Biological foundations Flashcards
Afferent vs Efferent
Afferent: Sensory division of PNS. Signals from sensory receptors to brain.
Efferent: Motor division of PNS. Sends signals from organs/glands/muscles.
Nervous system vs Endocrine system
Nervous system: Fast! Messages over synapses/neurons. Reaches only specific neuron sites.
Endocrine system: Slow. Transmits messages through hormones in blood flow. Depends on heart rate. BUT reaches entire body.
Both can be used at the same time. Are connected over the hypothalamus.
Which parts of the body does the endocrine system cover? Name 11.
- Testes/Ovaries
- Placenta
- Kidneys
- Pancreas
- Adrenal
- Thymus
- Thyroid
- Pituitary gland
- Hypothalamus
- Pineal gland
Name the 8 main areas of the brain (from the outside)
- Frontal lobe
- Primary motor cortex
- Parietal lobe
- Primary somatosensory cortex
- Occipital lobe
- Primary visual cortex
- Temporal lobe
- Primary auditory cortex
Name 4 methods for localizing brain functions
- Lesions (damage)
- Recording a single cell’s activity
- Brain imaging (PET, EEG, MRI, CAT)
- Stimulation (eg with electric shocks or magnetism)
What connects the two hemispheres?
The corpus callosum, located at the optic chiasm
What divides the two hemispheres?
The longtitudinal fissure
Right vs left hemisphere
Left hemisphere: Positive emotion, maths and logic, language, motor control of right side of body.
Right hemisphere: Negative emotion, creativity, spatial/pattern sense, motor control of left side of body
What does the somatosensory/motor cortex control?
Somatosensory:
- Lips, tongue, teeth, gums, jaw
- Face nose eye
- Thumb, fingers, hand, arm
- Neck
- Trunk
- Hip
- Knee, leg, foot, toes
- Genitals
Motor:
- Swallowing, tongue, jaw, lips
- Face, eye, brow, neck
- Thumb, fingers, wrist, arm
- Trunk
- Hip
- Knee, ankle, toes
Broca’s vs Wernicke’s area
Broca’s area: In frontal lobe, close to temporal lobe and median fissure. Forming of speech. Blabber when impaired
Wernicke’s area: In temporal lobe, but super close to both occipital and parietal lobes. In corner. Understanding of speech. When disturbed, speech stops making sense.
Name the 5 (6) parts of the limbic system, and what they are good for
- Amygdala (Emotion/fear)
- Hypothalamus (Motivated behaviour, 4 Fs, Homeostasis)
- Thalamus (Sensory input, NOT PART OF LS!)
- Pituitary gland (Master gland, manages hormones)
- Hippocampus (Memory)
- Olfactory bulb (Smell)
Name the 4 parts of the hindbrain and their function
- Reticular formation (Sleep/arousal)
- Cerebellum (Attention, balance, coordination)
- Medulla (Breathing, upright position)
- Pons (Coordination)
List 3 types of neurons
Motor neurons (build efferent nerves) Sensory neurons (build afferent nerves) Interneurons
Electric potential in neurons
Resting potential: -70mV
Describe the process of an action potential evolving (7 steps)
- Neuron is in resting potential (-70mV)
- Stimulation of dendrites by neurotransmitters leads to a graded potential. (In other words: Once neurotransmitters fit into the receptor sites, Na+ gates open.)
- Graded potential reaches excitatory threshold at trigger zone of axon.
- Na+ gates open. Depolarization (up to +40mV)
- Na+ gates close, K+ flushes out. Hyperpolarization!
- Potential is temporarily lowered below -70mV, to prevent neuron from firing again. Refractory period.
- Return to resting potential by restoring balance between Na+ and K+.
ACTION POTENTIAL PROPAGATES THROUGH AXON!
How do neurotransmitters deliver messages (Synapses)? (5 steps)
- Action potential arrives at the end of the axon
- Neurotransmitters have already been formed, and are stored in vesicles in the presynaptic neuron. They are released into the synaptic cleft fluid between the neurons.
- Neurotransmitters bind to the receptors in the postsynaptic neuron. They can only bind to a receptor site that fits them (like lock and key)
- Neurotrasmitters have an excitatory or inhibitory effect
- Deactivation: Reuptake OR Diffusion of neurotransmitter
What’s intracellular recording?
Measurement of current or voltage across the membrane of a cell.
What is a spike train?
A sequence of times in which a neuron fires a measured action potential.
What is the all-or-none law?
Threshold must be crossed for the reaction to happen. Either this or it doesn’t happen at all. Complete response or no response.
Name and describe 6 neurotransmitters
Achetylcholine (ACh): Motor control, sleeping and dreaming, memory and learning.
Norpinephrine: Arousal and eating
Serotonin: Mood regulation
Glutamate: Enhancement of action potential, learning and memory
Dopamine: Pleasure/reward, motor control
GABA: Inhibition of action potential
