Science assessment task 4 section 2: biology

biology: homeostasis, nervous system, reaction time, feedback loops, disease, immune system, lines of defence.

parts of the central nervous system (CNS)

brain, spinal cord

parts of the peripheral nervous system (PNS)

billions of nerves

function of CNS

manages all body functions, thoughts and movement

function of PNS

sending sensory information to CNS and carries out commands from brain

What is 1?

cerebrum

What is 2?

cerebellum

What is 3?

medulla

What is 4?

brain stem

cerebrum

wrinkled tissue, most of the brain. responsible for many functions e.g. senses, personality, language, decision making and organisation.

cerebellum

controls complex muscular movement

brain stem

connects cerebrum to spinal cord

medulla

lower part of brain stem. controls involuntary functions e.g. breathing, heartbeat

neurons

specialised cells that carry messages around the body

nerve bundle

a bundle of many nerve fibres enclosed in a protective sheath

What is A?

cell body

What is B?

dendrites

What is C?

axon

What is D?

myelin sheath

Where does the sensory neuron fit on the stimulus-response pathway?

B, between receptor and cns

Where does the motor neuron fit on the stimulus-response pathway?

C, between the cns and effector

reaction time

how long it takes for nervous system to detect stimulus, process the information and execute a response

feedback loop order

stimulus → receptor → control centre → effectors → response

stimulus

changes that occur

receptor

detects change

control centre

analyses messages and initiates actions

effectors

muscles, organs, glands

endocrine system function

coordinate the body’s organs, produces hormones through glands

what hormones does the piuitary gland secrete?

produces many hormones including anti-diuretic hormone

anti-diuretic hormone (ADH)

affects the amount of urine produced by the kidney

what hormones does the pancreas secrete?

insulin and glucagon

what hormones do testes (in males) secrete?

testosterone

what hormones does the ovary secrete?

oestrogen and progesterone

insulin

turns glucose into glycogen

glucagon

turns glycogen into glucose

where do these processes happen?

in the liver

cells involved in the nervous system

neurones

cells involved in the endocrine system

glands

type of signal nervous system

electrical (impulse)

type of signal endocrine system

chemical (hormone)

signal carrier nervous system

neurones

signal carrier endocrine system

blood/lymph

speed of signal transmission nervous system

fast

speed of signal transmission endocrine system

slow

size of the response generated by the nervous system

localised (a specific cell or tissue)

size of the response generated by the endocrine system

systemic (cells or tissue throughout the body)

duration of the nervous system response

temporary

duration of the endocrine system response

long-lasting

disease

a condition or disorder that stops the body from functioning normally

antigen

any foreign particle that triggers an immune response, usually a part of a pathogen

immune system

a network of cells, tissues, organs, and proteins that defends the body against pathogens

innate immune system

a non-specific first line of defence which reacts immediately and provides a general defence against all pathogens

adaptive immune system

provides a slower response but targets specific pathogens and provides long term immunity through memory cells

living pathogens

bacteria, fungi, protist

non-living pathogens

virus and prion

bacteria

unicelluar, prokaryote (no nucleus)

fungi

unicelluar (e.g. yeast) or multicelluar (e.g. mushroom), eukaryote, has cell wall, made of threads called hyphae forming mycelium (fungal body)

protist

unicelluar, eukaryote (has nucleus), no cell wall, animal-like or plant-like features

virus

acelluar, intracelluar, protein coat surrounds genetic material

prion

a protein found in the brain that can misfold if infected by a pathogenic prion

first line of defence

prevents pathogens from entering the body through physical and chemical barriers

first line of defence: innate/non-specific or adaptive/specific?

innate/non-specific

first line of defence physical barriers

skin and mucous

first line of defence chemical barriers

stomach acid, saliva, tears

second line of defence

fever, inflammation, phagocytes

what is it called when phagocytes engulf pathogens?

phagocytosis

second line of defence: innate/non-specific or adaptive/specific

innate/non-specific

third line of defence

targets pathogens using B and T lymphocytes and creates immunity

third line of defence: innate/non-specific or adaptive/specific

memory cell

an immune cell that can recognise a pathogen it has encountered before

memory cells last for…

many years

what do B lymphocytes do?

they change into plasma cells and produce antibodies

T lymphocytes (specifically cytotoxic) can…

bind to body cells infected with pathogens and destroy them

how long does it take for your body to produce the correct type of antibody?

10-17 days

vaccination

the process of giving a vaccine to stimulate the immune system and provide protection against a specific disease

vaccine

an antigen or a dead or weakened pathogen that is given by injection or as a liquid or tablet to stimulate the immune system to create memory cells