ANSC 423 EXAM 1 STUDY GUIDE
Contains a network of chromatin fibers (Histones and DNA)- Nucleoplasm
(RNA and proteins)-Nucleolus
Contains the genetic code
Director of cell processes
Regulator of protein expression
Mitochondrion (power house of the cell)
Enzymes for the citric acid ccle
Fatty acid oxidation
enzymes for nucleotide metabolism We also discuss several other topics like What forces laws and destroys capitalism?
DNA molecules (circular)
Code for synthesis of NADH dehydrogenase subunits,
cytochrome c oxidase, sysnthesis of ATP, tRNA, and rRna.
Crista If you want to learn more check out How did salutary neglect affect the colonies?
Rough (contains ribosomes)
Protein post-translational modficiations
Smooth (no ribosomes)
Calcium (Ca 2+) storage
Lipid (fat) synthesis
Biotransformation of drugs
Synthesis of secretory vesicles
Synthesis of proteins
Secretory- proteins are packaged in to be secreated later.
Storage- store lipid droplets
Lysosome- contains enzymes used to degrade waste materials in cell.
Cell Membrane (fluid mosaic model aka. A non-static always moving surface) Composition:
Transmission and information processing We also discuss several other topics like What is output in computer?
Organization of biochemical reactions
make RNA copies of genes
mRNA, tRNA, rRNA and microRNA are products
5' cap is added, and 3' poly A tail is added
Happens in the nucleus of the cell
Initiated by RNA polymerase protein binding to promoter. Don't forget about the age old question of How do you practice transcribing?
uses mRNA as template, rRNA for assembly and tRNA as translator to produce protein Produces proteins
post-translational modifications occur (phosphorylation, disulfide bridges
Happens in the cytoplasm
ribosome subunits initiation factors, and tRNA bind to mRNA near start codon
Exocytosis- transport outside of cell, uses membrane as a vesicle for transport. Endoctosis- transport of larger molecules into the cell (receptor independent)
-transport of lipoprotein into cell (receptor-mediated)
Pinocytosis- ingestion of small globules into the cell
Phagocytosis- ingestion of large particles, bacteria, cells, degenerating tissues. Simple Diffusion We also discuss several other topics like What is electric charge and electric field?
diffusion of lipid-soluble/ hydrophobic molecules. Ex: oxygen, nitrogen, carbon dioxide, steroids, and alcohols.
Concentration-dependent direction and rate of flow
Aided by integral membrane protein
Concentration-dependent direction and rate of flow
Carrier protein changes conformation during transport because of changes in the electrical potential (voltage gating or Chemical/Ligand gating) Ex: glucose,
amino acids, charged molecules/ions
Water diffuses through lipid bilayer via protein channels
Against concentration gradient (low to high)
Requires: carrier protein in cell membrane, and energy (ATP) Ex: Sodium (Na+) Potassium (K+) Pump
Against the concentration gradient
Requires: carrier protein, energy, and an additional molecule to attach to. Ex:
glucose transport via sodium ions.
Symproters- transport two different solutes at the same time in the same direction Ex: sodium/glucose transport We also discuss several other topics like What challenges exist that can make your analysis inadmissible in court?
Antiporters- transport two different solutes at the same time in opposite
Ex: sodium potassium
Uniporters- only transports one type of solute
Catalysis (increase rate of chemical reaction)
Reaction Coupling (transfer energy from a spontaneous to a non-spontaneous reaction) Transport (transport molecules in and out of the cell)
Structure (of cells and tissues)
Signaling (information transmission into receptor-mediated signal transduction) Shape determine function
Proteins can bind to other specific molecules
They can then change shape and provide 'lock' sites
Ligand (key) can then fit into the lock
Therefore the changes in shape alter the binding of ligands
Receptor activation signal transduction Second messanger mecanisms intracellular signaling Third Messaenger (Nuclear transcription factors) RESPONSE
Changes in cAMP or cGMP
Changes in IP3(inositol triphosphate)
Changes in calcium w/in cytoplasm
IP3 (inositol triphospate)
Activation of: transmembrane receptor, G=protein, and phosphlipidase C
IPSP- Inhibitory Post-Synaptic Potential: these decrease the probability that the cell will create another action potential.
Inhibitory synapses depolarize the neruotransmitters. This happens because the binding of certain neurotransmitters cause an increase in the negative ion flow into the cell, this raises it's membrane potential and inhibits the cell from creating an action potential, by counteracting the excitory signals.
