Chapters 32 & 37 Flashcards
What is the resting potential of a neuron?
Resting potential is the membrane potential of a neuron that is not sending signals
Where is the concentration of Na+ higher? K+?
(Inside of neuron is more neg. than outside). This is because there is a lot of Na+ ions on the outside which are positive and a bunch of K+ on the inside which make it more negative.
Inside of membrane is -70 mV.
What must you do to achieve an action potential?
A certain level of depolarization must occur.
What is depolarization? How does it occur?
Reducing the membrane potential making it more positive. How it occurs: Sodium channels stimulated to open. Sodium moves into the cell. Causes change in membrane potential.
What membrane conditions are primarily responsible for maintaining the resting membrane potential?
The gated Na+ and K+ channels are closed. Ungated channels maintain the resting state.
What events are primarily responsible for the depolarization or the membrane?
A couple sodium channels are opened by stimulus. The inflow of Na+ through those channels depolarizers the membrane. An action potential is triggered if depolarization reaches the threshold.
What events are primarily responsible for the repolarization of the membrane?
K+ outflow is responsible for the repolarization of the membrane. Remember that in the repolarization zone, the sodium channels are inactivated.
What events are primarily responsible for the hyper polarization of the membrane?
Hyper polarization is caused from anything that increases the outflow of positive ions or the inflow of negative ions. Close K+ channels.
What forms the myelin sheath?
Schwann cells
Hormones
Chemical signal secreted into body fluids (blood) communicating regulatory messages
Target cells
Body cells that respond to hormones. The receptors might be on the outside of the target cell or they could be inside the target cell.
Endocrine system/glands
Sum of all an animals hormone secreting cells and tissues
Endocrine glands
Are ductless and secrete hormones directly into body fluids
Feedback mechanisms
Negative and positive that regulate most of the endocrine secretion.
Excitatory synapse
making a neuron less negative on the inside. Sodium channels are opened to cause this.
Inhibitory synapse
turns off the cell, has it not send signals, and potassium channels are opened
Neurotransmitters
chemical messengers that help pass information between pre and postsynaptic cells.
Dendrite
One of usually numerous, short, highly branched extensions of a neuron that receive signals from other neurons.
Axon
A typically long extension, or process, of a neuron that carries nerve impulses away from the cell body toward target cells.
Synapse
The junction where a neuron communicates with another cell across a narrow gap via a neurotransmitter or an electrical coupling.
Resting potential
The membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside.
Action potential
An electrical signal that propagates (travels) along the membrane of a neuron or other excitable cell as a nongraded (all-or-none) depolarization.
Sodium potassium pump
A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell.
Hyperpolarization
A change in a cell’s membrane potential such that the inside of the membrane becomes more negative relative to the outside. Hyperpolarization reduces the chance that a neuron will transmit a nerve impulse.
Depolarization
A change in a cell’s membrane potential such that the inside of the membrane is made less negative relative to the outside. For example, a neuron membrane is depolarized if a stimulus decreases its voltage from the resting potential of –70 mV in the direction of zero voltage.
Threshold
The potential that an excitable cell membrane must reach for an action potential to be initiated.
Schwann cells
A type of glial cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system.
Neurotransmitter
A molecule that is released from the synaptic terminal of a neuron at a chemical synapse, diffuses across the synaptic cleft, and binds to the postsynaptic cell, triggering a response.
Hormone
In multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the body, changing the target cells’ functioning. Hormones are thus important in long-distance signaling.
Melatonin: Gland of origination? Role?
Pineal gland. It helps regulate other hormones and maintains the body’s circadian rhythm. The circadian rhythm is an internal 24-hour “clock” that plays a critical role in when we fall asleep and when we wake up.
ADH: gland of origination? Role?
Posterior pituitary. This travels in the blood to your kidneys and affects the tubules so more water is reabsorbed into your blood. As a result you make a smaller volume of more concentrated urine.
Insulin: gland of origination? Role?
Pancreas. Lowers blood sugar.
Epinephrine: gland of origination? Role?
Adrenal medulla. More commonly known as adrenaline, is a hormone secreted by the medulla of the adrenal glands. Strong emotions such as fear or anger cause epinephrine to be released into the bloodstream, which causes an increase in heart rate, muscle strength, blood pressure, and sugar metabolism.
