PSIO 487 Exam 2 Flashcards
(97 cards)
1
Q
Canities
A
hair graying
2
Q
Hair
A
-Hair is made of dead, keratinized epithelial cells
-Hair follicle surrounds hair root
− Active telomerase
-Graying of axillary hair correlates very closely with age
3
Q
The Integumentary System
A
Includes skin, hair, nails,
and sweat/oil glands
Functions:
− Protective barrier
− Contains sensory receptors
− Vitamin D production
− Temperature regulation
4
Q
Layers of the Skin
A
Epidermis
Dermis
Hypodermis
5
Q
Hypodermis
A
Mostly adipose tissue
− This is a subcutaneous
layer (not a part of the
integumentary system)
6
Q
Dermis
A
− Connective tissue
− Contains hair follicles and
sweat glands
7
Q
Epidermis
A
Epithelial tissue
Five layers of keratinized
stratified squamous epithelium
8
Q
Keratinocytes produce
A
keratin
− Lipid-like secretion
− Toughens & waterproofs skin
− Like ‘mortar’ between cells
− Some telomerase activity in
keratinocytes
9
Q
Melanocytes produce
A
melanin
− Involved in skin color
− Protects from UV exposure
10
Q
The dermal-epidermal junction (DEJ)
A
− Anchors epidermis to dermis
− Interface for nutrient exchange and
signaling between layers
11
Q
Connective tissue
A
Collagen provides tensile strength
− Elastin provides resilience
12
Q
Biological Characterization of Aging Skin
A
§ Dullness, thinning, dryness, more visible pores, increased redness,
uneven pigmentation, dark spots, wrinkles, fine lines, tissue ptosis,
loss of elasticity
13
Q
Intrinsic aging
A
naturally occurring aging of skin
14
Q
Extrinsic aging
A
earlier deterioration of skin from exposure to
sunlight or pollution, lifestyle, etc
15
Q
Collagen
A
− Provides structural network for support (tensile strength/firmness)
− Loss of collagen creates wrinkles and fragile skin
− With age collagenase activity increases, fibroblast synthesis of collagen
decreases
16
Q
Elastin
A
− Provides stretch (resilience) and keeps skin pulled tight
− Loss of elastin function creates rigid, sagging skin
− With old age, elastin fibers develop crosslinks and become frayed/fragmented
− In some body regions, elastin network is thickened (but disorganized) with age`
17
Q
Aging is associated with the appearance of
A
pseudoelastin
18
Q
Wrinkles (intrinsic Factors)
A
result from changes in the connective tissue of the dermis
19
Q
photoaging (extrinsic factors)
A
UV light exposure causes
20
Q
Sweat Glands
A
− Eccrine: in most areas of body
− Apocrine: axillary region, genital area; this sweat produces odor if
broken down by bacteria
21
Q
pheromones
A
axillary region, genital area; this sweat produces odor if
broken down by bacteria
22
Q
Sebaceous glands (oil glands)
A
− Surround hair follicles
− Deposit sebum (oil) into hair follicles
* Nourishes hair, keeps from breaking
23
Q
Nails
A
- Slowed nail growth
- Increased calcium deposition
causes yellowing - Disappearance of the lunula
- Appearance of longitudinal ridges
24
Q
Cortisol
A
is a glucocorticoid hormone released by
the adrenal gland in response to stress
− Trauma, illness, exercise, cold, heat
25
Thymus
§ Small gland in mediastinum
§ Secretes thymosin à T cell maturation
§ Destroys autoreactive lymphocytes
− Negative selection (aka central tolerance)
− Peripheral tolerance also involved
(regulatory T-cells)
26
Thymic involution
− Begins shortly after birth
− Not induced by senescence (as once thought)
27
T Lymphocytes
Derived from bone marrow; mature in the thymus
§ High proliferative potential
− Long cellular lifespan (months-years)
§ Defense against intracellular pathogens
§ Help B cells generate an antibody response
28
T Lymphocytes from aged
Hyporesponsive T cells
− Reduced T cell diversity
− Lower production of new T cells
− Accumulation of senescent T cells
− Appearance of ‘hybrid’ T cell/natural killer cells
29
B Lymphocytes fro aged
− Decreased number of circulating B cells
− Reduced B cell diversity
− Lower production of memory B cells
30
B Lymphocytes
Derived from bone marrow; mature in the spleen
§ Important for antigen processing and presentation
§ Differentiation into plasma cells à antibody secretion
31
Immunosenescence
describes the complex changes that
occur with age and reduce immune system function
32
The Aged Immune System in aged
− Increased incidence of infections
− Increased incidence of cancer
− Decreased incidence of organ transplant rejection
− Decreased wound repair
− Increased incidence of autoimmune disease
− Increased tissue inflammatory disease (inflammaging)
33
Innate Immunity
− First line of defense; non-specific immunity
− Physical barriers (epithelial and mucosal linings)
− Macrophages, natural killer cells, and more
34
Adaptive Immunity
− Activated by innate immune response
− Reacts to specific pathogens
− Mediated by lymphocytes (T cells and B cells)
35
Allostasis
the process of restoring homeostasis with adaptive
responses to acute stressors
− “Maintaining stability through change”
36
allostatic load
(the effort required to maintain stability) can result
in damage over time
