Study Guide Flashcards
7 What is the role of the primary motor cortex?
The motor cortex controls body movements. It sends an axon down to the spinal cord to control motor efferent nerves.
38 Describe the removal of glutamate?
Glutamate is terminated by reuptake, primarily by astrocytes and covert glutamate back to glutamine by the enzyme glutamine synthetase. It is then transported back into the neuron.
38 Describe the synthesis of glutamate?
Glutamine is converted into glutamate by glutaminase. It occurs in the presynaptic terminal. High levels of glutamate in extracellular fluid are dangerous, producing excessive neuronal excitation and even cell death.
39 What are the types of glutamate receptors?
Glutamate is released to excite ( stimulus) other neurons. It is the main excitatory neurotransmitter in the central nervous system (EPSPs.)
Enhances activation of NMDA receptors overexcites cells and causes cell death ( by Way of Ca2+ influx. Which is known as excitotoxicity.
- GIve drugs that mimic glutamate and bind to NMDA receptors and cell loss follows.
- Implicated in Alzheimer’s Disease
39 What are the different types of glutamate receptors?
Glutamate binds to both inotropic & metabotropic receptors. Inotropic: NMDA, AMPA, Kainate. Metabotropic: mGluR1 - mGluR8 receptors.
NMDA, AMPA, and Kainate allow the passage of sodium ( Na+) and as a result depolarization occurs when glutamate binds to these receptors.
NMDA also allows the passage of Calcium ( Ca++) which activates second messengers within the cell.
N/A What is glutamate?
An essential amino acid that is used in the synthesis of proteins ( complicates localizing it). It is found in 80% of Neurons in the cortex.
41 AWhat are the functions of glutamate?
Learning and memory is also dependent on glutamatergic activity at the NMDA receptor.
- Block the NMDA receptor and animals do not perform well on a test of memory.
- Morris Walter Maze
41 What are the main functions of glutamate in the central nervous system?
Glutamate is released to excite (stimulate) other
neurons – main excitatory neurotransmitter in the
central nervous system (EPSPs). Learning & memory
42 What is the synthesis of GAMMA- AMINOBUTRIC ACID? ( GABA)
Glutamate is converted into GABA by glutamatic acid decarboxylase ( GAD)
42 Describe the removal of Gamma-aminobutric acid ( GABA?)
GABA is terminated by reuptake by Neurons & Astrocytes, which take up the GABA and convert it eventually back to glutamate by GABA Aminotransferase ( GABA-T.)
Glutamate is then converted to glutamine and transported back to the neuron.
43 What are the two main types of GABA receptors?
GABA binds to two main receptors: GABA (a) ionotropic & GABA (b) metabotropic
43 What are the mechanisms of action for the two main types of GABA receptors? GABA ( a) ionotropic & GABA ( b) metabotropic?
GABA ( a) allows the passage of Chloride ( Cl-) and as a result hyperpolarization occurs when GABA binds to this receptor.
There are multiple binding sites on the GABA(a) receptor ( Not just the one for GABA.)
44 What are the main functions of GABA in the central nervous system?
GABA is found high in concentrations in the brain and spinal cord, but is absent in the peripheral nervous system.
GABA is not an essential amino acid and is not used for the synthesis of proteins.
44 What are the main functions of GABA in the central nervous system?
GABA is released to suppress/inhibit the activity of other neurons,
It is the main inhibitory neurotransmitter in the central nervous system ( IPSPs.)
Lack of GABA = epileptic seizures ( convulsions)
Enhancing GABA activity reduces, anxiety, induced sleep, and reduces convulsions.
45 How do benzodiazepine drugs affect GABAergic neurotransmitters?
When benzodiazepine drugs ( BDZ) bind to the GABA(A) receptor, it potentiates the effect of GABA.
Such as creating anxiolytic effects ( reducing anxiety.)
46What is the role of dopamine in Parkinson’s disease and schizophrenia?
Cells that produce dopamine die in Parkinson’s patients. Give L-DOPA ( converted to dopamine) to treat symptoms.
