Exam 1 Flashcards
In contact with the external environment. Ex) Kidney makes urine which is expelled from the body
Epithelial cell
Found inside the blood vessel, and is in contact with the blood; internal environment
Endothelial cell
Most of the water is found where?
Inside the cells
What is used to make larger molecules?
Dehydration synthesis
What is the breakdown of glycogen so that glucose is released into the blood?
Glycogenolysis
What are non-polar, and insoluble in water?
Lipids
What type of respiration is glycolysis?
anaerobic
What type of respiration is oxidative phosphorylation?
Aerobic
What is used to breakdown a larger molecule into a smaller molecule by removing H2O
Hydrolysis
peripheral membrane protein
Inside cell
Transmembrane protein
span the whole membrane
Integral membrane protein
on the outside of the membrane
Messenger releases signal that acts on the same cell
autocrine
signals act on an adjacent cell
paracrine
(pair of cells)
cell releases hormones that enter the blood and travel long distances to cells to cause an effect to those cells
endocrine
Multi-factoral control of signal
A given chemical messenger can fit into more than one category. Ex) steroid hormone cortisol affects the very cells in which it is made. The nearby cells that produce other hormones, and many distant targets, including muscles and liver
what are dense plaques, and have cadherins
Desmosomes
What does not allow extracellular space between cells, and are the entire band around the circumference of the cells? Where are these found?
1) tight junctions
2) found in the kidney
What links cytosols of adjacent cells and have connexins? Where are these found?
1) Gap junctions
2) found in the Gi tract and heart
What is it called when something moves from high concentrations to low concentrations?
Diffusion
What is the movement of water across a membrane that is PERMEABLE TO WATER BUT NOT TO SOLUTE leads to an equilibrium state involving a change in the volumes of the two components called?
Osmosis
What are tonic solutions?
Not permeable to solutes
What are water channels called? Where are they found?
1) Aquaporins
2) kidneys
what two mechanisms move solutes from high concentration to low concentrations?
1) Simple diffusion
2) facilitated diffusion
Which mechanisms need carrier proteins?
1) Facilitated diffusion
2) Active transport
Which mechanisms move from low concentrations to high concentrations and require ATP?
Active transport
What are the types of active transporters?
1) Ca2+ ATPase
2) H+ ATPase
3) H+/K+ ATPase
4) Na+/K+ ATPase
What uses an electrochemical gradient across a plasma membrane as its energy source?
Secondary active transport
What are the types of secondary activate transports?
1) Symporters
2) Antiporters
What type of secondary active transport transfers two substances in the same direction?
Symporters
What type of secondary active transport transfers two substances in opposite directions?
Antiporters
What type of transport has Apical (or luminal) and basolateral (or serosal) membranes?
Epithelial transport
What are the types of first messengers and these enter the cell?
Lipid soluble chemical messengers
1) Ligands
2) Neurotransmitters
3) Hormones
what have receptors located on the plasma membrane?
Water-soluble chemical messengers
What is the ability of a receptor to bond only one type or a limited number or structurally related types of chemical messengers, only cells that express the correct receptor can bind a particular messenger?
Specificity
What is the STRENGTH with which a chemical messenger binds to its receptor?
Affinity
What can enter straight into the cell and promote transcription?
Lipid soluble messengers
What has to bind to the cells plasma membrane?
Water soluble messengers
What are the types of water membrane receptors?
1) Ions channels
2) Receptors with intrinsic kinase activity
3) G-protein couples receptors
What is used in phosphorylation (Adds a phosphate to a molecule)?
Kinases
What is used to de-phosphorlation (remove a phosphate from a molecule)?
Phosphatases
What increases the intensity of a signal through networks of intracellular reactions?
Signal amplification
What are some membrane-bound receptors that do not include G-proteins?
Ligand gated channels
What have membrane -bound receptors that function as enzymes?
