Quizlet - Midterm Flashcards
Define the division of the brain created by the:
Saggital Plane
Right from Left
Define the division of the brain created by the:
Dorsal Plane
Dorsal from Ventral
Define the division of the brain created by the:
Coronal Plane
Rostral from Caudal
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Telencephalon
REGION –> Cerebral hemispheres
LUMEN –> Lateral ventricles (First & Second)
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Diencephalon
REGION –> Thalamus & Hypothalamus
LUMEN –> Third ventricle
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Mesencephalon
REGION –> Midbrain
LUMEN –> Aqueduct
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Metencephalon
REGION –> Pons & Cerebellum
LUMEN –> Fourth ventricle
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Myelencephalon
REGION –> Medulla
LUMEN –>Fourth ventricle
Name the regions that make up the following division of the brain, along with the associated ventricular lumen(s):
Spinal cord
REGION –> Spinal cord
LUMEN –>Central canal
Along the brain, the major blood vessels (and the CSF) travel in what space?
Subarachnoid space
List the layers of the brain from thick outer layer to thin inner layer.
Dura mater –>
Arachnoid mater –>
Subarachnoid space –>
Pia mater
T/F: White matter is made primarily of cell bodies.
FALSE
Axons, NOT cell bodies.
What is the difference between afferent and efferent?
Afferent –> axons Approaching brain
Efferent –> axons Exiting brain
Define “commisure”.
Axon bundle that crosses the midline.
Define “nucleus”.
Group of nerve cell bodies in the CNS (same as ganglion in the PNS).
In the spinal cord which type of neurons are in the dorsal horn, and which are in the ventral horn?
DORSAL –> Sensory (afferent)
VENTRAL –> Motor (efferent)
Brainstem usually refers to…?
Medulla, Pons, Midbrain, & Diencephalon
The cerebellum is an outgrowth of which major brain division?
Metencephalon
Which cranial nerves originate from the medulla?
CN VI & CN XII
Name three major features seen on the ventral surface of the medulla.
Pyramids, Trapezoid Body, & Caudal Olive
What is the reticular formation?
The vast middle portion of the medulla that extends from the medulla to the midbrain. This area can be thought of as a general system for receiving sensory input and crude motor output.
What cranial nerve originates from the pons?
CN V
What cranial nerves originate from the midbrain?
CN III & CN IV
Which major division of the mammalian brain is the largest, and continues to grow longer than the other regions?
Telencephalon
What separates the diencephalon from the subcortical telencephalon?
Rostral Commisure
What cranial nerve originates from the telencephalon?
CN I
What acts as a major neural highway in providing communication between the telencephalon and other brain regions?
Internal Capsule
T/F: Regions where there are fewer neurons and sparser connections remain thin and lie in the depth of the sulci.
TRUE
T/F: Lissencephalic means the brain is generally ungyrated. This isn’t found in any mammal.
FALSE
Common in most rodents, insectivores, bats, and manatees.
For each of the following regions of the neocortex, name the primary function/types of associated nerves:
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
Frontal –> motor cortex
Parietal –> somatosensory
Occipital –> visual
Temporal –> auditory
Between pyramidal neurons and non-pyramidal neurons, which are excitatory and which are inhibitory? Which act over distance, and which act in the immediate vicinity?
Pyramidal –> excitory; travel
Non-pyramidal –> inhibitory; immediate vicinity
The hippocampus has its own white matter bundle that contains axons entering and leaving. What is this bundle called?
Fornix
Axons from one hippocampus that cross to the other hemisphere comprise the ________________, which is the hippocampal version of the corpus callosum.
Hippocampal Commisure
What is a functional difference between grid cells and place cells?
Grid cells lay out a coordinate system for navigation whereas place cells construct a detailed map of specific locations.
Short-term memory is stored in the __________, whereas long-term memory is stored in the _________.
Hippocampus;
Cerebral Cortex
The pyriform lobe contains areas devoted to processing what kind of information?
Olfactory
The amygdala is associated with which primal emotion?
