The Mind (Biological) - HOSA Behavioral Health

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

Nerves exiting CNS, carry sensory/motor information to the rest of the body

Somatic Nervous System

Division of PNS, brings sensory information to the CNS and transmits commands to muscles

Autonomic Nervous System

Division of PNS, directs activity of glands, organs, and smooth muscle

Sympathetic Nervous System

Division of Autonomic NS, coordinates fight/flight (arousal and stress)

Parasympathetic Nervous System

Division of Autonomic NS, coordinates rest/digest (repair and energy storage)

Enteric Nervous System

Division of Autonomic NS, consists of nerve cells embedded in GI tract

Spinal Reflex

Reflexes initiated by the spinal cord without assistance from brain

Sensory Neuron

Carry external information back to the CNS

Motor Neurons

Carry commands from CNS to the rest of the body

Interneurons

Have no sensory/motor function, connect others together

The brainstem contains…

The medulla, pons, and midbrain

Medulla

Controls vital functions such as breathing and heart rate. Contains nerve bundles travelling to/from higher brain levels

Pons

Relay center between medulla and midbrain. Aids in controlling arousal, facial expressions, and sleep

Cerebellum

Participates in skilled movements (balance and coordination) and, in humans, complex cognitive processing

Midbrain

Between Pons and Cerebral Hemispheres, involved in sensory reflexes, movement, and pain

Reticular Formation

Collection of structures along the midline of the brainstem, participates in mood, arousal, and sleep

Subcortical Structures

Lies under the Cerebral Cortex

Thalamus

Involved in processing sensory information, states of arousal, learning, and memory

Basal Ganglia

Collection of structures that participate in voluntary movement

Hypothalamus

Involved in motivation and homeostasis through hunger / thirst / arousal / aggression

Hippocampus

Essential for forming long-term memories

Cingulate Cortex

Anterior segment aids in decision making and emotion, posterior segment aids in memory and visual processing - located above corpus callosum

Amygdala

In temporal lobe, believed to participate in fear/aggression responses

Nucleus Accumens

Participates in reward and addictions

Corpus Callosum

Wide band of nerve fibers connecting right and left hemispheres together

Cerebral Cortex

Thin layer of neurons comprimising outermost layer of the brain. Seperated into lobes

Frontal Lobe

Responsible for complex cognitive processing. Includes: prefrontal cortex, primary motor cortex, orbitofrontal cortex, and Broca’s area

Parietal Lobe

Lies at the top of the head (in the middle), location of primary somatosensory complex (processes touch)

Occipital Lobe

Back of brain, location of primary visual cortex (processes vision)

Temporal Lobe

Curves around the side of each hemisphere, location of Wernicke’s area and the primary auditory complex (processes hearing)

Mirror Neurons

A type of brain cell that fires both when an individual performs an action and when they observe the same action performed by another. Discovered in 1990s in animals

Lateralization

Localization of a function to the right or left hemisphere of the brain → movement/sensation on the right side of the body is controlled by the left side of the brain, and vice-versa. May be the reason we have the ability to multitask

Endocrine System

Moves hormones around the body. Especially relevant for growth, arousal, metabolism, and s*x

Pineal Gland

Helps maintain sleep-wake cycle through the release of melatonin → released early evening, breaks down in the presence of light

Pituitary Gland

Controls ovaries and testes (as well as other glands), and releases Oxytocin (involved in breastfeeding), Vasopressin (involved in maintaining fluid levels), and Human Growth Hormone

Thyroid Gland

Raises/lowers metabolism rate → low thyroid levels can mimic depression

Adrenal Glands

Activated in times of stress, releases cortisol (provides general wake-up message)

Islets of Langerhans

Located in pancreas, secretes digestive hormones such as insulin

Axon

Transmits information to other neurons

Dendrite

Receives information from other neurons

Glia

Establish blood-brain barrier, provide structure and support for neurons

Action Potential

Electrical signal arising in a neuron’s axon when membrane potential reaches its threshold

Resting Potential

Measure of electrical signal along a neuron when it is not processing information

Receptor

Special channel in a neural membrane that interacts with other neuron’s neurotransmitters

Reuptake

Molecules of neurotransmitter in the synaptic gap return to the axon they were released from (reabsorbed)

Steps for Chemical Signaling are.. (there are 6)

1. Action potential reaches axon terminal

2. Synaptic vesicles, carrying neurotransmitters, are released from protein anchors (triggered by an influx of calcium)

3. Vesicles fuse to the axonal membranes at the release site

4. Neurotransmitters released into synaptic cleft

5. Vesicle material recycled for future use

6. Vesicles are refilled with neurotransmitter

Acetylcholine (ACh)

Involved in learning and memory, implicated in Alzheimers

Norepinephrine

Released in brain for arousal/vigilance, implicated in bipolar and PTSD

Dopamine

Involved with movement, planning, reward, implicated in Parkinsons, Schizophrenia, and ADHD

Serotonin

Involved with regulation of sleep, appetite, and mood (with the 3 being tightly linked)

Endorphins

Modify pain responses

Which part of the brain stimulates eating behaviour?

Lateral hypothalamus

Which part of the brain terminates hunger?

Ventromedial hypothalamus

Which psychological circuit responds to stressors by initiating epinephrine/norepinephrine release?

SAM system

Glutamate

Excitatory neurotransmitter

GABA

inhibitory neurotransmitter