Insulin
(they have intrinsic enzyme activity)
-they are protein kinases (specifically phosphorylate the amino acid tyrosin RTKs)
insulin signaling pathway
insulin —> insulin receptor —–> PIP2 phosphorylated (by kinase) —> PIP3
What does not directly phosphorylate a substrate, it is a receptor which acts on enzyme that catalyses the formation of cyclic GMP?
Guanylyl Cyclase (GC)
cGMP functions as a
secondary messenger
cGMP activates
cGMP-dependent protein kinase
what is a cytoplamic protein kinase, these receptors DO NOT have intrinsic kinase activity, and when a ligand binds to receptor there is a conformational change?
Janus kinases (JAK)
This functions by a first messenger binding to a intrinsic membrane protein it activates this enzyme and this enzyme phosphorylates protein to add a phosphate group. What is this enzyme?
Janus kinase (JAK)
This located on the cytosolic surface and contains three subunits (Alpha, Beta and Gamma)
G-protein
What happens when a G-protein is activated?
The GDP attached to the subunits becomes GTP and the Alpha subunit separates from the beta and gamma subunits —> this causes the effector protein to be activated (can be an ion channel or enzyme) —> then it could either change membrane potential or activate a second messenger
Pathway of Gs protein?
(Gs protein is a G-protein)
Gs–> activates adenylyl cyclase (also known as adenylate cyclase) —> Adenylate cyclase —> catalyses the conversion of cytosolic ATP molecules to cAMP
(cAMP is a SECONDARY MESSENGER)
cAMP –> activates cAMP dependent protein kinase (PKA) —> then phosphorylates downstream
What is the cellular response from the use of cAMP?
1) Lipid breakdown
2) Glycogen breakdown
3) Protein synthesis and Ca2+ transport
What happens when cAMP is no longer needed?
cAMP is broken down to noncyclic AMP this occurs by cAMP PHOSPHODIESTERASE**
What inhibits the activity of cAMP phosphodiesterase?
Caffeine or theophylline which means cAMP isn’t broken down
What is the function of Gi protien?
Inhibit adenylyl cyclase which means less accumulation of cAMP which in turn decreases of phosphorylation of key proteins inside the cell
what neurotransmitters are used to activate Gi proteins?
Norepinephrine and epinephrine
Gq pathway
Gq activates phospholipase C (PLC) —–> PLC breaks down PIP2 to DAG and IP3 (DAG and IP3 are secondary messengers)
what is the function of IP3?
It is used to control the amount of Ca2+ that is secreted from the ER
What is the function of DAG?
its activates protein kinase C
What is the regulation of when a G protein opens an ion channel without the use of a secondary messenger?
Direct regulation
What is the regulation called when a G-protein uses a secondary messenger to open an ion channel?
Indirect regulation
Ca2+ can act as a?
Secondary messenger
Ca2+ can bind with?
1) calmodulin
2) troponin
3) nitric oxide
What effects does calcium have on the body?
1) Muscle contraction
2) Alter metabolism
3) Altered transport
Ca2+ as secondary messenger
1) Source?
2) Effects?
1) source: Enters cell through plasma membrane ion channels or is released into the cytosol from endoplasmic reticulum
2) Effects: Activates protein kinase C, calmodulin, and other Ca2+ binding proteins; Ca2+-calmodulin activates calmodulin-dependent protein kinase
What are the secondary messengers?
1) Ca2+
2) Cyclic AMP (cAMP)
3) Cyclic GMP (cGMP)
4) Diacylglycerol (DAG)
5) Inositol trisphosphate (IP3)
Cyclic AMP as secondary messenger?
1) Source?
2) Effects?
1) Source: A G protein activates plasma membrane adenylyl cyclase, which catalyzes the formation of cAMP from ATP
2) Effect: Activates cAMP-dependent protein kinase (Protein kinase A)
Cyclic GMP (cGMP) as secondary messenger?
1) Source?
2) Effects?
1) Source: Generated from guanosine triphosphate in a reaction catalyzed by a plasma membrane receptor with guanylyl cyclase activity
2) Effects: Activates cGMP-dependent protein kinase (protein kinase G)
Diacylglycerol (DAG) as secondary messenger?
