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
What are the 3 parts of the brain?
1) Forebrain
2) Midbrain
3) Hindbrain
What are the parts of the forebrain?
- Cerebrum
- Thalamus
- Hypothalamus
What are the parts of the midbrain?
- Tegtum
- Tegmentum
What are the parts of the hindbrain?
- Cerebellum
- Pons
- Medulla
Describe the cerebrum
- Largest part of the brain
- Associated with higher brain functions
- It has 4 sections:
1) Frontal lobe
2) Parietal lobe
3) Occipital lobe
4) Temporal lobe
Describe the role of the frontal lobe
- Reasoning
- Planning
- Movement
- Involved in speech
- Emotions
- Problem solving
Describe the role of the parietal lobe
- Controls movement
- Orientation
- Recognition
Describe the role of the occipital lobe
- Visual perception
- Processing
Describe the function of temporal lobe
- Controls perception
- Recognizes auditory stimuli
- Memory
- Speech
Describe the cerebral cortex
- Wrinkled = increases surface area = more neurons = brain more efficient
Describe the 2 hemispheres + functions
- Division of cerebrum into 2 halves
- Right = creativity
- Left = logical abilities
Define corpus callosum
- Bundle of axons connecting 2 hemispheres
Describe the cerebellum
- Similar to cerebrum = 2 hemispheres
- Has fold called cortex
- Involved in regulation + coordination of movement + posture + balance
Explain the limbic system
- Referred to as emotional brain
- Found in cerebrum
- Has 4 parts :
1) Thalamus
2) Hypothalamus
3) Amygdala
4) Hippocampus
Describe the role of the thalamus
- Grey matter in forebrain
- Centre for pain perception
Describe the role of hypothalamus
- Regulate homeostasis + emotion + thirst + hunger
- Controls autonomic NS
Describe the role of the amygdala
- Part of telencephalon = temporal lobe
- Involved in memory + emotion + fear
Describe the role of the hippocampus
- Important for learning + converting ST memory to LT
Describe the brain stem + function
- Underneath limbic system
- Most simple part of brain
- Responsible for vital life functions = breathing + heart beating + BP
Describe the role of tectum + tegmentum in midbrain
- Fuctions of vision + hearing + eye movement + body movement
Describe the role of medulla + pons in hindbrain
- Have centres for vital functions = breathing + heart beating