Fear
Which cranial nerves are solely sensory? (there are 3)
CN I (Olfactory) CN II (Optic) CN VIII (Vestibulocochlear)
Which cranial nerves are solely motor? (there are 5)
CN III (Oculomotor) CN IV (Trochlear) CN VI (Abducent) CN XI (Accessory) CN XII (Hypoglossal)
Which cranial nerves are a mixture of both sensory and motor? (there are 4)
CN V (Trigeminal) CN VII (Facial) CN IX (Glossopharyngeal) CN X (Vagus)
What is the difference between “somatic” and “visceral” nerves?
Somatic –> skeletal muscle
Visceral –> smooth muscle and glands
Remember the neural tube with the alar plate, basal plate, and sulcus limitans. From dorsal to ventral, name the order of the four types of nerves that pass through this tube.
Somatic Sensory –>
Visceral Sensory –>
Visceral Motor –>
Somatic Motor
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN I
- Olfactory Nerve
- Sensory
- Innervates olfactory receptor neurons in the nasal cavity; is responsible for scent.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN II
- Optic Nerve
- Sensory
- Innervates the retinas of the eyes; is responsible for sight.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN III
- Oculomotor
- Motor
- Innervates the dorsal rectus, ventral rectus, medial rectus, ventral oblique, and the levator palpebrae muscles; is responsible for movement and coordination of the eyes.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN IV
- Trochlear
- Motor
- Innervates the dorsal oblique muscle of the eye; is responsible for movement and coordination of the eyes.
- *is the only cranial nerve to exit the brainstem from the dorsal surface.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN V
- Trigeminal
- Both
- SENSORY: innervates the face and most of the internal surface of the nasal and oral cavities. Is the main sensory nerve of the face.
- MOTOR: innervates the muscles of mastication; is responsible for chewing.
- BOTH: only fibers of the Mandibular Branch are both.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN VI
- Abducent
- Motor
- Innervates the lateral rectus and retractor bulbi muscles; is responsible for movement and coordination of the eye.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN VII
- Facial
- Both
- SENSORY: innervates the neuroepithelial cells of the taste buds on the anterior 2/3 of the tongue, as well as a small portion of skin around the concha of the external ear.
- MOTOR: innervates muscles of facial expression, of jaw-opening, the hard and soft palate, the lacrimal glands, the submandibular glands, and sublingual glands.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN VIII
- Vestibulocochlear
- Sensory
- Innervates the cells of the cochlea; is responsible for hearing.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN IX
- Glossopharyngeal
- Both
- SENSORY: innervates the viscera of the posterior tongue and pharynx, and is responsible for taste from the posterior 1/3 of the tongue.
- MOTOR: innervates the muscles of swallowing and vocalization, and stimulates the parotid salivary gland.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN X
- Vagus
- Both
- SENSORY: innervates taste bud receptors on the epiglottis, carry visceral sensation from the pharynx and larynx, and innervate the pain receptors of the ear.
- MOTOR: innervates the palate, pharynx, larynx, and cervical esophagus muscles, as well as the intrinsic postganglionic neurons of the thoracic and abdominal viscera.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN XI
- Accessory (aka Spinal Accessory)
- Motor
- Innervates the trapezius, sternocephalicus, and brachiocephalicus muscles.
For the following cranial nerve list its name, sensory/motor/both, and what it is responsible for:
CN XII
- Hypoglossal
- Motor
- Innervates the extrinsic, intrinsic, and geniohyoideus of the ipsilateral tongue.
What are the three basic types of glia?
- Astrocytes
- Microglia
- Oligodendrocytes/Schwann cells
Where in the neuron is the action potential generated?
Axon Hillock
Where are interneurons typically found?
In the CNS.
Usually are confined to the vicinity of their cell body, interneurons are best-suited for traveling from one brain region to another.
Compared to normal cells, neurons have a (higher/lower) number of ribosomes and rER.
Higher
Name three functions the cytoskeletal components in neurons.
- Gross morphology
- Positioning of proteins (for APs)
- Neurotransmitter release
- Positioning of membrane-bound organelles
- Scaffolding for axonal transport
What is anterograde axoplasmic transport and how is it different from retrograde axoplasmic transport?
Axoplasmic transport is the movement of vesicles, lysozomes, mitochondria, or proteins along the microtubules lining the axon of a neuron.
