sensory Flashcards
what is the autonomic nervous system
conveys involuntary and automatic commands that control internal organs and glands
what is the somatic nervous system
conveys information into and out of the central nervous system; voluntary movements of skeletal muscles
what are the three layers of the meninges
dura mater (outer)
arachnoid membrane
pia mater (inner)
what is another name for the forebrain
prosencephalon
what is another name for the midbrain
mesencephalon
what is another name for the hindbrain
rhombencephalon
name the two parts of the rhombencephalon
metencephalon and myelencephalon
name the two parts of the prosencephalon
telencephalon and diencephalon
what is the function of the spinal cord
- Neuronal link between brain and PNS
- intergrating center for spinal reflexes
what is the ventricular system
a network of interconnected, fluid-filled cavities in the brain that produce, circulate, and regulate cerebrospinal fluid (CSF).
what is a doral root
afferent senory
what is a ventral root
efferent motor
what is in the myelencephalon
medulla oblongata (most caudal part of brainstem)
what is the function of the myelencephalon
It contains nuclei that control
vital functions such as control of
breathing and skeletal muscle tone
.
what is in the metencephalon
cerebellum and pons
what is the function of the cerebellum
Receives information from sensory systems, the muscles, and the vestibular system
It co-ordinates this information to produce smooth movements
what is the function of the pons
sleep and arousal
what is in the mesencephalon
red nucleus, periaqueductal grey matter and substantia nigra
what is the function of the red nucleus
coordinates sensorimotor information
what is the function of the substantia nigra
cells make dopamine and project to basal ganglia
what is the function of periaqueductal grey matter
involved in pain suppression due to
naturally high concentrations of endorphins.
what is in the diencephalon
thalamus and hypothalamus
what is the function of the thalamus
Separate but interconnected nuclei receive information from the sensory systems and relay this information to
sensory processing areas in the cortex.
(relay system)
what is the function of the hypothalamus
These control the autonomic nervous system and the endocrine system.
including feeding, sex, sleep,
temperature regulation, and emotional behaviour.
what are the hemispheres separted by
the longitudinal fissure.
what is in the telencephalon
cerebrum
what connects the left and right hemispheres
a bundle of nerve fibres called the corpus callosum.
how are neurons able to respond to various stimuli
by altering electrical charge across their membran
Interior of cell has a relative negative net charge in
comparison to outside of the cell due to ______________
due to ionic composition of
cytoplasm vs extracellular fluid
what is the membrane potential for the equilibrium potential for K+(Ek+)
Ek+ = 61(-1.477) = -90mV
what is nernst equation
Electrical potential required to oppose movement of ion (x) across a freely permeable membrane
* Provides a measure of the chemical driving potential established by the concentration gradient for ion (x)
what is the equilibrium potential for Na+
Ena+ =61(1) - 61mV
what is goldman equation used for
to find resting membrane potential
what is depolarization
decrease in potential and membrane less negative
what is repolarization
return to resting potential after depolarization
what is hyperpolarization
increase in potential and membrane more negative
what is gating
the transition betwen states in an ion channel
name the types of ion channels
voltage -gated
ligand-gated (extracellular ligand)
ligand gated (intracellular ligand)
mechanically gated
why is there a central porre in ion channles
so ions can diffuse
why are there polar amino acids in ion channels
for forming a selective filter
what is the function of the peripheral nervous system
a) Detect external and internal stimuli—sensory systems
b) Process and integrate different types of information and make relevant decisions—higher brain regions
c) Execute decisions—motor system
what are the two types of general senses
visceral afferent and somatic sensory
what is the visceral afferent senses
Incoming information from internal viscera
what is the somatic sensory
afferents Sensation from body surface and proprioception
what are the modalities of the sensory system
Visual system
somatosensory system
auditory system
olfactory system
gustatory system
what is a sesnory receptor
structures at peripheral endings of afferent neurons
what are vision receptors
photoreceptors
what are taste and smell receptors
chemoreceptors
what are temperature receptors
thermoreceptors
what are mechanoreceptors
touch, balance, proprioception and hearing receptors
what are pain receptors
nociceptors
what is transduction
The process of converting energy forms into electrical signals via a receptor/generator potential which triggers an action potential if it is large enough to reach threshold.
what are the stages of transduction in specialized afferent nerve endings
- stimulus opens stimulus-sensitive channels, permitting net Na+ entry that produced receptor potential
- ….
what are the stages of transduction in separate sensory receptors
how do you detect the quality of stimulus
- The frequency of AP transmitted down the afferent fiber
- The number of sensory receptors activated (higher number of cells activated)
what is The receptive field of a sensory neuron
a region of space in which the presence of a stimulus will alter the firing of that neuron. This region can be a hair in the cochlea
or a piece of skin etc
what is adaptation
A change in sensitivity in the receptor cell to a long-lasting stimulus
what are PHASIC receptors
rapidly adapting receptors that adapt to a constant stimulus
e.g. Pressure, touch, hearing, smell
what are TONIC receptors
slow-adapting receptors that respond for the duration of the stimulus
e.g. Pain, proprioception, chemicals in the blood or CSF
(the body needs to make continuous
responses to that kind of information, or because the stimulus needs to be constantly evaluated)
describe the receptor signal of phasic receptors
signals change in stimulus intensity (differential receptors)
describe the receptor signals of tonic receptors
continous flow of information about stimulus (proportional receptors)
what is a menchanical adaptation mechanism
induces the decrease in the response of a receptor neuron (specialized receptor endings in Pacinian cells of the skin)
what is a chemical adaptation mechanism
Membrane enzymes or intracellular signalling mechanisms induce response termination (common in olfactory responses)
what is mechanical adaptation for phasic receptors
Specialized receptor ending of concentric layers of connective tissue (onion-like).
Sustained pressure causes layers to slip, dissipating stimulus intensity
what is chemical adaptation in phasic receptors
depolarization of membrane
Ca2+ binding calmodulin decreases the activity of CNGC
what is the sequence of transduction
stimulus–>receptor–>receptor potential……
what is the Somatosensory System
The neural sense concerned with sensations from the body
* Cutaneous (Skin) sensations
* Visceral (internal organs and deep tissues)
* Proprioception
where is the primary visual cortex
occipital lobe
where is the primary somatosensory cortex
post-central sulcus
what is stimulated by paina nd heat
bare nerve endings
what is meissner corpuscle
respond to touch; are thought to be responsible for fine & discriminative touch in glabrous skin
what are merkels’ disks receptors
fiber connected to an epithelium-like cell
what is pacinian corpuscle
phasic receptor detecting vibration
what is ruffini’s ending
tonic touch receptor