Parkinson’s = shakiness ( tremors), stiffness, and slowed down movements.
Schizophrenia= thought to be result of too much dopamine ( blocks Dopamine D2 receptors.)
37 What is the mechanism of action of botulinum toxin ( Botox)?
Decreasing acetylcholine at the neurotransmitter junction will cause paralysis.
It blocks the release of acetylcholine
Causes a paralysis of that muscle due to a blockade of acetylcholine release from the incoming motor nerve fibers.
32 What are the two main types of acetylcholine receptors,and how do they differ in mechanisms of action?
Nicotinic ( ionotropic)
Nicotinic receptors allow the passage of sodium ( Na+)
Binding of nicotine receptors by acetylcholine causes depolarization.
Muscarinic ( metabotropic)
Are associated with stimulatory g-proteins
Leads to a series of intracellular signals.
Intracellular Signaling Mechanisms of Muscarinic Receptors
Figure for reference
33How can the same neurotransmitter have different effects on different target cells?
The same receptor can be associated with different functions. This is why location is important. The same neurotransmitter can have oppositive effects because of the different type of receptors. Hyperpolarization or depolarization??
31Describe the synthesis & removal of acetylcholine
Synthesis occurs in presynaptic terminal from choline ( organic compound), from fat in our diet.
Acetyl CoA and Choline are converted to Acetylcholine by the enzyme Choline Acetyltransferase ( ChAT).
Choline is the rate limiting step- determines the overall rate of synthesis
Removal
Acetylcholine is terminated by acetylcholinesterase ( AChE) in the synaptic cleft which converts acetylcholine into choline and acetate ( both of which are transported back into the cell)
34 What are the main functions of acetylcholine in the nervous system?
At the neuromuscular junction acetylcholine causes muscle contractions.
Associated with increased activity of the parasympathetic nervous system.
It is involved in learning & memory: scopolamine impairs acquisition of new information.
Sleep & wakefulness.
35 How is acetylcholine related to Alzheimer’s disease?
Donepezil ( Aricept) is used for Alzheimer’s Disease and it works by inhibiting acetylcholinesterase ( AChE) - treats the symptoms and not the disease
25 What is the blood-brain barrier, and how was it discovered?
I don’t know how? Tissue staining Histamine is produced in the periphery but does not cross the blood brain barrier. Synthesis enters the brain by active transport and is metabolized by two enzymes. Regulates food, water intake, thermoregulation, and sleep.
The BBB has selective permeability. If the BBB increases, more histamine and other substances enter the brain contributing to inflammation and neurological disorders.
The BBB typically limits the entry of larger molecules and many substances, including histamine. While small amounts of histamine can cross the barrier, the tight junctions between endothelial cells of the BBB restrict larger quantities.
26 What are the criteria a chemical must meet to be classified as a neurotransmitter?
- Synthesized in the neuron
- Present in the presynaptic terminal
- Released when action potential reaches terminals
- Recognized by specific receptors and causes a change in postsynaptic cell
- Inactivated
- Over 100 chemicals meet this criteria
27 How are neurotransmitters classified based on their size?
Small molecule : neurotransmitter
Large molecule: Neuropeptide Neurotransmitters
Gaseous: Neurotransmitters ( Nitric Oxide)
Small molecule:They are synthesized and packaged into vesicles in the presynaptic neuron and released in response to an action potential.
Neuropeptides: They are synthesized as larger precursor proteins that are cleaved into active forms.
Neuropeptides:
Amino Acids: Such as glutamate, gamma-aminobutyric acid (GABA), and glycine.
Biogenic Amines: Such as dopamine, norepinephrine, epinephrine, and serotonin.
Other Small Molecules: Such as acetylcholine and histamine.
30 What are the main types of small-molecule neurotransmitters?
Amino Acids
- glutamate ( excitatory)
-Gamma-amino butyric acid ( GAVA) inhibitory
Monoamines- derived from an amino acid
Catecholamines
- Norepinephrine
-Dopamine
Indoleamines
-Serotonin
-Melotonin
- histamine
-adenosine
-acetylcholine ( first to be discovered)
28 Describe the synthesis process of small-molecule neurotransmitters.
- Enzyme required for synthesis is synthesized in soma.
