Brain Notes

brain

brain

two cerebral hemispheres

diencephalon

brainstem

cerebellum

meninges

membranes that protect the brain and spinal cord

cerebrum

largest portion of the brain, superior to the spinal cord and brainstem, divided into two hemispheres

corpus callosum

bridge of nerve fibers that connects the two cerebral hemispheres

gyri

surface ridges

sulci

shallow grooves

central sulcus

separates frontal and parietal lobes

lateral sulcus

separates temporal lobe from other lobes

fissure

deep groove

longitudinal fissure

separates the two cerebral hemispheres

transverse fissure

separates the cerebrum and cerebellum

white matter

inner layer of cerebrum

bundles of interneuron myelinated axons

outer layer of spinal cord

gray matter

outer layer of the cerebrum (cerebral cortex)

bundles of interneuron cell bodies and unmyelinated axons

inner layer of spinal cord

frontal lobe

responsible for concentrating, planning, emotions, problem solving, and judging consequences

contains precentral gyrus (motor cortex)

contains Broca’s area (left side)

Broca’s area

motor speech area

controls muscles needed for speech and written communication

damage to this area results in people still being able to understand language but unable to physically form words

parietal lobe

detects sensations of temp, pain, pressure, touch

responsible for understanding speech

contains the postcentral gyrus (sensory cortex), gustatory cortex, and Wernicke’s area

gustatory cortex

receives sensory info from taste receptors in taste buds of the tongue

Wernicke’s area

responsible for interpretation of language and speech

damage to this area means a person can speak but their words make no sense in context

temporal lobe

responsible for hearing

integrates and regulates memory

contains part of Wernicke’s area

contains olfactory cortex

occipital lobe

responsible for vision

receives info from the photoreceptors and retina of the eye

diencephalon

contains two important areas of gray matter that directs sensory impulses to the appropriate areas of the cerebral cortex and regulates homeostasis

thalamus

relay station for all incoming sensory impulses except smell and directs them to the appropriate areas of the cerebral cortex

hypothalamus

regulates homeostasis

heart rate and bp

body temp

electrolyte balance

hunger and bodyweight

digestive movements and secretions

sleep-wake cycles

links nervous and endocrine systems

optic chiasm

formed by the optic nerves crossing over

pituitary gland

hypophysis

hangs from floor of hypothalamus

master gland, secretes hormones that stimulate other glands and organs in the body

has posterior and anterior lobes

pineal gland

releases melatonin

regulates circadian rhythm

limbic system

involved in emotional responses

controls emotional experience, expression, action

fear, anger, pleasure, sorrow

recognizes life threatening upsets

involved in sense of smell

amygdala

deep within each temporal lobe

recognizes potential threats and initiates fight or flight response

responsible for learning on the basis of reward and punishment

hippocampus

deep within each temporal lobe

responsible for declarative memory

brainstem

connects brain to spinal cord

serves as a pathway for incoming sensory signals and outgoing motor impulses

contains many cranial nerves

midbrain

short section of brainstem

lies between diencephalon and pons

joins lower parts of brainstem and spinal cord with higher parts of brain

pons

rounded bulge on underside of brainstem

between midbrain and medulla oblongata

relays nerve impulses between medulla oblongata and cerebrum

relays impulses from cerebrum to cerebellum

pontine respiratory group: regulates breathing rate

medulla oblongata

contains autonomic reflex center (homeostasis of vital organs)

cardiac center (force and rate of heartbeat)

vasometer center (constriction-increase, dilation-decrease)

respiratory center (depth and rhythm of breath)

non-vital reflex control (hiccup, sneeze, etc)

injuries are fatal

cerebellum

little brain

coordinates movement

posture and balance

muscle memory center

contains arbor vitae