Mid term 1 Flashcards
PAD
pia matter, arachnoid matter, sub arachnoid space, dura matter
Autonomic NS
Sympathetic: fight or flight, and Parasympathetic rest and digest.
Glial cells
oligodendrocytes, astrocytes, schwann cells
What are glial cells?
Non-neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the CNS and PNS.
Microglial cells
Are the only immune system in the brain. See auto immune disorders. Clearing cellular debris and dead neurons from nervous tissue through the process of phagocytosis (cell eating)
Astro- cytes
feed and keep the neurons in place *they can support multiple axons.
Motor effrant
signals from the brain to the body
nerve
A collection of axons in the CNS
Auto-receptor
(Pre-synaptic) Negative feedback loop. to reduce the release of NT in the presynaptic neuron.
Summation
all signals add IPSP and EPSP
summation
spatial summation and temporal summation
Depolarize
change from -70mv towards zero
hyperpolarize
a change from -70mv to -90mv.
Hormones
Molecules produced by glands and broadcast the signal. Hormones bind to receptors located in distant target organs which regulate and control physiological and behavioural activities.
Steroid hormones
Testerone and Cortisol, are fat-soluble and synthesized from cholesterol enter target cells to affect DNA controlling protein production.
peripheral NS– Somatic
All nerves that carry incoming affrerent sensory information from our sense organs to the CNS and outgoing efferent motor information to….
**Allows us to interact with our environment
Peripheral NS– autonomic
all sensory and motor connections to our internal organs.
**Regulates the internal organs and glands
Peripheral–autonomic—sympathetic
nerves send arousing signals from the CNS to the body preparing us for flight or fight.
**Arousing
peripheral–autonomic–parasympathetic
rest and digest
**Calming…
directions
anterior= rostral posterior = caudal
meninges
PAD
Brain
Cerebrum: largest, voluntary processes
Brainstem: involuntary processes (respiration, heart beat)
brain– outside
gyrus; bumps sulcus; groove Longitudinal fissure; sagital lateral fissure; temporal lobe central sulcus; coronal
the cerebrum
Right hemisphere: left side body, emotion, spatial orientation, facial recognition, appreciate art/music.
Left: language, math, logic
neocortex
frontal, parietal, temporal etc
corpus callosum
firm body
Basal ganglia
movement, habit
- caudate nucleus
- putamen (both together know striatum)
- globus pallidus
and… subthalamic nucleus and substantia nigra
limbic system
- cingulate cortex; emotion and memory
- amygdala; fear, agression, emotional memories
- hippocampus; learning, memory, spatial navigation
brainstem
oldest part of the brain
- diencephalon
- midbrain
- hindbrain
Diencephalon
integrates sensory and motor information
- thalamus; processes all incoming sensory information.
- hypothalamus; maintains homeostasis, hormones with pituitary gland
midbrain
contains neural circuitry required for vision, hearing, and alertness. it also contains nuclei composed of dopaminergic neurons involved in the regulation of movement and feelings of reward
Hindbrain
coordinates vital bodily functions.
- Pons
- medulla; breathing and heart rate.
3 main cells in the brain
- neurons
- astrocytes
- oligodendrocytes
wire
in the CNS it is called a tract
In the PNS it is called a nerve
equilibrium
a difference in states is known as potential, and it can be used to do work.
action potential
spreading depolarizations, starts at axon hillock, then spreads down; propagation…
action potential; speed
unmyelinated; 30 m/sex
myelinated; 120 m/sec
Neurotransmission
- neurotransmitters are synthesized and stored in vesicles at the axon terminal.
- Vesicles are transported to the presynaptic membrane and released
- Neurotransmitters bind and activate their receptors on post synaptic membrane
- Transmitters are deactivated; reuptake, diffuse, taken up by glia
postsynaptic potentials are graded
IPSP, EPSP; transmitters: glutamate are excitatory.
Transmitters; GABA are inhibitory.
Hormones
produced by glands
- Exocrine glands; outside, produce fluids and secrete them onto an endothelial surface by way of a duct (tears, sweat)
- Endocrine glands; inside, hormones to bloodstream (pituitary)
Autosecretory synapses
neurotransmitter to bloodstream, endfoot synapses on a blood vessel.
3 chemical classes of hormones
Steroid; synethesized from cholestrerol, fat soluble, synthesized on demand (testosterone)
- peptide/protein; chain of amino acids by cells own machinery based on its genetic material
- Monoamine; modified amino acids, stored in vesicles, may also act as transmitters in CNS.
Lipophilic
Steroid hormones are synthesized from cholestrerol, and pass easily through the cell membrane
Peptide and monoamine hormone.
Bind to metabotropic receptors, G proteins coupled to these receptors are activated leading to the release of secondary messengers.
3 classes of hormones
- homeostatic; insulin, essential to life, metabolic balance
- Gonadal; testosterone, reproductive function,
- Glucocorticoids; Cortisol, stress response.
Neuroendocrine integration
reciprocal, the endocrine system can modulate behaviour, increase the likelihood of a behaviour, BUT behaviour can alter hormones. The NS can override the normal control of the endocrine system (stress).
Hierarchical control of hormones
- hypothalamus
- pituitary gland (secretes releasing hormones influence—_
- Target enocrine glands (hormones to blood)
- Target organs and tissues (**Hormones affect almost every neuron in the brain.)
Pituitary gland
Master gland,
- anterior; connected to hypothalamus by blood vessels
- posterior; hypothalamus by axons.