Example: GABA neruotransmitters
EPSP- Excitory Post-Synaptic Potential: these increase the probability that a cell will create another action potential.
Excitroy synapses create positive action potentials. This occurs when the polarization of the postsynaptic membrane goes beyond it's threshold limit, because it is allowing an inflow of too many positive ions.
Example: glutamate neurotransmitters
Permitted to pass: small, uncharged, lipid soluble, and unbound to plasma proteins. Ex. Nicotine Glucose and some amino acids have to be carried through by specific transport mechanisms.
Neuravascular unit- pericyces, glail 'end-feet' and neurons
Important for development, maintenance and capillary endothelial BBB which helps maintain homeostasis of the brain.
another type of nervous system cell, that supports neuron function. Oligodendrocytes produce myelin proteins, but does not generate action potentials.
-Cells bodies and dendrites of motor neurons ( the axons exit through the ventral roots to the skeletal muscles or toward the smooth muscle.)
-Tracts of axons carrying sensory info to the brain and motor commands from the brain to the motor commands.
-Carry action potentials to the cord that were generated by the sensory receptors in the skin, muscles, tendons, joints, and visceral organs.
-Control simple reflexes (muscle stretch reflexes and limb withdrawal from painful stimuli)
Contents: cranial nerve nuclei (the cell bodies organized into aggregates that receive the sensory input and send out the motor output.)
Functions: receives information from the body's external and internal sensory receptors and then sends out commands to the skeletal and smooth muscles. Important for life support functions (respiratory and cardiovascular systems, vocalizations, and
Contents: large number of neurons in one two-neuron chain the relays information from the cerebral cortex and other parts of the brain to the cerebellum.
Functions: receive sensory information from facial touch and in motor control for chewing.
Contents: superior and inferior colliculi
Functions: Process and relay visual and auditory information
Cranial nerve nuclei
Functions: control eye movement and induce pupillary constriction of the pupil Reticular formation
is a netlike complex contain clusters of cell bodies (nuclei) and axonal
Functions: modulates consciousness and arousal, pain perception, spinal reflexes, and movement.
Contents: thalamus and hypothalamus
1. Thalamus- relay and modulator station for information moving from sensory systems and other parts of the brain to cerebral cortex.
2. Hypothalamus- regulates autonomic nervous system, hormone secretion by the pituitary gland, and aids in physiological and behavioral aspects of homeostasis.
Contents: cerebral cortex and a few subcortical structures ( basal ganglia and hippocampus) 3. cerebral cortex
Functions: sensory integration, conscious sensory perception, and voluntary movement 4. basal ganglia
Functions: motor functions of cerebral cortex
5. hippocampus (only place where new neurons are formed)
Functions: memory and spatial learning
-Important for smooth, accurate, coordinated movement for motor learning. Not for sensation or starting motion but for fine-tuning the motion. The cerebellum receives the signals for movement, and then it compares those signals with the actual movement that can happen from the body and makes the proper allowances for the motion to happen as close to the intended as possible for the body to execute.
Corebrocerebellum: signals the coritcospinal pathways and descending brain-stem to execute movement.
Spinocerebellum: signals motor functions to plan the coordinated and timed sequences of movement. Vestibulocerebellum: signals to vestibular nuclei which then coordinates eye movements and balance.
Produces sympathetic effects
From ATP via adenylate cyclase
mediates: insulin secretion and CFTR channel
Produces parasympathetic effects
From GTP via quanylate cyclase
Nitrates increases synthesis
Functions: cushions brain, transport hormones, and metabolites and acts as waste control for the brain.
Origin: Produced by choroid plexus inside ventricles.
Uses: Can be used to diagnose disease via a spinal tap.
Myelonated vs. Non-mylonated axons Action Potenitals travel faster Action Potentials travel slower
Synthesized in the soma Transported through axon as vesicles Stored in the presynaptic terminal Released to the sypnase Metabolized within the synapse or reabsorbed in the presynaptic terminal.
Synthesis: Acetyl coA and Choline form Acetylcholine via
cholineacetyltransferase then after the signals are transmitted
Acetylcholine is degraded by acetylcholineesterase which breaks it down
into Acetate and choline. The choline is recycled and via a high affinaty
tranporter protein is transported back to the presynaptic terminal to be
made into Acetylcholine again.
