BIOL exam review Flashcards
anatomy of the cerebellum (inc. fissures and lobes)
2 fissures are horizontal and primary; 3 lobes are anterior, posterior, and flocculonodular; foldings are called folia; and arbor vitae is the tree structure
superior cerebellar peduncle
projects to the red thalamus and the thalamus
middle cerebellar peduncle
carries information from the voluntary nucleus to the pontine nucleus
inferior cerebellar peduncle
carries information for balance and equilibrium
what in the hypothalamus regulates sleep?
the suprachiasmatic nucleus
what are the falx?
extensions of dura mater
where is the primary gustatory centre?
located in the insular lobe
where is the primary auditory centre?
located below the gustatory centre in the superior temporal lobe or sylvian fissure
anatomy of dura mater
dense irregular CT
process of CSF reabsorption name
arachnoid granulation
RAS anatomy
white and grey matter arranged in a net and includes ascending and descending tracts
3 nuclei of the RAS
lateral, medial, and raphe
functions of the RAS
behaviour, consciousness, falling asleep, waking up, and preventing sensory overload
cerebral peduncles
are extensions of the corticospinal tract and connect the cerebrum to the lower CNS; located in the ventral midbrain and pons
where is the hypothalamus located?
anterior to the thalamus
pons functions
respiration (via pneumotaxic and apneustic centres), connection between the cerebellum, and pontine nucleus
pontine nucleus
functions for the coordination of voluntary motor control
CSF composition
water, solutes (Na, K, Ca, Mg), lactic acid, glucose, urea, proteins, and sometimes WBCs
functions of CSF
protection, buoyancy, removal of waste, nourishment, and homeostasis via hormones from the hypothalamus
inferior olivary nuclei
relay sensory information from muscles and joints to the cerebellum
olives in medulla
contains many nuclei including inferior olivary, respiratory, cardiovascular, sneezing, vomiting, and coughing
what do somites develop into?
the dermis, skeletal muscle, and the axial skeleton
what does the neural crest develop into?
the PNS
what does the notochord develop into?
the nucleus pulposus of the vertebrae
what is the neural plate derived from?
the ectoderm
notochord
is derived from the mesoderm and is a cartilage rod in embryos
anatomy of ependymal cells
cuboidal with cilia
where is the tectum reflex located?
the midbrain
function of posterior and anterior lobes of the cerebellum
subconscious control of skeletal muscle
function of flocculonodular lobe
balance and equilibrium
are peduncles white or grey matter?
white
parietal lobe functions
touch, taste, and smell
Lateral cerebral sulcus
divides frontal and temporal lobes from the parietal lobe
straight sinus
at the bottom of the skull and receives blood from the inferior sagittal sinus that will later be returned to venous blood supply
strong acid + weak base
HCl + NaHCO3 > NaCl + H2CO3
strong base + weak acid
NaOH + H2CO3 > NaHCO3 + H20
relaxed bladder
motor neurons are firing, detrusor muscle is relaxed, and sphincter are contracted
full bladder
motor neurons stop firing and stretch receptors fire, detrusor muscle is contracted, and sphincters are relaxed
what cells does ADH act on?
principal cells, specifically binds to V2 receptors
what does aldosterone bind to?
mineralocorticoid receptors in the cytoplasm
what is aldosterone produced by?
the adrenal cortex
what does H+ buffer with in the urine?
NH3 and HPO4–, forming NH4+ and H2PO4-
hormones released when calcium is low
PTH and calcitriol
hormone released when calcium is high
calcitonin
where are proton pumps found?
intercalated cells in the CD
what does ANG II bind to?
