NS: The Brain
True of False. While the brain has outer Gray matter and inner White matter, the Medulla Oblongata and the Spinal Cord have outer White matter and inner Gray matter
True
True or False. Cerebellum is the 2nd largest brain area, after cerebrum
True
True or False. Cerebellum is the most posterior brain region and is most vulnerable to toxins.
True
True or False. Telencephalon grows more than other parts and covers the diencephalon. This is why the cerebrum covers the diencephalon.
True
What are the 4 main brain regions?
1. Cerebrum (biggest) 2. Cerebellum (2nd biggest) 3. Diencephalon (covered by cerebrum) 4. Brainstem
What are the 4 components that provide protection to the brain?
1. Skull (bone) 2. Meninges (membranes) 3. Cerebrospinal Fluid 4. Blood-Brain Barrier
Describe the Brain Ventricles: 2 Lateral Ventricles Third Ventricle Fourth Ventricle
2 Lateral Ventricles are large cavities in the cerebrum that is separated by septum pellucidum. Third Ventricle is a narrow space in the middle of diencephalon. Fourth Ventricle is a sickle-shaped (diamond) space between pons and cerebellum, and its connected to the Third Ventricle via cerebral aqueduct. Ventricles contain CSF!
CN I is called the ______ nerve. It is a ________ nerve for _________
CN I is called the olfactory nerve It is a sensory nerve for olfaction (smell)
Describe 3 types of cerebral white matter tracts: Association Tracts Commissural Tracts Projection Tracts
Association Tracts: connect cerebral lobes within same hemisphere (horizontal) Commissural Tracts: connect cerebral lobes of left and right hemisphere (horizontal) (ex. corpus callosum) Projection Tracts: connect superior regions of the brain to inferior regions and spinal cord (vertical); decussation (crossing of nerve fibers) occurs that allows left brain to control right side of the body.
Brainstem connects cerebrum, diencephalon, and cerebellum to the ___________. It consists of _____, _____, ______. The brain stem is very important because it keeps you alive, and controls _______ and ______ system
Brainstem connects cerebrum, diencephalon, and cerebellum to the spinal cord. It consists of midbrain, pons, medulla oblongata. The brain stem is very important because it keeps you alive, and controls heart and respiratory system
CN II is called the _____ nerve. It is a ______ nerve for __________
CN II is called the optic nerve. It is a sensory nerve for vision
CN III is called the _____ nerve. It is _____ nerve that controls skeletal muscle that moves _____ or lift eyelids. It also controls _______ muscle that helps with pupil dilation/constriction or changing lens shape. Therefore, it is a __________ and __________ motor nerve.
CN III is called the oculomotor nerve. It is motor nerve that controls skeletal muscle that moves eyes or lift eyelids. It also controls smooth muscle that helps with pupil dilation/constriction or changing lens shape. Therefore, it is both somatic and autonomic motor nerve.
CN IV is called the _____ nerve. It is a _______ nerve that controls ______ ______ eye muscle
CN IV is called the Trochlear nerve. It is a motor nerve that controls superior oblique eye muscle
CN IX is called the _____ nerve It is a ______ nerve that controls muscle of ________, and receives ________ and ______ sensations from the _______ It also increases _______ by stimulating _______ gland. Therefore, it is a __________ and __________ motor nerve.
CN IX is called the Glossopharyngeal nerve It is a mixed nerve that controls muscle of pharynx, and receives touch and taste sensations from the tongue It also increases saliva by stimulating salivary gland. Therefore, it is both somatic and autonomic motor nerve.
CN V is called the ______ nerve. It is a ______ nerve that receives somatic sensations from ______ (outside) and controls muscles involved in ________
CN V is called the Trigeminal nerve. It is a mixed nerve that receives somatic sensations from face (outside) and controls muscles involved in chewing
CN VI is called the _______ nerve. It is a ______ nerve that controls _______ _______ muscle that abducts eye (turning eye outward toward ear)
CN VI is called the Abducens nerve. It is a motor nerve that controls lateral rectus muscle that abducts eye (turning eye outward toward ear)
CN VII is called the ______ nerve It is a _____ nerve that controls muscles of ______ _______, and conducts ______ sensations from ______ It also increases _______ by stimulating _______ gland. Therefore, it is a __________ and __________ motor nerve.
