Body Basics

Question 1

cell membrane

Answer 1

lipid bilayer containing cholesterol for stability and various proteins, in contact with cytoplasm, intercellular space and extracellular matrix

Question 2

glycocalyx

Answer 2

molecules for cell-cell recognition, communication and adhesion

Question 3

ECM

Answer 3

network of molecules (secreted by cells) that provides structural support, adhesion and communication to surrounding cells eg. Plasma is the ECM of blood

Question 4

membranous organelles

Answer 4

membranes create cell compartments or separate processes

Question 5

examples of membranous organelles

Answer 5

nucleus, mitochondria, rough and smooth endoplasmic reticulum, Golgi apparatus, lysosome, peroxisome

Question 6

examples of non membranous organelles

Answer 6

ribosomes, flagella, cilia, centrosomes

Question 7

cytoskeleton components

Answer 7

actin microfilaments, tubulin microtubules, intermediate filaments

Question 8

function of actin microfilaments

Answer 8

cell movement, cell shape changes, microvilli structure

Question 9

function of tubular microtubules

Answer 9

structural support, intra/extracellular transport, spindle in cell division

Question 10

function of intermediate filaments

Answer 10

membrane support, localisation of organelles

Question 11

kinesin motors

Answer 11

structures that carry organelles along microtubules/nerves using ATP hydrolysis

Question 12

endocytosis examples

Answer 12

• Phagocytosis- cell membrane invaginates to engulf large molecules in a phagosome
• Receptor mediated (specific) endocytosis- clathrin forms a coat with deforms cell membrane to produce a vesicle in which molecules are taken into the cell eg. Insulin, LDL
• Non-specific endocytosis- a liposome containing large molecules fuses with lipid layer and contents are released into cell

Question 13

exocytosis examples

Answer 13

• Constitutive secretion= newly synthesised cell membrane components (released from Golgi in lysosomes) fuse with CM randomly
• Regulated secretion= hormone stimulates above process

Question 14

4 major tissue groups

Answer 14

epithelia, connective, nervous, muscle

Question 15

epithelia functions

Answer 15

• Functions= exchange, transport, protection, secretion

- Form boundaries between environments and must be crossed by substances entering or leaving internal environment

Question 16

what is epithelia formed from?

Answer 16

all 3 embryological layers

Question 17

epithelia tissue general structure

Answer 17

• Highly cellular (regenerate rapidly due to friction) with little ECM and avascular so substances must diffuse to and from blood
• Cells are polarised, apical surfaces have microvilli to maximise surface area and bases have basement membranes for mechanical support

Question 18

simple epithelia

Answer 18

one layer

Question 19

shapes of epithelial cells

Answer 19

squamous, cuboidal, columnar

Question 20

simple squamous cells examples and function

Answer 20

functions: filtration, diffusion, osmosis and secretion (little protection as it is thin)
examples: heart lining, blood vessels, lymphatics, alveoli

Question 21

stratified cells function

Answer 21

protection due to regenerative capacity and multiple layers

Question 22

cuboidal and columnar tissue function

Answer 22

secretion (bigger cells have more space to synthesise) and absorption (except stratified squamous)

Question 23

simple cuboidal cells examples

Answer 23

Ovary, pigmented layer of retina, kidney tubules

Question 24

simple columnar examples

Answer 24

GI tract lining, gall bladder, fallopian tubes

Question 25

stratified cuboidal cells

Answer 25

Ducts of sweat glands

Question 26

stratified squamous cells

Answer 26

Skin (keratinised), mouth/oesophagus (non keratinsed)

Question 27

stratified columnar cells

Answer 27

Urethra lining, large gland ducts

Question 28

glands

Answer 28

epithelia that secrete and store products like hormones

Question 29

goblet cells

Answer 29

unicellular glands

Question 30

endocrine glands

Answer 30

ductless so hormones are released directly into extra cellular fluid or blood to travel to target organs

Question 31

exocrine glands

Answer 31

secrete products through a duct onto epithelium

Question 32

3 types of exocrine glands:

Answer 32

* Merocrine- secretory product released from glandular cell in exocytosis * Apocrine- vesicle containing products is secreted from glandular cell * Holocrine- glandular cell dies and become secretory product

Question 33

how are epithelial cells tightly associated?

Answer 33

intracellular junctions

Question 34

tight junction structure and function

Answer 34

made of occuludins- interlocking protein links fuse membranes to give small intercellular space that limits permeability between cells

Question 35

gap junction structure and function

Answer 35

connexons (protein tubes) allow transport between cells)

Question 36

desmosome junction structure and function

Answer 36

cadherins (cell adhesion molecules)- gives stability to tissue

Question 37

connective tissue function

Answer 37

support, load-bearing, protection, binding and transport - not inert but responds to environments - poor repair potential

Question 38

basic structure of connective tissue, fluid and support

Answer 38

* Actual connective tissue = fat, ligaments * Fluid= blood, lymph * Supporting= bone, cartilage

Question 39

Structure of Connective Tissues

Answer 39

- Extensive ECM for structural and biochemical support and few cells - Through ECM, varying compositions of interstitial fluid, nerves, cells and capillaries - Load bearing, dense tissues like cartilage have low vascularity while loose tissue like adipose have high vascularity

Question 40

structure of ECM in connective tissue

Answer 40

Framework of extracellular fibres (collagen, elastin fibres and reticular fibres) with ground substance (proteoglycan molecules) filling gap between famework and any other structures present (cells, nerves, blood vessels and fluid)

Question 41

collagens, elastic fibres, reticular fibres functions in connective tissue

Answer 41

- Collagens= tensile strength - Elastic fibres= elasticity - Reticular fibres= thinner and branching

Question 42

integrins

Answer 42

proteins that signal between ECM and metabolic systems, allowing it to react to its environment

Question 43

proteoglycans

Answer 43

highly hydrated molecules allowing compressive strength