Central Nervous System

Primary role of CNS

interpret sensory info; plan/monitor mvmnt; maintain homeostasis; higher mental functions

3rd week of embryonic development

start of nervous system development

4th week of embryonic development

neural tube exhibits 3 ant dilations (primary vesicles)

Primary vesicles of brain

forebrain, midbrain, hindbrain

Forebrain (other name)

Prosencephalon

Midbrain (other name)

Mesencephalon

Hindbrain (other name)

Rhombencephalon

5th week of embryonic development

subdivision into 5 secondary vesicles

5 secondary vesicles

telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon

Forebrain becomes

telencephalon and diencephalon

Midbrain becomes

undivided; mesencephalon

Hindbrain becomes

metencephalon and myelencephalon

Telencephalon

becomes cerebral hemispheres

Diencephalon

becomes eye retina (has optic vesicles), thalamus, and hypothalamus

Metencephalon

becomes pons and cerebellum

Myelencephalon

becomes medulla

Gray matter

neuron bodies, dendrites

White matter

myelin, axon tracts

Limbic system

emotional center & fear related responses

Reticular formation

network of nuclei that maintains basic body functions (like sleep & breathing)

Cerebrospinal fluid

produced by ependymal cells; helps with buoyancy, protection, and chemical stability

Blood brain barrier

keeps CSF separate from blood circulation; selective filter for bloodstream & brain tissue fluid; obstacle for delivering medications

Parkinson’s

progressive loss of motor function; degeneration of dopamine-releasing neurons (which prevent excessive activity in motor centers)

Thalamus

relay center through which all sensory info passes to cerebrum (except olfactory)

Epithalamus

choroid plexus secretes CSF; pineal gland secretes melatonin

Dura mater

outermost brain meninge

Arachnoid mater

middle brain meninge

Pia mater

innermost brain meninge

Meningitis

inflammation of meninges (arachnoid & pia)

Bacterial meningitis

causes swelling in brain; enlarged ventricles; hemorrhage; diagnose w/ lumbar puncture/spinal tap

Hypothalamus

maintains homeostasis! hunger, thirst, body temp, sleep, emotions, fear; hormone release; circadian rhythm; pineal gland

Pituitary gland

releases ADH (vasopressin) & oxytocin

Cerebellum

receives input from proprioceptors (joint, tendon, muscles); coordinate movement

Frontal lobe

voluntary motor functions; motivation, planning, mood, memory, aggression

Parietal lobe

receives & integrates general sensory info, taste, & visual processing

Occipital lobe

visual interpretation center

Temporal lobe

hearing, smell, learning, memory, aspects of vision & emotion

Insula

hidden lobe; understand spoken language; taste & sensory info from visceral receptors

Medulla

contains all tracts that pass between brain and spinal cord; nuclei of cranial nerves; vital centers

Reticular activating system

ascending arousal system that originates in groups of neurons in the ponds, midbrain, reticular formation, hypothalamus, & basal forebrain

ACTIVATION - wakefulness

INHIBITION  - sleep

Cognition

range of mental processes by which we acquire and use knowledge

Traumatic brain injuries

memory impairment; diffuse axonal injury; metabolic changes occur after TBIs

Cerebral laterization

specialization of each hemisphere for certain functions; hemispheres control movement on opposite sides & communicate through corpus callosum

Left brain

language & analytical abilities (categorical)

Right brain

visuospatial tasks (representational); creative

Aphasia

language and speech disorders due to brain damage

Broca’s area

necessary for speech; motor program for larynx, tongue, cheeks, lip muscles

Wernicke’s area

involved in lang comprehension; create plan of speech; sends plan to Broca’s area

Synaptic plasticity

ability of synapses to change

Synaptic potentiation

process of making transmission easier

Immediate memory

ability to hold something in thoughts for a few seconds

Short-term/working memory

ability to hold information for few seconds to several hours

Long-term memory

declarative and procedural

Declarative long-term memory

retention of events you can put into words

Procedural long-term memory

retention of motor skills

Long-term potentiation

persistent, activity-dependent strengthening of synapses between neurons that’s crucial for learning and memory

Alzheimer’s disease

memory loss for recent events; moody, combative, loss of ability to walk, talk, eat; ACh & nerve growth factor deficiencies