W5: CNS - On FINAL

WCU ONT W5

Dura mater

tough, fibrous outermost layer of spinal meninges

Arachnoid mater

middle layer separated from pia mater by subarachnoid space, cerebrospinal fluid flows within space

Pia mater

deepest layer, has blood vessels, firmly bound to brain and spinal cord tissue

Gray matter

surrounds central canal of the spinal cord, consists of neuron somas and glial cells

White matter

located outside gray matter, consists of axons, nerves are organized into tracts or columns

Dorsal horn

somatic sensory plus visceral sensory

Lateral horn

visceral motor

Ventral horn

somatic motor

Somatic sensory

Carries sensory information from skin, skeletal muscles and joints to CNS.

Visceral sensory

Carries sensory information from internal organs to CNS.

Somatic motor

Sends motor commands from CNS to skeletal muscles for voluntary movement.

Visceral motor

Sends motor commands from CNS to smooth muscle, cardiac muscle and glands for involuntary control.

Medulla oblongata

consists of cardiovascular centers and respiratory centers,

Pons

prominent bulge above medulla, consists of cerebella peduncles

Mesencephalon

also called midbrain, consists of substantia nigra and cerebral peduncles, 2 pairs of nuclei corpora quadrigemina

Substantia nigra

regulates motor output of the basal nuclei, only blends and smooths slow deliberate movements

Cerebral peduncles

has ascending fibers that synapse in thalamus and descending fibers of corticospinal pathway

Auditory processing occurs in the....

inferior colliculus

Visual processing occurs in the....

superior colliculus

Reticular formation

involved in maintaining alertness

Corpora quadrigemina

responsible for processing auditory and visual stimuli

Diencephalon

consists of epithalamus, thalamus and hypothalamus

Epithalamus

contains pineal gland

Pineal gland

produces melatonin

Thalamus

relay station in the brain, processes and transmits sensory information to the cerebral cortex, like a gateway

Hypothalamus

controls endocrine system, body temperature, emotional, behavioral and sex drives

Hypothalamus drives

hunger, thirst and sex drives

Cerebellum

2 hemispheres, coordinates automatic ballistic and complex movements

Cerebrum

2 giant hemispheres, several lobes

Cerebral cortex

composed of gray matter, triples its size, approximately 40% of brain mass

Cerebral cortex functional areas

sensory, association and motor areas

Primary somatosensory cortex

receives and processes raw sensory information from the body.

Spatial discrimination

precisely locates a stimulus

Contralateral

cerebral hemispheres, receives sensory input from opposite side of body

Sensory homunculus

body map of sensory cortex

Somatosensory cortex

processes sensory input from body including touch, pressure, pain, temperature, and proprioception.

Primary visual cortex

largest sensory area, receives visual information from retina

Primary auditory cortex

conscious awareness of sound

Auditory association area

involved in the interpretation and recognition of sounds, especially speech and language.

Wernicke's area (Vernicke)

responsible for language comprehension.

Olfactory cortex

brain region that receives and processes smell information from olfactory nerves, involved with recalling specific smells

Rhinencephalon

meaning nose brain

Limbic system

explains why smells trigger emotions

4 basic motor sections

premotor cortex, primary motor cortex, frontal eye field and broca's area

Premotor cortex

involved in planning movements

Primary motor cortex

controls motor function

Pyramidal cells

large neurons of primary motor cortex

Corticospinal tracts

descend through brain stem and spinal cord, axons signal motor neurons to control skilled movement

Frontal eye field

controls voluntary eye movement especially when following a target

Broca's area

manages speech production, connected to language comprehension areas

Posterior association area

sensory perception, spatial awareness of body, language and speech comprehension

Anterior association area

also called prefrontal cortex, high level cognitive function

Limbic association area

emotional processing and memory

3 multimodal association areas

posterior, anterior, limbic

Prefrontal cortex

decision making, reason, abstract thought, judgment, impulse control, social skills, humor and empathy

Left hemisphere

speech center writing, language, logic and mathematics

Right hemisphere

analysis by touch, spatial visualization, intuition, reading facial expressions and artistic skill

Corpus callosum

large white matter tracts connecting the two hemispheres

Corpus callosotomy (Split brain syndrome and Alien hand syndrome)

due to severe epilepsy