Lab 8 Flashcards
What are the functional differences between neurons and neuroglia?
Neurons = responsible for the computation and communication that the nervous system provides. They are electrically active and release chemical signals to target cells.
Neuroglia (glial cells) = play a supporting role for nervous tissue.
Describe 1 major function for each of the 6 neuroglia cells.
Astrocytes (CNS) = support
Oligodendrocytes (CNS) = insulation, myelination
Microglia (CNS) = immune supervision & phagocytosis
Ependymal cells (CNS) = making CSF from filtrate
Satellite cells (PNS) = support
Schwann cells (PNS) = insulation and myelination
List important anatomical features of a neuron and relate each part to its function.
Cell Body (Soma) = contains nucleus
2 types of processes = dendrites (receptor region) & axons (conducts action potentials)
Axon collateral = propagates the electrical signal.
Axon hillock (initial segment) = where the axon emerges from the cell body. Elicits a nerve impulse that travels down the axon.
Myelinated fibers = acts as insulation; myelin sheath is formed by schwann cells.
Myelin Sheath Gaps (nodes of Ranvier) = allow electrical signals to “jump” from gap to gap, increasing speed of conduction.
Terminal branches = at the end of the axon where there is an enlarged bulb called the axon terminal.
Synaptic vesicles = store neurotransmitter in axon terminals.
Synaptic cleft = small gap that separates the presynaptic neuron and postsynaptic neuron.
Nucleus = collection of neuron cell bodies in CNS.
Ganglion = collection of neuron cell bodies in PNS.
Classify neurons structurally:
Structurally - the number of processes attached to cell body.
Unipolar (pseudounipolar) = 1 process emerging from the cell. Sensory neurons.
Bipolar = 2 processes (1 axon & 1 dendrite). Primarily found in the olfactory epithelium (where smell stimuli are sensed), and part of the retina.
Multipolar = have 1 axon and 2 or more dendrites.
Classify neurons functionally:
Sensory (Efferent) Neurons = Carry info towards CNS.
Interneurons (Association Neurons) = found exclusively within CNS; receive info from sensory neurons or other interneurons.
Motor (Efferent) Neurons = Carry info away from CNS; receive information from interneurons or directly from sensory neurons in order to stimulate responses.
Name, number (in Roman numeral), and state general and specific functions of all 12 cranial nerves:
GF = general function; SF = specific function.
Olfactory (I) = GF (sensory); SF (olfaction).
Optic (II) = GF (sensory); SF (vision).
Oculomotor (III) = GF (motor); SF (opening of eyelid, movement of the eyeball; accommodation of lens; constriction of pupil).
Trochlear (IV) = GF (motor); SF (movement of eyeball).
Trigeminal (V) = GF (sensory and motor); SF (sensory - touch, pain, and temp; motor - chewing)
Abducens (VI) = GF (motor); SF (movement of eyeball).
Facial (VII) = GF (sensory & motor); SF (sensory - taste; motor - facial expression and secretion of saliva and tears).
Vestibulocochlear (VIII) = GF (sensory & motor); SF (sensory - vestibular - equilibrium; sensory - cochlear - hearing; motor - altering the motility of outer hair cells which is responsive to hearing).
Glossopharyngeal (IX) = GF (sensory & motor); SF (sensory - touch, pressure, and pain from tongue, pharynx and middle ear; sensory - taste, regulation of blood pressure and respiration, sensory input for gag reflex; motor - secretion of saliva).
Name, number (in Roman numeral), and state general and specific functions of all 12 cranial nerves:
GF = general function; SF = specific function.
Olfactory (I) = GF (sensory); SF (olfaction).
Optic (II) = GF (sensory); SF (vision).
Oculomotor (III) = GF (motor); SF (opening of eyelid, movement of the eyeball; accommodation of lens; constriction of pupil).
Trochlear (IV) = GF (motor); SF (movement of eyeball).
