unit 12

structures protecting the brain

-protecting from trauma bone meninges (membranes) cerebrospinal fluid (watery cushion) -protection from infection and toxicity blood brain barrier

spinal cord

-provides two-wat communication to and from brain -contains spinal reflex centers

limbic system

-structures parts of diencephalon some cerebral structures and encircle brain stem -functions emotions/emotional response memory via hippocampus

reticular activating system

-structures three broad columns running length of brain stem -functions filters out repetitive familiar, or weak stimuli inhibited by sleep centers, alcohol, drugs servers injury results in permanent unconsciousness

meninges

-three layers dura mater arachnoid mater pia mater -functions cover and protect CNS protect blood vessels and enclose sinuses contains CSF -inflammation is called meningitis

Lateralization of cerebral function

right hemisphere -usually dominates for visual-spatial skills, intuition, emotion, and artistic skills

Functional areas of the cerebral cortex

sensory: parietal, insular, temporal, and occipital lobes, conscious awareness of sensation

alzheimers disease

-a neurogenerative disease that results in dementia and emotional changes -causes are hotly debated -associated with amyloid plaques, neurofibrillary tangles -brain shrinkage

medulla oblongata functions

-addition centers regulate vomiting hiccuping swallowing coughing sneezing

white matter fibers tracts connect parts of the CNS to each other

-association fibers connect different parts of same hemisphere -commissural fibers (connect corresponding part of different hemispheres) -projection fibers (connect cortical areas to parts outside the cortex)

blood Brian barrier

-astrocytes are responsible for BBB formation -barrier is much tighter than in capillaries in other parts of body -epithelial tight junctions -controls the chemical environment for the brain -separates brain from blood borne substance water soluble drugs, pathogens, immune cells

brainstem functions

-autonomic behaviors for survival -fiber tracts between higher and lower centers -nuceli associated with 10/12 cranial nerves

medulla oblongata functions

-autonomic reflex center functions overlap with hypothalamus -cardiovascular center adjusts force and rate of heart contraction adjusts blood vessel diameter for blood pressure regulation -respiratory centers generate respiratory rhythm control rate & depth of breathing (with pons)

hypothalamus functions

-body temperature -hunger and satiety -thirst and water balance -sleep-wake cycles -endocrine system control

major sulk of the human brain

-central sulcus separates frontal lobe and parietal lobes -longitudinal fissure separates hemispheres -transverse cerebral fissure separates cerebrum and cerebellum

four major adult brain regions

-cerebral hemisphere -diencephalon -cerebellum -brain stem midbrain pons medulla oblongata

cerebrospinal fluid

-compostion mostly water & electrolytes -functions protects CNS from blows and other trauma nourishes brain and carries chemical signals

diencephalon

-consists of three paired structures 1. thalamus 2. hypothalamus 3. epithalamus -diencephalon encloses the third ventricle

pia mater

-deepest of the meninges -contains many small blood vessels -clings tightly to brain

pons

-fourth ventricle separates pons and cerebellum -relay impulses between motor cortex and cerebellum -nuceli help maintain normal rhythm of breathing

Basal ganglia (basal nuclei)

-group of there nuclei caudate nucleus putamen globus pallidus -functions filter out incorrect or inappropriate response (emotional & motor) starting and stopping slow and stereotypes movements

the human cerium is not smooth

-gyri are ridges on the cerebral surface -sulci are shallow grooves -fissures are deep grooves

choroid plexuses

-hang from roof of each ventricle -clusters of capillaries -lines with ependymal cells -produced and circulate CSF -CSF is replaced every 8 hours

hypothalamus

-inferior to thalamus -contains many nuclei for many tasks -connected to the pituitary gland by the infundibulum

cerebellum

-input from cortex, brain stem and sensory receptors -abor vitae is the treelike pattern of cerebellar white matter -regulates smooth and coordinated movements muscle memory

thalamus

-largest structure of the diencephalon -relay station for input to the cerebral cortex

contusion

permanent neurological damage caused by concussion-related bruising of the brain

medulla oblongata

-joins spinal cord ay foramen magnum -decussation of the pyramidal tracts

brainstem structures

1. midbrain 2. pons 3. medulla oblongata

formation and circulation of CSF

1. produced by choroid plexus of each ventricle 2. flows through ventricles into subarachnoid space 3. flows through subarachnoid space 4. absorbed into dural venous sinuses

neurons are organized topographically in the

primary motor cortex and primary somatosensory cortex

Specific sensory functions are concentrated in brain areas

olfaction (smell) - temporal gustation (taste) - insular vestibular (balance) - insular

concussion

a temporary alteration in brain function following a blow to the head. mild TBI

Functional areas of the cerebral cortex

association: nearby related motor and sensory areas, integrate diverse information

cerebral edema

brain swelling;ong caused by excess fluids. very serious and can cause death on its own

major regions of the cerebrum in cross section

cerebral cortex (gray matter) white matter basal ganglia

flax cerebrium

extension of dura mater into the longitudinal fissure attached to crest Galli

tentorium cerebelli

fold of the dura mater over the cerebellum -in the transverse fissure

five cerebral lobes

frontal lobe insula temporal lobe parietal lobe occipital lobe

arachnid mater

intermediate layer of the meninges subarachnoid space contains CSF and large blood vessels arachnid villi protrude into superior sagittal sinus and permit CSF reabsorption

four ventricles

lateral ventricle cerebral aqueduct fourth ventricle third ventricle

Lateralization of cerebral function

left hemisphere -usually dominates for language, math and logic

four ventricles contain cerebrospinal fluid

lined by ependymal cells that circulate CSF

dura matter

most superficial of the meninges limits excessive brain movements

Functional areas of the cerebral cortex

motor: frontal lobe, control voluntary movement

functional brain systems

networks of neurons that work together but span wide areas of the brain

epithalamus (pineal gland)

the roof of the third ventricle secretes melatonin -regulates sleep-wake cycle

Specific sensory functions are concentrated in brain areas

visual - occipital touch, temp, pressure - parietal auditory - temporal