Bio 30 Final review unit A1/2 Flashcards
What are the divisions of the nervous system
The Peripheral system is further divided into the somatic and autonomic systems, and the Central nervous system.
What is a neuron and its function
A neuron is a single electrically excitable cell that transmits information through electrical and chemical signals
What is the somatic nervous system and its function
The somatic nervous system is the voluntary division of the nervous system and is responsible for transmitting motor and sensory information to and from the central nervous system, it also controls the skeletal muscles
what is the Autonomic nervous system and its function
The Autonomic nervous system is the involuntary division of the nervous system. It controls the body’s unconscious functions, also known as the parasympathetic(rest and digest) and sympathetic(fight or flight) responses. The Parasympathetic response relaxes the body and slows activity, whereas the sympathetic response prepares the body for intense physical activity
What are dendrites and their functions?
They are extensions of the cell body that contain the receptors which receive the chemical stimulus, initiating the transfer of information(receives stimulus)
What is the cell body and its function
Contains the organelles responsible for powering and nourishing the neuron. Dendrites extend from the cell body
What is the axon and its function
A long narrow section of the neuron that carries the electrical impulse away
What is the myelin sheath and its function
Insluates the axon and accelearates the impluse speed
What are Schwann cells and their function
Makes the myelin that insulates the axon
What is neurilemma and its function
Only found in the PNS, used to regenarate the neuron after damage
What are the nodes of Ranvier
Gaps in the myelin sheath that speed up the impulse transmission by allowing it to hop(making it clap)
What are the synaptic knobs and their function
Found at the end part of the axon, transmits information to the dendrites of other neurons
What are the parts of the neuron
Dendrites, cell body, axon, myline sheath, schwann cells, neureliema, nodes of ranvier, synaptic knobs(axon terminal)
What is white and grey matter? What’s the difference?
White matter: Parts of the nerve cells of the CNS that have myeilnated fibers (appeared white)
Grey matter: Parts of the nerve cells In the CNA that have no myline(appear darker)
What are the steps of the neural transmission pathway?
- sensory receptors: Highly modified dendrites of a sensory neuron that are activated by environmental stimulus
- sensory neuron: Carries impulses to CNS
- Interneuron: A neuron of the CNS that connects with sensory, motor and other interneurons to integrate sensory input with motor output
- Motor neuron: Carries impulses from the CNS to an effector
- Effector: A cell or organ that produces a physiological response when stimulated by a nerve impulse
What are oligodendrocytes and their function?
Specialized glial cells that produce myelin in the CNS
What are glial cells?
Cells that nourish the neurons, remove their waste and defend against infection. myelin is produced by specialized glial cells called oligodendrocytes found in the CNS and Schwann cells found in the PNS
What is the reflex arc and what are the steps of it?
The reflex arc is the simplest nerve pathway. There is no coordination by the brain, instead the information is read by the spinal cord. Therefore a much quicker response is generated
1. sensory receptors are activated by enviornmental stimulus
2. sensory neurons carry the information to the spinal cord
3. the neurons in the spinal cord respond to the information
4. motor neuron carries the information from the spinal cord to the effector
5. effector responds to the information before it gets prossed in the brain
What is the Patellar reflex
“the knee-jerk response” Tapping the ligament under the knee cap causes the lower leg to raise in response
What is the pupillary reflex?
pupils restrict in response to light, more light=pupils restrict and become smaller. less light=pupils dilate to become smaller
What are the steps of a nerve impulse/action potential
- resting potential
- depolarization
- action potential
- repolarization
- hyperpolarization
- refractory period
What is the first step of a nerve impulse
Resting potential: -70mV(inside of the cell) higher concentration of k+ ions inside the cell and a higher concentration of Na+ outside the cell. Sodium/potassium pump working to maintain a resting state (3Na+ out, 2K+ in).
What is the second step of a nerve impulse
Depolarisation: Na+ channels open. Enough depolarization needs to happen to meet the threshold of -55mv.
What is the third step of a nerve impulse
Action potential: Once inside becomes positive(+40mv) Na+ channels close and charge is restored. (impulse is created)
What is the fourth step of a nerve impulse
Repolarization: K+ channels open and K+ rushes out of the cell. this restores the original polarity
What is the fifth step of a nerve impulse
Hyperpolarization: K+ channels close slowly and the inside of the cell becomes more negative than a resting state(below -70mV)
what is the sixth step of a nerve impulse
Refractory period: Time taken to restore the membrane to the resting potential, NA+/K+ pump is working to restore the resting state
What are the steps of a synaptic transmission
- Impluse/action potential
- Ca2+ channels open causing the movement of vesicles to the membrane to release NTs
- Diffusion of NTs across synaptic cleft
- Reception(NTs attach to receptor sites)
- Impluse is created
- cholinesterase pulls NTs off the receptor site and the reuptake begins(recycling of NTs)
What are the different kinds of neurotransmitters and their functions
Excitatory neurotransmittors: Opens sodium channels on the postsynaptic neuron causing the inside to become more positive
Inhibitory neurotransmittors: Opens channels such as potassium or anions(negative ions) channels which make the cell more negative
What is a threshold level?
The minimum voltaic charge that a neuron must have in order to fire an action potential (-55mv in humans)
What is the skull
The bone that surrounds the brain
What are the meninges
protective layer that surrounds the spinal cord and brain
What is cerebrospinal fluid
cushioning fluid that circulates between the innermost and the middle layer of the brain and spinal cord
What is the spinal cord
The part of the CNS that transports signals from the brain to the body and emerges from the skull through an opening called the foreman magnum
What is the cerebrum
The uppermost part of the brain that contains the major lobes of the brain, these lobes are the Frontal lobe, Parietal lobe, Occipital lobe, and Temporal lobe.
what is the forebrain
The frontmost part of the brain contains the cereberum, the corpus callosum, the hypothalamus, and the thalamus
what is the hindbrain?
The back part of the brain containing the cerebellum, and the brain stem( medulla oblongata and the pons)
What is the frontal lobe
The frontmost part of the brain responsible for voluntary muscle movement, intellectual activities, personality, speach and creativity
What is the pituitary gland
A small bean-shaped gland responsibal for hormone production
What is the temporal lobe
Part of the brain responsible for hearing and memory
What is the pons
relay station which sends messages between the cerebellum and the medulla