chap 11 and 12
Terms
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- Central Nervous system
- brain and spinal cord
- peripheral nervous system
- nerves and receptors
- afferent
- transmit impulses from receptors to CNS
- efferent
- transmit impulses from peripheral division to motor division
- autonomic nervous system
- involuntary processes innervated by nervous system. broken down into 2 parts: parasymphatetic and sympathetic
- sympathetic nervous system
- involuntary process that acts under emergency situations
- parasympathetic
- nonemergency situations
- somatic nervous system
- voluntary muscle. impulses from CNS to motor muscles
- 2 nervous cell types
-
1. neurons-only cells in body to carry an action potential
2. neuroglia (glia, glial tissue) - 5 neuroglia cells
-
astrocyte
microglial
ependydmal
schwann
oligodendrocyte - astrocyte
- anchors by wrapping around capillaries and nerve cells. Determines also what can and cannot leave the cappilary. Maintains interstitial fluid chemical balances
- microglial cell
- important in immune function of nervous system. Phagocytizes bacteria, virus, toxins, etc. Kin to a WBC
- ependydimal cell
- transports CSF
- oligodendrocyte
- produces myelin sheith of CNS
- Schwann neurolemmocyte
- insulates axons with myelin sheith of the PNS. Contains satelite cells
- ganglion
- group of nerve cell bodies within the PNS
- nucleus
- group of nerve cell bodies within the CNS
- Neuron characteristicas
- has cell body (soma, pericaron) w/ nucleaus, nissil bodies w/ R ER, dendrites that relay incoming pusles, axon hillock, terminal branches
- nodes of ranvier
- area on the axon between shwann cells
- axosomatic synapse
- axon of one neuron attaches to a body of another
- axodendritic synapse
- axon of one nerson attaches to dentdrites
- axoaxonic
- axon of one neuron attaches to an axon of another
-
multipolar, bipolar, and unipolar
structural classification - many process, 2 processes or one process extending from soma.
- functional classification of neuron
- direction of impulse. afferent, efferent, association
- neurolemma
- cell membrane of schwann cell
- chemically gated ion channel
- intergral proteins sit in the phosolipid bilayer. need a chemical to bind to receptor site
- voltage gated ion channel
- inside of cell is negative, outside is positive, when depolarized channel opens
- sodium potassium pump
- K+ and Na+ try to sneak out through cell membrane. if it gets out it is pumped back in
- depolarization
- `Na+ floods in, K+ floods out
- repolarization
- K+ pumped out of cell
- threshold
- amount of stimulus needed to creat an action potential
- absolute refractory period
- period where neuron is resting to such an extent that you can zap it all you want and nothings gonna happen. all Na+ gates are open
- relative refractory period
- associates with repolarization. not all Na+ gates are open so if the stimulus is great enough, depolarization can occur
- saltatory conduction
- action potential jumps from one node to the next skipping the myelinated part. faster transmission then unmyelinated
- neurotransmitters
-
catecholamines
indolamines - catecholamines
- norepinethrine, dopamine, epinephrine
- indolamines
- seratonin, histamine
- diencephalon
- thalamus, hypothalamus and epithalamus
- hypothalamus
- caps the brain stem. main visceral control center of the body. overall body homeostasis. autonomic, emotional responce, body temp, apetit, water balance and thirst, sleep cycle, endocrine system
- epithalamuc
- pineal gland- sleep awake cycle and aspects
- brain stem
- 3 structures- pons, medulla, midbrain
- centers in brain stem
- pyramid- wiring to muscles involved in motor skills. dicussation of pyramids- crossing over of wiring
- cerebellum
- - helps maintain posture and balance, fine control of skeletal muscles
- lymbic system
- has an important rol in how we respond emotionally to stimuli
- eeg
- graphic representation of electrical activity of the brain
- protective coverings of the brain
- hair, scalp, periosteum, skull, dura mater, arachnoid mater, pia mater
- 2 layers of dura mater
- periostel and menigeal
- subdural space
- space between dura mater and arachnoid
- subarachnoid space
- space between arachnoid and pia mater. this is where CSF circulates
- Arachnoid villi
- soak up excess CFS and transports it to venus system
- superioe sagital sinus
- cavity below dura mater
- septum pellucidum
- separates 2 ventricles
- coroid plexus
- produced by capillaries, produces CSF. CSF produced in lateral ventricales, it merges then to 3rd ventricle then in cerebral aquaduct into 4th ventricle
- apature
- pening in 4th ventricle into arachnoid space and central canal of spinal cord
- functions of CSF
-
cushion brain, provide nutrients to maintain good environment
removes waste products - conus medillaris
- between l1 and l2. spinal cord ends because vertebral column grows too fast
- choroid plexus
- produces CSF. Pia mater has a fold, around fold is a capillary then a layer of ependymal cells. the ependymal cells say what gets ito the capillaries and what doesnt. it filter the CSF
- cause equina
- strip of pia mater that holds to the sacrum. tail of nerves for lumbar and sacral area
- gray matter of spinal cord
- gray matter , looks like butterfly. separeated into horns, posterior, anterior, and lateral. anterior median fissure, posterior median sulcus
- white matter of spinal cord
- separted into column. veniculus. posterior, anterior and lateral
- tracts
- bundles of axons
- blood/brain barrier
- only allos certain things get through. lipid soluable substances. tight junctions and astrocytes
- gray commisure
- gray matter of spinal cord with central canal. associated with 4th ventrical
- simple reflex arc
-
sensory to association to motor. same as afferent to intergrate to efferent
unipolar to nulti to multi - spinal cord
- central cavity surrounded by a gray amtter core, external to which is white matter composed of myelinated fiber tracts
- brain
- similair to spinal cord but with additional areas of gray amtter. cerebelum has gray matter in nuclei, cerebrum has nuclei and additional gray amtter in the cortex
- ventricles of the brain
- arise from the expansion of the lumen of the neural tube. they are c shapes lateral ventricles. 3rd found in diencephalon 4th in the hindbrain dorsal to the pons
- cebral hemisphere
- 83% of brain mass. has ridges gyri, and grooves, sulci. contain deep grooves fissures. and separated by longitudinal fissure. 3 basic regions cortex, white matter and basal nuclei
- 5 lobes divided by deep sulci
- frontal, parietal, temporal, occipital and insula
- central sulcus
- separated the brain into frontal and parietal lobes. surrounded by the precentral and postcentral gyri
- cortex
- superficial gray amtter accounting for 40% of the mass of the brain. enables sensation, comm, memory, understanding and movements
- functional areas
-
motor areaa- volun. movement
sensory area- conscious awareness of sensation. association area- integrate diverse information - broca's area
- located anterior to the inferior region of premotor area. present in only 1 hemisphere usually left. a motor speech area that directs the muscles of the tounge.. it is active as you prepare to speak
- wernicke's area
- involved in sounding out unfamilair words
- infundibulum
- stalk of the hypothalamus, connects to the pituitary gland. main visceral control of the body