A weak change in membrane potential which can die out.
A weak stimulus ( below threshold level) causes only a few WHAT to open?
SODIUM
An action potenial is NOT?
Reached
Synapse Where a "blank" "Blank" is passed from one neuron to another?
Action Potential
SYNAPSE What kind of messenger is involved when crossing a synaptic cleft?
A chemical messanger
There are two kinds of Synapes what are they?
1. Excitatory
2. Inhibitory
What brings post-synaptic cell to action potential?
Exitatory Synapes
What prevents post-synaptic cell from reaching action potential?
Inhibitory synapes
What happens when you have more complex movements?
More synapes are working
Do you need the brain to involve a reflex?
NO you do not!
What is synaptic delay?
The time it takes from:
Action potential reaching the axon terminal end of the presynaptic cell UNTIL action potential begins in postsynaptic cell.
SO-the MORE synapse in a nerve pathway the LONGER it takes an impulse to reach its destination.
What is it called when (one cell is influenced by many other) during IMPUT?When there are many cells to one Neuron?
CONVERGENCE
What is it called when during OUTPUT ( one cell influences many others)? not is influenced BY many others but is influencing many others?
DIVERGENCE
What does graded potential at a synapse mean?
If a few presynaptic cells release neurotransmitter ( in a convergence) were it is influenced by many cells, it may not be enough to trigger an action potential in the postsynaptic cell.
What is SUMMATION in a nerve pathway?
Temporal Summation:
Stronger stimulus= more frequent action potetials.
Weaker stimulus=less frequent action potentials.
Temp.....Tempo how fast and how long....
Think of the beeping during class demenstraion
FREQUENCY=
SUMMATION
Spatial summation: is what?
Stronger stimulus= freater number os neurons reach action potential.
Weaker stimulus= less neurons reach action potential.....
Spatial summation=
NUMBER
HORMONES: What are they and what do they do? A list of five different things?
1) chemical messsangers made up of Proteins and Lipids.
2)released by endocrine glad into the bloodstream.
3)carried throughout the bady in the blood.
4)Act on other TARGET cells within other organ systems ( or other Endocrine glands) changing the activity of those cells.
5) they are controlled through Negative feed-back regulation.
What are Hormones (Chemical messangers) made up of?
Protein & Lipids
Where are the hormones released into and where do they come from?
1) Released into the bloodstream
2) by the Endocrine glands
How are hormones carried thorughout the body?
In the blood
Where are the hormones released into and where do they come from?
They are released into the blood and come from the Endocrine glands
What kind of cells do they act upon?
TARGET CELLS
Hormones are controlled through what kind of feedback? Negative or Positive?
NEGATIVE feed-back
The nervous system is what? 4 things
1) major regulatory system
2)Rapid electrical signals ("WIRED")- like a phone line! Class discussion.
3)SHORT distant chemical messangers ( Neurotransmitters)
4) Resonse is repid, but short in duration.
What two systems are major regulatory systems?
The NERVOUS & ENDOCRINE systems
What system is ("WIRELESS")?
ENDOCRINE system
The endocrine system is invoved in what kind of messangers?
LONG distant CHEMICAL messangers.
The ENDOCRINE system has what kind of response & what kind of duration?
Slower response and longer duration.
The brain requires a steady supply of what two things?
Oxygen and glucose
The brain uses glucose for energy.
Can the brain store glucose for later use?
NO
How much of our total body weight is our brain when we are born?
10%
Movements on the right side of our bodies are controlled by which side of the brain?
The Left
Nerve pathways carrying instructions from the cetral nervous to the muscles are called?
MOTOR NEURONS
Nerve pathways carrying information to the central nervouse are called?
SENSORY NEURONS
SENSORY neurons are Efferent or Afferent?
Afferent
MOTOR neurons are Efferent or Afferent?
Efferent
Afferent=
Carries infomation to the (CNS)
Effernet=
(CNS) to effernet, muscles or glands carry out orders and bring out the disired effect.
What is SOMATIC?
Fibers that innervate motor neurons that supply the skeletal muscles.
AUTOMATIC=
Fibers that innervate smooth muscle, cardiac muscle and glands
SYMPATHETIC=
FIGHT or FLIGHT
PARASYMPATHETIC=
Innervates most of the organs supplied by the automatic system. (CALM) REST & DIGEST.
Everyday life it is a balance between both parasympathetic and sympathetic.....
What are the ways the brain is protected?
1) enclosed by CRANIUM, vertable cortex that surronds the spinal cord.
2)There are protective layers three of them Meninges between bony covering and the nervouse tissue.
3)Brian floats in Cerebrospinal fluid.
4)(BBB) Protects from materials into the brain and has a tight junction.
Photoreceptors are?
Responsible for visual wavelengths of light.
Mechanoreceptors=
sensitive to micanical energy
Thermoceptors are?
sensitive to heat and cold
Osmoreceptors are?
detects changes in the concentration of solute in the (ECF) and sresulting in changes in osmotic activity.
Chemoreceptors=
sensitive to certain chemicals
Nocireceptors or pain receptors are?
are sensitve to tissue damage such as cutting or burning.
The brain and spinal cord are part of what?
The Central Nervous System
What does the Central Nervous System process and integrate?
information coming from and going to the peripheral nervous system
The Peripheral Nevous System consists of what two pathways?
Afferent & Efferent
What carries information from receptors to the central nervous system?
The Afferent pathways
What patway carries information from the central nervous system to tissues and organs?
The Efferent pathways
An Afferent pathway is what kind of stimuli?
Sensory and Visceral stimuli
The Efferent pathway controls what two nervous systems?
The SOMATIC and AUTONOMIC nervous systems
The SOMATIC controls what neurons?
MOTOR NEURONS
The Autonomic nervous system controls what three systems?
