Ch 11: Control: The Nervous and Endocrine Systems Flashcards
The nervous system consists of billions of _____ which do what?
Neurons, carry impulses/ electrical signals between body parts
Label the neuron
|\____|\_____||||\
——————————–|\________________
———–O—————– __________________0
_____||\___|\_____
|\____|\_____||||\
- —cell body—————|\_________________
- ———-O-
How does an impulse travel through a neuron?
It is received at the dendrites, then transmitted through the cell body and down the axon
What does it mean when we say a neuron is polarized?
It is different on one side of its membrane than the other (the inside is negatively charged when compared to the outside of the neutron)
What is the resting membrane potential of most cells?
-70 mV
The ________ is a membrane protein that pumps 3 sodium ions out of the cell and 2 potassium ions into the cell
sodium-potassium pump (Na+/K+ ATPase)
Can sodium ions cross back into the cell after being pumped out?
No
Do dendrites receive or transmit an electrical impulse?
Receive
The direction in which an impulse travels through a neuron is _____ to _____ to _____
dendrites, cell body, axon
Is potassium concentration is ______ inside the cell than outside
Higher
The resting membrane potential of the cell is _____
-70 mV
Sodium concentration is _____ inside the cell than outside
lower
The axon of a neuron carries the nerve impulse _____ the cell body
away from
What is a leak channel?
Channels that will always allow potassium to leak out of the cell according to its gradient (there is more potassium inside the cell than outside, so it will leak out)
What is a voltage-gated channel?
Channels that open when the cell membrane reaches a particular voltage (-50 mV) (also known as threshold potential)
What does it mean when a neuron is polarized?
The state of the membrane at rest, negative on the inside and positive on the outside
What is depolarization?
The membrane potential moves in the positive direction
What is repolarization?
The membrane potential returns to its resting value
What does depolarization result from?
An influx of sodium ions
Rapid, “jumping” conduction is called:
saltatory conduction
A return to the resting, polarized state is called:
Repolarization
The small portion of a neuron’s membrane that is undergoing an action potential is relatively ____ on the inside and _____ on the outside.
positive, negative
Repolarization results from an ____ of ____ ions
efflux, potassium
The time during which a portion of the membrane is unable to fire an action potential (because it just fired one) is called the:
Refractory period
In a myelinated axon, action potentials occur only at the:
nodes of Ranvier
Ion channels that open at a particular membrane potential are said to be:
voltage-gated
A neuron whose resting potential is moving away from threshold is said to be ______
inhibited
The small space between the axon terminus of one neuron and the dendrites of the next neuron is called the _________
synaptic cleft
A synapse can be found between a neuron and _____
neuron or organ
The most common neurotransmitter in the body is _________
acetylcholine
A neurotransmitter is released from ______ and binds to _______
vesicles, receptors
Receptors that open sodium channels would cause the neuron to _______
depolarize
A neuron will fire an action potential only if its membrane potential reaches _____
threshold
What do chemical synapses use to pass the impulse from one neuron to the next?
neurotransmitters
What is a synapse?
The point where the impulse gets transferred
The CNS consists of the _____ and the _________
brain, spinal chord
Motor neurons are part of the ____ and send information from the ____ to the _____
PNS, CNS, organs
Interneurons are part of the ___ and connect sensory and motor neurons.
CNS1
The _________ maintains body homeostasis
hypothalamus
Conscious awareness is controlled by the _______ of the brain
cerebrum
The _______ division of the PNS controls the skeletal muscles
somatic
The primary neurotransmitter used by the parasympathetic division of the ANS is
acetylcholine
The ________ division of the PNS is in control of a person watching TV
parasympathetic
Which part of the brain smooths and coordinates body movement?
cerebellum
Neurons of the PNS are _______ neurons of the CNS
connected to
Conscious thought processes are carried out by the _______
cerebrum
What do sensory neurons do?
Send information to the CNS from the sensory organs of the body
What do motor neurons do?
Send information from the CNS to the organs of the body
What does the cerebrum do?
