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