CN VII is called the Facial nerve It is a mixed nerve that controls muscles of facial expression, and conducts taste sensations from tongue It also increases saliva by stimulating salivary gland. Therefore, it is both somatic and autonomic motor nerve.
CN VIII is called the _____ nerve It is a _____ nerve involved in _______ and _______
CN VIII is called the Vestibulocochlear nerve It is a sensory nerve involved in hearing and equilibrium
CN X is called the ______ nerve It is a ______ nerve that controls muscle of ______ and ______, and conductions sensations from many ________. It serves all throacic and abdominal _______ (heart, lungs, etc.), and accounts for 90% of preganglionic parasympathetic fibers in body
CN X is called the Vagus nerve It is a mixed nerve that controls muscle of pharynx and larynx, and conductions sensations from many viscera. It serves all throacic and abdominal viscera (heart, lungs, etc.), and accounts for 90% of preganglionic parasympathetic fibers in body Therefore, it is both somatic and autonomic motor nerve.
CN XI is called the _____ nerve It is a _____ nerve that controls muscles of _____, _____ (Trapezius muscle, Sternocleidomastoid muscle)
CN XI is called the Accessory nerve It is a motor nerve that controls muscles of neck, pharynx (Trapezius muscle, Sternocleidomastoid muscle)
CN XII is called the ______ nerve It is a _____ nerve that controls ________ muscles
CN XII is called the Hypoglossal nerve It is a motor nerve that controls tongue muscles
How is CSF formed? Describe the circulation of CSF in the brain.
CSF is formed by choroid plexus (contains ependymal cells) in each ventricle (lateral ventricles, third ventricle, fourth ventricle). CSF flow: Lateral Ventricles --> 3rd Ventricle --> 4th Ventricle --> Path 1 or Path 2 Path 1: lateral/median aperture --> subarachnoid space --> *Dura venous sinus (via Arachnoid villi) Path 2: Central canal of spinal cord *CSF needs to go to the Dura venous sinus for circulation (otherwise it can cause hydrocephalus)
Cerebellum contains ________ cortex, which is outer convoluted surface of gray matter with _____ (folds like gyrus), and the ______ _______, which is the internal region of white matter. The left and right cerebellar hemispheres are divided by _______
Cerebellum contains Cerebellar cortex, which is outer convoluted surface of gray matter with Folia (folds like gyrus), and the Arbor vitae, which is the internal region of white matter. The left and right cerebellar hemispheres are divided by Vermis.
What are Cranial Meninges? Describe the layers from superficial to deep.
Cranial Meninges are membranes composed of three connective tissue layers that separate and support soft tissue of the brain, enclose and protect blood vessels supplying the brain, and help contain and circulate cerebrospinal fluid. Dura Mater (thick) Arachnoid Mater Pia Mater (thin)
Epithalamus contains a _______ gland which secretes ________, and helps maintain circadian rhythm
Epithalamus contains a pineal gland which secretes melatonin, and helps maintain circadian rhythm
What are the 3 components of the Diencephalon?
Epithalamus, Thalamus, Hypothalamus
Describe the functions of the 5 lobes of the cerebrum: Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe Insula
Frontal Lobe: motor control, concentration, verbal communication, decision making, planning, personality Parietal Lobe: general sensory functions (skin, muscle) Occipital Lobe: vision, visual memories Temporal Lobe: hearing and smell Insula: gustatory (taste)
_________ is the stalk of the pituitary gland that extends from the hypothalamus (connection). Describe the functions of the Hypothalamus: 1. Control of Autonomic Nervous System 2. Control of Endocrine System 3. Regulation of body temperature 4. Food intake 5. Water intake 6. Emotional Behavior
Infundibulum is the stalk of the pituitary gland that extends from the hypothalamus (connection). 1. Control of Autonomic Nervous System -influences heart rate, blood pressure, digestive activities, respiration (pulse rate) 2. Control of Endocrine System -secretes hormones that control activities in anterior pituitary gland 3. Regulation of body temperature (37 C) 4. Food intake (regulate hunger, controls appetite) 5. Water intake (regulate thirst, controls appetite) 6. Emotional Behavior (controls feelings)
Left hemisphere of the cerebrum interprets ______ visual field, and Right hemisphere of the cerebrum interprets _____ visual field.
