Week 2 Flashcards
What are the divisions of the nervous system ?
Peripheral
* Autonomic - Sympathetic and Parasympathetic
* Somatic - Sensory input and motor output
Central
* Brain
* Spinal cord
What is part of the central nervous system ?
- Forebrain
- Midbrain
- Hindbrain
What are the structures of the forebrain ?
Telencephalon
* Cerebral cortex; Limbic system; Basal ganglia
Diencephalon
* Thalamus; Hypothalamus
What is involved in the cerebral cortex ?
- 4 lobes: frontal; temporal; parietal; occipital
- Prefrontal cortex (PFC): important for executive functioning and behavioural regulation
What is involved in the limbic system ?
- Hippocampus (HC), amygdala, anterior cingulate cortex (ACC)
- Memory (HC) and emotion/fear (amygdala)
- Emotional control (ACC)
What is the basal ganglia important for ?
- Important for movement control, vigilance/attention, learning (procedural)
What does the thalamus do ?
- A regulatory gateway: relays sensorial and motor information
- Regulates consciousness, sleep, alertness
What does the hypothalamus do ?
- Regulation of homeostasis
- Controls the autonomic nervous system and endocrine system
- Fighting, feeding, fleeing, mating, drinking
- Exert effects through the pituary gland
What is the structure within the hindbrain and midbrain ?
Brain stem
What does the brain stem contain ?
- Pons
- Medulla
- Midbrain
What is within the parts of the brain stem ?
- Locus Coeruleus (NE)
- Substantia Nigra (Dopamine)
- Raphe nuclei (serotonin)
- Reticular formation
What is Locus coeruleus ?
- located in the pons
- Nuclei involved in physiological response to stress (produces NE)
What is reticular formation ?
- Bundles of nuclei
- Extends through the hindbrain and midbrain
- Transmits information b/w CNS and PNS
- Important for attention, arousal, movement, and vital reflexes (e.g. cardiovascular control)
- Fight-or-Flight Response
What is the somatic nervous system ?
innervates the skeletal muscles, the skin and the sense organs
What are efferent pathways ?
Neural pathways that send signals from the brain to the periphery
What are afferent pathways ?
Neural pathways that send signals from the periphery to the brain
What does the FoF response activate ?
Activates the striated (skeletal) muscles
What can too much stress cause ?
Lead to over-activation of stirated muscles, resulting in muscle pain and tension
What is the autonomic nervous system ?
Innervates the body’s viscera (i.e., internal organs) through pre- and post-ganglionic neurons
What does Viscera consists of ?
- Organs
- Ducts and glands
- Smooth muscles
- Blood vessels
What is the sympathetic branch responsible for ?
Responsible for activating the FoF responses
What is the parasympathetic branch associated with ?
Associated with rest-and-digest responses
What is the endocrine system ?
A system of organs and glands that secrete hormones into the blood stream to send messages to cells and organs
What system does the endocrine system work with ?
Works with the SNS during FoF activation to reach a common ground
What hormones are involved with the hypothalamus ?
- Corticotropin-releasing hormone (CRH)
- Oxytocin
- Vasopressin
What hormones are invovled with the pituary gland ?
- Adrenocorticotropic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Beta-endorphin
What hormones are involved with the adrenal cortex ?
Glucocoticoids (GC)/cortisol
What hormones are invovled with the adrenal medulla ?
- Epinephrine (E)
- Nonrenpinephrine (NE)
What are the 2 stess response systems ?
- Sympathetic-Adrenal-Medeulla (SAM) Axis
- Hypothalamic-Pituary-Adrenal (HPA) Axis
How do the SAM and HPA differ ?
- SAM: Faster, within seconds and ending in minutes
- HPA: Slower, within minutes and lasting hours
What occurs in the SAM axis ?
Hypothalamus -> Brain stem (reticular formation) -> ANS -> Adrenal Medulla -> Release adrenaline (epinephrine) and noradrenaline (norenpinephrine) -> Physiological events
What occurs in the HPA axis ?
