quiz Flashcards
What two body systems work together to deliver messages to other parts of the body to maintain homeostasis?
Nervous and endocrine systems
Differentiate between sensory and motor neurons.
- Sensory neurons carry signals from the outer parts of your body to the CNS
- Motor neurons carry signals from the CNS to your muscles, glands, and skin
What do dendrites do? Axons?
Dendrites receive signals and axons transmit
Give the main divisions of the peripheral nervous system and what is controlled by each.
- Automatic - involuntary processes (blinking, digestion, breathing)
- Somatic - voluntary processes (moving muscles, chewing)
What are the two types of nerve cells?
Neurons and glial cells
What neuroglia form myelin in the PNS? The CNS?
- PNS: Schwann Cells, or neurolemmocytes
- CNS: Oligodendrocytes
What is a nerve? A ganglion? A plexus?
- A nerve is a bundle of neurons that transmit electrical signals throughout the body
- a ganglion is a collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system (PNS)
- A plexus is a network of nerves
Give the main divisions of the nervous system controls the things we cannot consciously control?
Autonomic nervous system
Compare myelinated and unmyelinated axons as to appearance and speed of conduction.
- Myelinated:
a. Appearance:
extensions of Schwann cells (PNS) or oligodendrocytes (CNS) repeatedly wrap around a segment of an axon to form tightly wrapped membranes.
Constitute the myelin sheath and gives these axons a white appearance, myelin sheath interrupted by nodes of ranvier
b. Speed of Conduction:
Conduct nerve pulses faster than unmyelinated because they jump from one node of ranvier to the next, up to 120 m/s - Unmyelinated:
a. Appearance:
Lack myelin sheath, has thin schwann cell membrane
b. Speed of Conduction:
Slower because it must travel across entire axon due to no nodes of ranvier, much slower- .5 - 2 m/s
Describe the term resting membrane potential. Be sure to tell what establishes it.
- Refers to the difference in electric charge across the membrane of a neuron when it is not actively transporting an impulse
- Established by ion distribution, selective permeability,
Give the function of these neurons: efferent, afferent, motor, and interneurons (integrative neuron)
- Efferent
Carry signals from brain to PNS to initiate an action - Afferent
Bringing sensory information from the outside to the CNS - Motor
Sends commands from the brain the muscles - Interneuron
Relays information to and from the brain
Define excitability.
the ability of a neuron to respond to stimuli by generating and transmitting an action potential
What is the difference between continuous conduction and salutatory conduction?
Continuous conduction is slow and unmyelinated while saltatory conduction is the faster jumping of an action potential from one node of ranvier to another
What are the major steps in nerve impulse transmission? What happens in each step? Be sure to include polarization and repolarization.
- Polarization
Where neuron maintains negative internal charge - Depolarization
Where sodium ions rush in and causes the inside to become positive, triggers an action potential - Repolarization
Where potassium ions flow out and restores negative charge inside the neuron
What is the significance of “threshold” in nerve impulse transmission?
It is the requirement that must be met for an action potential to be generated
How are the terms synapse, gap junction, and neurotransmitter related?
Because they all are involved in the communication between neurons or between neurons and other cells
Explain the parts of the chemical synapse.
- Presynaptic terminal: which contains neurotransmitters
- Synaptic cleft: the gap between neurons
- Post synaptic membrane: has receptors that bind to neurotransmitters, allows for signal transmission
What are ascending and descending tracts?
- Ascending:
Sensory neurons that carry sensory information from the body to the brain - Descending
Bundles of motor neurons that transmit signals from the brain to muscles and glands
Differentiate between gray matter and white matter.
- Gray matter:
Contains neuron cell bodies, dendrites, and unmyelinated axons - White matter:
Contains myelinated axons
Name in order the three meninges, the subarachnoid space, and the epidural space, from outside in.
- epidural space
- dura mater
- arachnoid mater
- subarachnoid space
- pia mater
Name and explain the parts of a reflex arc.
- Sensory receptor
Detects stimulus - Sensory neuron
Transmits signal to CNS - Interneuron
Processes signal - Motor neuron
Carries signal to effector - Effector organ
Executes response
What are some of the autonomic reflexes controlled by ANS?
Heart rate, digestion, salivation
What part of the brain connects it to the spinal cord?
brainstem
Name the parts of the brain stem and diencephalon.
Brainstem: Medulla oblongata, pons, midbrain, reticular formation
Diencephalon: thalamus. Subthalamus, epithalamus, hypothalamus,
