Flashcards in Exam 2 Deck (100):
Groups of neurons that influence each other's activity by communicating at neuronal synapses
The site or junction where electrical signals are transmitted from one cell to another cell
Type of Synapse - Found between successive neurons in a neuronal pathway
Type of Synapse - found between somatic a-motor neurons and myofibers of skeletal muscles
Type of Synapse - Found between autonomic motor neurons and autonomic effectors including smooth muscle and glandular cells
Neuron that carries impulse INTO the synapse
Neuron that carries the impulse AWAY from the synapse
Two cells forming the synapse are separated by a physical space called the synaptic cleft
Narrow Space (bout 20-30nm) that separates the presynaptic neuron from the postsynaptic neuron (or effector)
ESM's released by neurons that diffuse across a synaptic cleft to stimulate or inhibit activity in a postsynaptic neuron or effector (muscle or gland).
Membrane proteins found on the postsynaptic neurons (or effectors) that bind a specific NT and generate a response in the postsynaptic cell
Excitatory Postsynaptic Potential
Depolarizing graded potential that brings a postsynaptic neuron closer to the threshold for creating APS
Inhibitory Postsynaptic Potential
Hyper polarizing graded potential that moves a postsynaptic neuron further away from the threshold for creating APS
the process of integrating the input from multiple synapses
Effect produced by the simultaneous release of NT from more than one (usually large number) synaptic knobs on a single postsynaptic neuron
Effect produced by stimulation of NT release from the same presynaptic knob(s) in rapid succession on a postsynaptic neuron
Facilitation occurs when the membrane potential of a postsynaptic neuron is held nearer to the threshold then normal but not yet above threshold
Pathways in which a signal entering into a section of a neuronal pathway excites a greater number of neurons leaving that section. Used for amplification and divergence into multiple tracts
Pathways in which signals from multiple input fibers (or multiple axons terminals from a single input fiber) come together to excite a single output fiber. With this type of pathway, spacial summation is used to get a postsynaptic neuron to fire
Efferent (motor) neurons
Neurons that carry impulses away from the CNS out to the motor neurons
Somatic motor neuron
Type of efferent neuron - controls skeletal muscle contraction
Autonomic motor neuron
Type of efferent neuron - control involuntary effectors - cardiac muscle, smooth muscle, exocrine and endocrine glands and some adipose tissue
Pupil diameter changes due to contraction of smooth muscle within the iris (colored part of the eye) to control the amount of light entering the eye
Dilation of pupil in response to pain, emotional excitement, and dim light. Involves contraction of radial muscle fiber of iris, which are controlled by the sympathetic division of ANS
Constriction of pupil in response to increased light entering pupil (pupillary light reflex) or to near vision. Constriction involves contraction of the circular muscle fibers of the iris, which are controlled by the parasympathetic division
"Thoracolumbar division" or "Emergency" or "Fight or Flight" division
"Craniosacral division" or "Rest and Repair" or "Rest and Digest" division
Sympathetic Chain ganglia (sympathetic trunk)
Cell bodies of many postganglionic neurons - found on both sides of the vertebral column.
Long. Extend all over the body. "Cholingergic" - they secrete acetylcholine
Short. Autonomic ganglia and axons extend to nearby effectors. (Parasympathetic - "Cholinergic" - secrete acetylcholine) (Sympathetic - "Adrenergic" - secrete norepinephrine)
"Cholinergic" - secrete acetylcholine
"Adrenergic" - secrete norepinephrine)
80% of adrenaline. Catecholamines and act as neurohormones.
20% of adrenaline. Catecholamines and act as neurohormones.
Activated by acetylcholine
Type of Cholingeric Receptor. Ligand-gated Na+ (cation) channels found at the synapses between preganglionic and postanglionic neurons
Type of Cholingeric Receptor. G-protein coupled receptors that activate produciton of intracellular messagers that control ion channel permeability or metabolic activity of the cell. Found on teh postganglionic effectos of the parasympathetic divison
Activated by binding of the catecholamines including both norepinephrine and epinephrine
Respond my strongly to neoepinephrine. Contain a1 and a2 receptors
Found in neuroeffector junctions on most sympathetic effectors.