- Golgi apparatus packages enzyme and transports it to terminal
- Precursors are taken up at terminal button that are required for synthesis,
- Newly synthesized neurotransmitter is transported to vesicle.
- Release by exocytosis.
29 How does the synthesis of neuropeptide transmitters differ from that of small-molecule transmitters?
The difference is that the golgi apparatus packages the enzyme and the polypeptide transports it to the terminal.
( In small-molecules, the golgi apparatus sends it back to th terminal.)
Also, enzymes cleave polypeptides to produce smaller peptide that functions as neuortransmitter.
(In small molecules - prescursors are taken up at terminal button that are required for synthesis.
47 What are endogenous neuropeptides?
Endogenous neuropeptides are naturally occurring peptides produced within the body that function as signaling molecules in the nervous system and other tissues. They are synthesized by neurons and act as neurotransmitters or neuromodulators, influencing a variety of physiological processes.
Key Features of Endogenous Neuropeptides:
Synthesis:
Endogenous neuropeptides are synthesized from larger precursor proteins through enzymatic cleavage. This process allows for the production of multiple active neuropeptides from a single precursor.
Functions:
They play diverse roles, including regulating pain, stress responses, appetite, mood, social behaviors, and hormonal release. For example, endorphins are involved in pain relief and reward pathways.
Receptors:
Endogenous neuropeptides bind to specific receptors, usually G-protein coupled receptors (GPCRs), to exert their effects. Each neuropeptide typically has one or more specific receptors that mediate its actions.
Examples:
Common endogenous neuropeptides include:
Endorphins: Involved in pain relief and pleasure.
Substance P: Associated with pain perception and inflammation.
Neuropeptide Y: Involved in appetite regulation and stress responses.
Oxytocin: Plays a role in social bonding and reproductive behaviors.
48 Beta endorphin is an endogenous optiod. What does this mean in terms of its function?
plays a critical role in pain modulation, emotional well-being, and overall homeostasis,
Beta-endorphin is an endogenous opioid, meaning it is a naturally occurring peptide in the body that binds to opioid receptors.
Functions: Pain relief, mood regulation, stress response, reward & pleasure, hormonal regulation.
49 How does the activation of mu-opioid receptors by beta-endorphin affect pain signals?
47 What are endogenous neuropeptides?
Natural neuropeptide ligand that binds to
receptors
Large propeptides (precursor peptides)
are processed into smaller active opioid
peptides
- Pro-opiomelanocortin ( POMC)
- Proenkephalin
- Prodynorphin
- Pronociceptin/orphanin FQ
45 Beta - endorphin is an endogenous opioid. What does this mean in terms of its function?
Endogenous opioids are produced by the body and interact with the same receptors that opioids like morphine do.
49 How does the activation of mu-opioid receptors by beta-endorphin affect pain signals?
In the brainstem, beta-endorphin binds to opioid receptors that activate descending pain control pathways to inhibit pain,
Endorphin is a combination of endo & morphine. It binds to a mu-opioid receptor,
Activation of mu-opioid receptor leads to the opening of potassium channel.
In the spinal cord beta-endorphin block pain signals to the brain.
What are the three main types of opioid receptors, and what broad functions are they associated with?
- DOP - Delta Opioid
- KOP - Kappa Opioid
- MOP - Mu Opioid
- Analgesia & reinforcement
- Dyspohoria & temperature control
- Euphoria, analgesia, respiratory, depression.
50 What are some functions associated with beta-endorphin?
-Linked to mood elevating effects after exercise
-Linked to pleasure associated with food & sexual behavior.
- Interacts with dopamine system to drive euphoric/rewarding effects
- Released as part of the stress responsible and may inhibit pain during acute stress.
52 If a subject lacks mu-opioid receptors, what outcome would you expect in a “hot plate analgesia” test?
This would result in a reduced ability to tolerate pain.
