Chapter 13 Flashcards
Neural plate
Flat plate of ectodermal tissue on dorsal surface of embryo
Brain stem includes
Medulla oblongata, pons, midbrain
Notochord
Rod shaped, influences neural plate in embryo
Neural folds
Lateral sides of neural plate elevate to become waves
Neural groove
Center of the neural plate, the neural crest is the top of the fold
Neural tube
Neural crests fuse together to create the neural tube. Becomes the brain and spinal cord.
Neural crest cells
Separate from neural crests and create sensory, autonomic and enteric neurons
Forebrain, hindbrain, midbrain
Pouches that develop in embryo brain
Telencephalon
Embryo- becomes cerebrum and diencephalon
Midbrain of embryo
Stays single unit, mesencephalon
Hindbrain of embryo
Divides into the metencephalon becoming pons and cerebellum
Myelencephalon
From hindbrain- becomes medulla oblongata
Medulla oblongata
Most inferior part of brainstem. Vital reflexes: heart rate, blood vessel diameter, respiration, swallowing, vomiting, hiccuping, coughing, sneezing
Pyramids
Medulla oblongata. Prominent enlargements
Olives
Medulla oblongata. Oval structures protrude anterior surface. Balance, coordination, modulation of sound
Cranial nerves of medulla oblongata
V trigeminal, VII facial, IX glossopharyngeal, X vagus, XI accessory, XII hypoglossal
Pons
Superior to medulla oblongata. Has ascending and descending tracts.
Pontine nuclei
Pons. Relays information from cerebrum to cerebellum. Sleep center, REM, respiratory
Midbrain cranial nerves
Smallest region. III oculomotor, IV trochlear, V trigeminal
Pons cranial nerves
V trigeminal, VI abducens, VII facial, VIII vestibulocochlear
Tectum
Roof of midbrain.
Corpora quadrigemina
Four nuclei mounds on tectum
Colliculus
Each mound that makes up corpora quadrigemina.
Superior colliculi
Pair of colliculus. Receive sensory input from visual, auditory, tactile, reflex movements of head, and cerebrum
Inferior colliculi
Pair of colliculus. Hearing, auditory pathway in CNS
Tegmentum
Midbrain. Ascending tracts
Red nuclei
Midbrain, tegmentum. Unconscious regulation and coordination.
Cerebral peduncles
Midbrain, ventral to tegmentum. Descending tracts.
Substantial nigra
Midbrain, black substance between tegmentum and cerebral peduncles. Muscle tone and coordination
Reticular formation
Several loosely packed nuclei scattered throughout brainstem. Receives sensory from many axons, especially in face. Alertness, consciousness, sleep wake cycle
Cerebellum, major parts
(Little brain) flocculondular lobe, vermis, two large lateral hemispheres
Flocculnodular
Cerebellum, control balance and eye movements
Vermis
Cerebellum, posture, locomotion, fine motor coordination
Lateral hemispheres of cerebellum
Work with frontal lobes on planning, practicing, learning complex movements
Primary fissure
Divides lateral hemispheres of cerebellum. Anterior, posterior
Superior, middle, inferior cerebellar peduncles
Three tracts that connect the cerebellum with midbrain, pons, medulla oblongata.
Folia
Cerebellar Cortex ridges
Arbor vitae
Cerebellum. White matter of medulla resembles a branching tree
Nuclei of cerebellum
Located deep inferior center of white matter.
Purkinje cells
Cerebellum, receive 200,000 synapses, inhibitory neurons. Only cerebellar cortex neurons that send axons to cerebellar nuclei.
Diencephalon
Between brainstem and cerebrum. Includes thalamus, subthalamus, epithalamus, hypothalamus
Thalamus
Diencephalon, largest part. Sensory relay center. All sensory except smell.
Interthalamic adhesion
Stalk that connects lateral portions of thalamus. Third ventricle of the brain.
Dorsal tier
Thalamus, axons that originate in central posterior nucleus that registers pain.
Thalamus functions
Also influences mood, actions of strong emotions fear and rage
Subthalamus
Small, inferior to thalamus. Ascending and descending tracts. Associated with basal nuclei, control motor functions
Epithalamus
Consists of habenula and pineal gland
Habenula
Epithalamus, sense of smell, emotional and visceral response to odor
Pineal gland
Epithalamus, sleep-wake cycle and other biorhythms
Hypothalamus
Most inferior portion of diencephalon. Control center of endocrine system, body temperature (sweating, shivering) hunger, thirst, sex drive, mood, motivation, emotion
Mammillary bodies
Hypothalamus, olfactory reflexes, emotion response to odors, memory
Infundibulum
Hypothalamus, connects hypothalamus to pituitary gland
Longitudinal fissure of cerebrum
Divides into left and right hemispheres
Gyri
Folds, increase surface area on cerebrum
Sulci
Grooves between gyri
Central sulcus
Cerebrum, divides into anterior and posterior.
