EXAM II Material Flashcards
(170 cards)
1
Q
Which of the following is NOT a characteristic of fibrocartilage?
Type II Collagen
Not surrounded by perichondrium
Found in intervertebral discs
Increased collagen in the matrix
Neither A nor B are characteristic of fibrocartilage
A
Type II Collagen
2
Q
Which of the following is not part of a Haversian system?
Periosteum
Lacunae
Lamellae
Volkmann canals
Canalciuli
A
Periosteum
3
Q
Parathyroid hormone stimulates osteoblasts to secrete/express which of the following?
Osteoprotegerin
M-CSF
RANKL
All the above
Only B and C
A
Only B and C
4
Q
Hyaline Characteristics & Locations
A
- Most common; avascular
- Isogenous groups
- External Auditory meatus, Larynx, Trachial/Bronchial cartilages, Fetal long bones, articular ends of bones
- Type II Collagen
- Appositional & Interstitial growth
- Translucent- bluish white
5
Q
Elastic Cartilage Characteristics & Locations
A
- Single Chondrocytes
- Auricle/Pinna of ear, Epiglottis
- Type II & Elastic fibers
- Opaque and flexible
6
Q
Fibrocartilage Characteristics & Locations
A
- Singly sparse chondrocytes
- LACKS perichondrium
- Intervertebral discs, pubic symphysis, some tendon/ligament insertions
- Type I Collagen
- opaque
7
Q
Describe Cartilage in terms of:
Cells (2)
ECM
Matrix
& other characteristics
A
- Chondroblasts = cartilage-forming (matrix), Chondrocytes = cartilage-maintaining (both in lacunae)
- ECM = Collagen fibers, Amorphous ground substance (gel-like)
- Matrix - Collagen type II, GAGs (hyaluronic acid, chondroitin sulfate, keratan sulfate, heparin sulfate)
- Avascular - nutrients diffuse thru matrix, slow to heal
- Territorial and Inter-territorial matrix
- Perichondrium - inner fibrous layer, outer chondrogenic layer
- Isogenous groups - chondrocytes
8
Q
What is meant by bone tissue being based on a canalicular system?
A
Bone matrix is penetrated by various channels with various characteristics
9
Q
Bone Tissue Characteristics
Matrix components?
Cell types? Type of growth?
A
- Appositional growth - hyaline cartilage model
- Continuously resorbed, reconstructed, remodeled
- Formed by osteoblasts –> osteocytes
- Matrix w/ organic and inorganic components
10
Q
What is the organic & inorganic component of bone referred to as?
A
Organic - Osteoid (soft component)
Inorganic - hydroxyapatite (35-65%)
O = O
H = I
11
Q
Characteristics of woven bone
A
- Development & bone repair
- also called cancellous/trabecular
*
12
Q
Characteristics of Compact bone
A
- Found in adults - lamellar
- Components:
- Haversian canal - vessels w/ nerves
- Lacunae - osteocytes
- Lamellae - H.C. layers w/ lacuna in b/w
- Caniculus - connects lacunae to vessels
- Volksman Canal - connects HC
- Fibrous periosteum & Osteogenic periosteum
13
Q
What are bones macroscopic components?
A
Endosteum - lines marrow cavity
Periosteum - surrounds bone
Marrow/Medullary cavity - runs down inner shaft
Sharply a fibers - connects periosteum to bone
E.PMS Erin (has) PMS
14
Q
Characteristics of Spongy/Trabecular Bone
A
Contain bony spicules that intertwine to form trabeculae surrounding bone marrow spaces in long and flat bones
15
Q
What are osteoblasts characterized by, derived from, give rise to, and the major protein products?
A
Derived from osteoprogenitor cells
Give rise to osteocytes
Characterized by Alkaline phosphatase and Vit D3
Major protein - Type I collagen, Noncollagenous proteins:
Osteocalcin, osteonectin, osteopontin, osteoprotegerin, RANKL
16
Q
Function of Vitamin D3 in Osteoblast cells?
A
Regulates the expression of osteocalcin
17
Q
Where is Alkaline phosphatase NOT found?
A
Osteocytes
18
Q
Unique characteristic of Osteocalcin?
A
Has a high binding affinity for hydroxyapatite which inhibits osteoclast maturation
19
Q
How are osteoclasts able to reabsorb bone matrix?
A
HI KO
inorganic = H+
K+ = secreted for organic
Via Osteoclasts
20
Q
Define Joint
A
Where two bones come together
21
Q
What are the 3 types of joints
A
Cartilage Joint
Synovial Joint
Fibrous Joint
Joints allow you to Cum, Swallow & Fuc
22
Q
What are the types of Cartilaginous Joints?