Higher pain perception and lower pain tolerance in the hot plate test.
Without mu-opioid receptors, the subject would not be able to effectively utilize endogenous opioids like beta-endorphin or exogenous opioids (like morphine) for pain relief. Therefore, they would likely show heightened sensitivity to the painful stimulus on the hot plate.
Longer Latency to Withdraw:
The latency time before the subject withdraws from the hot plate (indicating a pain response) would likely be shorter. They may exhibit less tolerance to the heat compared to subjects with functional mu-opioid receptors.
Lack of Analgesic Response:
If opioids are administered during the test, the lack of mu-opioid receptors would mean that the subject would not experience the typical analgesic effects, rendering the opioid treatment ineffective.
54 What are the key distinction between endocrine and exocrine glands?
Endocrine glands release hormones within the body.
Exocrine glands use ducts to secrete fluid outside the body, such as tears and sweat.
Hormones are chemicals, secreted by one cell group, that travel through the bloodstream to act on targets.
53 Differentiate between synaptic, endocrine, pheromone, and allomone chemical communication methods.
- Synaptic: neurotransmitter release and diffusion across a synapse.
- Endocrine: In endocrine communication, a hormone is released into the bloodstream to selectively act on target tissues
- Pheromone: Chemicals released outside the body to affect other individuals of the same species are pheromones.
4.Allomone: Chemicals released outside the body to affect individuals of another species are allomones.
55 What are the three main chemical classes of hormones, and what are their structural characteristics?
- Protein hormone/peptide hormone = a string of amino acids
- Amine hormones- modified version of a single amino acid, called monoamine hormones.
- Steroid hormone = derived from cholesterol and made of four rings of carbon atoms.
56 Compare and contrast how protein/amine hormones and steroid hormones exert their effects on target cells.
** Protein & Amine Hormones*
Protein and amine hormones bind to specific receptors on the surface of the cell and cause release of a chemical signal– a second messenger in the cell.
56 Compare and contrast how protein/amine hormones and steroid hormones exert their effects on target cells.
Steroid hormones pass through the cell membrane and bind to receptors inside the cell.
- The steroid receptor complex binds to specific regions of DNA and controls expression of specific genes
60 What are the primary functions of oxytocin & vasopressin?
When the posterior pituitary is stimulated — action potentials in these neurons travel down their axons and cause release of oxytocin and vasopressin onto capillaries in the posterior pituitary.
Oxytocin is involved in reproductive and parenting behavior, uterine contractions, and the milk letdown relfex.
Arginine Vasopressin or Vasopressin ( AVP) - Promotes water conservation and increases blood pressure. – Exclusive pair-bonds formed by prairie voles depend on the distribution of vasopressin receptors.
57 Hormones have diverse effects. Explain this using the example of testosterone.
Almost all hormones act on more than one target organ. Hormones can have different effects on each target, and act to coordinate different parts of the body. One target organ may respond to several homones.
Testosterone: sperm production, muscle development, beard growth, sexual behavior, aggression
57 Explaining affect of testosterone hormones.
LH stimulates the testes to produce and secrete testosterone and other androgens. FSH stimulates the testes to produce sperm.
59 How does the posterior pituitary gland receive & release hormones?
It releases oxytocin and vasopressin into the bloodstream. The hormones are produced in the hypothalamus in the supraoptic and paraventricular nuclei. When stimulated, action potentials in these neurons travel down their axons and cause release of oxytocin and vasopressin ontio capillaries in the posterior pituitary.
58 Describe the role of the pituitary gland in the endocrine system.
The pituitary gland has two parts. ( anterior & posterior). How it receives input from the hypothalamus is different.
It releases two hormones into the blood stream ( oxytocin & vasopressin.)
The pituitary gland releases hormones by neuro endocrine cells that release hormones into the blood.
- The pituitary stalk is the bridge between the hypothalamus and pituitary
61 How does negative feedback regulate hormone release in the endocrine system?
Production begins, the body recognizes that too much of cortisol is being produced, so the body stops producing it. A positive feedback loop. An example of this is cortisol. A positive feedback loop example would be for Oxytocin.
