Nervous System Need to Know CBIO 2200

Brain stem

Brain Stem : connects brain to spinal cord,, Made up of the medulla oblongata, pons and midbrain. -Responsible for: - Breathing - Swallowing - Heartbeat - Blood pressure

Cerebrum -Fornix

Bridge of white matter inferior to the corpus callosum; links regions of the limbic system ('emotional' brain) together.

Identify the functions of the spinal cord

Information highway between brain and body Extends through vertebral canal from foramen magnum to L1 Each pair of spinal nerves receives sensory information and issues motor signals to muscles and glands Spinal cord is a component of the Central Nervous System while the spinal nerves are part of the Peripheral Nervous System

Interventricular foramen

Interventricular foramen: An opening between the lateral and third ventricles in the system of four communicating cavities within the brain that are continuous with the central canal of the spinal cord.

Cerebrum Important fissures - precentral gyrus, central sulcus, postcentral gyrus, parieto-occipital sulcus, lateral sulcus, transverse fissure

Longitudinal fissure Deep fissure that separates the two hemispheres (right and left) of the cerebrum. Central sulcus Deep groove that separates the frontal lobe from the parietal lobe of the cerebrum. Parietal lobe Region contains the primary sensory cortex (postcentral gyrus) Parieto-occipital sulcus Groove on medial surface of hemisphere that separates the parietal lobe from theoccipital lobe of the cerebrum. Lateral sulcus Deep groove that separates the frontal and parietal lobes from the temporal lobe of the cerebrum. Transverse fissure Deep fissure that separates the cerebrum from the cerebellum.

Distinguish between monosynaptic and polysynaptic reflex arcs

Monosynaptic reflexes involve only one central synapse in the spinal cord grey matter, between the afferent and the efferent neurons. On the other hand, polysynaptic reflexes involve two to several synapses involving one or more interneurons

Identify and describe the elements of a reflex arc on a model or diagram

Most reflex arcs involve only three neurons. The stimulus, such as a needle stick, stimulates the pain receptors of the skin, which initiate an impulse in a sensory neuron. This travels to the spinal cord where it passes, by means of a synapse, to a connecting neuron called the relay neuron situated in the spinal cord.

Classify neurons according to structure and function o Sensory o Motor o Interneuron

Motor neurons are cells that carry information from the central nervous system to the muscles and glands Sensory neurons send signals from body parts to the central nervous system. Interneuron create neural circuits, enabling communication between sensory or motor neurons

Identify important structures of a neuron on a microscope slide, model or diagram o Cell body o Axons and dendrites o Axon terminal

Nerve Cell: Dendrites receive messages from other neurons. The message then moves through the axon to the other end of the neuron, then to the tips of the axon and then into the space between neurons. From there the message can move to the next neuron.

Identify important anatomical areas of the spinal cord on a model or diagram o Dorsal root o Ventral root o Posterior median sulcus o Central canal o Gray commissure o Dorsal, ventral and lateral horns o Anterior median fissure

Refer to picture The ventral roots (anterior roots) allow motor neurons to exit the spinal cord. The dorsal roots (posterior roots) allow sensory neurons to enter the spinal cord.

Describe the difference between gray and white matter

The CNS has two kinds of tissue: grey matter and white matter, Grey matter, which has a pinkish-grey color in the living brain, contains the cell bodies, dendrites and axon terminals of neurons, so it is where all synapses are. White matter is made of axons connecting different parts of grey matter to each other.

Identify the enlargements of the spinal cord o Cervical o lumbar

refer to pic Why enlargements? BECAUSE INCREASED NUMBER OF CELL BODIES FOR MOTOR CONTROL.

Brain Stem -Corpora quadrigemina -Cerebral aqueduct -Cerebral peduncles -Pons -Medulla

refer to picture

Discuss the formation, circulation and drainage of CSF

The CSF is formed in the lateral ventricles Blood Brain Barrier Neurons of the brain and spinal cord are protected from many chemical damage and biological substances by "blood brain barrier", interposed between the blood and the CSF by the endothelial cells of the capillaries and the choroid plexus.

Cerebrum -basal ganglia

The basal ganglia (or basal nuclei), are situated at the base of the forebrain. Basal ganglia connect with the cerebral cortex, thalamus, and brainstem, etc.. The basal ganglia control voluntary motor movements, procedural learning, routine behaviors or "habits" such as teeth grinding, eye movements, cognition, and emotion.

