NEUR 1201 midterm 1

What are the lobes of the brain

What are the lobes of the brain

Frontal lobe - motor functions and executive functions

Temporal lobe - auditory functions, language perception and taste senses

Pariental - sense of self in space + touch sensations

Occipetal - vision

Define white matter

area of NS containing fat sheathed axons

define grey matter

areas of NS containing blood vessels and cell bodies

define synaptic proning

process of getting rid of unnecessary and inactive synapse

Explain the autonomic NS

Regulates homeostasis and involuntary body functions

Sympathetic NS - (fight or flight), fear and stress response, breathing and heart rate increases, digestion stops

Parasympathetic NS - (calming) relaxed and calmed homeostasis, brething and heart rate slows, digestion increases

Brain stem

comprises deep brain structues, conects brain to spinal cord, critical to sustain life

Cerebrum

major structure of forebrain, consists of 2 hemispheres (left and right)-only large-brained creatures develop it

Cerebellum

involved in motor coordination and other mental process

What are the different sections of the brain?

Coronal section: cut in the vertical plane from crown of head down, yields frontal view of brain

Horizontal section: viewed looking down (dorsal view) cuts along the horizon

Sagittal section: lengthways from front to back viewed from side

What are the 2 divisions of the nervous system

CNS: brain and spinal cord
PNS: somatic and autonomic NS
- sensory connections to receptors in skin
- Neurons and nerves outside CNS
- Motor connections to body muscles
- sensory and motor connections to internal body organs

Define gyrus

bumps between grooves in the cerebral cortex

Define sulcus

grooves in the cerebral cortex

what do fluids in the brain do

Fluids help cleanse away toxins - during sleep less throughout the day

What is the medical approach to treatment

Etiology: what caused it
Pagnosis: what are the long term and short term effects
epidiology: how common is it

What can trauma do?

can cause epigentic changes thar can be passed on to offsprings if changes reach sperms/ovaries

Define hypothalamus

Define cerebral cortex

Define medical model

Mental illnesses come from underlying physiological, biological and genetic causes

Define meninges

special membranes that support brain and spinal cord - infections in the meninges can cause meningitis

draw neuron + know synapses

define hormone

define neurotransmiter

how do neurotransmiters and hormones differ

what is the equivalent of the macrophage in the brain

macroglia

define cerebrospinal fluid

Fluid that fills ventricules and surrounds brain and spinal cord. made of glucose, salts and minirals and very little protein. allows brain to float comfortably in the skull.

what is the general adaptation syndrome

Alarm: initial response to the stressor (fight or flight) is activated
Resistance: psychological adaptations take place to help the body cope with prolonged stress - involves cortisol and HPA axis
Exhaution: psychological resources depletes as the body fails to cope with stress - deseases can begin to occur.

What is a synapse

• point between two neurons

• site of interneuron info transfer

• transfer signals by passing chemicals from neuron to neuron

• synapes communication depends on chemical interactions

• target for exogenous chemical reactions

What does the stress response achieve

1. temporarily puts the brain and body in overdrive to deal with stress

2. suspends body response, construction and growth to conserve energy

How does info flow in neuron

dendrites → cell body → axon → axon terminal

What are the stress-response pathways

SAM axis (fast pathway) - mediates initial alarm phase of the stress response
HPA axis (slow pathway) - mediates psychological adaptation involved in dealing with prolonged stress

How do neurons maintain electrical charge

by flowing (-) ions into the membrane and (+) ions outside the membrane - across membrane

What is a critical gland for stress response

adrenal gland

what is the resting potential of neurons

-70mV. uses active and passive mechanisms to maintain charge
As long as the neuron is alive, the neuron would do anything to work towards that charge
changes in resting potential will reduce depolarisation - the membrane becomes more molecules

Define stressor

stimuli that challenges the body’s homeostasis and trigger a response - short-lived in most animals

define stress-response

response to challenge of stimuli. involves psychological and behavioural changes, produce a pattern of psychological changes

What are the 2 types of glial cells

astroglial: during the early stages of fetus development
microglial: act as immune cells in the brain by destroying pathogens that could be harmful
- too much of these cells can cause cell death
- provide chemicals to the brain that arent usually there

What are the steps of the synaptic transmission

1. Neurotransmitters are synthesised and stored in pre-synaptic synapses

2. action potential triggers neurotransmitters to release into the synaptic cleft

3. Neurotransmitters bind to receptors in post-synaptic membrane

4. receptors in postsynaptic membrane are ligand-gated but contain ion channels that open when neurotransmitters bind to membrane - causing post-synaptic potential

Define corpus callosum

connects the 2 hemispheres of the brain, so the 2 sides know what’s happening on the other side

Guromater

fluid that passes through the ventricle - helps prevent concussion

what are the parts of the somatic nervous system

efferent (outgoing nerves): motor nerves that connect the CNS to skeletal muscles
afferent (incoming nerves): sensory nerves that carry info from sense against to CNS

what are the dirrectional terminology of the neuroanatomy

Dorsal: atop the brain
medial: toward brain midline
lateral: toward side of brain
ventral: toward bottom of brain
posterior: toward back of brain
anterior: toward front of brain

Define ventricular system

Brain is supported by series of interconnected hollow spaces called ventricles that are visible in coronal and horizontal sections of the brain

Define blood-brain barrier

tight gaps between endothelial cells (cells that line blood vessels) prevent large molecules from passive brain
blood-brain barrier is a protective mechanism of NS that prevents lethal substances from entering brain - weak in 3rd ventricle

