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Gross Anatomy of Brain and Cranial Nerves

Exercise 19; Human Anatomy & Physiology Laboratory Manual (cat version; 10th edition)
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What are the 2 principal divisions of the nervous system?
1. Central Nervous System (CNS)
2. Peripheral Nervous System (PNS)
consists of the brain and spinal cord; interprets incoming sensory information & issues instructions based on that information and past experience
Central Nervous System (CNS)
consists of the cranial and spinal nerves, ganglia, and sensory receptors; serve as communication lines as they carry impulses - from the sensory receptors to the CNS & from CNS to glands, muscles, or other effector organs
Peripheral Nervous System (PNS)
What are the 2 major subdivisions of the PNS and their function?
1. sensory portion: consists of nerve fibers that conduct impulses TOWARD the CNS
2. motor portion: contains nerve fibers that conduct impulses AWAY from the CNS
Name and describe the 2 parts of the motor portion of the CNS.
1. somatic division: controls the skeletal muscle [voluntary divison]
2. autonomic nervous system (ANS): controls smooth and cardiac muscles and glands [involuntary nervous system]; sympathetic and parasympathetic branches play a major role in maintaining homeostasis
CNS first makes its first appearance as a simple tubelike structure called the _____?_____, that extends down the dorsal median plane.
Neural Tube
The developing brain is divided into what 3 major regions?
1. Forebrain
2. Midbrain
3. Hindbrain
After development of the brains 3 major regions, what does the remainder of the neural tube become?
Spinal Cord
The central canal of the neural tube, enlarges in 4 regions of the brain, forming chambers called what?
Ventricles
The ________?________ are the most superior portion of the brain.
Cerebral Hemispheres
elevated ridges of tissue that cover the surface of the brain
Gyri
shallow grooves in the brain
Sulci
deep grooves in the brain
Fissures
What single deep fissure divides the cerebral hemispheres?
Longitudinal Fissure
The ____? ____ divides the frontal lobe from the parietal lobe.
Central Sulcus
The ____? ____ seperates temporal lobe from the parietal lobe.
Lateral Sulcus
The ____? ____ on the medial surface of each hemisphere divides the occipital lobe from the parietal lobe.
Parieto-Occipital Sulcus.
A fifth lobe of each cerebral hemisphere, the __________, is buried deep within the lateral sulcus, and is covered by portions of the temporal, parietal, and frontal lobes.
Insula
The ____? ____ is located in the postcentral gyrus of the parietal lobe.
Primary Somatosensory Cortex
Impulses traveling from the body's sensory receptors (such as those for pressure, pain, and temperature) are localized in what area of the brain?
Primary Somatosensory Cortex
What area immediately posterior to the primary somatosensory area analyzes the meaning of incoming stimuli?
Somatosensory Association Area
What area allows you to become aware of pain, coldness, a light touch, and the like?
Somatosensory Association Area
The olfactory area is deep within the temporal lobe along its medial surface, in a region called the _? _.
Uncus
The ____? ____, is responsible for conscious or voluntary movement of the skeletal muscles.
Primary Motor Area
Where is the primary motor area located?
Precentral Gyrus (of the frontal lobe)
Specialized motor speech area called the ___?___ is found at the base of the precentral gyrus just above the lateral sulcus.
Broca's Area
Damage to this area (located in only one cerebral hemisphere) reduces or eliminates the ability to articulate words.
Broca's Area
Many areas involved in intellect, complex reasoning, and personality lie in the anterior portions of the frontal lobes, in a region called the ____? ____
Prefrontal Cortex
Region at the junction of the parietal and temporal lobe where unfamiliar words are sounded out.
Wernicke's Area
houses centers associated with language skills and speech; "language brain"
Left Hemisphere
concerned with abstract, conceptual, or spatial processes - skills associated with artistic or creative pursuits.
Right Hemisphere
The cell bodies of cerebral neurons involved in the special functions of each hemisphere are found only in the outermost gray matter of the cerebrum, the ____? ____
Cerebral Cortex
The deeper ____? ____ is composed of fiber tracts carrying impulses to or from the cortex.
Cerebral White Matter
Sometimes considered the most superior portion of the brain stem; embryologically part of the forebrain, along with the cerebral hemispheres.
Diencephalon
pituitary gland, olfactory bulbs, tracts, optic nerves, optic chiasma (where fibers of optic nerves partially cross over), optic tracts, mammillary bodies ... are found in the ____? ____
Diencephalon
cerebral peduncles, pons. medulla oblongata, decussation of pyramids ... are structures of the ____? ____
Brain Stem
The ____? ____ consist primarily of motor and sensory fiber tracts connecting the brain with lower CNS centers.
Pons
Lowest brain stem region, composed primarily of fiber tracts.
Medulla Oblongata
What is the major crossover point for the major tracts descending from the cerebrum to the cord?
