 24

Due to large amounts of myofilament in cytoplasm

Question 25

Describe endomysium

Answer 25

Supporting reticular fibre network which carries capillaries and nerves to the muscle cells (fibres)

Question 26

Describe perimysium

Answer 26

Surrounds muscle fascicles

Question 27

Describe epimysium

Answer 27

Surrounds whole muscle with collagen and elastic fibres embedded, it is continuous with tendons and muscle attachments

Question 28

What are satellite cells?

Answer 28

Stem cells which can add to muscle, and are found beneath the basement membrane

Question 29

What do fibroblasts do in muscle?

Answer 29

Help produce endomysium

Question 30

What is the H-zone?

Answer 30

Just the myosin filament, no overlap with actin

Question 31

What is the I-band?

Answer 31

Just the actin filament

Question 32

What is the A-band?

Answer 32

All of the myosin filament, including overlap with actin

Question 33

What is the M-line?

Answer 33

Thickest portion of the myosin filament

Question 34

What is the Z-line?

Answer 34

Marks end of sarcomere (actin)

Question 35

Describe cardiac muscle cells

Answer 35

Branching, multinucleate cells which meet at intercalated discs

Question 36

Why does a fibrocollagenous scar form in cardiac damage?

Answer 36

Cardiac muscle doesn't have any satellite cells and therefore cannot repair itself and a scar forms instead

Question 37

Describe smooth muscle cells

Answer 37

Spindle-shaped cells with a central nuclei, no striations and that are closely arranged to form sheets

Question 38

What are myoepithelial cells?

Answer 38

Cells which have processes which surround secretory portions of exocrine glands, and contraction allows movement into the duct

Question 39

What are myofibroblasts?

Answer 39

Specialised cell that produces collagen it also have actin and desmin filaments which have a large role in wound healing --> proliferate to produce fibrocollagenous scar --> contraction reduces the size of damaged area in healing process

Question 40

What are pericytes?

Answer 40

Stem cells that are associated with capillaries and venules, and following injury proliferate to form new endothelial cells, fibroblasts or myofibroblasts

Question 41

What does a Nissl stain show?

Answer 41

It stains RNA and DNA

Question 42

What is a nervous system nucleus (or PNS ganglion)?

Answer 42

Collection of neurones with common circuity and function (in grey matter)

Question 43

What is neuropil?

Answer 43

Dense tangle of neuroal axons, dendrites and glial processes and is site of communication between various components

Question 44

What glial cells are present in the central nervous system?

Answer 44

Oligodendrocytes, astrocytes and microglia

Question 45

Describe astrocytes

Answer 45

Highly branched cell that surrounds the surfaces of neurones and blood vessels in the CNS and an important part of the BBB; proliferates at the site of injury to form a 'glial scar'

Question 46

Describe oligodendrocytes

Answer 46

Produce myelin by wrapping membrane around axons (one cell can myelinate many axons)

Question 47

Describe microglia

Answer 47

Specialised macrophages in CNS (smallest cell and hard to see without stain)

Question 48

What glial cells are present in the peripheral nervous system

Answer 48

Schwann cells and satellite cells

Question 49

Describe Schwann cells

Answer 49

Myelinate axons (1 Schwann cell segment per axon)

Question 50

Describe satellite cells

Answer 50

Similar to the astrocytes of the CNS (physical and metabolic support)

Question 51

Define 'motor unit'

Answer 51

Motor neurone and all of the skeletal muscle fibres it contracts

Question 52

What does immunohistochemistry involve?

Answer 52

Using labelled antibodies to detect specific antigens in tissue secretions; primary antibody binds to antigen and then a secondary antibody binds to that antibody with a marker e.g. fluorescence