The median eminence contains blood vessels
that form the hypothalamic-pituitary portal
system
Hypothalamic neurons synthesize releasing
hormones that are secreted into local blood
vessels and travel to the anterior pituitary
The secretion rate of releasing hormones
governs the rate of tropic hormone release
into the general circulation
20
62 What is the process of converting light into a signal that the brain can recognize?
64 Explain how photoreceptors work to convert light into action potentials.
Light is converted into a signal that is recognized in the brain by converting it into action potentials. Rods & cones convert light into a neural impulse. They differ in structure, light absorbed, and location. The retina contains photoreceptors that contain rods and cones that create neural impulse and 4 other types of cells.
66 What are the two visual systems, and what are their functions?
Two visual systems: cone vision & rod vision. Conditions that are necessary. More light means more cone use. Low conditions of light, rods are more on alert. Photopic system are cone and scotopic system is rods.
65 What are the differences between rods & cones?
Rods and cones convert light into neural impulses. They are the sctopic system. They work in dim light ( high sensitivity) and responsive to moving stimuli but are insensitive to color ( colorless.
63 Describe the anatomy and function of the lens.
Lens is the structure that focuses light onto the back of the retina. Light has to be focused onto the back of the retina for sharp vision.The ciliary muscle controls the shape of the lens. A change in the shape of the lens by the ciliary muscles maintains the focus of an image onto the back of the retina.
67 What are the two visual systems, and what are their functions?
Photopic system ( cones) - requires more light and allows color vision
Scotopic system : works in dim light ( high sensisitvity) and responds to
68 What is the role of the lateral geniculate nucleus ( LGN) in visual processing?
Things are organized and separated by where the information is coming from. Specizalize in informatoin from the cones ( color.) Magnoceullular: two inner layers
69 What is the primary visual cortex (V1), and what happens when it is damaged?
Damaged: loses abity to perceive some kind of information. They have blindsight. The information is travelling somewhere. It receives infromation from the LGN and is responsible for the first stage of visual processing. Blindsight: an ability to respond to visual stimuli they are not seeing. It is located on the back of the head. Glaucoma is when the optic merve is damaged.
70 Explain the difference between the ventral stream and the dorsal stream in visual processing?
Ventral: “what path” Damage to this is not able to recognize objects.
Dorsal: “Where” to parietal area. Has to do with movement. Unable to drive.
71 What is object agnosia and what area of the brain is damaged?
Think of the picture of the man made of vegetablees. Object agnosia is a deficit of the ventral stream. You are unable to recognize that the man is comprised of vegetables and flowers. Inability to perceive objects Lateral occipital complex damage.
72 What is prosopagnosia and what are of the brain is damaged?
Inability to see faces. Can recognize objects, but cannot see the face. Able to see the vegetables and flowers, but unable to recognize that it is a man. Damge to the ventral visual pathway.
73 What are the three major symptoms of Balint’s syndrome, and what are of the brain is damaged?
Optic ataxia ( disorderly): visually difficlut to reach for objects. Movement is mis-directed. Depth perception.
Ocular ataxia ( without visual action): Cannot mainaint fixation on object
Simultagnosia: Not able to perceive more than one object at a time.
It is damage to the parieto-occipital region.
( Understand the visual graphs)#74 What is visual neglect, and what area of the brain is usually damaged?
Neglecting events in the visual field. Lack of response to stimuli in their visual field which cannot be narrowed down to be from damage to a primary geniculostriate area. This is when they cannot attend o or acknowledge stimuli on one side of their visual field. Typically the left side causes damage to the right,
75 How can visual field deficits help predict the location of damage in the visual pathway?
Because of topographic organization. Occipital love damage can be predicted from the visual field deficits.