Diencephalon Choroid plexus

The choroid plexus (ChP) is the principal source of cerebrospinal fluid (CSF), which has accepted roles as a fluid cushion and a sink for nervous system waste in vertebrates

Define reflex and reflex arc

A reflex arc defines the pathway by which a reflex travels—from the stimulus to sensory neuron to motor neuron to reflex muscle movement.

Identify the root, the rami, the spinal nerve proper, the dorsal root ganglia

A spinal nerve is formed by the joining of a Ventral root Dorsal root Dorsal root ganglion Functional differences between dorsal roots and ventral roots Ventral roots are motor Dorsal roots are sensory The two primary branches of a spinal nerve are called the Ventral primary ramus - both motor and sensory Dorsal primary ramus - both motor and sensory Comparison of the function of roots vs. the function of rami Roots are EITHER motor OR sensory (ventral = motor, dorsal = sensory) Rami are BOTH motor AND sensory (contain a mixture of motor and sensory axons

Locate the well-recognized functional areas of the human cerebral hemispheres o Broca's area o Wernicke's area o Visual areas (motor and sensory)

Broca's area is a region of the frontal lobe of the left hemisphere. Broca described a patient who had lost the use of speech, and was only able to pronounce the syllable 'tan', but was still able to comprehend spoken language, and communicate with hand gestures. On autopsy, the patient was found to have a lesion in what is now known as Broca's area (1). Wernicke's area is associated with other aspects of language, and is named after the German physician Carl Wernicke. In 1864, Wernicke described a patient who was able to speak, but unable to comprehend language. The patient was found to have a lesion in the posterior region of the temporal lobe (2).

Cerebrum - Lateral ventricles

C-shaped chambers buried deep within each cerebral hemisphere; house choroid plexi that produces cerebrospinal fluid

Cerebellum -Fourth ventricle -Cerebellar hemispheres -Vermis -Arbor vitae

Cerebellum Controls balance, posture and coordination

Identify the 4 major nerve plexuses and identify at least one nerve that arises from each o Cervical o Brachial o Lumbar o Sacral

Cervical plexus - serves the head, neck and shoulders (C1-C8) -major motor branch is the phrenic nerve Brachial plexus - serves the chest, shoulders, arms and hands (C1-C8) - 1. Axillary nerve 2. Radial Nerve 3. Median nerve 4. Musculocutaneous nerve 5. Ulnar nerve Lumbar plexus - serves the back, abdomen, groin, thighs, knees, and calves (L1-L5)-femoral nerve Sacral plexus - serves the pelvis, buttocks, genitals, thighs, calves, and feet (S1-S5)- sciatic nerve

Identify and describe the following o Conus medullaris o Cauda equina o Filum terminale

Conus medullaris: located at L2. This is the tapered termination of the spinal cord proper. Filum terminale: continuation of the pia mater inferior to the conus medullaris. It descends all the way to the coccyx, anchoring the spinal cord. Cauda equina: the collection of nerve roots coming from the end of the spinal cord, within the lumbar cistern, traveling to the vertebral foramina inferior to the conus medullaris. (Latin, cauda equina = horse's tail)

Diencephalon Mammillary bodies

Each mammillary body joins the pretectum, thalamus, and other parts to make up the greater diencephalon part of the brain. Along with the dorsomedial and anterior nuclei of the thalamus, each mammillary body plays in active role in how recognitional memory (like seeing someone's face and remembering you've met before) is processed.

Describe the structure of a nerve, identifying the connective tissue coverings o Epineurium o Perineurium o Endoneurium o Myelin sheath

Epineurium - The outermost layer of dense, irregular connective tissue surrounding a peripheral nerve. Perineurium -A protective sheath covering nerve fascicles. Endoneurium -A layer of connective tissue that surrounds axons. Fascicles-A small bundle of nerve fibers enclosed by the perineurium. Myelin Sheath- The myelin sheath is a greatly extended plasma membrane wrapped around the nerve axon in a spiral fashion. The myelin membranes originate from and are a part of the Schwann cells in the (PNS) and the oligodendroglial cells in the (CNS).