Storage: presynaptic terminal
Release: triggered by the presence of an action potential on a motor neuron.
These are called Cholinegic.
Synthesis: Tyrosine is converted into Dopa by Tyrosine hydroxylase. Dopa is
converted Dopamine by L-aromatic acid decarboxylase. Dopamine is
converted to Norepinephrine by Dopamine hydroxylase. Norepinephrine
is then converted to Epinephrine by Phenylethanolamine N
Storage: floating within cytosol
Release: triggered by the body experiencing SHOCK and it is released from the adrenal medulla of the brain.
Metabolism: Catecholomine is then broken down by Monoamine oxidase and Catechol-O-methyl transferase.
Corticospinal tract (Pyramidal Tract)
Contains: large number of neurons/axons that travel toward then brain-steam
The majority or the neurons leave the motor cortex and then cross to the opposite side of the body before traveling down the spinal cord and to the limbs on the opposite side. Ex. The motor controls for your left hand are on the right side of your brain, and vise versa for the right hand.
However there are about 10% of the neurons that do not cross over to the other side but instead stay on the same side and travel to the neck and upper throasic region of the body.
The motor cortex can be divided into two parts:
Lateral corticospinal tract: travels to the spinal cord and affects the lateral white
matter and the lateral gray matter. This results in movement of the distal
musculature of the periphery nervous system.
Ventral corticospinal tract: travels to the spinal cord and affects the medial white matter and the medial gray matter. This results in movement of the axial
and proximal musculature of the periphery nervous system.
Descending Motor Pathways (Extrapyramidal tract)
Maintains posture by constantly stimulating the postural muscles of the spinal cord. Organization:
The motor cortices start in the telencephalon and travel to the brainstem entering the red nucleus or the reticular formation. If it travels to the red nucleus
the neurons go through the rubrospinal tract and onto affecting the lateral
white matter and lateral gray matter of the spinal cord, and finally
affecting the distal musculature of the periphery nervous system.
If the neurons travel through the reticular formation they continue down the
reticulospinal tract and affect the medial white matter and the medial gray
matter, and finally affect the axial and proximal musculature of the
periphery nervous system. But there are also signals coming from the
sensory organs of the head which travel through the superior colliculus
then to the tecospinal tract and affect the medial white matter and medial
gray matter and finally the axial and proximal musculature of the
periphery. Or the signals from the head travel through the vestibular
nuclei and the vestibulospinal tract, and then affect the medial white
matter and the medial gar matter and finally the axial and proximal
musculature of the periphery nervous system.
Quiz 3 and New Material:
CNS Part 3
Lacrimal gland-gland that secretes tears and is located at the corner of the eye. The lacrimal duct runs from the corner of the eye to the nose via the nasolacrmal duct for drainage of the eye.
Sclera- outside of eyeball
Cornea- epithelial layer that is clear/transparent in the front of the eye.
Choroid- is the next layer toward the inside of the eyeball and has a vascular and pigmented layer.
Retina- located in the back of the eye, and is where the photo-receptors are
Aqueous Humor- fills the anterior (between the cornea and the pupil) and the posterior chamber ( between the pupil and the lens)
Iris- contains dilator and constrictor smooth muscle and separates the anterior and posterior chambers of the eye.
Pupil- is an opening in the eye created by the iris where light passes through.
Lens- a transparent structure suspended by ligaments
Vitreous humor- a gelatinous fluid that fills the eyeball behind the lens
Tapetum Lucidium- a light reflecting pigment located in the rear of the eye in nocturnal animals.
The shape of the lens changes by the contraction and dilation of ciliary muscles to focus on images.
Contains Rhodopsin ( cannot discriminate wavelength) light
Longer than cones
More sensitive to light, used during night vision
Low acuity (detail)
Used for color vision
Shorter than rods
Less sensitive to light, used for day vision
High acuity (detail)
Bipolar cells- connects rods/cones to ganglion cells
Horizontal cells- connect rods, cones, and bipolar cells to each
Amacrine cells- connect bipolar and ganglion cells
Ganglion cells transmit visual signal through the optic nerve
these signals/impulses then reach the lateral geniculate nucleus in the
brain and the images are finally recreated within he visual cortex.
External-used to funnel the sound waves into the ear.
