Topic 2: barin mechanisms + behavior Flashcards
Define biological psychology
Studies relationship between psychological processes + underlying physiological events = mind-body phenomenon
What did philosophers say about mind-body phenomenon
- Rene = both mind + soul are spiritual entities separate from body
- Leibniz = mind + body separate but activities parallel to each other
- Watson = focused on observable human behavior + relationship with nervous system instead of spiritual/mental
Describe the parts of the nervous system
CNS:
- Brain
- Spinal cord
PNS:
- Sensory division
- Motor division:
- SNS
- ANS:
- Sympathetic
- Parasympathetic
Describe the parts of the embryonic brain
1) Prosencephalon = Forebrain
- Telencephalon = Cerebrum
- Diencephalon = Thalamus + epithalamus + hypothalamus
2) Mesencephalon = Midbrain = Corpora quadrigemnia + tegmentum + cerebral peduncles
3) Rhombencephalon = Hindbrain
- Metencephalon = Pons + cerebellum
- Myelencephalon = Medulla oblongata
Describe the structure of a neuron
- Central body has dendrites coming out
- There is terminal button at the end of every axon = pre-synaptic end = area where axon releases chemical substances
- Messages sent through axon = action potential
How is potential achieved in a cell?
- Intracellular fluid is negatively charged = A-/K+
- Extracellular fluid is positively charged = Na+/Cl-
- Na+/K+ transporter in cell membrane pumps out 3 Na+ and 2K+ in
What are the 2 types of structures of the PNS?
1) Nerves = enclosed bundle of axons
- Provides common pathway for electrochemical nerve impulses to be transmitted along
2) Ganglion = lumps attached to nerves + contain cells body of some neurons
What are the 2 types of nerves?
1) Afferent = carry info TO CNS
2) Efferent = carry info AWAY from CNS
What are the type of cells in the NS?
1) Unipolar/pseudounipolar = dendrite + axon from same process
2) Bipolar = axon + dendrite on opposite ends of cell body
3) Multipolar = 2/more dendrites separate from axon
4) Anaxonic = axon cannot be distinguished from dendrites
Define the neuroglia
- Non-neuronal cells
- Maintain homeostasis
- Form myelin
- Provide support + protection for neurons in CNS + PNS
- 10x smaller than neurons but take 10x more space than neurons in brain
Give examples of the types of glial cells in the CNS + PNS
CNS:
- Oligodendrocytes
- Astrocytes
- Ependymal cells
- Microglia
PNS:
- Schwann cells
- Satellite cells
Explain the functions of the glial cells in the CNS
1) Astrocytes = has projections that link neurons to blood supply + forms blood-brain barrier
- regulate external chemical environment
2) Oligodendrocytes = produce myelin sheath for insulating axon = electrical signals more efficient
3) Ependymal cells = creation + secretion of cerebrospinal fluid
Explain the functions of the glial cells in the PNS
1) Schwann cells = myelination to axons in PNS
- Phagocytotic activity + clear cellular debris = allow regrowth of neurons
2) Satellite Cells = regulation of external chemical environment
Explain how the blood-brain barrier was discovered
- Paul Ehlirch found injecting dye into blood stream = tissue tinted other than spine + brain
- But dye injected in ventricles of brain = color throughout CNS
- Shows that there is a barrier between blood and fluid around brain cells
Describe the function of the BBB
- It is selectively permeable
- It is not uniform
- E.g. area postrema = BBB weaker = neurons able to detect toxins in blood = once in circulatory system can stimulate this area to vomit
Explain what causes control of the reflex to withdraw
- Action potential in axon of sensory neuron = activates excitatory interneuron
- Action potential in action from brain = activates inhibitory interneuron
- Inhibitory effect = prevents motor neuron firing
Explain how neurons communicate
- Via synaptic transmission
- Messages carried by neurotransmitters released at terminal buttons
- Diffuse across fluid-filled gap between terminal buttons + membrane of synapse
- Presynamptic membrane at end of terminal faces postsynaptic membrane on neuron receiving
- Space in between = synaptic cleft = extracellular fluid where diffusion takes place
- Cytoplasm of terminal button = synaptic vesicles = lots in presynaptic membrane
- Synaptic vesicles produced in cell body + carried by axoplasmic transport to terminal buttons
What are the 3 types of synapses?
- Axodendritic = terminal button on dendrite
- Axosomatic = terminal button on somatic membrane
- Axoaxonic = synapse between 2 terminal buttons
What is the size of the synaptic cleft?
1nm
Identify 7 important neurotransmitters + behaviours
1) Acetylcholine = Voluntary muscle control + P.sympathetic NS + attention + alertness
2) Epinephrine = Fight/Flight + wakefulness + alertness
3) Norepinephrine = Fight/Flight + wakefulness + alertness
4) Dopamine = Smooth movements + postural stability
5) Serotonin = Mood + sleep + eating + dreaming
6) GABA = Brain stabilization
7) Endorphins = Natural painkiller
Define somatic reflexes
Control involuntary movement + skeletal muscles
Explain how reflexes work
- Developed via repetition
- Learning complex motor patterns
- Spinal cord controls many motor functions/reactions
