Lesson 5: Brain Anatomy Flashcards
What is a receptor protein?
A protein that is sensitive to and capable of communicating some signal
- either ionotropic or metabotropic
What is an ionotropic receptor?
A receptor protein that is an ion channel. The properties of the pore of the ion channel determine if it will produce ESPSs or IPSPs
- turn toward ions to mediate their effects
What is a metabotropic receptor?
A receptor protein that is not an ion channel. These receptors typically trigger an intracellular signaling cascade that involves g proteins, which can produce a vairety of cellular effects
- turn toward metabolism to mediate their effects
How are g proteins activated?
By metabotropic receptors
What molecules do g proteins use?
GTP molecules (instead of ATP molecules) for the energy they need to perform chemical reactions
When is a g protein “on”? When is a g protein “off”?
A g protein is on when:
- g protein is bound to GTP (can trigger chemical reactions)
- g protein lets go of GDP
A g protein is off when:
- g protein converts GTP to GDP
- g protein is still bound to GDP
How does a metavotropic g protein receptor cause an ion channel opening?
- Neurotransmitter binds to a metabotropic receptor
- Activated g proteins transmit the message intracellularly
- Some ion channels are gated (directly or indirectly) by activated (“on”) g proteins
What does g-protein signaling cascades do?
- Opening g-protein gated ion channels
- Changes in gene transcription
- Secretion of substances from the cell
- Anything the cell wants
Where can synapses form?
- Between axon terminals
- Dendrites (dedritic shafts)
- Dendritic spines
- The soma (cell body)
- Other axon terminals (axoaxonic synapses)
Where do synapses for to cause an action potential?
- Dendrites (dendritic shafts)
- Dendritic spines
- The soma (cell body)
What are axoaxonic synapses?
They regulate the amount of neurotransmitter that the second neuron will release when it has an action potential
What is presynaptic inhibition? Presynaptic facilitation?
Presynaptic inhibition: hyperpolarizing the axon terminal so that the voltage-gated calcium channels will not open at all (or for very long)
Presynaptic facilitation: depolarizing the axon terminal so that the voltage-gated calcium channels are more likely to open
What is an autoreceptor?
Detects the neurotransmitter that the cell is releasing
- generally metabotropic and inhibitory
- main source of presynaptic inhibition
What is the neuraxis?
The line that can cut an individual in half
What are all the anatomical directions and what do they mean?
Anterior/Rostral: in front/beak
Posterior/Caudal: behind/tail
Superior/Dorsal: above/back
Inferior/Ventral: below/belly
What are the three types of planes of the brain?
Transverse (coronal): cutting banana
Sagittal: split brain surgeries
Horizontal: cutting onion
What does medial and lateral mean?
Medial: toward midline
Lateral: away from midline
What is contralateral and ipsilateral?
Contralateral: structures on the opposite side of the body (ex: right brain controls left hand, etc.)
Ipsilateral: structures on the same side of body (ex: taste and smell)
What is brain nuclei?
In the brain, the word nuclei means a collection of neurons that are clustered together that all work together to serve some function
What are the two parts of the nervous system?
Central nervous system (CNS) and the Peripheral nervous system (PNS)
What are the two types of myelin and where do each belong?
Oligodendrocytes belong in the CNS and Schwann cells belong in the PNS
What is the blood-brain barrier and where is it located?
No leakage occurs in the CNS, so nothing can leave from the blood-brain barrier
Where does lymph come from and where is it located?
It comes from the blood vessels that release plasma which then becomes lymph
- collects waste
- only in PNS (because of blood-brain barrier in CNS)
What are the 3 types of meninges?
- Dura mater: thick, tough, unstretchable tissue
- Arachnoid membrane: soft and spongy
- Pia mater: blood vessels