Feedback
A cycle where the output of a system is looped back to act as an input thereby regulating the system
2 types feedback
positive; uterine contractions lead to oxytocin release which stimulate more contractions.
Negative; insulin in response to high blood glucose, stimulate glucose uptake, thus lower blood glucose.
Stress: HPA axis
- hypothalamus (releases corticotropin-releasing hormone (CRH)
- CRH stimulates the anterior pituitary to release Adreno-cortico-tropic releasing hormone (ACTH)
- ACTH acts on the adrenal glands which releases glucocorticoids; cortisol.
GAS
- Alarm SAM acis activated, epinephrine, norepinephrine
- Resistance; adaptations take place to help cope with prolonged stressors; HPA activate, cortisol,
- Exhaustion; resources depleted, unable to cope with the prolonged stressor.
Monoamine hormones
epinephrine, norepinephrine
Stress
shuts down pre-frontal,
BUT the problem is that all stressors are considered equally important….
epinephrine receptor
The adrenergic receptors are a class of G protein-coupled receptors that are targets of the catecholamines, especially norepinephrine and epinephrine.
Somatic cell
Has 46 strands of DNA, 23 pairs, or chromosomes which holds an organisms entire DNA sequence
Genes
Gene stretch of DNA encode a protein, each gene may take multiple forms: allele.
Allele
dominant, recessive, the set of alleles an organism possesses for a specific gene is referred to as its genotype.
Huntington
Is an autosomal dominant genetic disease that appears around midlife and results in motor and cognitive disturbances.
Tay-Sachs Disease
Autosomal recessive disease. Caused by the loss of a gene that encodes the enzyme necessary for breaking down gangliosides, these accumulate in the cell membrane thus killing the cell.
Down syndrome
Extra copy chromosome 21
Phenotype
Siamese cats have an allele that allows for temperature sensitive pigmentation,
Observable charateristics from genotype envr interaction
Epigenetics
The study of changes in gene expression without changes to the DNA sequence
Influences to gene expression
- DNA methylation
- Histone modification (methylation, acetylation)
- Non-coding RNA’s
DNA open or closed
open = euchromatin closed = heterochromatin
Histone modification–acetylation
Acetylation of histones is associated with open chromatin that attracts readers or transcription factors which promote transcription.
Depending on the location of the methylation on the histone
- suppress by blocking the DNA from unspooling.
2. Stimulate transcription by loosening chromatic
Immune system
decentralized, all immune cells develop from precursors found in the bone marrow, organs of the immune system are connected by the circulatory system allowing immune cells to travel take action.
2 phases of immune response
- innate immune response, fast, non-specific, Macrophages.
2. Adaptive; slow specific, cellular and antibody mediated component. also has an immune memory.
innate immune
express Toll like receptors (TLR) which recognize general molecular patterns present on most pathogens and lead to the phagocytosis.
when activated, release cytokines into circulation and may present antigens to cells of the adaptive immune system.
Antigens
Are molecules derived from pathogens, allergens or even host-cells.
Adaptive immune
Cytokine mediated, antigen specific response, 4-7 days,
develop pathogen specific effectors, immune memory
2 parts adaptive immune
- Cellular mediate immunity; T cells directly attack.
- Antibody mediated immunity; B-cells, bone marrow, antibodies bind to antigens on the pathogen in order to neutralize or kill
immune system
chemical communication, cytokines, specific receptors. Coordinate immune response.
Immune privileged
tolerate antigens without the induction of inflammatory response. (eyes, CNS)
Blood-brain-barrier
The endothelial cells, same cells in the body, but the brain have tight junctions.
Microglia
immune system in the brian
Theory embodied cognition
That the brain maintains a dynamic relationship with the rest of the body.
Vagus nerve 10
parasympathetic innervation of heart, digestive,
*90% of the afferent connections
Psychoneuroimmunology
Rat with sweet, it is the study of the interaction between the mind and the immune system.
Hormetic stress
produces a positive biological response.
long term stress
Stress leads to impaired HPA axis, high levels of cortisol = depressed immune system, cause break down in signaling,
Limbic system
Cingulate cortex; emotional processing, memory
Amygdala; fear, sex
cerebellum
movement; ex, a sloth would have a small cerebellum.
2 organizations of cell bodies
layers, and clusters (clusters are what create the white and grey matter,)
action potential
Domino from axon hillock, each ion channel snaps open; propagating,
Saltatory conduction
Nodes of Ranvier; the signal can skip down the axon much faster.
Neurotransmitter
glutamate = excitatory GABA = inhibitory
Action potential threshold
threshold -50mv
3 neurotransmitter categories
Small molecules
- Amines (dopamine, serotonin)
- Amino acids (glutamate)
- other; Acetylcholine (Ach)
Peptides (oxytocin.
Transmitter gasses (nitric oxide).
NS
the nervous system can override the endocrine system (blood glucose level).
stress
Is anything that moves us from our homeostatic balance.
Cortisol
Inform of what is going on in the body. Important for metabolism, ion channels, immune system, memory formation
Stress pathway
The SAM axis and HPA axis are not mutually exclusive.
Acetylations
Reader, transcription factor, epigenetic marks can persist.
Glucocorticoid receptor
Activated during high stress needed to shut off cortisol. Inattentive moms created babies with an inability to shut off stress response.
T cells
cytoxix
Cytokines
chemical communication of the immune system. Specific receptors,
CNS no longer immune privileged.
The lymphatic system wraps around the brain.
How does the vagus nerve communicate?
Paraganglia; If it is severed, individuals dont show sickness behaviour.