Trigeminal (V) = GF (sensory and motor); SF (sensory - touch, pain, and temp; motor - chewing)
Abducens (VI) = GF (motor); SF (movement of eyeball).
Facial (VII) = GF (sensory & motor); SF (sensory - taste; motor - facial expression and secretion of saliva and tears).
Vestibulocochlear (VIII) = GF (sensory & motor); SF (sensory - vestibular - equilibrium; sensory - cochlear - hearing; motor - altering the motility of outer hair cells which is responsive to hearing).
Glossopharyngeal (IX) = GF (sensory & motor); SF (sensory - touch, pressure, and pain from tongue, pharynx and middle ear; sensory - taste, regulation of blood pressure and respiration, sensory input for gag reflex; motor - secretion of saliva).
Vaxus (X) = GF (sensory & motor); SF (sensory - taste, monitoring blood pressure, and blood O2 & CO2 concentration, sensations from viscera; motor - swallowing, coughing and speech, smooth muscle activity of the GI tract, secretions of digestive organs, regulation of heart rate and breathing).
Accessory (XI) = GF (motor); SF (cranial - swallowing, spinal - movement of head and shoulder).
Hypoglossal/tongue (XII) - GF (motor); SF (tongue movement for speech, food, manipulation and swallowing).
Describe the general structure of a nerve:
The outer surface of a nerve is a surrounding layer of fibrous connective tissue (epineurium). Within the nerve, axons are further bundled into fascicles, which are surrounded by their own layer of fibrous connective tissue called perineurium. Finally, individual axons are surrounded by loose connective tissue called the endoneurium.
List the four adult brain regions:
Cerebrum
Diencephalon
Brainstem
Cerebellum
Describe the Cerebrum:
Covered by the cerebral cortex (a continuous layer of wrinkled gray matter). A gyrus is the ridge of one of the wrinkles, and a sulcus is the superficial groove between two gyri.
Cerebrum is divided into left and right hemispheres via the longitudinal fissure.
Deep within the cerebrum, the white matter of the corpus callosum provides the major pathway for communication between the two cerebral hemispheres.
Many of the higher neurological functions (memory, emotion, and consciousness) are the result of cerebral function.
- Central Sulcus = separates the frontal lobe from the parietal lobe.
- Lateral Sulcus = separates the temporal lobe from the parietal lobe.
- Occipital lobe = the posterior region of the cortex.
- Insular lobe (insula) = deep within the lateral sulcus; fifth lobe of the brain.
- Parietal lobe = processes general sensations associated with the body.
- Posterior to the central sulcus is the postcentral gyrus, where the primary somatosensory cortex is located.
- Frontal lobe = responsible for complex functions –> motor functions (planning and executing movements via commands sent to the spinal cord and periphery).
- Primary motor cortex is in the precentral gyrus, located anterior to the central sulcus.
- Broca’s area = at the base of the left cerebral hemisphere’s precentral gyrus - controls movements responsible for speech.
- Prefrontal cortex = serve critical cognitive functions associated with short-term memory and consciousness.
- Wernicke’s area = damage causes receptive aphasia (a loss of understanding rather than a loss of speech).
Describe the Cerebrum:
Covered by the cerebral cortex (a continuous layer of wrinkled gray matter). A gyrus is the ridge of one of the wrinkles, and a sulcus is the superficial groove between two gyri.
Cerebrum is divided into left and right hemispheres via the longitudinal fissure.
Deep within the cerebrum, the white matter of the corpus callosum provides the major pathway for communication between the two cerebral hemispheres.
Many of the higher neurological functions (memory, emotion, and consciousness) are the result of cerebral function.
- Central Sulcus = separates the frontal lobe from the parietal lobe.
- Lateral Sulcus = separates the temporal lobe from the parietal lobe.
- Occipital lobe = the posterior region of the cortex.
- Insular lobe (insula) = deep within the lateral sulcus; fifth lobe of the brain.
- Parietal lobe = processes general sensations associated with the body.