Voluntary actions, conscious awareness of sensations
What does the cerebellum do?
Coordinates muscle movement
What does the medulla do?
involuntary acts, like breathing and blood pressure regulation
What does the hypothalamus do?
Maintain body homeostasis
The 2 subdivisions of the PNS are the:
somatic nervous system and autnomic nervous system
What does the somatic nervous system do and what neurotransmitter does it use?
Voluntary system, conscious control over the organs that it controls (skeletal muscles), uses acetylcholine (ACh)
What does the autonomic nervous system do?
It is an involuntary system, no conscious control over the organs
The autonomic nervous system can be further subdivided into:
Sympathetic division and parasympathetic division
How does the endocrine system control the body?
Through the use of hormones
What are the 2 classes of hormones?
peptide hormones and steroid hormones
Peptide hormone shave receptors _______ the cell and steroids have receptors ______ the cell
outside, inside
The organs that are affected by a particular hormone are referred to as that hormone’s ____________
target organs
the endocrine system is ______ than the nervous system
slower
Peptide hormones cause their effects ____ rapidly than steroid hormones
more
Steroid hormones cause their effects by
binding to DNA and modifying transcription
Steroid hormones are derived from
cholesterol
How do peptide hormones cause their effects?
Turn existing enzymes in the cell on or off
What lobes is the pituitary gland split into?
Anterior lobe and posterior lobe
Anterior pituitary gland hormones
Hormones: Growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone, follicle stimulating hormone, luteinizing hormone, and prolactin
Growth hormone
Target organs: all tissues and organs
Effects:causes to grow and stimulates rate at which older cells are replaced with newer cells
Thyroid stimulating hormone
Target organ: thyroid gland
Effects: secrete thyroid hormones
Adrenocorticotropic hormone
Target organ: stimulates adrenal cortex
Effects: secretes its hormones
Follicle stimulating hormone
Target organ: gonads
Effects: maturation of ova, release of estrogen, creation of sperm
Luteinizing hormone
Target organ: gonads
Effects: development of a corpus luteum, testosterone creation
Prolactin
Target organ: mammary glands
Effects: make breast milk
What is the release of anterior pituitary gland hormones controlled by?
special releasing hormones from the hypothalamus
What hormones does the posterior pituitary gland store and secrete?
Oxytocin and antidiuretic hormone
Oxytocin
Causes uterus to contract during childbirth and mammary glands to release milk during breastfeeding
Antidiuretic hormone (ADH)
Causes the kidneys to retain water, also known as vasopressin
What is the acronym for the 6 anterior pituitary gland hormones?
FSH (follicle stimulating hormone)
LH (luteinizing hormone)
ACTH (adrenocorticotropic hormone)
TSH (thyroid stimulating hormone)
Prolactin
GH (growth hormone)
lives in the Ant Pit
What are the hormones in the thyroid gland?
Thyroxine and calcitonin
Thyroxine
Target organ: most
Effects: increase rate of metabolism
Calcitonin
Target organ: bone
Effects: remove calcium from blood and use it to build new bone, reduces blood calcium levels
Parathyroid gland hormone
Parathyroid hormone (parathormone)
Parathyroid hormone
Activates special cells in bone that dissolve the bone to release calcium into the blood
Adrenal medulla hormones
Epinephrine and norepinephrine
Epinephrine and norepinephrine
increase and prolong the effects of the sympathetic nervous system
Adrenal cortex hormones
Steroids (glucocorticoids, mineralocorticoids, sex steroids)
Glucocorticoids
Target organ: liver and other organs
Effects: produce glucose from fat and release into blood
Mineralocorticoids
Target organ: Kidneys
Effects: causes kidney to retain sodium
Pancreas hormones
Insulin and glucagon
Insulin
Target organ: all cells
Effects: take glucose out of blood and use it in cellular respiration
Glucagon
Target organ: liver
Effects: liver breaks down glycogen and releases glucose into blood
Sex steroids
Testosterone, estrogen and progesterone
Develop secondary sex characteristics