Anterograde –> AWAY from the cell body
Retrograde –> TOWARDS the cell body
T/F: Viruses and toxins can use retrograde axoplasmic transport to enter the CNS from the periphery.
TRUE
In a synapse, the presynaptic side contains _______________ which are released to match with the _____________ on the postsynaptic side.
Vesicles filled with neurotransmitters;
Neurotransmitter receptor proteins
The lamina of the spinal cord is divided into how many layers?
10
Peripheral information enters the spinal cord through which root and associated horn?
Dorsal root & Dorsal horn
The ventral horn and intermediate zone contain the cell bodies of ___________.
Motor neurons
From outside to inside, name the three protective sheathes that cover the individual axons in a nerve.
Epineurium –>
Perineurium –>
Endoneurium
T/F: Both the brain and the spinal cord have the same organization of white matter on the outside and gray matter on the inside.
FALSE
Brain –> gray outside, white inside
Spine –> white outside, gray inside
Name some differences of glial cells from regular neurons.
- Do not form synapses
- Are electrically inexcitable (= no APs)
- Can readily divide
- Are as numerous as neurons
What are the major functions of astrocytes?
- Provide a structural matrix that contributes to both the blood-brain barrier and the glia limitans.
- Are involved in homeostasis.
- Clean-up excess neurotransmitters from synapses.
What are two main differences between Schwann cells and oligodendrocytes?
Schwann Cells
- Only in the PNS
- 1 cell = 1 myelin segment on 1 axon
Oligodendrocytes
- Only in the CNS
- 1 cell = multiple myelin segments on multiple axons.
T/F: Schwann cells also act like CNS glial cells.
TRUE
What is a node of Ranvier, and what is an internode?
A node of Ranvier is the gap between two myelin sheathes on an axon. An internode is the space between two nodes of Ranvier, including the myelin.
What is the main function of mircoglia?
Microglia serve as the macrophages of nervous tissue, being activated after injury or infection.
Name some functions of ependymal cells.
- Line the ventricular system
- Help circulate CSF via cilia
- Choroid Plexus cells are specialized ependymal cells that produce/secrete CSF.
What are the three layers of the cerebellum?
From outside to inside:
Molecular layer –>
Purkinje cell layer –>
Granule cell layer
What histological structure contains the input cells of the hippocampus?
Dentate Gyrus
In older horses, ______________ may accumulate in the choroid plexus due to chronic bleeding.
Cholesterol crystals
Define cranioschisis.
A malformation of the brain and/or skull.
What is the difference between meningocele, meningoencephalocele, and exencephaly? (apart from obnoxious spelling)
Meningocele = meninges + skin Meningoencephalocele = meninges + skin + brain tissue Exencephaly = meninges + brain tissue
Dicephalus is most often seen in what species?
Bovine
What is/causes prosencephalic hypoplasia?
A partial failure of the outpocketing of the telecephalon from the neural tube causes a malformation in the cerebral cortex where it is either underdeveloped or absent.
List the characteristics and likely causes of the malformation known as hydrancephaly.
- Cererbal neocortex is missing
- Hippocampus, pyriform lobe, and basal ganglia may be present.
- Usually due to viral infection during critical period for neurogenesis.
In calves, what disease is most commonly responsible for cerebellar malformations?
BVD - Bovine Virus Diarrhea virus
The double cortex malformation gene (DCX) is x-linked. What does this mean for each sex?
- Females can have x-inactivation which causes two populations of neurons.
- Males exhibit Type 1 lissencephaly.
- Both sexes experience seizures.
A malformation characterized by incomplete bilateralization of the hemispheres, accompanied by facial dysmorphologies is called…?
Holoprosencephaly
Protein-mediated transport is (faster/slower) than simple diffusion.
Faster
T/F: Facilitated transport does not expend ATP and moves ions against a gradient.
FALSE
Facilitated transport does NOT move ions against a gradient.
For the following ions, are their concentrations highest intracellularly or extracellularly?
- Sodium (Na)
- Potassium (K)
- Chloride (Cl)
Sodium –> Extracellularly
Potassium –> Intracellularly
Chloride –> Extracellularly
T/F: Roughly 2/3 of a neuron’s ATP budget is spent on the Na/K antiporter.