Estrogen: gland of origination? Role?
Ovary. The estrogenic hormones are uniquely responsible for the growth and development of female sexual characteristics and reproduction in both humans and animals. The term “estrogen” includes a group of chemically similar hormones: estrone, estradiol (the most abundant in women of reproductive age) and estriol.
Growth hormone: gland of origination? Role?
Anterior pituitary gland. It’s a growth hormone helping all tissues of the body (including bone) grow.
Glucagon: gland of origination? Role?
Pancreas. It works to raise the concentration of glucose in the bloodstream.
Androgen: gland of origination? Role?
Male testes. It stimulates or controls the development and maintenance of male characteristics in vertebrates by binding to androgen receptors.
Water Vs Lipid soluble, where each binds, and acts
The action of water soluble hormones differs from the lipid soluble hormones in that the water soluble hormones dock with a protein on the surface of a cell and since they are water soluble they can’t gain entry to the cell so they send a signal transduction pathway to the nucleus to make specific genes or proteins. Lipid soluble hormones can move through the cells membrane and into the nucleus.
Signal transduction pathway
A series of steps linking a mechanical, chemical, or electrical stimulus to a specific cellular response.
Study the simple endocrine pathway on mind map
Okay
Glucose homeostasis controlled by hormones.
Study podigal activity on diabetes
Hypothalamus
It receives info from nerves, analyzes, and starts endocrine. The ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary.
Pituitary gland (2 parts and their roles)
An endocrine gland at the base of the hypothalamus; consists of a posterior lobe, which stores and releases two hormones produced by the hypothalamus, and an anterior lobe, which produces and secretes many hormones that regulate diverse body functions.
Homeostasis
The steady-state physiological condition of the body. When an environment is the same on the inside while the outside environment changes.
Ectotherm conformer
They have a lower metabolic rate, not using energy
Endotherm
Type of regulator. They have a high metabolic rate because they use energy to maintain body temperature.
Conformer
An animal for which an internal condition conforms to (changes in accordance with) changes in an environmental variable.
Regulator
An animal for which mechanisms of homeostasis moderate internal changes in a particular variable in the face of external fluctuation of that variable.
Describe the parts of homeostatic system
A body maintains a variable (such as body temperature) near a SET POINT. Fluctuations in the variable above or below the set point serve as STIMULUS detected by a receptor, or SENSOR. Upon receiving a signal from the sensor, a control center generates output that triggers a response, a physiological activity that helps return the variable to the set point.
Stimulus
In feedback regulation, a fluctuation in a variable that triggers a response.
Sensor
In homeostasis, a receptor that detects a stimulus.
Negative feedback
A form of regulation in which accumulation of an end product of a process slows the process; in physiology, a primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change.
Where do hormones travel? What do they elicit a response from?
Released by endocrine cells into the blood system where they then move to anywhere in the body. Hormones elicit a response at their target tissue, target organ, or target cell type through receptors.
Study blood glucose regulation given blood sugar level low/high and be able to describe the response of the body.
Okay study podigi and hoe work for this.
Nervous system
Neurons transmit signals along dedicated routes connecting specific locations in the body.
Nervous system book definition
The fast-acting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with the endocrine system to effect internal regulation and maintain homeostasis.
Cerebrum
The dorsal portion of the vertebrate forebrain, composed of right and left hemispheres; the integrating center for memory, learning, emotions, and other highly complex functions of the central nervous system.
Cerebellum
Part of the vertebrate hindbrain located dorsally; functions in unconscious coordination of movement and balance.
Hypothalamus
Links the nervous system to the endocrine system via the pituitary gland (hypophysis).
Acetylcholine
A chemical released by nerve cells to send signals to other cells. Acetylcholine functions in the brain and body as a neurotransmitter.
Neuron structure
Review mind map
Describe the 2 cellular response pathways by discussing reception location, reaction, type of hormone, and end product
1) water soluble: reception location is protein on surface of cell. Reaction: 2) neuroendocrine pathway:
Where do hormones elicit a response from?
The hypothalamus I think
Type 1 diabetes
Little or no insulin is produced
Cells can’t absorb sugar (glucose), which they need to produce energy
Can’t be prevented
Type II diabetes
No response to insulin signals
Can be prevented with a healthy lifestyle, including eating healthy and doing exercise often