− Stress increases allostatic load
37
Stress-related inflammation has implications in many late-life diseases
Late-life depression and anxiety, cognitive decline, Alzheimer’s disease
38
Perceived stress
is strongly correlated with shortening of telomeres
39
Chronic stress
‘overrides’ negative
feedback signals to hypothalamus and
cortisol remains elevated
− Long-term suppression of immune system
40
Hypothalamic-Pituitary-Adrenal (HPA) Axis
− CRH = corticotropin-releasing hormone
− ACTH = adrenocorticotropic hormone
41
Menopause
the point in time when menstruation ceases as a
result of an age-related depletion of ovarian oocytes
begins with the final menstrual period (FMP)
− Median age of FMP is 51.4
42
Perimenopause
begins with the first skipped or irregular period
− Median age of perimenopause onset is 47
43
Male Hypogonadism
- Low serum testosterone = below 200 ng/mL
- Some symptoms may occur with 200-400 ng/mL serum T
Symptoms
− Fatigue/loss of energy
− Low libido and erectile dysfunction
− Reduced muscle mass
− Increased fat mass
− Osteoporosis
-sometimes these symptoms are mistaken with lack of exercise
44
Male HPG Axis
Hypothalamus - GnRH - anterior pituitary - 1. FSH - sertoli cells - inhibin (neg feedback to FSH through anterior pituitary) OR 2. LH - Leydig cells - testosterone
45
Testosterone Replacement Therapy (TRT)
Monitoring of serum testosterone level is essential
Risks
− Prostate cancer
* SARMs
− Cardiovascular disease and/or cardiovascular events
Benefits
− Improve/maintain muscle mass and bone density
− Restore/maintain libido and erectile function
− Alleviate other symptoms of hypogonadism
- it works for patients but not without risk (prostate cancer) do not increase the risk for prostate cancer or cause prostate cancer but if you have prostate cancer it will make it worse!
46
Andropause
is an inaccurate term
− Androgen production and secretion does not cease
§ Androgen production and secretion DOES decline with age
− Symptoms are ‘real,’ but may be over-diagnosed and/or over-treated
as hypogonadism
− TRT is not always the answer
47
The Menstrual Cycle
Day 0 = menses
Days 4-14
− Follicular phase (ovary)
− Proliferative phase (uterus)
Day 14 = ovulation
Days 14-28
− Luteal phase (ovary)
− Secretory phase (uterus)
48
Cell Theory of Estrogen Production
FSH: acts on granulosa cells
to stimulate follicle growth and
estrogen production
LH: acts on theca cells to
stimulate androgen production;
LH surge triggers ovulation
49
Granulosa cells
express
aromatase
50
Estrogen levels rise
during
follicular phase
51
Female HPG Axis
Hypothalamus - GnRH - anterior pituitary - 1. FSH = granulosa cells - inhibin (neg feedback for FSH) 2. LH = Theca cells - androgens
52
neg feedback loop for female HGP Axis
Feedback loops between the
hypothalamus (GnRH),
pituitary (FSH & LH),
and ovary (inhibin and estrogen)
53
The Macula
Located in the center of the
retina
NOT OPTIC DISC
-Responsible for central
vision (straight-ahead)
− Important for reading,
driving, recognition of
faces
-Highest concentration of
cone photoreceptors
− Color vision
− Less sensitive to light
than rod photoreceptors
54
Damage to the macula
=macular degeneration = blurred central vision
55
LH acts on
theca cells to
stimulate androgen production;
LH surge triggers ovulation
56
FSH acts on
granulosa cells
to stimulate follicle growth and
estrogen production
57
Granulosa cells
express
aromatase
58
Estrogen levels rise
during follicular phase
59
Retinal Pigment Epithelium (RPE)
Controls delivery of oxygen and nutrients to
the retina; also removes wastes
60
Photoreceptors depend on
RPE for phagocytosis of outer segments
-a source of cellular debris
61
Photoreceptors and RPE are subject
to chronic irradiation by visible light
62
RPE sits on Bruch’s membrane
-Inner-most layer of the choroid
− Choriocapillaries are immediately deep to Bruch’s membrane
63
Related Macular Degeneration (AMD)
is the leading cause of blindness in the US for people 55+
Risk factors:
− Age
− Race (Caucasian = higher risk)
− Smoking
− High cholesterol
− Genetics
64
Dry (Non-Neovascular) AMD
Most common form of AMD
65
Drusen
are deposited under the macula
− Drusen do not immediately cause
visual changes
66
drusen can coalesce and cause
geographic atrophy of retinal pigment epithelium
67
Wet (Neovascular) AMD
Invovles choroidal neovascularization (CNV)
− Blood vessels grow through macula after it is weakened by dry AMD
− Causes bleeding and scar tissue formation
68
Pathogenesis of AMD
Abnormalities are observed in:
− Photoreceptors
− Retinal pigment epithelium
− Bruch’s membrane
− Choriocapillaries
-Dysregulation of RPE cell function is likely the most crucial event
69
Treatment for Wet AMD
Susvimo: a port delivery system for anti-VEGF drugs
− Gene therapy
70
innate immunity
-first line of defense , non specific immunity
-physical barriers
-macrophages, natural killer cells
71
adaptive immunity
-activated by innate immune response
-reacts to specific pathogens