AT1 receptors
renal capsule anatomy
innermost layer and is fibrous, irregular CT
renal fascia anatomy
outermost layer and is dense irregular CT and collagen
3 layers of the ureters
transitional epithelium with lamina propria, 2 layers of muscularis, and adventitia
adventitia anatomy
fibrous irregular CT
bladder 3 layers
transitional epithelium with lamina propria, goblet cells, and rugae, muscularis which is 3 layers of detrusor, and adventitia or serosa (only superior region)
urethra epithelium
transitional near top, pseudostratified columnar in middle, and nonkeratinized stratified squamous at bottom
macula densa cells function and locaton
are chemoreceptors that respond to NaCl concentration are are found lining the ascending limb
mesangial cells function and location
send signals between MD and JG cells and control HSP via contractile abilities and are found between the tubule cells and the arterioles
JG cells function and location
are mechanoreceptors that sense BP and contract and/or release renin and are found lining the afferent arteriole
general vs special senses
general senses have their cells distributed throughout the body whereas special senses have an organ devoted to them, ex. the ear
somatic sense
detect mechanical stimuli and are all tactile senses (touch), pain, and proprioception
visceral sense
are conscious/subconsciousness awareness of visceral organs, ex. blood pressure
first order neurons
receive sensory information from sensory receptors are there are three types (free nerve endings, encapsulated endings, and specialized receptor cells)
second order neurons
synapse with FON in the dorsal horn or medullary nuclei and extend up to the thalamus or cerebellum to synapse with TON
third order neurons
synapse with SON in the thalamus and extend to the postcentral gyrus in the primary somatosensory area
where does the gracile fasciculus receive input from?
the lower limbs
where does the cuneate fasciculus receive input from?
the upper limbs
dorsal column medial lemniscus pathway
FON will travel from the sensory receptor to the spinal cord and up the gracile or cuneate ascending pathway; it will synapse with the SON in the gracile or cuneate nucleus of the medulla and then immediately decussate; this will synapse with the TON in the thalamus and extend up to the primary somatosensory area in the postcentral gyrus
free-nerve endings
dendrites will detect the stimulus directly and these are abundant in epithelia and CT; associated with pain, temperature, and light touch
encapsulated endings
dendrites are wrapped in a specialized CT and these are associated with mechanical stimuli like pressure and vibration; ex. meissner’s corpuscles and pacinian corpuscles
specialised-receptor cells
FON interacts with a neurotransmitter released by a specialised receptor cell; usually is associated with the special senses
proprioceptor
sensory receptors that respond to stretch in muscles, ligaments, tendons, etc. and inform the brain of one’s movement
adaptation
refers to how quickly you become acclimated to a stimulus when it is sustained; types are rapidly adapting and slow adapting
basal nuclei
group of CNS neurons that are involved in emotion and habitual behaviour; includes the caudate nucleus and the putamen
examples of direct pathways
anterior and lateral corticospinal tracts; UMNs synapse directly with LMNs
lateral corticospinal tract
decussates and controls fine, precise movements of the digits
anterior corticospinal tract
does not decussate and controls posture and balance in the axial muscles
3 main differences between sympathetic and parasympathetic systems
their origin sites, the length of their fibres, and the location of their ganglia
origin site of parasympathetic system
brain and sacral spinal cord, hence crainosacral
origin site of sympathetic system
thoracic and lumbar vertebrae, hence thoracolumbar
length of parasympathetic fibres
long preganglionic and short postganglionic
length of sympathetic fibres
short preganglionic and long postganglionic
location of ganglia for parasympathetic system
near their effector
location of ganglia for sympathetic system
near the spinal cord, forming the sympathetic trunk
preganglionic fibres
cell body is located in the CNS and axon is myelinated
postganglionic fibres
cell body is located in PNS and axon is unmyelinated
thoracolumbar region landmarks
T1-L2
3 splanic nerves and function
greater, lesser, and lumbar; these innervate the celiac plexus to inhibit digestion
ventral ramus
is one of the two primary branches exiting the spinal nerve and further breaks down into white and grey rami communicantes
white ramus communicantes
carries the preganglionic fibre that is myelinated to synapse with the post in the sympathetic trunk
grey ramus communicantes
carries the postganglionic fibres that is unmyelinated after it synapses with the pre in the sympathetic trunk
sympathetic trunk
is a chain of sympathetic ganglia lying on either side of the spinal cord
passing through the trunk without synapsing
the preganglionic nerve will travel through additional branches to the splanic nerve to synapse in a distant collateral ganglion; associated with controlling organs in the abdominal cavity
visceral reflex
has the same components as a normal reflex arc but the effector is a viscera and there is a pre and post nerve
two types of general senses
somatic senses and visceral senses
components of tears
water, saline, lysozyme, antibodies, and mucus
cornea composition
stratified squamous on one side and simple squamous on the other side; Na pumps keep inside clear; nerve endings are abundant here
retinal in the presence of light
takes the all-trans shape
trochlea
is the fibrocartilaginous ring that the tendon of the superior oblique muscle hooks through
ora serrata
is the point where the retina terminates into the posterior ciliary body
where does aqueous humor come from?