Middle-made up of three bones called the ossicles (malleus, incus, and stapes) also used to funnel the sound to the cochlea
Inner- contains the boney labyrinth and the membranous labyrinth.
• contians cochlea and vestibular organ
• filled with perilymph (fluid)
• Scala vestibuli (dorsal)
• Scala tympani (ventral)
– Contains membranous labyrinth
– filled with endolymph
– Scala media
Organ of Corti (hair cell receptor)
transduces the sound waves into action potentials which are then carried to the brain by the auditory nerve.
Transduction of Sound to Neuronal Signal
Hair Cell Spiral ganglion (Peripory) Cochlear Nuclei (Medulla) Cranial Nerve VII Trapezoid Body
Superior Olivary complex (Medulla-Pons) Inferior colliculus (Mesencephalon)
Lateral LemniscusBrancium of Inferior
Medial Genculate Nucelus (Diencephalon) Auditory Cortex (Telencephalon) Auditory Radiations
Vestibular System (bilateral system located in the inner ear)
Provides sensory information mainly equilibrium and balance for the spinal motor neurons, cerebellum, and extra-ocular muscles reflexes.
These reflexes coordinate the head and eye movements to obtain optimal visual acuity (detail).
The Utricle and Saccule parts of the inner ear detect linear motion and head tilt when the head is still.
The Semicircular ducts detect rotary motioning of acceleration and declaration of the head. The membranous labyrinth contains a region of specialized epithelial cells that act as secondary receptor cells.
Autonomic Nervous System
Self-governing and independently functioning
Contributes to peripheral motor and sensory system functions with smooth, cardiac muscles and glands.
Regulates: blood pressure, heart rate, intestinal motility, pupil size, secretion of glands, and vasoconstriction/dilation
Essential for homeostasis
Axons from CNS go to ganglin site then to a post-ganglionic nerve and finally to the target organ.
Ganglion: collection of neuronal soma outside the CNS
Nucleus: Collection of neuronal soma inside the CNS
Autonomic Reflex arc at the spinal cord level via mechanoreceptors and pain nocicptive signals
Autonomic control centers in the brainstem and hypothalamus, within the Hypothalmus there is the Paraventricular nucleus (PUN) the Endocrine system (para), the ANS (ventricular), and the Solitary nucleus (Vagus)
starts at spinal cord goes to the autonomic ganglion then to the post ganglionic fiber and finally to the target organ.
Increase heart rate Production of thick viscous saliva Pupil dilation Relaxes Uterine smooth muscle
Dilation of bronchial smooth muscle Penis ejaculation
Inhibit bronchial secretion
Inhibit intestinal motility and secretion
Nicotinic receptor (Ion-channel protein)
found in sympathetic ganglia and adrenal medulla
Stimulated by acetylcholine and nicotine
No effect by muscarine
Tubocurarine- powerful nicotinic receptor blocker
α1- Smooth muscle
α2- Pancreatic Islets
Functional difference from parasympathetic stimulation
effects are widespread througout body
effects are in discrete organs too
effects last longer, because of norepinephrine/Epinehrine circulation
Ex: Fight vs Flight response
Localized to visceral organs and eyes
Overall effect expends energy
Increases basal metabolic rate, burns energy, and stress response
starts at the spinal cord and then goes to the parasympathetic or peripheral ganglion and finally tot he target organ.
Decrease heart rate Production or watery saliva
Pupil constriction May relax or flex Uterine muscle Constriction of bronchial smooth muscle Penis erection
Stimulate bronchial secretion
Increase intestinal motility and secretion
muscarinic receptor (cell membrane receptro- coupled to G-protein)
Found in parasympathetic effector organs
Stimulated by acetycholine and muscarine
No effect by nicotine
Atropine-pupil dilator, blocks muscarinic receptor in iris. (deritropa
β1- heart, kidneys
β2- Smooth muscle
β3- Adipose tissue
Functional difference from sympathetic stimulation
effects are seen in discrete organs
Does complete opposite from the sympathetic system
Ex: anabolic or vegetative functions of daily living
1. Olfactory nerve
2. Optic nerve
3. Oculmotor nerve (parasympathetic) 4. Trochlear nerve
5. Abducens nerve
6. Facial nerve
7. Vestibula-Auditory nerve (parasympathetic)
8. Glossopharyngeal nerve 9. Vagus nerve (parasympathetic) 10. Spinal Accessory nerve 11. Hypoglossal nerve