WEEK 5 Flashcards
define the autonomic nervous system
component of the peripheral system that regulates involuntary physiologic processes including heart rate, blood pressure
what is the role of the hypothalamus
highest centre in the brain
- controls the autonomic nervous system
what is a ganglia vs ganglions
ganglia= several ganglions
ganglion= bunch of nerve cell bodies
describe the sympathetic nervous system ( origin of fibres, length of fibres and location of ganglia)
origin of fibres= thoracolumbar region of the spinal cord
length of fibres= short preganglionic and long postganglionic
location of ganglia= close to spinal cord
describe the parasympathetic nervous system ( origin of fibres, length off fibres and location of ganglia)
origin= brain and sacral spinal cord
length = long pregnaglionic and short postganglionic
location of ganglia= in visceral effector organs
define the sympathetic nervous system and give three organ examples on the effects of sympathetic discharge
mobilises the body during fight or flight
skin= vasoconstriction
sweat glands= secretion
eye= dilated pupil
define the parasympathetic nervous system and give 3 organ examples on the effect of parasympathetic discharge
promotes maintenance activities and conserves bodies energy for “rest” or “digest”
organ examples:
heart- decreased heart rate
lung= constricts bronchioles
gut= relax sphincter’s
what is noradrenaline
post ganglionic neuron will release the neurotransmitter when being stressed during an exam
what are muscarinic receptors
activation of these receptors will occur after lunch in the digestive system
what are preganglionic neurons
neuron will release any acetylcholine
what is acetylcholine
when having a rest, this type of neurotransmitter will be released by both pre and post ganglionic neurons
define a reflex
involuntary, fast and automatic response to a specific sensory stimulus
what does areflexia mean
absence of reflexes
what does hyperrelfexia mean
increased or overreactive reflexes
what is hyporeflexia
decreased reflexes
what does innate mean for reflexes
basic neural reflexes, formed before birth and disappear with age
what does acquired reflex mean
rapid, automatic and learned motor patterns
what does visceral reflex mean
autonomic such as control of heart rate
what does somatic reflex mean
stretch such as patellar reflex
what does cranial reflex mean
involving brain only integration centre
what does mono reflex mean
one synapse involved in the patellar reflex
what does post synaptic reflex mean
crossed extensor reflex or withdrawal reflex
what does the reflex arc consist of ( x5) and describe them
1= sensory receptor- activated in response to stimulus
2= sensory neuron- conducts impulses form receptor
3= integrating center- one or more regions within the CNS that relay impulses
4= motor neuron- neuron conducting impulses from integrating centre to effector
5= effector- muscle or gland that responds to motor nerve impulses
what are the 4 different types of spinal reflexes
1- stretch= monitors muscle length
2- tendon= monitors external tension produced during muscular contraction
3- flexor or withdrawal reflex= when pain receptors are activated it causes automatic withdrawal of threatened body part
4- closed extensor reflex= complex reflex consisting of ipsilateral withdrawal and contralateral extensor reflex.
describe neurogenesis, neural proliferation and migration folding ( stage 1 of age changes in nervous system)
neurogenesis starts at 3 weeks in the utero
neural tube develops into brain vesicles
week 12 = gradual thickening of cortex and formation of cortical layers
describe neural connectivity and myelination ( phase 2 of age changes in the nervous system)
starting in utero and begins to develop after birth
20 weeks= direct contact between cortex and CNS
myelination= commences from end of third month continues all through childhood
head control first, standing and walking
describe synaptogenesis and synaptic pruning ( stage 3 of age affecting nervous system)
- immature synapses form in the nervous system
- synaptic pruning= process of synapse elimination, completed by sexual maturation
brain increases in size reaching adult volume
what are some of the effects on the nervous system while ageing
- reduction in biochemical activity
- reduced number of receptors
- loss of memory
