5.1.5-animal and plant responses Flashcards
what is the nervous system
5.1.5(g)
network of all the neurons in the body
what does the CNS consist of
5.1.5(g)
relay, sensory and motor neurons
what does the PNS consist of
5.1.5(g)
sensory and motor neurons
what is the role of the autonomic nervous system
5.1.5(g)
conducts action potential from the CNS to effector
-involuntary
what is the role of the somatic nervous system
5.1.5(g)
sensory receptor to CNS to muscle
-voluntary
what is the role of the sympathetic nervous system
5.1.5(g)
make involuntary bodily processes more active by increase fight or flight
-increase heart rate/breathing rate, dilates pupils, reduces digestive activity
what is the role of the parasympathetic nervous system
5.1.5(g)
make involuntary bodily processes less active to restore normal physiological functioning
-decreases heart rate/ breathing rate, constricts pupils and increases digestive activity
what is the cerebrum
5.1.5(h)
-has 2 hemispheres connected by the corpus callosum
-controls voluntary movement
-controls conscious thought and actions
what is the cerebellum
5.1.5(h)
controls involuntary movement and balance
-it does this through receiving information from sensory receptors
what is the hypothalamus
5.1.5(h)
controls homeostatic mechanisms
eg-thermoregulation and osmosregulation
-it either releases hormones or stimulates the pituitary gland to release hormones
what is the role of the posterior pituitary gland
5.1.5(h)
stores and release hormones from the hypothalamus eg-ADH
what is the role of the anterior pituitary gland
5.1.5(h)
produces and release hormones in response to releasing factors produced by the hypothalamus eg-FSH
what is the role of the medulla oblongata
5.1.5(h)
regulates function of ANS
eg-breathing and heart rate
label the structures of the brain
5.1.5(h)
in booklet
what is a reflex action
5.1.5(i)
an involuntary response in response to a stimulus.
what are some positives of reflex action
5.1.5(i)
-its fast
-minimises/prevent damage
what type of reflex is the knee-jerk reflex
5.1.5(i)
spinal reflex as it passes through the spinal column
describe the knee-jerk reflex
5.1.5(i)
- Patellar tendon stretches
- stretch receptors detect this
- Sends an impulse to a sensory neuron
- In the spinal cord the sensory neuron transmits this information to a motor neuron
- The motor neuron carries this information back to an effector
- this causes the leg muscles to contract and therefore kick
are there any relay neurons in the knee-jerk reflex
5.1.5(i)
no
this makes it faster as there only one synapse involved
what type of reflex is the blinking reflex
5.1.5(i)
cranial reflex
describe the blinking reflex
5.1.5(i)
- object hits the cornea
- sensory neurons in cornea detect this
- they send an action potential to a sensory to a relay neuron to a motor neuron to the effector which eyelid muscles which then close
what is the difference between a cranial and spinal reflex
5.1.5(i)
cranial reflex- if the relay neuron is found in the brain
spinal reflex-if the relay neuron is found in the spina cord
describe the fight or flight response
5.1.5(j)
- receptors detect a threat
- sensory neurons sends AP to the hypothalamus
- hypothalamus increases activity in sympathetic nervous system and stimulates release or hormones from anterior pituitary gland
- the adrenal medulla is activated causing adrenaline secretion
describe how adrenaline works
5.1.5(j)
- adrenaline is a peptide hormone
- it binds to G-coupled proteins on CSM of target cells
- G-protein activates adenyl cyclase inside cells
- Adenyl cyclase converts ATP into cAMP
- cAMP activates other enzymes that cause cells response to adrenaline
describe the release of hormones from the anterior pituitary gland
5.1.5(j)
hypothalamus secretes releasing factors
the anterior pituitary gland detects this and release tropic hormones into the blood and target cells which are found in endocrine glands
what are the 2 releasing hormones called
5.1.5(j)
corticotropin releasing hormone
thyrotropin releasing hormone
describe the action of corticotropin releasing hormone
5.1.5(j)
- hypothalamus secretes corticotropin releasing hormone
- this causes the release of ACTH
- ACTH binds to receptors on the adrenal cortex
- This causes them to release corticosteriods such as cortisol. Cortiscosteriods also cause gluconeogensis and glycogenolysis
describe the action of thryotropin releasing hormone
5.1.5(j)
- hypothalamus secretes thyrotropin releasing hormone
- This causes release of thyroxine from thyroid gland
- thyroxine binds to target cells and causes metabolic rate to increase.
what are chemoreceptors and where are they located
5.1.5(k)
monitor the pH of the blood
located in the carotid arteries and aorta
what are baroreceptors and where are they located
5.1.5(k)
monitor blood pressure
located in the carotid arteries
what happens if blood pressure or pH is too low
5.1.5(k)
- baro/chemo receptors detect BP or pH change
- sends impulses along the medulla oblongata
- if BP or pH is too low then cardio stimulatory centre is triggered to send impulse via accelerator nerve to SAN to increase HR
- if BP or pH is too high then cardioinhibitory centre is triggered to send an impulse via vagus nerve to SAN to decrease HR
describe the hormonal control of heart rate
5.1.5(k)
cardiac muscles have receptors for adrenaline on there CSM so they can respond to adrenaline directly. Adrenaline causes a increase in the rate of cardiac muscle contraction so heart rate increases.
describe the unpaired t-test
5.1.5(k)
in booklet
what is skeletal muscle
5.1.5(l)
function-to move limbs and contains antagonistic pairs where one contracts and the other relaxes.
structure-multinucleated, tube-shaped and striated