capillaries of ciliary bodies
where is aqueous humor drained from?
scleral venous sinus
retinal
is a vitamin A derived molecule and part of the rhodopsin complex; can take 11-cis or all-trans shape
PDE
phosphodiesterase
phototransduction in the photoreceptor simple
light presence causes retinal to take all-trans shape, releasing G protein transducin; this binds to PDE which converts cGMP to GMP; this causes the cation gates to close and for the cell to hyperpolarize and for no neurotransmitter to be released
visual pathway G protein name
transducin
olfactory epithelium
is pseudostratified ciliated (nonmotile) epithelium; mucus secreting columnar cells and basal cells are also present
what is superior to the olfactory epithelium?
the cribriform plate of the ethmoid bone and mitral cells
olfactory G-protein pathway simple
odorant binding to a receptor releasing G protein Golf; this binds to adenylate cyclase; this converts ATP to Camp; this causes cation channels to open and for depolarization to occur
most abundant papillae
fungiform
foliate papillae
found on the lateral sides of the tongue
two main cells for taste
gustatory cells and basal cells
cranial nerves for taste
facial is responsible for the first 2/3 of the tongue; glossopharyngeal is posterior 1/3; vagus is epiglottis
gustatory pathway for salty and sour
Na+ and H+ ions simply move into channels and cause a depolarization of the membrane, firing an AP
gustatory pathway for sweet, bitter, and umami
tastant molecule binds to a receptor, releasing G protein gustducin; this binds to phospholipase C; this causes IP3 to causes Ca+ intracellular stores to be released, causing a depolarization and an AP
where do vibrations travel through in the cochlea?
first the scala vestibuli then the scala tympani; at the scala tympani, the vibrations are transmitted to the basilar membrane which vibrates against the stationary tectorial membrane, causing the hair cells to bend
organ of corti
is located within the cochlea and transmits sound vibrations into electrical signals through the cranial nerve VIII
what are the name of hair cells in the organ of corti?
stereocilia
organ of corti, which membrane is moving and which is stationary?
the basilar membrane is moving and the tectorial membrane is stationary
semicircular canals
detect rotational acceleration along 3 axis
what are otoliths?
CaCO3 crystals embedded in gel at the tips of stereocilia
urticle
detects horizontal movement
saccule
detects vertical movement
temporal vs nasal sides in the visual pathway
nasal decussates whereas temporal does not
visual pathway synapses
FON will synapse with the SON in the thalamus and project to occipital lobe; decussation occurs for nasal side only
olfactory pathway synapses
FON will synapse with SON (mitral cell) and extend to the primary olfactory centre; no decussation occurs
gustatory pathway synapses
FON synapses with SON in the gustatory nucleus in the medulla; SON synapses with TON in the thalamus; TON extends to primary somatosensory region; no decussation occurs
auditory pathway synapses
FON will synapse with SON in the lower pons (decussation may occur here); SON synapses with TON in the upper pons; TON extends to inferior colliculi of the midbrain to synapse with another neuron; this neuron synapses with another neuron in the thalamus which extends to the primary somatosensory region