1) Source?
2) Effects?
1) Source: A G protein activates plasma membrane phospholipase C, which catalyzes the generation of DAG and IP3 from plasma membrane (PIP2)
2) Effects: Activates protein kinase C
IP3 as secondary messenger?
1) Source?
2) Effects?
1) Source: A G protein activates plasma membrane phospholipase C, which catalyzes the generation of DAG and IP3 from plasma membrane (PIP2)
2) Effects: Releases Ca2+ from endoplasmic reticulum into the cytosol
What produces Eicosanoids?
Arachidonic acid (AA)
What are the types of Eicosanoids?
1) Cyclic endoperoxides
2) Prostaglandins
3) Thromboxins
4) Leukotrienes
AA pathway
Ligand binds to receptor—> causing Phospholipase A2 to split off of membrane phospholipid —-> forming AA –> (AA are metabolized into 2 pathways) 1. COX and 2. Lipoxygenase pathway —-> these form the Eicosanoids
Drugs that inhibit COX?
Aspirin and NSAID (Non-steroidal anti-inflammatory drug)
Drug that inhibit Lipoxygenase pathway?
Singular
How is the brain and spinal cord made?
Neural plate——> neural groove, neural fold, and notocord—-> brain and spinal cord
What are the glial cells of the CNS?
1) Astrocytes
2) Ependymal cells
3) Microglia
4) Oligodendrocytes
This functions by the formation of blood brain barrier (helps control the amount of substance that goes into the CNS. What is this?
Astrocyte
This help in the regulation of CSF and take care of waste. What is this?
Ependymal cells
This helps with injury repair and provides support for the neuronal cells
microglia
This helps with formation of myelin sheaths (only found in the CNS). What is this?
Oligodendrocyte
What produces myelin sheaths in the PNS?
Schwann cells
What provides insulation enhancing the speed and transmission of electrical signals along the axon?
Myelin
what type of channels open and shut very quickly?
Na+ channels
What is mechanism of membrane potential?
1) Leaky K+ channels keep membrane channel negative
2) Local membrane is brought to threshold by stimulus
3) Voltage gated Na+ channels cause depolarization
4) Inactivation of Na+ channels and delayed opening of K+ channels stop depolarization
5) K+ leaks out of cell causing repolarization
6) K+ keeps leaking causing hyperpolarization. when this happens action potential cannot occur
7) K+ channels are close bring the cell back to resting membrane potential
What drugs and toxins inhibit action potentials?
Drugs:
1) Procaine
2) Lidocaine
Toxins:
1) Tetrodotoxin
2) Alpha- bungarotoxin
3) Conotoxin
What is the period of time where an action potential cannot be fired it is when a AP is actually occurring?
Absolute refractory period
What is the period of time where an action potential can be fired but a strong stimulus is needed (it happens normally around the time of hyperpolarization is occurring)?
Relative refractor period
AP are…
All or none
What is needed prior to the action potential to hit threshold?
Graded potentials
what are the main differences between AP and Graded potential?
1) Graded potential can be depolarization or hyperpolarization
2) AP can only be depolarization
3) AP is generated by a graded potential
many pre-synaptic neurons go to one post-synaptic neuron this is called?
Converge synapses
When 1 pre-synaptic neuron sends signals to multiple post-synaptic neurons this is called?
Divergent synapses
What is the mechanism of neurotransmitter release?
1) AP reaches axon terminal
2) Voltage-gated Ca2+ channels open
3) Calcium enters axon terminal
4) Neurotransmitters is released and diffuse into the cleft
5) Neurotransmitters bind to post-synaptic receptor
6) Neurotransmitters removed from synaptic cleft
What is involved in causing the fusion of the vessels (filled with neurotransmitters) with the membrane inorder to promote the release of the neurotransmitter?
SNAREs
Neuron Channel-linked receptor (fast and direct acting) are called?
Ionotropic receptors
What are neuron with G-protein linked receptors (slow acting) called?