Cerebrum Lobes - frontal, parietal, occipital, temporal

Frontal- contains voluntary motor functions and areas for planning, mood, smell and social judgement Parietal- contains areas for sensory reception & integration of sensory information Occipital- is visual center of brain Temporal- contains areas for hearing, smell, learning, memory, emotional behavior

Distinguish between neurons and glia structurally and functionally

Glia: Insulates, supports, and nourishes neurons Neurons: microscopic nerve cells that make up the brain, spinal cord. Process information Sense environmental changes Communicate changes to other neurons Command body response

List and describe the types of glial cells

Glial cells support neurons and maintain their environment. Glial cells of the (a) central nervous system include oligodendrocytes, astrocytes, ependymal cells, and microglial cells. Oligodendrocytes form the myelin sheath around axons. Astrocytes provide nutrients to neurons, maintain their extracellular environment, and provide structural support. Microglia scavenge pathogens and dead cells. Ependymal cells produce cerebrospinal fluid that cushions the neurons. Glial cells of the (b) peripheral nervous system include Schwann cells, which form the myelin sheath, and satellite cells, which provide nutrients and structural support to neurons.

Diencephalon

In adults, the diencephalon appears at the upper end of the brain stem, situated between the cerebrum and the brain stem. It is made up of four distinct components: the thalamus, the subthalamus, the hypothalamus, and the epithalamus.

Name the meningeal coverings of the spinal cord

The dura mater is the outermost of the three layers making up the meninges. It is a thick, durable membrane, and is closest to the skull. It is responsible for keeping in the cerebrospinal fluid, and for surrounding and supporting the dural venous sinuses that carry blood from the brain to the heart. The arachnoid mater is the middle layer of the meninges, and is named from its spider web-like appearance. It provides a cushioning for the central nervous system. The pia mater is the innermost layer of the meninges. It envelopes and firmly attaches to the surface of the brain and spinal cord. The pia mater contains blood vessels and capillaries that are responsible for nourishing the brain.

Cerebrum -Corpus Callosum

The major bridge of white fibers that connects the two hemispheres of the cerebrum

Diencephalon Optic chiasma and optic nerve

The optic chiasm or optic chiasma is an X-shaped space, located in the forebrain, directly in front of the hypothalamus. Crucial to vision, the left and right optic nerves intersect at the chiasm, thus creating the hallmark X-shape Optic nerve- transmits impulses to the brain from the retina at the back of the eye.

Diencephalon Pineal body

The pineal gland, also known as the pineal body, is an important endocrine gland that produces the hormone melatonin.

Diencephalon Pituitary gland

The pituitary gland is often called the master gland because it controls several other hormone glands in your body, including the thyroid and adrenals, the ovaries and testicles.

Define the following o Gyrus / gyri o Sulcus / sulci o Fissures

The sulci and fissures are both grooves in the cortex but they are differentiated by size. A sulcus is a shallower groove that surrounds a gyrus. A fissure is a large furrow that divides the brain into lobes, and also into the two hemispheres as the medial longitudinal fissure does

Diencephalon Thalamus Hypothalamus

The thalamus plays a major role in regulating arousal, awareness level, and activity. The hypothalamus controls body temperature, hunger, thirst, fatigue, sleep, and circadian cycles.

Cerebrum -Septum pellucidum

Thin vertical partition that separates lateral ventricles

Classify neurons according to structure and function o Unipolar o Bipolar o Multipolar

Unipolar cells have one primary process that give rise to several branches. One of these is the axon and the rest serve as dendritic receiving structures. These cells occur in certain ganglia of the autonomic nervous system of vertebrates. Bipolar cells have two processes emerging from the cell soma: a peripheral process or dendrite which conveys information from the periphery and a central process, the axon, which carries information toward the brain. These cells have mainly sensory functions: retina, olfactory epithelium and sensory cells of the spinal ganglia Multipolar neurons have a single axon and one or more dendritic branches emerging from all parts of the cell body. Multipolar cells vary in the number and length of their dendrites and the length of their axons.

Identify the meningeal coverings of the brain and the spaces between them

dura mater -outermost layer -made of tough, white, fiborous connective tissue -contains many blood vessels -attaches to inside of cranial cavity arachnoid mater -middle layer -thin, web-like membrane -lacks blood vessels -between dura and pia *subarachnoid space: between arachnoid and pia, contains cerebrospinal fluid pia mater -innermost layer -thin, contains blood vessels -attached to surface of brain and spinal cord -nourishes brain cells & protects

Cerebrum Olfactory bulb

located in the forebrain of vertebrates that receives neural input about odours detected by cells in the nasal cavity.