B13.1 & 13.2 - Coordination and Response Flashcards
What is the nervous system made up of? [3]
- brain
- spinal cord
- nerves
What does the peripheral nervous system consist of? [1]
- nerves that branch out of the spinal cord and brain
What is the role of the nervous system? [2]
- coordination and regulation of body
- gets feedback about the world
Which bone is the brain protected by? [1]
the skull
How do muscles respond? [1]
by contracting
What are the three main stages of the nervous system? [3]
- stimulus
- sensory receptors
- effectors
Which bone is the spinal cord protected by? [1]
vertebral column (backbone)
What is the stimulus? [1]
a change in the environment
What are the sensory receptors? [2]
- group of cells
- detect the stimulus
What is an effector? [2]
- carries out a response
- muscles or glands
Where are receptor cells found? [1]
sense organs
How do glands respond? [1]
by secreting a substance
What is the receptor in the eye and what is the stimulus? [2]
- photoreceptors (light receptors)
- light
What is the receptor in the tongue and what is the stimulus? [2]
- chemoreceptors (taste receptors)
- chemicals in food
What is the receptor in the skin and what is the stimulus? [4]
- temperature receptors
- pressure receptors
- heat
- pressure
What is the receptor in the nose and what is the stimulus? [2]
- smell receptors
- chemicals in the air
What does the receptor cells do with the stimulus? [1]
change into an electrical impulse
How long does the whole process of a voluntary response take? [1]
0.7 seconds
Describe the steps involved in a voluntary response in a nervous reaction. [9]
- stimulus
- receptor cells
- sensory neurone
- spinal cord
- brain
- spinal cord
- motor neurone
- effector
- response
What is a conscious response? [2]
- if information from the sensory neurone goes to the brain
- you deciding what to do
What does a reflex action do? [3]
- occur without thinking
- automatic and protective
- go past the brain for extra speed
What is a reflex action? [3]
a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors
How long does the whole process of a reflex action take? [1]
0.2 seconds
Examples of when reflex actions occur. [4]
- breathing
- heart rate
- digestion
- when in danger
Describe the pathway taken for a reflex action or an involuntary response. [7]
- stimulus
- receptor
- sensory neurone
- spinal cord
- motor neurones
- effector
- response
What do electrical impulses travel along? [1]
neurones
3 examples of neurones. [3]
- sensory neurones
- relay neurones
- motor neurones
What is a hormone? [4]
a chemical substance which is produced in endocrine glands and carried in the plasma which travels in the blood stream to specific cells found in target organs
What do the adrenal glands produce? [1]
adrenaline
What do the ovaries produce? [1]
oestrogen
What does the pancreas produce? [1]
- insulin
- glucagon
What do testes produce? [1]
testosterone
How long is a hormone carried around the body for? [2]
- until it finds a target cell
- should have receptors which are specific to that hormone on the cell membrane
What does a hormone do after it finds a receptor in the target cells? [2]
- binds to these receptors
- causes a response within the cell
What is the speed of communication in NERVES vs. HORMONES? [2]
- N: very fast
- H: slower
What is the method of transport in NERVES vs. HORMONES? [2]
- N: electrical impulse
- H: in the blood
What is the duration of response in NERVES vs. HORMONES? [2]
- N: short acting
- H: longer acting
What is the area targeted in NERVES vs. HORMONES? [2]
- N: very precise area
- H: larger area
What is adrenaline? [2]
the hormone secreted in ‘fight or flight’ situations
How is adrenaline released? [5]
- brain detects stressful, dangerous or exciting situation
- brain sends nerve impulse to adrenal glands
- secretes adrenaline into the blood
- adrenaline travels to target organs
- gets body ready for action
What does adrenaline cause after being released? [4]
- increased rate of respiration
- increased rate of breathing
- increased heart rate
- diverting of blood
Why is there an increased rate of respiration? [1]
to release more energy
Why is there an increased rate of breathing? [1]
to cope with extra demand for oxygen due to increased respiration
Why is there an increased heart rate? [2]
delivers oxygen to cells more quickly for increased respiration
Why is there a diverting of blood away from certain areas? [1]
to go to the muscles from the skin or digestive system
Where does blood get diverted from? [2]
- digestive system
- skin
What does adrenaline also cause? [4]
- pupils widen
- heightens sensitivity
- makes a person more alert
- causes liver to break down glycogen stores to release glucose
What are the main target organs for adrenaline? [4]
- heart
- lungs
- eyes
- liver
How does increasing the breathing and pulse rate increase metabolic activity? [4]
- adrenaline causes heart muscle to contract more and with more force, leading to increased heart and pulse rates
- blood flow to muscles increases and cells receive more oxygen and glucose for increased respiration
- adrenaline causes liver to break down glycogen stores to release glucose
- blood glucose concentrations increase because of this so there’s more glucose in the blood to be transported to the cells
Why do we look pale when frightened? [2]
- blood in skin is diverted to muscles
- blood going away from skin to muscles
What is a cell body? [2]
- where the nucleus is
- controls the neurone
What is a dendrite? [2]
- receives the impulse
- branched to connect with many neurones
What is an axon? [2]
- transmits the impulse away from the cell body
- long so that impulses can travel fast
What is a dendron? [1]
transmits the impulse towards the cell body
What are the nerve endings? [1]
- forms junctions with other cells
What is a myelin sheath? [2]
- insulates the axon to stop electrical impulses leaking away
- speeds up transmission of nerve impulse
What is a sensory neurone? [2]
- carries electrical impulses from receptor cells to CNS
What is a relay neurone? [2]
- carries electrical impulses from a sensory neurone to motor neurone
What is a motor neurone? [2]
- carries electrical impulses from the CNS to effectors