- Posterior to the central sulcus is the postcentral gyrus, where the primary somatosensory cortex is located.
- Frontal lobe = responsible for complex functions –> motor functions (planning and executing movements via commands sent to the spinal cord and periphery).
- Primary motor cortex is in the precentral gyrus, located anterior to the central sulcus.
- Broca’s area = at the base of the left cerebral hemisphere’s precentral gyrus - controls movements responsible for speech.
- Prefrontal cortex = serve critical cognitive functions associated with short-term memory and consciousness.
- Wernicke’s area = damage causes receptive aphasia (a loss of understanding rather than a loss of speech).
- Primary auditory cortex = in the temporal lobe; where auditory information is processed; crucial for memory formation and long-term memory.
- Primary auditory cortex = located in the occipital lobe; where visual processing begins.
Describe the Diencephalon:
2 major regions: thalamus & hypothalamus.
Most of the CNS and PNS send info to the cerebrum through the diencephalon.
Thalamus = collection of nuclei that relay info between the cerebral cortex and the periphery, spinal cord, or brain stem. All sensory info passes through the thalamus before processing by the cortex. The cerebrum interacts with the basal nuclei is to the thalamus, which relays that output to the cerebral cortex.
Pineal Gland = tiny endocrine gland that produces and secretes melatonin.
Hypothalamus = a collection of nuclei largely involved in regulating homeostasis (heart rate, digestion, and respiratory rate) and endocrine functions (growth and development via hormone secretion).
Pituitary Gland = bean-sized organ suspended from hypothalamus by a stem called the infundibulum.
Hypothalamus-pituitary complex is the “command center” of the endocrine system - secretes hormones.
Describe the Cerebrum:
Covered by the cerebral cortex (a continuous layer of wrinkled gray matter). A gyrus is the ridge of one of the wrinkles, and a sulcus is the superficial groove between two gyri.
Cerebrum is divided into left and right hemispheres via the longitudinal fissure. Deep within the cerebrum, the white matter of the corpus callosum provides the major pathway for communication between the two cerebral hemispheres.
Many of the higher neurological functions (memory, emotion, and consciousness) are the result of cerebral function.
- Central Sulcus = separates the frontal lobe from the parietal lobe.
- Lateral Sulcus = separates the temporal lobe from the parietal lobe.
- Occipital lobe = the posterior region of the cortex.
- Insular lobe (insula) = deep within the lateral sulcus; fifth lobe of the brain.
- Parietal lobe = processes general sensations associated with the body.
- Posterior to the central sulcus is the postcentral gyrus, where the primary somatosensory cortex is located.
- Frontal lobe = responsible for complex functions –> motor functions (planning and executing movements via commands sent to the spinal cord and periphery).
- Primary motor cortex is in the precentral gyrus, located anterior to the central sulcus.
- Broca’s area = at the base of the left cerebral hemisphere’s precentral gyrus - controls movements responsible for speech.
- Prefrontal cortex = serve critical cognitive functions associated with short-term memory and consciousness.
- Wernicke’s area = damage causes receptive aphasia (a loss of understanding rather than a loss of speech).
- Primary auditory cortex = in the temporal lobe; where auditory information is processed; crucial for memory formation and long-term memory.
- Primary auditory cortex = located in the occipital lobe; where visual processing begins.
Describe the Brainstem:
Contains midbrain and hindbrain (composed of the pons and medulla oblongata).
Midbrain = coordinates sensory representations of the visual, auditory, and somatosensory perceptual info.
Pons and Medulla = regulates cardiovascular and respiratory systems and rates. Pons is the main connection between the cerebellum and the brain stem.
Describe the Cerebellum:
Covered in gyri and sulci.
Has an outer cortical area of gray matter and an inner area of treelike branching white matter (arbor vitae).
Midline regions = involved in comparing visual info, equilibrium, and proprioceptive feedback to maintain balance and coordinate movements (walking/gait).