Precentral gyrus
Anterior part of cerebrum. The primary motor cortex
Postcentral gyrus
Posterior cerebrum, The primary somatic sensory cortex
Frontal lobe
Voluntary motor function, motivation, aggressions, smell, mood
Prefrontal cortex
Anterior region of frontal lobe. Personality, decision making
Parietal lobe
Major receiving and evaluating center for sensory information. NOT smell, hearing, taste, vision
Occipital lobe
Receiving and integrating visual input
Temporal lobe
Relieves and evaluates input for smell and hearing and important to memory
Lateral fissure
Separates the temporal lobe
Insula
Deep within lateral fissure. Received and evaluates taste information. Often called fifth lobe
Cerebral medulla
White matter of the brain between cortex and nuclei.
Association fibers
Connect areas of cerebral cortex within same hemisphere
Commissural fibers
Connects one cerebral hemisphere to another (CORPUS CALLOSUM)
Projection fibers
Connect cerebrum to other parts of brain and spinal cord. Forms the internal capsule.
Basal nuclei
Group of functionally related nuclei located bilaterally in the inferior cerebrum, diencephalon, midbrain. Motor functions
Limbic system
Cerebrum and diencephalon. Basic survival functions: memory, reproduction, nutrition.
Meninges
3 connective tissue membranes; periosteal dura, menu heal dura, dura mater
Dural folds
Tough connective tissue partitions that extend into major brain fissures
Falx cerebri
Largest dura fold in longitudinal fissure, anchors to crusts Galli
Tentorium cerebelli
Dura fold, horizontal between cerebrum and cerebellum
Dural venous sinuses
Spaces that form where the two layers of dura mater are separated from each other. Transports blood and CSF away from brain to jugular veins
Superior Sagittal sinus.
Largest dura venous sinuses
Septa pellucida
Separates lateral ventricles of cerebrum
Fourth ventricle
In the inferior part of pontine region and superior of the medulla oblongata at the base of cerebellum
Cerebral aqueduct
Third ventricle communicates with fourth ventricle. Extends length of spinal cord.
Cerebral spinal fluid
Clear, similar to plasma without proteins. Baths and cushions CNS. 80-90% specialized ependymal cells
Choroid plexus
Ependymal cells, support tissue, blood vessels
Median and lateral apertures
Allow CSF to pass from fourth ventricle to subarachnoid space
Internal carotid arteries
Ascend to the head along the anterior-lateral part of the neck
Vertebral arteries
Blood ascends through posterior part of the neck through transverse formina of cervical vertebrae
Basilar artery
Vertebral arteries join to form, lies on ventral surface of pons
Cerebral arterial circle
Basilar artery and internal carotid arteries. Branches from basilar arteries supply brain
Cerebral cortex blood supply
Anterior, middle, posterior cerebral arteries
Cranial nerves has one or more functions
Sensory, somatic motor, parasympathetic
Somatic motor
Control of skeletal muscles
Proprioception
Informs brain about the position of various body parts
Parasympathetic
Regulation of glands, smooth muscles, cardiac muscle
Cranial nerves I and II
Olfactory, optic
Oculomotor III
Innervates four of six muscles that move eyeball
Trigeminal nerve V
Somatic motor nerve, proprioceptive, cutaneous sensory. Allows chewing food without biting tongue or cheek
Trochlear nerve IV
Somatic motor nerve. One of six eye ball muscles
Sensory cutaneous innervation
Trigeminal V, sensory to blood vessels in meninges associated with migraine and headache
Alveolar nerves
Innervates the teeth (comes from V)
Abducens nerve VI
Somatic nerve that innervates one of six muscles in eyeball
Facial nerve VII
Somatic, sensory, parasympathetic. Facial expressions, middle ear, two hyoid muscles, taste in 2/3 of tongue, spit, tears
Vestibulocochlear nerve VIII
Sensory, inner ear, balance, special senses
Glossopharyngeal nerve IX
Somatic, sensory, parasympathetic. Pharynx, spit, taste in 1/3 of tongue, middle ear and carotid arteries
Vagus nerve X
Soft palate, pharynx, larynx, taste I. Root of tongue, aortic arch (monitor blood) heart, lungs, kidneys, abdomen
Accessory nerve XI
Somatic, both cranial and spinal roots. Same as vagus nerve, but also sternocleidomastoid and trapezius muscles
Hypoglossal nerve XII
Somatic, intrinsic tongue muscles, thyrohyoid and geniohyoid muscles