Left hemisphere of the cerebrum interprets right visual field, and Right hemisphere of the cerebrum interprets left visual field.
What is the function of the Cerebellum?
Muscle coordination to distribute our weight; balance.
Describe these functional areas of the cerebrum Primary motor cortex Secondary/Premotor cortex (somatic motor association area) Primary somatosensory cortex Somatosensory association area (secondary) Primary visual cortex Secondary visual cortex (visual association area) Primary auditory cortex Secondary auditory cortex (auditory association area)
Primary motor cortex: -housed within frontal lobes (precentral gyrus) -controls skeletal muscle activity on opposite side of body (ex. left hemisphere controls right side of body) -controlled body regions map as motor homunculus (ex. hands are large on homunculus because large area of the brain control their precise movements) Secondary motor/Premotor cortex (somatic motor association area): -located anterior to primary motor cortex -coordinates learned, skilled activities Primary somatosensory cortex: -located in parietal lobes (postcentral gyrus) -receives somatic sensory information (touch, pressure, pain, temperature receptors) -areas of body sending input can be mapped as sensory homunculus (distorted proportions) Secondary somatosensory cortex (Somatosensory association area): -located immediately posterior to postcentral gyrus -integrates touch information allowing us to identify objects by feel (sensation based on memory) Primary visual cortex: -located within occipital lobe Secondary visual cortex (visual association area): -surrounds/anterior to primary visual cortex -integrates color, form, memory; helps us identify things we see (faces) Primary auditory cortex: -located within temporal lobe Auditory association area: -located within temporal lobe -helps us interpret sound; stores/retrieves memory of sounds
Be able to identify: Medial Longitudinal Fissure (deep sulcus separating L/R hemisphere) Lateral fissure (sulcus) Corpus callosum Lateral ventricles Third ventricle Septum pellucidum (membrane between lateral ventricles) Thalamus Hypothalamus
See Diagram
Identify the following areas in the diagram: Olfactory Tract (CN I) Optic Tract (CN II) Optic Chiasm
See Diagram
Identify the regions of the Diencephalon: Epithalamus Pineal Gland Thalamus Mammillary Body Interthalamic adhesion Hypothalamus Infundibulum Pituitary Gland
See Diagram
In the diagram of the cerebrum, be able to identify: Left/Right hemispheres Longitudinal fissure Precentral Gyrus (primary motor cortex) Postcentral Gyrus (primary somatosensory cortex) Sulcus
See Diagram
In the midsagittal view of the brain, be able to identify: Corpus Callosum Septum pellucidum Cerebellum Diencephalon (Epithalamus, Thalamus, Hypothalamus) Brain Stem (Midbrain, Pons, Medulla Oblongata)
See Diagram
Describe the functions of Falx cerebri, Falx cerebelli, and Tentorium cerebelli.
See Diagram Falx cerebri: Meningeal layer of Dura mater that projects into longitudinal fissure between 2 cerebral hemispheres (vertical) Falx cerebelli: separates 2 hemispheres of cerebellum (vertical) Tentorium cerebelli: separates the cerebrum from the cerebellum (horizontal)
Be able to identify: 5 lobes of cerebrum (Frontal, Parietal, Occipital, Temporal, Insula) Central sulcus Lateral sulcus (fissure) Parieto-occipital sulcus
See Diagram Insula is deep to frontal and temporal lobe (fissure) Central sulcus is between frontal and parietal lobes, Lateral sulcus is between frontal + parietal and temporal lobes, Parieto-occipital sulcus is between parietal and occipital lobes.
