Comparative Vertebrate Anatomy: Nervous system
What is the parietal organ or eye?
Can be well-developed with corneal, lens-like structure Important for sunning and temperature regulation
What is Transmissible Spongiform Encephalopathy?
Caused by prions (protein fragments) that cause misfolding of proteins Invade CNS, cause lesions, and destroy tissue Ex: CWD
What is craniosacral outflow?
Cell bodies from brainstem (cranial nerves: VII, IX, X) or the sacral spinal cord
What is Chronic Wasting Disease?
Cervids (deer and elk) Brain and body waste away Captivity concentrates spreads through contaminated bodily fluids, tissue, drinking water and food
What are spinal reflexes?
Circuit of neurons from receptor to spinal cord + out to effector May or may not send signal to brain to aid in coordination Examples: knee-jerk reflex
What does the encephalization quotient do?
Compares brain mass to the average brain mass for an animal of equivalent body mass
What are the olfactory bulbs?
Cranial nervs zero and one Big and important in fish and other big smellers Important rely center to cerebral cortex
What is the cerebellum?
Dome-shaped expansion of hindbrain Coordinates locomotion (physical activity) and equilibrium Coordinates, does not initiate
What are the dorsal and ventral roots?
Dorsal root - afferent (sensory) - NCC Ventral root - efferent (motor) - spinal cord
What are spinal nerves?
Emerge between each vertebrae Innervates restricted area linked to myotome and dermatome (useful for injury detection)
What are the 12 cranial nerves?
I. Olfactory II. Optic III. Occulomotor IV. Trochlear V. Trigeminal VI. Abducens VII. Facial VIII. Acoustic IX. Glossopharyngeal X. Vagus XI. Spinal Accessory XII. Hypoglossal
What are the three nerves that are the motor for 6 extrinsic eye muscles?
III, IV, and VI make the eyes do tricks
Which nerve goes with the 3rd visceral arch (first gill in fish)?
IX. Glossopharyngeal
What are neurons?
Specialized nerve cells for long distance transmission of electrical stimuli
What are microglia?
Support cells that engulf foreign bodies
What are Schwann cells?
Support cells that facilitate electrical signal by forming myelin sheaths
What are astrocytes?
Support cells that pass nutrients to neurons
What are synapses?
Where neurons connect single passes electrical-chemical-electrical Neurotransmitters released between cells (axon to dendrite)
Which nerve goes with the 4th, 5th, and 6th arches?
X. Vagus
What is the Pineal eye complex?
a morphologically and functionally connected set of organs that originates as an evagination of the roof of the diencephalon
What are axons?
nerve fibers carries impulse to next cell
What is thoracolumbar outflow?
neurons begin at the thoracic and lumbar (T1-L2) portions of the spinal cord
What is the sympathetic?
"fight or flight" Prepares body for action Promotes: Slows digestion Spleen contracts = more RBC's Glucose mobilized from liver
What is Kuru?
"trembling with fear", "laughing sickness" a prion-based disease prevalent in the people of the fore tribe in Papua New Guinea From eating brains of deceased
What is the spinal accessory XI nerve for?
Small motor neuron for derivatives of cucullaris
What is the pituitary gland (hypophysis)?
endocrine gland affects growth, kidney, repro, thyroid, adrenal gland
The processing of information of the central nervous system is from what 3 sources?
1. Internal from organs and muscles 2. External i.e. 'normal' sensations 3. Memory
What are the functions of the cerebral spinal fluid?
1. Liquid cushion for brain + spinal cord 2. Supports delicate structures 3. Nourishes brain + waste removal
What are Mauthner cells?
Actinopterygians (ray-finned fish) have these Pair of giant cells Axons run length of spinal cord Rapid escape
What is the thalamus?
All sensory input (except olfaction) moves through here Coordination center of sensory input Important rely center to cerebral cortex
Which animals expand different regions of their pallium?
Birds
T/F Anamniotes have 12 cranial nerves whereas amniotes have 10
False Anamniotes have 10. Amniotes have 12
T/F Swimmers, flyers, climbers, and fish with electroreception have large cerebellums so if this is removed it will affect behavior
False The cerebellum is not essential for respiration or digestion so it can be removed without affecting behavior
What is the hypothalamus?
Floor of the forebrain (diencephalon) Regulates homeostasis (the state of steady internal, physical, and chemical conditions maintained by living systems) Acts on the Autonomic nervous system, pituitary gland
What are the pons and where are they located?