Decussation of Pyramids
What houses many autonomic centers involved in the control of heart rate, respiratory rhythm, blood pressure, and involuntary centers involved in vomiting, swallowing, and so on.
Medulla Oblongata
Large cauliflower-like ____? ____ which projects dorsally from under the occipital lobes of the cerebrum.
Cerebellum
The deeper area of white matter in the cerebral hemisphere is composed of what?
Fiber Tracts
Fiber tracts found in the white mater of the cerebral hemisphere are called ____? ____ if they run connect two portions of the same hemisphere.
Association Tracts
Fiber tracts that run between the cerebral cortex and lower brain structures or spinal cord are called ____? ____.
Projection Tracts
Fiber tracts are called ___________ if they run from one hemisphere to another.
Commisures
What is the large, major commissure connecting the cerebral hemispheres.
Corpus Callosum
What is the bandlike fiber tract concerned with olfaction as well as limbic system functions?
Fornix
What seperates the lateral ventricles of the cerebral hemispheres?
Septum Pellucidum
In addition to gray matter of the cerebral cortex, there are several islands of gray matter (clusters of neuron cell bodies) called ____? ____ buried deep within the white matter of the cerebral hemisphere.
Nuclei
What important group of cerebral nuclei flank the lateral and third ventricles?
Basal Ganglia
What important subcortical nuclei are involved in regulating voluntary motor activites?
Basal Ganglia
The most important of basal ganglia are the arching, comma-shaped ____? ____, and the ____? ____, composed of the putamen and globus pallidus nuclei.
Caudate Nucleus. Lentiform Nucleus.
The ____? ____, a spray of projection fibers coursing down from the precentral gyrus, combines with sensory fibers traveling to the sensory cortex to form a broad band of fibrous material called the ____? ____.
Corona Radiata. Internal Capsule.
What passes between the diencephalon and the basal ganglia (through parts of it as well), giving them a striped appearance?
Internal Capsule
The caudate nucleus and the lentiform nucleus are collectively called the____? ____
Corpus Striatum
What are the 3 major internal structures of the diencephalon?
1. Thalamus
2. Hypothalamus
3. Epithalamus
The ____? ____ consists of two large lobes of gray matter that laterally enclose the 3rd ventricle of the brain. Major integrating and relay station for sensory impulses passing upward to the cortical sensory areas for localization and interpretation.
Thalamus
The ____? ____ makes up the floor and the inferolateral walls of the 3rd ventricle. Important autonomic center involved in regulation of body temp, water balance, and fat and carbohydrate metabolism as well as drives like sex, hunger, thirst, etc.
Hypothalamus
The ____? ____ form the roof of the 3rd ventricle.
Epithalamus
What 2 important structures are found in the epithalamus?
1. Pineal gland
2. Choroid plexus
What travels through the midbrain and connects the 3rd ventricle to the 4th ventricle?
Cerebral Aqueduct
The cerebellus is composed of two lateral hemispheres each with 3 lobes connected by a midline lobe called the ____? ____
Vermis
The treelike branchinig of the cerebellar white matter is referred to as the ____? ____, or "tree of life"
Arbor vitae
The brain and spinal cord are covered by 3 connective tissue membranes called ____? ____.
Meninges
What are the 3 parts of the meninges?
1. Dura Mater: outermost meninx; double-layered membrane
2. Arachnoid Mater: middle meninx; weblike
3. Pia Mater: innermost meninx; delicate, highly vascular
Name and describe the 2 layers of the dura mater.
1. Periosteal Layer: attached to inner surface of skull, forming the periosteium
2. Meningeal Layer: outmost brain covering, continuous with dura mater of the spinal cord
specialized projections of the arachnoid tissue that protrude through the dura mater to allow the cerebrospinal fluid to drain back into the venous circulation via the superior sagitttal sinus and other dural sinuses
Arachnoid Villi
The cerebrospinal fluid, much like plasma in composition, is continually formed by the ___?___; small capillary knots hanging from the roof of the ventricles of the brain.
Choroid Plexuses
Within the brain, cerebrospinal fluid circulates from the two later ventricles (in the cerebral hemispheres) into the 3rd ventrical via the ____? ____.
Interventricular Foramina
Mnemonic to help remember the 12 cranial nerves:
On Occasion Our Trusty Truck Acts Funny---Very Good Vehicle Any How.
1 Cranial Nerve
Olfactory (filaments of)
2 Cranial Nerve
Optic
3 Cranial Nerve
Oculomotor
4 Cranial Nerve
Trochlear
5 Cranial Nerve
Trigeminal
6 Cranial Nerve
Abducens
7 Cranial Nerve
Facial
8 Cranial Nerve
Vestibulocochlear
9 Cranial Nerve
Glossopharyngeal
10 Cranial Nerve
Vagus
11 Cranial Nerve
Accessory
12 Cranial Nerve
Hypoglossal