Describe the development of brain divisions (Neurulation)
See Diagram Neurulation begins in the 3rd week of embryonic development. a) Neural Tube: The anterior portion of the neural tube becomes the brain, and the posterior portion of the neural tube becomes the spinal cord. Therefore, both brain and spinal cord come from 1 neural tube. b) Primary brain vesicles: Prosencephalon or Forebrain (most anterior) Mesencephalon or Midbrain Rhombencephalon or Hindbrain (most posterior) c) Secondary brain vesicles: Telencephalon (from Prosencephalon, most anterior) Diencephalon (from Prosencephalon) Mesencephalon (from Mesencephalon) Metencephalon (from Rhombencephalon) Myelencephalon (from Rhombencephalon, most posterior) d) Adult brain structures: Telencephalon --> Cerebrum Diencephalon --> Diencephalon Mesencephalon --> Brain stem (midbrain) Metencephalon --> Brain stem (pons), Cerebellum Mylencephalon --> Brain stem (medulla oblongata) e) Adult neural canal regions Telencephalon --> Lateral Ventricles Diencephalon --> Third Ventricle Mesencephalon --> Cerebral Aqueduct Metencephalon --> Fourth Ventricle Mylencephalon --> Fourth Ventricle Spinal Cord --> Central Canal
Be able to identify structures near Cranial Meninges: Periosteal layer (layer of Dura mater attached to skull) Meningeal layer Arachnoid mater Subarachnoid Space (contains CSF) Pia mater (goes into sulcus/fissures) Falx cerebri (meningeal layer of Dura mater between L/R Hemis.) Dural venous sinus Arachnoid villus
See Diagram Periosteal layer is the layer of Dura mater attached to the skull. Subarachnoid Space contains CSF Pia mater goes into sulcus/fissures Falx cerebri is the Meningeal layer of Dura mater that occupies space between left and right hemispheres of cerebrum Dural venous sinus is a triangle shaped space that is formed by between Periosteal and Meningeal layer which contains blood. Arachnoid villus causes CSF to go into the Dural venous sinus.
The 12 pairs of cranial nerves are part of the _________ nervous system, and originate from the brain.
The 12 pairs of cranial nerves are part of the Peripheral nervous system, and originate from the brain.
The Gray matter is made of neuron ________, dendrites, __________ axons. The Gray matter appears dark because ________. Cerebral ______ is the superficial layer of Gray matter that is the majority of Gray matter, while Cerebral ______ are regions of Gray matter are deeper within the brain. The White matter consists of ________ axons, and are organized in bundles called _______. In the brain, White matter is deeper to the Gray matter and appears white because it contains _______. The _________ _________ is a White matter that connects the left and right hemispheres of the brain.
The Gray matter is made of neuron cell bodies/soma, dendrites, unmyelinated axons. The Gray matter appears dark because soma contains nuclei, which appear dark. Cerebral cortex is the superficial layer of Gray matter that is the majority of Gray matter, while Cerebral nuclei are regions of Gray matter are deeper within the brain. The White matter consists of myelinated axons, and are organized in bundles called tracts. In the brain, White matter is deeper to the Gray matter and appears white because it contains lipids. The corpus callosum is a White matter that connects the left and right hemispheres of the brain.
The outer surface of the brain is folded. _______ are the ridges, and ______ are the depressions between the ridges, where ______ are deep sulci.
The outer surface of the brain is folded. Gyrus/Gyri are the ridges, and Sulcus/Sulci are the depressions between the ridges, where Fissures are deep sulci.
The right and left thalamus are connected by ____________. The Thalamus serves as a relaying center, as it receives signals from all conscious senses except ________, which is actually received by _________, (relays signal to the ________ lobe). The Thalamus, as a relay center, relays signals to appropriate part of the cortex and to appropriate lobes.
The right and left thalamus are connected by interthalamic adhesion. The Thalamus serves as a relaying center, as it receives signals from all conscious senses except olfaction, which is actually received by Mammillary Body, (relays signal to the temporal lobe). The Thalamus, as a relay center, relays signals to appropriate part of the cortex and to appropriate lobes.