Stressor -> Hypothalamus is alerted and secretes CRH -> Hypothalamus alerts the Pituary to secrete ACTH -> ACTH travels through the blood and alerts the adrenal cortex -> Adrenal cortex secretes and releases GC/Cortisol -> chain of physiological events
What is cortisol ?
A major stress hormone that helps your body respond to stress and helps maintain your BP, heart function, immune system and blood gluclose levels
What occurs in Addison’s disease and what causes it ?
- Adrenal cortex does not produce enough cortisol
- Caused by autoimmune disorder or damage to the adrenal glands
What are the symptoms of Addison’s disease ?
- muscle weakness
- low BP
- Fatigue
- Appetite and weight loss
- low blood sugar
- GI disruption
What occurs in Cushing’s disease and what causes it ?
- Adrenal cortex produces too much cortisol
- Caused by years of glucocorticoid tx, tumor on pituitary or adrenal gland
What are symptoms of Cushing’s disease ?
- muscle weakness
- emotion dysregulation
- cognitive difficulties
- high BP
- infection
- bone loss
- bruising
- truncal obesity
- buffalo hump
What is the function of the immune system ?
Protects us from harmful pathogens such as bacteria, fungi, and viruses
What do pathogens have ?
Pathogens have antigens that are detected by the immune system to begin their line of defense
What is the innate immune system ?
Defense at the level of the skin and mucous membranes; bacteria that enter the skin are engulfed by phagocytes and destroyed by natural killer cells. Inflammatory response via cytokines may also come into play
What is the adaptive immune system ?
takes 4-5 days to defend against a novel intruder. Once the novel antigen is recognized, the immune system responds quickly in the future.
What are the types of Lymphocytes ?
- Natural killer cells
- Helper T cells
- Killer T cells/cytotoxic T cells
- B cells
- Memory B and T cells
What are natural killer cells ?
cytotoxic, destroys antigens as part of innate immune reaction
What are Helper T cells ?
identify antigens and stimulate multiplication of Killer T and B cells, produce cytokines to alert the system
What are Killer T cells/cytotoxic T cells ?
destroy antigens by puncturing and killing the invaded cells
What are B cells ?
produce antibodies (immunoglobins; lgs) that bind to antigens
What are Memory B and T cells ?
recognize and respond quickly to future antigens
What are antibodies ?
cell proteins of the immune system that recognizes antigens on the pathogen and fight them
What are cytokines ?
cell proteins that serve as a chemical alarm bell (interleukin, interferon, tumor necrosis factor)
What does immune dysregulation cause ?
Overactive immune system can result in allergies, arthritis, and lupus; while an underactive immune system can result in cancer and cold/flu outbreaks
What are telomeres and what is its function ?
- chromosome aglets
- Protect the ends of choromosomes
What is shoter telomere length associated with ?
- Smoking
- Poor diet
- Greater adipose composition
- Increasing weight and increased insulin resistance
- Lower antioxidant
- Sedentary (dose response effect)
What did Shultz and Beach (1999) find ?
- observational study on older spousal caregivers and non-caregivers control (66-96 yrs)
- Found that 63% relative risk of mortality among caregivers experiencing caregiver burden
What did Kiecolt-Glaser et al. find ?
- 13 women caring for relative vs 13 age and income-matched controls
- found that for 13 women caring for relatives it took their cut 49 days to heal in comparison to the control group (39)
What did Damjanovic et al (2007) find ?
- participants: 41 spousal/child caregivers of PWLD reporting chronic stress vs 41 age/gender matched controls
- caregivers reported greater symptoms of depression
- Activation-induced T cell proliferation is lower in caregivers (poorer immune response)
- Greater pro-inflammatory cytokine production in caregivers
- Telomere length of leukocytes are shorter in caregivers
What did Epel at al (2004) find ?
- 58 heathy mothers of chronically ill child or healthy child; measures psychological distress, TL and telomerase
(Results) - Caregiver status was not associated w/ TL or telomerase
- High stressed women had shorter telomeres
- High stressed women had 50% lower levels of telomerase
- Greater preceived stress and longer stress duration = shorter telomere length
What did Epel et al (2006) find?
Found that shoter telomeres are associated with higher cortisol and higher nonrepinephrine and epinephrine