-medicated by B cells and T cells
72
aged immune system
-increase infections
-increases cancer
-decrease wound repair
-increase autoimmune disease
-increases inflammatory disease (inflammaging)
73
immunosenescence
describes the complex changes that occur with age and reduce immune system function
74
B lymphocytes
-derived from twh bone marrow: ,mature in the spleen
-important for antigen processing and presentation
- differentiation into plasma cell for antibody secretion
75
B cells in aged individuals
-decreases number of circulating B cells
-reduces B cell diversity
-lower production of memory B cells
-older can fight less pathogens than younger
-also worse at fighting past infections
76
T lymphocytes
-derived from bone marrow: mature in the thymus
-high proliferative potential
-long cellular lifespan
-defense against intracellular pathogens
-help B cells generate an antibody response
77
T cells in aged individuals
-hyporesponsive T cells
-reduced T cell diversity
-lower T cell production of new T cells
-accumulation of senescent T cells
-appearance of hybrid T cell/natural killer cells
78
the thymus
-secretion of thymosin to mature T cells
-destroys autoreactive lymphocytes with negative selection (aka tolerance control)
79
thymic involution
-begins shortly after birth
-not induced by senescence as once thought
80
increase age with CVD
increased age is the greatest notifiable risk factor for CVD
81
the prevalence of CVD
-increase with age
-lower prevalence of CVD in women before age 50 because of menopause
-estrogen is cardioprotective
82
increase age for the heart
-left ventricular hypertrophy (mTOR, AMPK)
-diastolic dysfunction
-diminished cardiac reserve
-degeneration of the valve (mitral valve)
-cardiac fibrosis
-increase arterial stiffness
-loss of pacemaker cells (leads to resting heart decrease)
83
cardiomyocytes and fibroblast with age
-large and flattened
-growth arrest
-telomere shortening
-SASP (senescence phenotype)
84
atherosclerosis
-disease characterized by deposition of plaques (fat, cholesterol) on artery walls
85
what does vascular aging contribute too
-inflammation of arterial vessel walls
-increase overall vascular diameter but narrowed lumen
-increase in fibrosis of intima layer
86
estrogen favors what kind of fat distribution
-gynoid or pear shape
-menopause changes fat distribution
87
lack of estrogen of cortisol favors what kind of fat distribution
-apple shape or android fat distribution
-increase risk for CVD and hypertension
88
aging and the neurovascular unit
-pericyte (tight junctions) function decrease
-microglia (macrophages) number increase but function altered M1 ->M2
-cerebral endothelial cells have reduced NO production and impaired vasodilation
89
Blood pressure with aging
-hypertension most common treatable risk factor in individuals with CVD
90
What Happens in an Aging Brain?
§ Reduced brain volume in certain regions
§ Decreased number of neurons and
decreased speed of neurotransmission
− Oxidative stress, mitochondrial dysfunction,
and altered metabolism in neurons
§ Reduced blood flow to brain
§ Increased inflammation
91
Perceptual Memory
§ Very short lasting (seconds)
§ Sensory memory
− Only stored momentarily in sensory
regions of the brain (e.g. occipital
lobe for visual stimulus)
§ Relies on primary sensory regions
§ The sensory areas that control
perceptual memory experience
little change with age
92
Short-Term (Working) Memory
§ Information can be moved from perceptual
stores to working stores
§ Slightly longer (15-45 seconds)
§ Relies heavily on prefrontal cortex (PFC)
− PFC also important for concentration
§ Aging à short-term memory deficits
− Cell loss and shrinkage in PFC
− Reduced speed of neurotransmission
(especially pronounced in PFC)
NOTE: Older people are slower to reason
through decisions, but are better able to
make ‘gut decisions’
93
Long-Term Memory
§ Requires learning of information
− Strategies: imagery, associations
§ Minutes to years
§ Relies on hippocampus
§ Requires storage and retrieval
§ Aging à long-term memory deficits
− Reduced activity, loss of cells, and
shrinkage in hippocampus
− Less cells = more overlap of information
between cells à interference/confusion
94
Semantic Memory
§ Vocabulary & factual knowledge
− Lose details regarding time and
place of memory acquisition
§ Relies on temporal lobe
§ Mostly preserved with age
95
Remote Memory
§ Memory from the distant past
§ Important for story-telling/‘folklore’
− Can include time and place that an
event occurred
§ Relies on temporal lobe
§ Typically preserved with age
96
Normal cognitive aging
a gradual, age-related decline in memory,
conceptual reasoning, and cognitive processing speed
97
Pathological Cognitive Decline
§ Dementia –- a condition characterized by a
decline in cognitive function that impairs an
individual’s ability to perform everyday tasks
§ Most common types of dementia:
1. Alzheimer’s Disease
2. Vascular Dementia
3. Lewy Body Dementia