1) Sympathetic
2) Parasympathetic
3) also the ENTERIC nervouse system....which is part of the stimuli in the digestive tract
The MOTOR neurons control what muscles?
Skeletal muscles
The sympathetic and parpasympathetic systems control what ?
Smooth muscle, cardiac muscle,exocrine gland, and some endocrine glands.
The ENTERIC nercouse system controls what?
Digestive organs ONLY
The Effector organs are made up of what?
Muscle and gland tissue.....
When your biceps feel a stimulis what does it do?
CONTRACTS is EXCITATORY
When the TRICEPS feel stiulis what does it do?
RELAXES and INHIBITORY
The central nervouse system consists of what?
The brain and the spinal cord
What does Plasticity of the brain mean?
When you learn new connections between neurons are made, NOT NEW NERVE CELLS
What is it called when you are a little baby and you are learning how to grab things and learn new small movements?
Your brain has PLASTICITY
Maintaining Homeostasis in the brain: How do we do that?
The homeostasis conditions are monitored more closly than those of the rest of the body.
The (BBB) helps to keep the enviorment in the brain in a steady state.
What three things does the (BLOOD Brain Barrier) help protect the brain against?
1) Fluctuations in the electrolytes
2) circulating hormones from reaching the brain
3) Harmful BBB from reaching the brain
Is there a constant supply of blood to the brain?
YES AT ALL TIMES....
Flow of blood and blood pressure to the brain does not fluctuate!
What does the brain need a constant supply of?
OXYGEN,GLUCOSE
What is needed to supply the ATP in the brains blood?
Oxygen, and Glucose
What does the Cerebral cortex control?
Sensory
movment
language
personality
memory
decisions
creativity
consciousness
What does the Basal Nuclei control?
Muscle tone
Movements
What does the Thalamus control?
Synaptic imput
Sensation
Consciouness
Motor control
What does the Hypothalamus control?
Temperature
Thirst
Urine
Food intake
Link between nervous and Endocrine system
Emotion & behavior
What does the Cerebellum control?
Balance
Muscle tone
Coordination
What does the Brain Stem (midbrain, pons and medulla) control?
Crainial nerves
Cardiovascular,respiratory,digestive
Reflexes
Equilibrium
Synaptic imput from spinal cord
Arousal
Sleep-wake cycle
Afferent pathways are?
Sensory imput
Homeostaaic conditions usually never reach a conscious awarness level in what pathway? Afferent or Efferent?
Afferent
Conscious sensations are?
Somatic and Specialized
What are the sensations for somatic sensations?
Touch,pressure,heat,cold,pain
What are the sensations for specialized senses?
Vision,hearing,taste
A specialized ending os a neuron or a seperate cell that is closely associated with a neuron? what kind of receptor is it?
Sensory receptors
Stimulus ( Heat, sound,light,pressure) must be converted to electrical energy ( action potenial) what is the name of this?
If a stimulus is reaching threshold (strong) what is it?
Action Potential
Photoreceptor?
Light
Mechanoreceptor?
Includes stretch receptors in the skeletal muscle, receptors in the ear
Baroreceptors?
Monitor blood pressure
Thermoreceptors?
Heat or cold
Chemoreceptors?
detect chemicals like co2 & o2 smell, taste
Osmoreceptors?
Change in solute concentration...(osmosis)
Norciceptor?
PAIN
Sensory Adaptation:
receptor adapts to sustained stimulus by not responding to it to the same degree.
Phasic receptors are they Important or Unimportant?
They are Unimportant adapt reapidly to sustained stimulus.
Tonic receptors are they important or unimportant?
Important.... DO NOT ADAPT or it they do VERY slowly... important to any change in PH.
Sensory Acuity: The area around a sensory receptor= receptive feild.......
What is Sensory Acuity mean?
The area around a sensory receptor= receptive feild
When the receptors are more DENSE what is the receprtive field? & What is the ACUITY?
Smaller receptive feild and Higher the Acuity
In the peripheral nervous system the EFFERENT pathways are what two things?
Autonmic and Somatic
Autonomic goes out to what part of the body?
The organs and glands
The somatic goes out to what part of the body?
The skeletal muscle
The autonommic nervouse system does what?
Innervates CARDIAC and SMOOTH musle, most exocrine glands and some endocrine glands.
Neurotransmitters at effector organs?
Parasympathetic: ACETYLCHOLINE
Sympathetic: NOREPINEPHRINE
Parasympathetic is what?
Sleepy, resting
Sympathetic is what?
Higher activity level... Fight or Flight
What are the two neurons in the autonomic nerve pathway?
preganglionic fiber and postganglionic fiber
The hypothalamus and adrenal glands are border line being nervous system or endorcrine system.
Epinepherine is found mostly where?
In the blood
The adrenal medulla is a modified part of?
sympathetic nervouse system
The adrenal medulla produces what?
Norepinephrine 20% and epinephrine 80%
The adrenal medulla releases the norepinephrine and epinephrine into?
The blood as hormones instead of as messengers to postganglionic fiber.
The adrenal medulla reinforces the effect of the?
sympathetic nerve pathways
The receptors of the effecot organs canstimualte activity on some organs and inhibit in others? True or false?
This is true.....
The response of the effector organ depends on the type of receptor on the tissue cells? True or false?
This is true
What are the two types of Autonomic receptors?
Cholingergic receptors and Andrenergic receptors
Cholinergic binds to ACh? True or false?
True
Nicotinic receptors - found on postganglionic cell bodies of all autonomic gaglia Muscarinic receptors- found on effector cell mambranes. Are part of what receptors?
autonomic receptors....
Alpha (a) receptors & Beta (b) receptors are part of what receptors?
Andrenergic receptors...They bind to norepinephrine and epinephrine....