Metabotropic receptors
Binding of neurotransmitter to receptor causes the movement of ions this is this receptor called?
Ionotropic receptor
Binding of neurotransmitter to receptor activating G-protein what is this receptor called?
Metabotropic receptor
Towards threshold of post-synaptic cell is called?
EPSP
Away from threshold of post-synaptic cell is called?
IPSP
One pre-synaptic neuron trying to bring the cell to threshold is called?
Temporal summation
When multiple pre-synaptic neurons are trying to bring the cell to threshold this is called?
Spacial summation
What are used for rapid communication and are release and re-uptake is quickly?
Neurotransmitters
What are slow acting and amplify or dampen the effectiveness of ongoing synaptic activity (help neurotransmitters)?
Neuromodulators
What are found in both in the CNS and PNS, they are produced from cholinergic neurons and act on Muscarinic and Nicotinic receptors?
Acetylcholine (ACH)
This is synthesized in the pre-synaptic neuron terminal and act on the post-synaptic receptor?
Acetylcholine
This synthesizes acetylcholine?
Choline acetyltransferase
This is found in the synaptic cleft and catalyses the breakdown of ACH and is recycled back into the presynaptic terminal what is this?
Acetylcholine esterase
If you have a patient where the acetylcholine is deficient one way to make sure the acetylcholine is no longer degraded is by?
Inhibiting the function of acetylcholine esterase
What inhibits the function of acetylcholine esterase?
Sarin
what receptors serve as important receptors in the brain causing excitation of neurons?
Nicotinic receptors
This is caused by the degeneration of cholinergic neurons normally occurs at 85 years of age or older?
Alzheimer’s disease
What are the enzymes that degrade the biogenic amine neurotransmitter?
1) Monoamine oxidase (MAO)
2) Catechol-o-methyltransferase
What disease has loss of dopamine-releasing neurons in areas of the brain?
The symptoms include:
1) Persistent tremors
2) Head nodding and pill rolling behavior
3) Stiff facial expression
the treatment for this:
Increase- L-Dopa, deprenyl, or gene therapy
Parkinson’s disease
Adrenergic receptors use what type of receptors?
G-protein coupled receptors
These receptors are located on vascular smooth muscle and in the pupil of the eye, and cause vasoconstriction?
Alpha 1
These receptors are in the CNS on presynaptic neurons, some vascular smooth muscle cells, adipose tissue and platelets and they inhibit cAMP?
Alpha 2
These receptors are located on cardiac muscle and in the kidneys, usually excitatory (activate cAMP), equal affinity of NE and EPI, and INCREASE HEART RATE AND STIMULATE RENIN RELEASE which increases blood pressure?
Beta 1
These receptors are located on blood vessels and smooth muscle, usually inhibitory (activate cAMP), they have a GREATER AFFINITY FOR EPI AND NE, and they ACTIVATE BRONCHIAL SMOOTH MUSCLE CELL RECEPTORS CAUSE RELAXATION?
Beta 2
These are receptors located on adipose tissue, usually excitatory (activate cAMP), equal affinity for NE and EPI, and STIMULATE LYPOLYSIS OF FATS IN THE ADIPOSE TISSUE?
Beta 3
Effect of EPI in liver and adipose tissue?
Increase blood glucose
Nicotinic receptors are what type of receptors?
Ionotropic (ligand gated)
Muscarinic receptors are what type of receptors?
Metabotropic (G-protein)
Effect of binding to nicotinic receptors?
Excitation
What are the major locations of Nicotinic receptors?
1) all ganglionic neurons; adrenal medullary cells (ALSO NEUROMUSCULAR JUNCTIONS OF SKELETAL MUSCLE)
What are the major locations of Muscarinic receptors?
All parasympathetic target organs
What is the effect of binding to a Muscarinic receptor?
Excitation mainly; except the heart
Adrenergic receptors bind what type of neurotransmitters?
NE and EPI
Where are Beta 1 receptors located?
