1.1 Tissue Architecture and Organisation

Question 1

Longitudinal section

Answer 1

A section that is cut along the long axis of a structure.

Question 2

Transverse section

Answer 2

A section that is cut perpendicular to the longest axis of a structure.

Question 3

Oblique section

Answer 3

A cut that is at any angle between the longitudinal and transverse planes.

Question 4

Dyes of histology (most common)

Answer 4

Haematoxylin - stains nuclei (nucleic acid) blue/purple

Eosin - stains cytoplasm (proteins) pink

Question 5

Tissue types (5)

Answer 5

blood

epithelial tissue

supporting/connective tissue

muscle

nervous tissue

Question 6

The blood

cell types

Answer 6

Leukocytes- white blood cells, defence against infection

Erythrocytes - red blood cells, oxygen transport

Thrombocytes - platelets (cellular fragments), clotting factor

Question 7

Types of epithelium

Answer 7

Simple squamous

simple cuboidal

simple columnar

stratified squamous

stratified cuboidal

pseudostratified columnar

transitional

Question 8

Simple epithelium (e.g.)

Answer 8

A single layer of cells, can be found in:

gut epithelium

epidermis of skin

endothelium

Question 9

Types of muscle

Answer 9

skeletal/striated

cardiac

smooth

Question 10

Cardiac muscle

Answer 10

long cylindrical cells

striated

branching

syncytial (cells are discrete but behave as a functional syncitium

divided by intercalated disks

Question 11

Intercalated disks

Answer 11

Critical in the propagation of action potentials between cardiomyocytes.

They link cells via gap junctions, desmosomes and adherents junctions

Question 12

Gap junctions

Answer 12

Protein tubes form hydrophilic pores across plasma membrane of adjacent cells for movement of small solutes.

Question 13

Desmosomes / Adheres junctions

Answer 13

Desmosomes link intermediate fibres

Adherens junctions bind to actin filament

Question 14

Cytoskeleton componenets (3)

Answer 14

microfilaments

intermediate filaments

microtubules

Question 15

Microfilaments

Answer 15

made of actin molecules

Question 16

Intermediate fibres

Answer 16

composed of a range of proteins depending on types

Question 17

Microtubules

Answer 17

made of tubulin proteins

Question 18

Structure of venous and arterial blood vessels (3 layers)

Answer 18

Tunica intima

Tunica media

Tunica adventitia

Question 19

Tunica intima

Answer 19

single layer of simple squamous epithelia

contains perforations within the internal elastic lamina

Question 20

Tunica media

Answer 20

mainly smooth muscle (produced ECM and IEL)

Question 21

Tunica Adventitia

Answer 21

ECM (produced by fibroblasts) where nerves, lymphatic vessels, immune cells (macrophages), and progenitor cells are found

Question 22

Capillaries

Answer 22

Only have tunica intima

Allows movement of cells and molecules

Endothelial cells attach to basement membrane.

Question 23

Function of tunica intima

Answer 23

Facilitates the unidirectional flow of blood as well as allowing the uninterrupted, smooth flow of blood

Question 24

Function of the tunica media

Answer 24

Provides architectural support for the vessel and regulates vessel diameter and blood pressure

the thickest layer (usually)

Question 25

Function of the tunica adventitia

Answer 25

Prevents overexpansion of the blood vessel

Question 26

Types of capillaries (3)

Answer 26

Continuous - uninterrupted lining, e.g., blood-brain barrier Discontinuous - openings within (permeable), e.g., liver, spleen, bone marrow Fenestrated - small pores for passage of molecules, e.g., intestinal villi, kidney glomeruli.

Question 27

Function of pericyte

Answer 27

controls blood flow via contracting/releasing endothelial cells within vessels architectual of vessels