What are the 2 types of brain cells

neurons: basic info processing units of the brain (80B in humain brain)
Glial cells: support and modulate neuron’s active, creates myelin sheath (100B humain brain)

what are the different part of neurons

Dendrites: gather info from other neurons
Cell body: core region contains nucleus and DNA
Axon hillock: junction of the cell body and the axons where action potential begins
Axon: carries info to be passed onto other cells
Terminal button: knob at the tip of an axon that conveys info to other neurons

Define Cerebral cortex

part of the outer layer of brain’s grey matter
- part of cerebrum
- wrinkled structures enables more grey matter
-site of our higher function (consciousness)

What is the biopsychosocial model

Biological functions: genetics and chemicals
psychological functions: mood,personality, trauma, stress
Social factors

What are the risks factors for mental health disorders

• genetics

• early life expereience

• stressfull life events

• Environmental influences on a foetus

define metal illness

reduced ability for a person to perfom to function prperly over a prolonged period of time due to:
- significant levels of distress
- changes of thinking, moood or behaviour
-feeling of loneliness and sadness
- feeling of disconnection from people/ activities

Define tracts and nerves

Tracts: large collection of axons in CNS that connect nuclei to each other - majority of white matter

Nerves: large connections of axons in PNS

What is a myelin sheath

myelin is a fatty substance produce by glial cells - increases the speed and effiency of electrical signal conductions

What are action potentials caused by?

When chemicals rush into the axon. sodium-potassium pumps help regulate sodium (outside) and potassium (inside axon)
takes place when pumps are open

How do neurons transmit signals

through action potentials

define depolarization and
hyperpolarization

depolarization: Two EPSPs in a row create
a larger positive charge

hyperpolarization: Two IPSPs in a row create
a larger negative charge

Major classes of
neurotransmitters

Amino acids: Glutamate and Glycine
Monoamines: Dopamine, Norepinephrine
Peptides: Oxytocin
Others: Acetylcholine , Adenosine

define: Ligands

molecules that bind to and activate
receptors. Neurotransmitters and
hormones are ligands for their receptors

What are main ways of neurotransmitter deactivation

1. Reuptake: Neurotransmitters are reabsorbed by the presynaptic neuron through specific transporters.

2. Enzymatic Degradation: Enzymes break down neurotransmitters in the synaptic cleft

3. Diffusion: Neurotransmitters diffuse away from the synaptic cleft and are no longer able to bind to receptors.

4. Glial Cell Uptake: Glial cells can absorb neurotransmitters from the synaptic cleft, assisting in their removal.

List the main differences between IPSPs and EPSPs

IPSPs:
-Inhibitory
-opens Cl⁻ or K⁺ channels
-mediated by GABA or glycine
-decreases action potential

EPSPs:
-Excitatory
-opens Na⁺ or Ca²⁺ channels
-mediated by glutamate or acetylcholine
-increasex

Where are the voltage-gated receptors located?

in the axon hillock and along the axon

define
Hippocampus

medial temporal lobe structure implicated in the formation of memories
-Highly susceptible to stress

what are three steps in HPA axis
activation

1. The hypothalamus releases CRH into the
   anterior pituitary

2. CRH stimulates the anterior pituitary to release
   ACTH into circulation.

3. ACTH stimulates the release of
   cortisol from the adrenal
   cortex.

define:
Cortisol

steroid hormone released by the
adrenal cortex, and a member of the glucocorticoid
family of hormones. produce in adrenal cortex

what are the
receptors of cortisol

Mineralocorticoid receptor (MR)
Glucocorticoid receptor (GR)

what do Epinephrine and norepinephrine

Increased heart rate.
Bronchodilation (enlargement of airways.)
Decreased digestion.
Increased blood pressure by peripheral
vasoconstriction.

what are two steps in SAM
pathways

1. Neural circuits in the
   hypothalamus project to the
   the spinal cord, where they bind
   with neurons of the SNS.

2. SNS neurons project to the
   adrenal medulla. The adrenal
   medulla releases epinephrine
   and norepinephrine into
   circulation.

what are Cortisol’s metabolic effects

-Reduce bone and connective tissue formation.
– Increase breakdown of lean body mass.
– Increase blood sugar level by increasing the production of new glucose and
the release of stored glucose from glycoge.
– Altered sensitivity of tissues to other hormones

how does Cortisol secretion regulate

through negative feedback:
1. when cortisol levels rise hippocampus, hypothalamus and anterior pituitary work to stop secretion

2. hippocampus and hypothalamus reduce CRH secretion

3. The anterior pituitary reduce ACTH secretion

4. low amounts of ACTH and CRH stop the adrenal cortex from producing cortisol. Stopping stress response

what are the 3 parts of the brainstem

Diencephalon:
– Thalamus: All sensory information (except smell) passes through
– Hypothalamus: Controls homeostasis and regulates hormone secretion from the pituitary gland.
Midbrain:
-Contains neurons that produce dopamine that project to various other brain regions.
Hindbrain:
– Pons: Connects the cerebellum to the brainstem.
– Medulla: Controls breathing & heart rate. - Connects the brain to the spinal cord

define: sickness behavior

The behavioral and cognitive changes
that accompany physical illness

psychoneuroimmunology

The study of the interaction between the
mind, brain, and immune system

define:
immune system

• responsible for protecting your body from microbial growth.

• monitors the internal environment for signs of invasion by bacteria or viruses

• decentralised unlike NS

what are the factories for immune cells

spleen,
lymph nodes, thymus, and
bone marrow

what are the 2 divisions of the immune system

-Innate immune system.
– Adaptive immune system
-Cell-mediated immunity (T cells)
-Antibody-mediated immunity (B cells)

what do Cytokines do

molecules that coordinate the immune response, and tell the body that it is under attack.

They:
Trigger an inflammatory response (redness,
fever, aches, etc.)
– Attract more innate immune cells.
– Activate the adaptive immune system.