1 Explain the difference between gray matter and white matter in the brain?
2 Name the three major axonal fiber tracts that connect the two hemispheres of the brain.
3 Describe the two main divisions of the peripheral nervous system and their functions.
4 What is the role of the dorsal root ganglion in the somatic nervous system?
5 Explain how sensory information from the body reaches the somatosensory cortex.
6 How is the somatosensory cortex organized?
8 What are cranial nerves, and how do they differ from spinal nerves?
9 Briefly describe Bell’s Palsy, including its cause and symptoms.
10 List the four major regions of the central nervous system and the five regions of the brain.
Median Eminence
The median eminence contains blood vessels
that form the hypothalamic-pituitary portal
system
Hypothalamic neurons synthesize releasing
hormones that are secreted into local blood
vessels and travel to the anterior pituitary
The secretion rate of releasing hormones
governs the rate of tropic hormone release
into the general circulation
20
Hormone Summary Image
Image for review
How do the ciliary muscles contract when seeing an object close up or far away?
Object near: Contract and lens get rounded.
Far: Muscles relax and lens flattened
Understand the anatomy of the lens
The Iris controls light that is entered through the pupil. The retina contains photoreceptors that covert light into nerual impulses and 4 other types of cells. The ciliary muscle controls the shape of the lens. The opic nerve is the bundle of axons that leave the eye. The optic disk is the portion of the retina that does not contain photoreceptors.
What is transduction?
The conversion of physical energy to an electrochemical signal that neurons can recognize. Coding is when signals are analyzed and we execute a response. Photoreceptors in the dark release neurotransmitters triggers hyperpolarization of the cells, so it releases less neurotransmitters. The size od the hyperpolarizing signal determines how much neurotransmitter is releases.
How do photo receptors work to convert light into an action potential?
This is through transduction.
What are photoreceptors?
These are receptors sensitive to photons. Light can be thought of particles of energy ( photons) and waves of electromagnetic radiation ( described in three ways.)
What are rods?
They are responsible for vision in low light. They are highly ensitive. They do not detect color. Only black and white vision. They are dound in the peripheral regions. Rod vision i heightened in the dark, so the pupils dilate.
What are cones?
They are responsible for color vision and sharpness in bright light ( photopic) vision. They require bright light for activation and are less sensitive compared to rod. There are three types of cones. They are concentrated in the fovea, in the central part of the retina. 6 million in the retina.
Describe the pathway that visual information takes from the eye to the brain.
Ganglion cells conduct action potentials that send information to the brain. The axons are in the optic nerve which travel to the occipital cortex in the brain. Some or all of the optic nerve crosses a the midline ( center) ( where they cross.) This is known as the optic tract.
What is the role of the laterl geniculate nucleus ( LGN) in visual processing?
The LGN holds 80-90% of retinal cells and the Superior Colliclus holds 10 -20 %.
It is part of the thalamus and is specialized for visual information. It receives input from both retinas and is the destination for most ganglion cell axon. ** It sends axons to other parts of the thalamus and to the visual areas of the occipital cortex. The primary visual cortex receives information from the LGN.
General overview of visual system
Neurons in the eye are sitmulated which send a projection towards the brain through the optic nerve. The axons are send to the occipital lobe on the back of the head.
Here is some information on ventral and dorsal paths.
The ventral stream is the path that goes through the temporal cortex. It is the “what” path and is specialized for identifying and recognizing objects. The dorsal streatm is the path in the parietal cortez. It is the “where” path. It is important for visually-guided movements.
If there is damage to the right V1, what happens to your vision?
When damage occurs on the right, the left is not visualized by the brain. So, the brain takes the right visual information and flips it to take place for the left.
What if there is damage in the left visual field?
The right visual field is missing, so it takes perception from the right and flips it.
Explain the difference between grey matter and white matter in the brain.
Gray matter is the location of cell bodies and dendrites. The ventral root has motor neuron axons ( cell bodies.) Gray matter processes signals.
White matter is the axonal fibers that project to various brain regions to transmit messages
Name the three major axonal fiber tracts.
The corpus callosum. Anterior Commissure. Posterior Commissure.
Name the two main diviisions of the peripheral nervous system and their functions.
The autonomic nervous system and the somatic nervous system.
