week 2

Question 1

Microorganisms

Answer 1

living organisms
reproduce independently
are everywhere

Question 2

Prokaryotes (list some characteristics)

Answer 2

small
always unicellular
no nucleus
no cytoskeleton
asexual

Question 3

Eukaryotes (list some characteristics)

Answer 3

Lagre
often multi-cellular
has nucleus
has cytoskeleton
sexual or asexual (mitosis/ meiosis)

Question 4

Types of prokaryotes and eukaryotes

Answer 4

protozoa - eukaryote
fungi - eukaryote
helminths - eukaryote
virus - not living
bacteria - prokaryote

Question 5

Growth requirements

Answer 5

TEMP: optimal - 37 C
Thermophile - 60 C
Mesophiles - 25-30 C
Pyschrophiles - 10 C

PH: 7 neutral

OXYGEN:
aerobes - in the presence of oxygen
anaerobic - without the presence of oxygen
facultative anaerobes - with or without oxygen

Question 6

Gram-negative and gram-positive bacteria

Answer 6

gram-negative - capable of forming spores

gram positive - most difficult to kill, produce endotoxins

Question 7

Normal flora (3 locations + characteristics)

Answer 7

skin - reduces pH
oral + vagina - completes + inhibits pathogens + yeast
intestine - excrete bacteria, synthesise + secrete vitamins and stimulate immunity

Question 8

Mode of transmission

Answer 8

air-borne
contact
water-borne
blood + tissue borne
vector-borne
fomite-borne
vertical

Question 9

Chain of infection (list the parts)

Answer 9

infectious agent 
reservoir
portal of exit
means of transmission
portal of entry
susceptible host

Question 10

Skin layers

Answer 10

epidermis
dermis
hypodermis/ subcutaneus

Question 11

Epidermis role

Answer 11

protects underlying tissue from:
dehydration
infection
mechanical stress
chemical stress
UV radiation

Question 12

Dermis role

Answer 12

strength + flexibility
thermoregulation
protection
sensation

Question 13

Hypodermis/ subcutaneus role

Answer 13

insulation + thermoregulation
protection
storage

Question 14

Cell types - epidermis

Answer 14

keratinocyte
langerhans
merkel
melanocyte

Question 15

Thermoregulation (3 parts)

Answer 15

vasoconstriction - increase blood pressure, skin veins constrict in cold weather to conserve heat

vasodilation - decrease blood pressure, skin veins dilate in hot weather to lose heat

goosebumps and sweat - other methods of losing and conserving heat

Question 16

Lymphatic system components

Answer 16

immune cells
lymph - fluid tissue
lymph vessels -organs

Question 17

Functions of lymphatic system

Answer 17

drain excess fluid + proteins from all tissues back to blood circulation

transport fats and vitamins from gut to liver (digestion)

defends the body against external and internal threats

Question 18

Immunity (definition)

Answer 18

ability to resist infection + disease

immune system has two parts:

• non-specific defences
• specific defences

Question 19

Lymphocytes

Answer 19

are white blood cells, are 3 types (B cells,T cells and natural killer cells)
recognise antigens, produce antibodies, and destroy cells that could cause damage

Respond to:
environmental pathogens
toxins
abnormal body cells

mature in the bone marrow or thymus

Question 20

Lymph tissue

Answer 20

is a fluid 
contains lymphocytes + macrophages that seek out and destroy enemies
- foreign cells
- foreign proteins
- cancer cells

Question 21

Lymph organs

Answer 21

lymph flows through special tubes from tissue to the large veins and heart
tubes: lymph capillaries, vessels, trunks and ducts

Question 22

Lymphatic capillaries

Answer 22

have one-way valves
allows fluids, solutes, viruses and bacteria to enter
prevents return to inter-cellular space

Question 23

Lymph vessels

Answer 23

thin walls
resemble veins with more valves
lymph nodes at intervals

Question 24

Lymph ducts

Answer 24

vessels unite to form 2 thoracic ducts
right side - right lymphatic duct
left side - main thoracic duct

Question 25

Lymph nodes

Answer 25

filter lymph: foreign materials enter,foreign matter is trapped in fibres and then destroyed by macrophages , B & T cells

Question 26

Label a bacteria cell

Answer 26

capsule
cell wall
cytoplasm
plasmid
cell membrane
chromosome
flagellum
ribosomes

Question 27

Label skin structure

Answer 27

capillaries
hair follicle
sensory neurons
fat
sebaceuous (oil) glands
sweat glands