TRUE
T/F: Ion transports are specific to one ion.
TRUE
In the Na/K antiporter, how many sodium ions are being moved (and where), and how many potassium ions are being moved (and where)?
3 Na are pumped extracellularly
2 K are pumped intracellularly
What is the main function of the Chloride-bicarbonate antiporter?
Prevents cytosol from becoming too basic.
What are two ways by which transmembrane channels are activated/inhibited?
- Voltage
- Ligands
Describe the effects of ketamine.
- A dissociative anesthetic
- Blocks ion channels for Na and Ca
- As a result, no APs can generate
Which portion of a phospholipid is hydrophobic and which is hydrophyllic?
Head –> Hydrophyllic
Tails –> Hydrophobic
For the following categories of molecules, describe whether or not they are able to diffuse through a lipid bilayer unaided.
- Hydrophobic molecules
- Small, uncharged, polar molecules
- Large, uncharged, polar molecules
- Ions
Hydrophobic molecule –> YES
Small, uncharged, polar molecules –> YES
Large, uncharged, polar molecules –> NO
Ions –> NO
What three factors influence the movement of ions across a membrane?
- Concentration gradient
- Electrical gradient
- Permeability
Electrochemical equilibrium is defined as:
Concentration gradient
Electrical gradient
What is the average RMP (resting membrane potential) of a cell?
Roughly -70 to -90.
Remembering Physics (noooo!!!), what is capacitance?
Capacitance is the ability of an object or surface to maintain/hold a charge.
Define threshold.
Threshold: the membrane voltage at which the AP is initiated.
In the order of occurrence, name the types of polarization that occur in an AP.
Depolarization –>
Repolarization –>
Hyperpolarization
What is a difference between “absolute” refractory period and “relative” refractory period?
The absolute refractory period occurs first, and is when another AP cannot occur. This prevents the AP from backfiring and going both directions along an axon.
The relative refractory period occurs immediately after the absolute refractory period. While it is no longer impossible for an AP to occur, it is still more difficult than during a resting state.
The larger the diameter, the (higher/lower) the resistance.
Lower
Name the three major pathways of blood to the brain.
- Internal carotid artery
- Maxillary artery
- Basilar artery
Name the five major vessels that branch off of the Circle of Willis
- Rostral cerebral arteries
- Middle cerebral arteries (**the largest)
- Caudal cerebral arteries
- Rostral cerebellar arteries
- Caudal cerebellar arteries
The basal morphotype of cranial arteries is best seen in what specie(s)?
- Horse
- Dog
- Human
Name the two layers of the dura mater.
- Periosteal layer
- Meningeal layer
For a given species, no matter what the extracranial supply to the brain is, a(n) _________________ is always reconstituted and forms the parent arterial supply to the Circle of Willis.
Intracranial internal carotid artery
What is the sole arterial supply for the brains of fish, amphibians, and many reptiles?
Internal carotid arteries
The internal carotid arteries are the major supply of blood for which two species?
Dog & Horse
What is a rete mirabile?
It’s a Latin term meaning “wonderful network”. A rete is a tree-like vascular structure that forms from the branching of a vessel into progressively smaller vessels.
What species shows the greatest elaboration of a rete mirabile?
Cows
For each of the following domestic species, list the main arterial supply to both the forebrain and the hindbrain.
- Horse
- Dog
- Cat
- Cow
HORSE
Forebrain –> Internal carotid
Hindbrain –> Basilar artery
DOG
Forebrain –> Internal carotid and some external carotid
Hindbrain –> Basilar artery
CAT
Forebrain –> External carotid and some internal carotid
Hindbrain –> Basilar artery
COW
Forebrain –> External carotid and Basilar artery
Hindbrain –> Basilar artery
Name the five venous pathways for blood drainage from the brain.
- Internal jugular veins
- Maxillary veins
- Vertebral veins
- Internal vertebral venous plexus
- Emissary veins
For the following sections of spinal cord, name the major arteries associated:
- Cervical
- Thoracic
- Lumbar
Cervical –> vertebral arteries
Thoracic –> dorsal intercostal arteries
Lumbar –> lumbar dorsal segmental arteries