Autonomic has the sympathetic & parasympathetic nervous system. Sympathetic ( fight or flight ) MNEMONIC ( SIMP) Simps with fight for the girl. Parasympathetic: Parasites digest food. Somatic nervous system has afferent and efferent nerves. Afferent is sensory intake and efferent is motor action.
What is the role of the dorsal root ganglion in the somatic nervous system?
Is is the sensory neruon cell bodies. Nucelus and ganglion are a cluster of cell bodies that work together to form a function. It is the hub for sensory input. It transmits information to the CNS after being a collection point for sensory nerve cell bodies.
What are cranial nerves and how do they differ from spinal nerves?
Direct link for sensory receptors of the head to brain and the brain to muscles in
the head (i.e., no connection via spinal cord. There are 12 pairs of cranial nerves. There are 31 pairs of spinal nerves. They innervate the spinal cord at four main regions representing different portions of your body. Cervical, thoracic, lumbar, and sacral.
Briefly Describe Bell’s Palsy with causes and symptoms
Sudden weakeness and paralysis on one side of the face due to injury of cranial nerve 7. Exact cause unknown: head, facial injuries, tumors, strokes, ear infection, cold/flu. Effects: Drooped eye, eyelid, mouth, smile.
What is the role of the thalamus in sensory and motor processing?
It is in the forebrain. Medial geniculate nucleus relays auditory information and lateral geniculate nucleus relays visual information.
What are the four major regions of the central nervous system and the five subregions of the brain.
Central Nervous System: CTLS. Cervical, thoracic, lumbar, sacral.
Subregions of the brains Forebrain, midbrain, hindbrain, spinal cord
What is the significance of the neural tube in the development of the central nervous system?
It is a tube during embryonic development. It’s outer layer is cells and is filled with fluid. 40 days - forebrain, midbrain, and hindbrain. 5o days, telencephalon and diencephalon. 100 days - cerebral hemispheres and other brainstem
What changes occur in gray matter as we age, and what is the significance of these changes?
Gray matter thins as we age due to a decrease in synapses ( rearrangement.) Cortical thickness changes. Results in decline in cognitive, functions, memory, attention, and decision making. Like alzheimers and dementia. Brain plasticity.
What is the difference between a a nucleus and a ganglion?
They both work together to perform a function. A nucelus is in the central nervous system and a ganglion is in the peripheral system
What are the primary functions of the medulla oblongata?
Respiration, heart rate, vomiting, salvation, and blood pressure. Afferent and efferent nerves are here.
What are the role so the substantia nigar and dopamine in Parkinson’s disease?
Degeneration is associated with it. Because it produces dopamine neurons. Loss of cells result in less dopamine travelling to the basal ganglia which controls voluntary movement. It is a disorder of movement.
What are the functions of the limbic system?
Emotions, anger, happiness, and fear and memory of emotional experiences. ( Amygdala) (Hippocampus) Storage and retrieval of memories.
What are the functions of the cerebellum and the pons and where are they located?
Associated with development, coordination, gait, and somatosensory information. The pons is a bridge for many sensory axons passing from one side to the other side of the brain. Axons that control sleep, arousal,and dreaming are found here.
What is the tectum, and what are its primary functions?
Is is in the mesencephalon and it relays visual and auditory information, eye and ear orientation movements. Superior = visual. Inferior = auditory
Describe the protective layers of the central nervous system.
Meninges: Dura matter has a otugh outer membraine. Arachnoid matter has a web like membrane. Subarachnoid space ( blood vessels and cerebrospinal fluid.) & Pia mater - delicate and is a layer adjacent to the CNS.
The blood brain barrier are endothelial cells that make up the blood that prevent most chemicals from passing into the brain. ( skull and verterbral columb)
How is the somatosensory cortex organized?
The body is represented in an orderly fashion. ( touch, pain, pressure, temperatue, and body position)
Explain how sensory information from the body reaches the somatosensory cortex.
This is through the dorsal column system. Receptors send axons via the dorsal spinal cord to synapse onto neurons in the brainstem. Axons cross the midline and go to the thalamus.