Heart mainly, but also on kidneys and adipose tissue
What is used for the treatment of glaucoma (opens aqueous humor drainage pores), it mimics effects of Ach, enhances PNS effects, and it binds to muscarinic Ach receptors?
Pilocarpine
What is used for the treatment Myasthenia gravis (increasing availability of Ach), indirectly effect at all ACH receptors (prolongs the effects of ACH) it binds to the enzyme (AChE) that degrades ACH)?
Neostigmina
What is used for asthma (dilates bronchioles by binding to Beta 2 receptors), it enhances sympathetic activity by increasing NE release or bonding to adrenergic receptors, and binds to adrenergic receptor (BETA 2)?
Albuterol (ventolin)
What is used for hypertension (member of a class of drugs called BETA blockers that decrease heart rate and blood pressure), it decreases sympathetic activity by blocking adrenergic receptors or inhibiting NE release, and binds to adrenergic receptors?
Propranolol
What synthesizes serotonin?
Tryptophan
(very important) What amino acid neurotransmitters are at excitatory synapses?
1) Aspartate
2) Glutamate
(very important) What amino acids are found at inhibitory synapses?
1) Glycine
2) GABA
Glutamate has two type of ionotropic receptors what are they?
1) AMPA
2) NMDA
what is implicated in mediating excitotoxicity, death of glutamate-containing neuronal cells die due to injury, and increased accumulation of intracellular Ca2+ can be toxic to these receptors?
NMDA receptors
This is a major inhibitory neurotransmitter in the brain (inhibitory effect could be due to influx of CHLORIDE ion into the postsynaptic membrane causing hyperpolarization, and can bind to ionotropic or metabotropic receptors?
GABA
Receptor for GABA are target by?
ethanol in alcohol
what drugs are used to produce GABA?
Benodiazepine
1) Alprasolam (Xanax)
2) Diazepam (valium)
What is released from inhibitory interneurons in the spinal cord and brainstem (it binds to ionotropic receptors on postsynaptic cells that allow CHLORIDE IONS to enter)?
Glycine
these neurons are essential for SKELETAL MUSCLE CONTRACTION?
Glycinergic neurons
(GLYCINE)
What are some examples of neuropeptides?
Pain killers
1) Enkephalins
2) Endorphins
3) Morphine
4) Codeine
what coordinates information from other associated areas and is used for REASONING SKILLS?
Frontal Lobe
What connects the right and left hemispheres of the brain?
Corpus callosum
What releases dopamine and is used for for voluntary muscle control?
Basal ganglia
What controls skeletal muscle movement?
Primary motor cortex
What is the area of the brain used for hearing?
Temporal lobe
This is the location where sensory information from skin musculoskeletal system, viscera, and taste buds is located?
Parietal lobe
This is the location where vision occurs?
Occipital
What controls emotional behavior, and learning?
Limbic system
This is the synaptic relay stations and important integrating centers for most inputs to the cortex, controls arousal and attention?
Thalamus
This is the master command center for neural and endocrine coordination?
Hypothalamus
This houses the pineal gland?
Epithalamus
This is the area that plays a role in movement and coordination?
Cerebellum
This plays a role in breathing, relay and sensations
Pons
this is the area that plays a role in breathing and has cardiovascular center?
Medulla oblongata
this is involved in motor functions, cardiovascular and respiratory control, and the mechanism that regulate sleep and wakefulness and focus of attention?
Reticular formation
Somatic nervous sytem control…
skeletal muscle by voluntary control
autonomic nervous system controls….
1) Sympathetic
2) Parasympathetic
Both are INVOLUNTARY CONTROL
the sympathetic nervous system controls…
Cardiac and smooth muscle glands
The parasympathetic nervous system controls…
Enteric nervous system
Somatic nervous system go from…
CNS directly to skeletal muscle
The autonomic nervous system go from…
CNS (preganglionic fiber)–> GANGLION (postganglionic fiber) —> Smooth muscle or cardiac muscle, glands, or GI tract
This contains the nerves for hearing
Cochlea
This contains receptors for balance
Vestibule
This contains receptors for bal