Found in neuroeffector junction on the GI tract and pancreas
Equally responsibe to either NE or EPI. Found in neuroeffector junctions on all cardiac effectors and renin-secreting cells in kidneys
Respond most strongly to Epi. NOT found in sympathetic neuroeffector junctions.
Respond most strongly to NE than Epi. Found primarily on adipose tissue. Activation of these receptors leads to fat breakdown
Circulation will stimulate vasodilation of blood vessels in the heart, skeletal muscle and liver that contain B2 receptors
The regulatory chemicals made and secreted into the ECF by endocrine cells. The secreted hormone reaches its target cells through transport in the ECF (plasma and IF)
Specific receptors for the hormone sent
Hormones that regulate the release of other hormones
Endocrines or circulating hormones
Hormones released by endocrine glands taht are carried in the blood plasma to act on distant target cells.
Local hormones that act on neighboring cells
Local hormones that act on the same cell that secreted them
Hormones released by neurons that are carries in plasma to act on distant target cells
Hormones that are synthesized from cholesterol
intracellular small molecules and ions that act as intracellular signals to activate various components of a signaling pathway
proteins that can be switch from an inactive state to an active state in response to an appropriate signal
Enzymes that catalyze the addition of phosphate to protein effectors to turn them "on"
Enzymes that catalyze the removal of phosphate from protein effectors to turn them"off"
molecular switches that link plasma membrane receptors with intracellular signaling pathways
the effects of small amounts of hormone binding to target cells are greatly AMPLIFIED in intracellular signaling pathways; thus, allowing very small amount of hormone binding to a receptor to activate a powerful response throughout its target cell.
major integrating link between the nervous and endocrine systems.
Attached to the hypothalamus by a delicate stalk-like structure called the "hypophyseal stalk or infundibulum" which contains the hypothalamo-hypophyseal tract.
Hypophyseal stalk or infundibulum
track made up of axons extending from cell bodies in the hypothalamus to axon terminals in the neurohypophysis
Anterior pituitary - glandular portion consisting of secretory epithelial cells
Posterior pituitary - nervous portion consisting of axons and axon terminals of neurons that have their cell bodies in the hypothalamus
secrete growth hormone - type of glandular cells
secrete prolactin (PRL) -type of glandular cells
secrete primarily ACTH - type of glandular cells
secrete thyroid-stimulating hormones (TSH) - type of glandular cells
secrete two gonadotropins called follicle-stimulating hormone and luteinizing hormone - type of glandular cells
include both releasing hormones and inhibiting hormones. most are peptides
a system of blood vessels in which blood after passing through a capillary bed of one organ, is conveyed directly through venules or veins to a capillary bed of a second organ.
secreted by the somatotropes of the anterior pituitary gland
growth hormone releasing hormone or GHRH
growth hormone inhibiting hormone or GHIH
Insulin-like growth factor or GIF
if a hormone is produced at a higher tahn normal level, the effects of that hormone are exaggerated
High during the growth period and can result in humans that grow up to 8 feet tall
high after the growth period ends result in increased growth and thickening of bones like cranial bones, nose, jaw, vertebrae and other
If a hormone is produced at a lower than normal level, the effects of the hormone are diminished
lack of production of GH or IGF leads to decreased lengthening of long bones during the adolescent growth period , which results in individuals of short stature
secreted by the lactotropes of the anterior pituitary gland
regulates the adrenal cortex
regulates the thyroid gland
a gonadotrophin that regulates the gonads
a gonadotrophin that regulates the gonads
between the hypothalamus and neurohypophysis
Uterin contraction and milk letdown - controlled by neurohormone reflex pathways
consists of two lobes of glandular tissue located along trachea just below the larynx
substance surrounding the follicular cells
cells found between the numerous thyroid follicles
T4 and T3
Basal metabolic rate
resting rate of calorie expenditure by the body
congenital hypothyroidism results in severely stunted physical and mental growth
is an enlarged thyroid gland that can be present in either hypothyroid or hyperthyroid conditions; in which the concentration of TSH increases
Vitamin D deficiency
made from vitamin D
hormone produced here
essential for animal's survival