Neuroscience of Communication : Chapter 4

Neuroanatomy of Human Nervous System

grey matter is the

cortex in which groups of cell bodies are organized into

Gray matter constitutes neural tissue that consists of the somas (cell bodies) of neurons,

convolutions in cerebral cortes are ___ and ___.

the hills are the and the valleys are the ____

hills gyrus

valley sulcus

nuclei is

groups of cell bodies in the cns

groups of cells bodies in the pns are called ganglia

white matter consist of

whereas white matter consists of collections of axons organized into different-sized bundles

bundles of axons in the pns are called

bundles of axons in the cns are called

pns = NERVES

cns = tracts, fibers, fiber tracts, pathways, peduncles, fasciculus(i), lemniscus(i), capsules, and commissures.

boney protection of the brain and spinal cord is

(this is a source of injury because ..)

skull and vertebral column

major function of the spinal cord is

reflexive activity

reflec is an involuntary motor response to some type of sensory input

normal reflexes are

primitive and present throughout the lifespan

pathological reflexes are

bodily responses rapidly changing environmental conditions without the need for cognitive perception of an event.

spinal cord is continuous wit hlower brainstem beginning at the __foramen which is the

large whole at the bottom of the skull : foramen magnum

identify dorsal/ventral median sulcus, dorsal/ventrolatreral sulci, dorsointermediate sulci

pic

dorsal roots are motor or sensory

sensory

The dorsal pair of fibers is known as the dorsal roots and is comprised of axons that transmit afferent information into the CNS from peripheral sensory endings in the skin, muscle, connective tissues, and viscera, to name a few.

ventral roots are motor or sensory

motor

The ventral pair of fibers is called the ventral roots, consisting of axons of motoneurons that transmit efferent information from the CNS to skeletal muscle, smooth muscle tissue, and glands.

spinal nerves contain sensory or motor fibers

both

dorsal nd ventral rami contain sensory or motor fibers

both

rami communicans supply the

viscera

what parts of the body a re innercated by the cervical, thoracic and lumbra/sacral nerves?

the area of the body that is supplied by a single dorsal root is called

dermatome

myotome

lower motor neuron?

upper motor neuron?

whats their relationship?

LOWER - The primary type of motoneuron populating this ventral gray region is the alpha motoneuron, also known as the lower motoneuron

what is ascending / descending tracts

spinal cord variation in appearance ??

3 major structures of brain stem and location

The three key anatomical elements of the brainstem from rostral to caudal are the mesencephalon (midbrain), the pons, and the medulla oblongata (or more simply the medulla)

the brainstem is found inferior to the cerebrum, rostral to the spinal cord, and anterior to the cerebellum.

what are CNs and why are they included in brainstem

The nerve fibers projecting from the brainstem’s surface are the famous cranial nerves (CNs)

Nuclei of the cranial nerves are discrete collections of gray matter that mediate all incoming sensory information and outgoing motor signals transmitted via the cranial nerves.

what is reticular formation

The brainstem also houses key neural circuits within an ill-defined central core of tissue called the reticular formation. This region regulates everything from cardiopulmonary function to digestion, to motivation, and even attention.

LOCATION OF CNs

what are central pattern generators

The networks that produce these highly coordinated outputs are called central pattern generators (CPGs) and form the neural bases of many brainstem reflexes

• including the gag, laryngeal adductory response to a foreign substance trying to enter the glottis, swallowing, sucking, and aversive facial expressions,

CPGs are highly responsive and sensitive to sensory inputs to remain adaptable to different environmental and task conditions

why are brainstem injuries the worst :/

medulla oblongata

• functions

• respiration control differing in species?

a passageway or conduit for various axon tracts that allow for both motor and sensory communication between the spinal cord and higher areas of the CNS, such as the cerebrum and the cerebellum.

Respiratory neural centers in the medulla control respiration rate. ventral respiratory group is a region of the medulla called the pre-Bötzinger complex - mammal specifc

external features of medulla oblongata

the anterior median fissure, the pyramids, the pyramidal decussation, the olivary eminence, and the nerve roots of the hypoglossal nerve

internal features of medulla oblongata

hypoglossal nucleus, the accessory nucleus, and the dorsal motor nucleus of vagus.

pons

• 3 major functions

• respiration control differ from visceral functions?

functions

• continues the function of the medulla as a major passageway

• facial muscles

• respiratory function

unique visceral becus

• because it can be voluntarily taken over through descending connections when necessary. ex: pausing rhythm to cough or swallow

external of pons

internal of pons

exter: trigeminal system

inter: pontine nuclei

midbrain

• location

• 3 anatomical/functional zones

• external features and internal features

uppermost segment of the brainstem

major conduit for both ascending and descending axon pathways, and a center for cranial nerve functions associated with motion of the eyes

3 zones

• crus cerebi

• tegmentum

• tectum

external

• lateral geniculate nucleus, medial geniculate body

internal

• frontopontine fibers