Anatomy lecture test 4 (chapter 12,13,14,15,16)
What is the voltage threshold for depolarization to occur
-55mV
What voltage is the resting membrane potential?
-70mV cell is polarized
What are some of the neurotransmitters used by the body?
-Acetylcholine -Glutamate -Aspartate -Gamma aminobutyric acid -Glycine -Norepinephrine -Epinephrine _dopamine
What is the enzyme that can break down the neurotransmitter acetylcholine?
-Acetylcholinesterase
What are the two types of electrical signals?
-Action potentials that travel long distances -Gradient potentials that are local membrane changes only
What are the factors that affect the speed of propagation of a signal through the nervous system?
-Amount of myelination -Axon diameter -Temperature
cerebral cortex motor areas
-Primary motor area- precentral -Brocca's speech area- left cerebral hemisphere
cerebral cortex Sensory areas
-Primary somatosensory area-postcentral gyrus -Primary visual area- occipital lobe -Primary auditory area- temporal lobe -Primary gustatory area- base of the postcentral gyrus -Primary olfactory area- temporal lobe
If a neuron is said to be depolarized, it will restore itself to the resting state in a processes called______
-Resting state
What are the subdivisions of the peripheral nervous system?
-Somatic(voluntary) nervous system(SNS): neurons from cutaneous and special sensory receptors to the CNS motor neurons to skeletal muscle -Autonomic(involuntary) nervous system (ANS): sensory neurons from visceral organs to CNS motor neurons to smooth and cardiac muscle and glands -Enteric nervous system(ENS) involuntary sensory and motor neurons control GI tract neurons function independently of ANS and CNS
What voltage gated channel opens during depolarization?
-Voltage-gated Na+ channels
What type of channel responds to a direct change in the membrane potential?
-Voltage-gated channels
What are the vital centers of the medulla oblongata?
-_Cardiovascular center -Respiratory center Also includes centers for -vomiting, swallowing, sneezing, coughing and hiccupping -houses 5 pairs of cranial nerves, VIII-XII portion of the fourth ventricle (emotional responses)
What causes the resting membrane potential?
-concentration of ions different inside and outside -extracellular fluid rich in Na+ and Cl -cytosol full of K+, organic phosphate and amino acids
What are the 3 cranial meninges?
1- Dura mater 2- Arachnoid 3- Pia mater
How many cranial nerves at in the human body?
12 pairs of cranial nerves (24 total)
How many spinal nerves emerge from the spinal cord?
31 pairs of spinal nerves
Anything that enhances a transmitter effect is an______
Agonist
Anything that blocks the action of a transmitter is an_______
Antagonist
What neurons analyze sensory information, store some aspects, and help make decisions regarding behavior?
Association or interneurons
What part of the brain if found deep within the cerebral hemisphere that helps to initiate/terminate unwanted movements, and regulate muscle tone?
Basal ganglia 1. globus pallidus 2. putamen 3. caudate nucleus
Once -55mV has been reached, what channel open?
Both
What does the central nervous system consist of?
CNS: Brain and spinal cord
What is know as the "emotional brain" for the role it plays in governing the emotional aspects of behavior?
Limbic system includes: cingulate gyrus, hippocampus, dentate gyrus, amygdala, mammillary bodies, thalamus, and the olfactory bulb
What is the branch of medical science that deals with normal functioning and disorders of the nervous system?
Neurology
What is the functional unit of the nervous system?
Neuron: have capacity to produce action potentials (electrical excitability)
What does the peripheral nervous system consist of?
PNS: Cranial nerves, spinal nerves, ganglia, enteric plexuses in the small intestine, sensory receptors in the skin (sensory and motor fibers) Connects CNS to muscles, glands and all sensory receptors
There is a short period where the neuron cannot generate another action potential, what is this period called?
Refractory period
What protects the spinal cord?
