BIO 264 Lecture Notes - Lecture 30: Smooth Muscle Tissue, Inferior Vena Cava, Pulmonary Circulation
Neurotransmitter Review
Neurotransmitters are made in the neuron cell cell body or axon terminal and packed into
synaptic vesicles
Released from axon terminals of presynaptic neurons, cross synaptic cleft, bind to receptors on
postsynaptic membrane
Effects are terminated through removing/degrading
Type of receptor a neurotransmitter binds to determines response
Ionotropic receptors: ligand gated, control movement of ions in/out neuron
Metabotropic receptors: found within plasma membrane associated with a separate ion
channels, directly connected to metabolic processes that are initiated when neurotransmitter
binds
Neurotransmitters binding either leads to EPSP or IPSP
-Most can do both just depending on receptor
ACh- “cholinergic” (response to ACh)
-Mostly either Muscarinic or nicotinic
-Almost always excitatory
Amine:
-Catecholamines: epinephrine, norepinephrine, dopamine
-Serotonin
-Histomeme
Amino Acid Neurotransmitters:
Glycine: major inhibitory neurotransmitter of PNS, IPSP
Glutamate: major excitatory neurotransmitter in cNS, generate EPSP
GABA: major inhibitory neurotransmitter in CNS, generate IPSP
Neuropeptide neurotransmitter:
Substance P → pain and temp perception
Opioids: pain control/relief and depression of CNS
Neuropeptide Y → feeding behaviors/feeling full
ACH
1. Nicotinic receptors- postganglionic neurons
2. Mus
Adrenergic receptors- bind to epinephrine and norepinephrine
find more resources at oneclass.com
find more resources at oneclass.com
1. Alpha
a. Alpha 1: smooth muscle, blood vessels, skin, GI tract, kidneys
b. Alpha 2: preganglionic sympathetic neurons (not target cells)
2. Beta
a. Beta 1: cardiac, kidney, adipose
b. Beta 2: smooth muscles, urinary bladder, skeletal muscle fibers, salivary glands
c. Beta 3: adipose, smooth muscle cell walls
Alpha 2:
1. AP → ACh release
2. Norepinephrine binds to alpha 2, hyperpolarizes to cancel AP
3. When hyperpolarized, the action potential decreases (i.e. -70 → -85 mV)
Norepinephrine
Cardiac Muscle Effect
Beta 1:
-Increases rate/force of muscles
-Ion channels open
-Amount of blood delivered increases
-Blood pressure increases
Smooth Muscle Effect
Alpha 1:
-Constriction of blood vessels
-Decrease blood flow
Beta 2:
-Relaxes airways, allows more oxygen
Sympathetic Nervous System
Adrenal Medulla: composed of modified sympathetic postganglionic neurons
-ACh binds
-Release epinephrine (and norepinephrine) into blood stream
Enhances mental alertness
Adrenaline rush
Increase tendency to clot
Goosebumps
Parasympathetic Nervous System
Both pre and postganglionic release ACH
1. Nicotinic
2. Muscarinic
Cardiac:
-Decreases heart rate and blood pressure
find more resources at oneclass.com
find more resources at oneclass.com
-Vagus Nerve/CN X
Smooth Muscle
-Constriction of pupil
-Constriction of bronchioles/smooth muscle lining, reduce airflow
-Contraction of muscle lining digestive tract
ANS Overview:
Dual Innervation: both para and sympathetic innervate same organs
-Dominance switches depending on needs
Exceptions: sweat glands, blood vessels, errector pili muscles, adrenal medulla (only
sympathetic)
Hypothalamus = homeostasis
Autonomic centers:
1. Reticular formation
2. Contact hypothalamus
3. Contain neurons
Autonomic tone: neither division is completely shut down
-Sympathetic tone: dominates in blood vessels, partially constricted
-Parasympathetic tone: dominates in heart, keeps average beat
Cardiovascular System
Consists of
1. Heart: pumps blood
-faster/more force = higher blood pressure
2. Blood vessels: distribute blood
3. Blood
Arterial System: delivering blood to body from lungs
-Also nutrients/waste products
Venous System: returns deoxygenated blood to lungs
-Transport system
Heart Chambers:
-2 atrium: receive venous blood
-Ventricles: eject blood
Apex: points down on left side
Base:
Superior and and inferior vena cava drain into right atrium
-SVC and IVC carry deoxygenated blood
One way valves between atria and ventricles
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Neurotransmitters are made in the neuron cell cell body or axon terminal and packed into synaptic vesicles. Released from axon terminals of presynaptic neurons, cross synaptic cleft, bind to receptors on postsynaptic membrane. Type of receptor a neurotransmitter binds to determines response. Ionotropic receptors: ligand gated, control movement of ions in/out neuron. Metabotropic receptors: found within plasma membrane associated with a separate ion channels, directly connected to metabolic processes that are initiated when neurotransmitter binds. Neurotransmitters binding either leads to epsp or ipsp. Most can do both just depending on receptor. Glutamate: major excitatory neurotransmitter in cns, generate epsp. Gaba: major inhibitory neurotransmitter in cns, generate ipsp. Alpha 2: ap ach release, norepinephrine binds to alpha 2, hyperpolarizes to cancel ap, when hyperpolarized, the action potential decreases (i. e. -70 -85 mv) Adrenal medulla: composed of modified sympathetic postganglionic neurons. Release epinephrine (and norepinephrine) into blood stream. Both pre and postganglionic release ach: nicotinic, muscarinic.