Floor of the hindbrain Separate area in mammals (pons) Crossroads of info V, VI, VII arise here In the Myelencephalon
How is the brain organized in a three-part construction?
Fore Mid Hind
What are the structures around the 3rd ventricle?
Forebrain (diencephalon)
In what part of the brain is the location of the 4th ventricle?
Hindbrain
What is the Hypoglossal XII nerve for?
Hyoid and tongue muscles
What is meningitis?
Inflammation of meninges due to viral or bacterial infection
What is the purpose of the acoustic (auditory) nerve?
Inner ear, hearing, balance + orientation
What is the myelencephalon composed of?
Medulla oblongata, pons
What are some diseases that cross the blood brain barrier i.e. infection of the CNS?
Meningitis Chronic Wasting Disease Mad cow disease Kuru
What is the largest part of the brain in anamniotes and also the primary integration center of sensory input?
Midbrain
What are effectors?
Muscles and glands are called effectors because they cause an effect in response to directions from the nervous system
What is the gray matter in the spinal cord?
Nerve cell bodies, "butterfly" pattern in cross-sections
What is the white matter in the spinal cord?
Nerve fibers linking levels
What is the telencephalon composed of?
Olfactory bulb, cerebral hemispheres
What is the cortex?
Outer wall of cerebrum Forms through inversion, except Actinopterygians Mammals expand different part (dorsal pallium) than birds/reptiles (lateral pallium + DVR, dorsoventricular ridge)
What is the cerebrum?
Paired cerebral hemispheres Ventricles 1 and 2 Anamniotes - largely olfactory in function Amniotes + some anamniotes have expanded ones, 5-20x bigger in reptiles, birds and mammals, integrates senses and functions, processing and data extraction
What is the medulla oblongata?
Relay center with ascending and descending pathways Center for basic (vital) functions like respiration, visceral activity, and heartbeat
What is parasympathetic?
Rest + digest Restores body to restful state Craniosacral outflow Acetylcholine as transmitter Opposite actions to sympathetic
What is the terminal nerve?
Runs to blood vessels of olfactory sac In all gnathostomes except birds Restricted to pheromone detection
What is the purpose of the olfactory nerve?
Sense of smell, to olfactory bulb
What is the mesencephalon composed of?
Tectum with optic lobes, tegmentum
What are the three parts of the brain subdivided into?
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
What is the diencephalon composed of?
Thalamus, epithalamus, hypothalamus, epiphysis
What is the tegmentum?
The floor of the mesencephalon Initiates motor output
What is the tectum?
The roof of the mesencephalon Receives sensory input - optic directly but auditory, lateral line, skin, smell indirectly Relays to thalamus
What is the epithalamus?
This forms the roof of the third ventricle. This houses the pineal eye complex (median eye complex)
T/F Like the brain, the spinal cord has gray matter and white matter
True
What are the lateral line nerves?
Up to six pairs of cranial nerves for lateral line system No Roman numerals - recognized after numbering Fish and some amphibians Rooted in medulla near root of VII (Octavolateralis Line System)
Which nerve goes with the 1st visceral arch (mandibular arch)?
V. Trigeminal
Which nerve goes with the 2nd visceral arch (hyoid arch)?
VII. Facial
What is the purpose of the optic nerve?
Vision, outgrowth of brain, to thalamus + midbrain
What are receptors?
detect a change in the environment (stimulus) and stimulate electrical impulses in response
What are the meninges?
membranes that surround the brain and spinal cord Fish -- brain wrapped by 1 layer Non-mammalian tetrapods -- 2 layers Mammals -- 3 layers
What is Mad Cow Disease?
or BSE (bovine spongiform encephalopathy) is progressive neurological disorder of cows; The cause is thought to be a prion which is a type of infective protein From feeding central nervous tissue (brains) to cattle
What does the autonomic nervous system do?
part of your nervous system that controls involuntary actions, such as the beating of your heart and the widening or narrowing of your blood vessels
What is the purpose of the blood brain barrier?
to protect brain from harmful substances in blood
What is the function of the epiphysis (a.k.a. pineal gland)?
to receive information about the state of the light-dark cycle from the environment and convey this information to produce and secrete the hormone melatonin
What are dendrites?
where a neuron receives input from other cells initiates nerve impulse