5.1.3 - animal responses

what are the two nervous systems

central nervous system and peripheral nervous system

what is the cns made up of

brain and spinal cord

what is the pns made up of

nerves and neurons

what is the pns split up into

somatic ns and autonomis ns

what does the somatic nervous system control

voluntary activities e.g running

what does the autonomic nervous system control

involuntary activity e.g digestion

what is the autonomic nervous system split up into

the sympathetic and parasympathetic nervous system

what does the sympathetic nervous system do and what enzyme is released

get the body ready for action (fight or flight)

noradrenaline is released

what does the parasympathetic nervous system do and what enzyme is released

get the body to relax (rest and digest)

acetylcholine is released

what is the role of he hypothalamus

-maintains core body temperature

-produces hormones that control the pituitary gland

what is the role of the pituitary gland

it releases hormones which stimulates other glands to release hormones

what is the role of the medulla oblongata

controls breathing rate and heart rate

what is the role of the cerebellum

controls muscle coordination, posture, balance

what is the role of the cerebrum

controls vision, hearing, learning and thinking

what is a reflex

where the body responds to a stimulus without making a conscious decision to respond

what is the role of the knee-jerk reflex

to quickly straighten your leg if the quadricep is suddenly stretched

how does the knee jerk reflex work

-stretch receptors in the quadricep muscle detect that the muscle is being stretched

-a nerve impulse is sent alone a sensory neurone which directly communicates with a motor neurone in the spinal cord

-the motor neurone carries the impulse to the effector causing it to quickly contract so the lower leg quickly moves forward

which types of neurons are in the cns

sensory, relay, motor

which type of neurones are in the pns

sensory and motor

what are the two parts of the pituitary gland

anterior and posterior

what does the anterior pituitary gland do

produces and releases hormones

what does the posterior pituitary gland do

stores and release hormones from the hypothalamus

why do animals need to respond to their environment

to protect themself from harm

what are the effects of adrenaline being released

-increased heart rate

-glycogenolysis

-vasoconstriction of vessels to unvital organs

-erector pilli muscles contract

how does the nervous system control heart rate

-san generates electrical impulses causing cardiac muscle to contract

-rate of san beat controlled by medulla

-baroreceptors (detect changes in pressure)

-chemoreceptors (monitor oxygen levels, pH, carbon dioxide levels)

-electrical impulses send to medulla via sensory neurones where information is processed

what processes occur when there is high blood pressure

-detected by baroreceptors

-impulse sent to medulla

-medulla sends impulse along vagus nerve

-acetylcholine released

-acth binds to receptors on san

what processes occur when there is low blood pressure

-detected by baroreceptors

-impulse sent to medulla

-medulla sends impulse along accelerator nerve

-noradrenaline released

-binds to receptors on san

what processes occur when there are high blood o2/low co2 levels

-detected by chemoreceptors

-impulse sent to medulla

-medulla sends impulse along vagus nerve

-acetylcholine released

-binds to receptors on san

what processes occur when there are low blood o2/high co2 levels

-detected by chemoreceptors

-impulse sent to medulla

-medulla sends impulse along accelerator nerve

-noradrenaline released

-binds to receptors on san

which neurotransmitter is released along the vagus nerve

acetylcholine

which neurotransmitter is released along the accelerator nerve

noradrenaline

why is it important for plants to respond to their environment

-to avoid abiotic stress

-to maximise photosynthesis

-to avoid herbivory

-help ensure germination/fertilisation

what is phototropism

a plants growth response to light

how does the blinking reflex occur

when the cornea is stimulated by touch, loud noise or bright light, the eyelid closes to prevent anything from entering the eye

why are reflexes important for survival

-involuntary

-don’t have to be learned

-very fast as reflex arc is short