The vertebral column and the meninges protect and provide stability
The order of the middle 4 cranial nerves
V Trigeminal VI Abducens VII Facial VIII Vestibulocochlear
What is the order of signal for a reflex?
a. sensory receptor b. sensory neuron c. integrating center d. motor neuron e. effector
A__________ is a sequence of events occurring that reverse the membrane potential is called__________. Action potential;depolarization
action potential(AP) or impulse, depolarization
The_______ nervous system signals the_______ glands to release epinephrine and norepinephrine
autonomic ;adrenal
How is the nervous system regeneration ability limited?
lack of neurogenesis in other regions of the brain and spinal cord formation of new neurons from stem cells was not though to occur in humans factors preventing neurogenesis in CNS: inhibition by neuroglial cells, absence of growth stimulating factors, lack of neurolemmas, and rapid formation of scar tissue.
The__________ nervous system is associated with conserving energy and digest food at rest.
parasympathetic
________pain is felt deep in the skin overlying an organ or in an area far from the organ.
referred
The___________ nervous system is associated with the fight or flight response.
sympathetic
________sense temperature
thermoreceptors
The order of the last cranial nerves
IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal
What is the cell process of a neuron? Dendrites and Axons
-Axon: conductive region, generates (extends) an action potential (output) -Dendrites: (like trees) input area, receives signals from other neurons (receptive area) -Cell body(soma): centrally integrative, input area, main nutritional and metabolic area.
What prevents harmful substances from reaching the brain?
-Blood-brain barrier (BBB)
What is the second largest part of the brain?
-Cerebellum Back portion, anterior and posterior lobes control subconscious aspects of skeletal movement, flocculodular lobe controls equilibrium and balance Arbor vitae- tracts of white matter cerebellar cortex- gray matter (folia)
What helps to absorb shock and protects the brain and spinal cord?
-Cerebrospinal fluid (CSF)
What is the largest part of the brain?
-Cerebrum or cortex "seat of intelligence" -Gyri Cerebral cortex-gray matter -Sulci (indentations) -Longitudinal fissure (middle) -Cerebral hemispheres
What is the function of the hypothalamus?
-Control of ANS -Production of hormones -Regulation of emotional and behavioral patterns, eating and drinking, body temperature, circadian rhythms
The parasympathetic nervous system includes:
-Craniosacral division: preglanglionic neurons originate from the cranial nerves III, VII, IX and sacral spinal nerves S2-S4 -Parasympathetic ganglia: terminal ganglia -Presynaptic neuron usually synapses with 4-5 postsynaptic neurons all of which supply a single visceral effector
What are the 2 types of synapses for signal transmission?
-Electrical: ion current spreads to next cell through gap junctions, faster, two-way transmission and capable of synchronizing groups of neurons -Chemical: one-way information transfer from a presynaptic neuron to s postsynaptic neuron Axodendritic: from axon to dendrite Axosomatic: from axon to cell body Axoaxonic: from axon to axon
What type of channels are always open?
-Leakage (nongated) channels nerve cells have more K+ than Na+ membrane permeability to K+ is higher resting membrane potential of -70mV in nerve tissue
What type of channels open and close in respond of stimuli?
-Ligand-gated channels results in neuron excitability
What type of channel responds to mechanical vibration or pressure?
-Mechanically gated ion channels
What subsystem of nerves helps to regulate the digestive system?
Enteric plexuses
What are the small masses of nervous tissue containing primarily cell bodies of neurons?
Ganglia, located outside the brain and spinal cord
Remember the order of the cranial nerves with "On Old Olympus' Towering Top A Friendly Viking Grew Vines And Hops"
I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Vestibulocochlear IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal
The order of the first 4 cranial nerves
I Olfactory II Optic III Oculomotor IV Trochlear
Epithalamus produces______ which hormone that helps induce sleep?
Melatonin
What neurons respond to stimuli by initiation action?
Motor(efferent) neuron (Me)
What two systems keep controlled conditions within limits to maintain homeostasis?
Nervous system and endocrine system Nervous system is responsible for all our behaviors, memories, and movements.
Cells that myelinated axons in the peripheral nervous system are called?
Schwann cell
What neurons sense changes in the internal and external environment through sensory receptors?
Sensory (afferent) neuron (Sa)
Neural plasticity refers to:
Sprouting of new dendrites -synthesis of new proteins -changes in synaptic contacts with other neurons
What protects the brain?
The cranium The cranial meninges: 1. dura mater 2. arachnoid mater 3. pia mater