A
S.F.S.H.
SoFarSonicHedgehog
Symphysis - joined by fibrocartilage
intervertebral discs and pubic symphysis
Synchondrosis - joined by hyaline cartilage
Epiphyseal plates, 1st sternocoastal joint
23
Q
What are cartilaginous joints joined by?
A
Hyaline or Fibrocartilage
24
Q
What are Fibrous Joints joined by?
A
Collagenous and/or Elastic Fibrous CT
25
What are the types of Fibrous Joints?
"Brain-dosis"
**Suture**
Joints b/w skull cap
**Syndesmosis**
b/w tibia and fibula
**Gomphosis**
teeth in alveoli
26
Characteristics of Synovial Joints
Moveable joints w/ connective capsule surrounding a fluid-filled joint space
3 Types: **Monaxial Joint** movement via 1 plane
Hinge and pivot joints
**Biaxial Joint** (condyloid joints; atlantooccipital joint)
**Triaxial Joint** 3 planes (ball & socket) Glenohumeral
27
Properties of Erythrocytes
Major Contents: **lipids, ATP, Carbonic anhydrase, Hb**
Major Peripheral Proteins: **Spectrin, Actin, Ankyrin** (binds spectrin & transmembrane protein)**, Protein 4.1, Adducin, Anion Transporter Channel**
No organelles
28
Neutrophil Characteristics
**PMNs**; **3-5 lobes**
**Active phagocytes**
Both small (specific; ) and large granules (less numerous azurophilic granules; primary);
**S**mall **R**adicals **L**ove **L**ying to **P**lease
**SMALL** secrete free radicals, lysozyme, lactoferrin, proteases
**LARGE** secrete elastase, defenSins, myeloperoxidase
smallest blood cell
29
Basophil Characteristics
**Bilobed Nucleus**
**Large, membrane bound basophilic granules** = mask the membrane
Heparin = anticoagulant
Kallikrein = attracts eosinophils
Leukotrienes = vascular permeability
Serotonin
**H**e **K**ills (his) **L**ittle **S**isters
30
Eosinophil Characteristics
**Bilobed Nucleus**
Specific granules
**MNP** = Major basic protein = parasite membranes, histamine release
**Peroxidase** = neutralizes heparin & anti-parasitic
**M**en **C**an't **P**erform
Allergic Rxns & Parasites
31
Lymphocyte Characteristics
**Large, round Nucleus** - slightly indented
B and T Lymphocytes (immune response)
Contain small, medium, and large (largest blood cell)
32
Monocyte Characteristics
**Kidney Nucleus**
LARGEST
Precursor of **MO and Osteoclasts**
33
Platelets Characteristics
Derived from megakaryocytes
**Enhance aggregation**, **Promote clot formation, retraction** (via prostacyclin from endothelial cell) **and dissolution**
Platelet plug (repair vessel damage), Adhesion via integrins
Release Thromboxane
2um; 200,000-400,000/uL of blood
34
3 Steps of extravasation of inflammatory cells into connective tissue:
1. Leukocyte Extravasation
2. Selectin phase
3. Integrin phase
35
Basic steps of extravasation, what is released and what ICAMs are involved
**Cytokines** (via mast cells, platelets, damaged tissue cells) activate
**Endothelial cells releases NO,** **Leukocytes move toward endothelial vessel wall**
Leukocyte membranes w/ bodies bind to endothelial ligand **P-selectin** causing leukocyte rolling
Activated **integrin** receptors on leuks bind to **ICAM-1 & ICAM-2** = **Transendothelial migration of leuks**
36
Erythroblastosis fetalis basic concepts
What antigen is involved?
Ag D
Mom is Rh-, baby is Rh+
Mother makes **IgM** during 1st baby = cannot cross placenta
Second baby = mother has **IgG** = crosses placenta
**Rh Incompatibility**
37
Totipotent
Pluripotent
Multipotent
1. Give rise to **All cells** including embryonic & XE tissues
2. Give rise to **Adult tissue and embryo** **NO XE**
3. Give rise to **Adult only** - a given lineage
38
What are the 4 features of bone marrow histology?
**S**ome **S**ouls **P**refer **H**ate
**Sinusoids** - connect arterial and venous vessels, access for mature blood cells to move into circulation
**Stroma** - background/framework for growth/dev. of blood cells (fibroblasts, adipose cells, ect.) **Forms and secretes hematopoietic GFs**
**Parenchyma** - various lineages of hematopoietic cells in diff stages of differentiation
**Hematopoietic Cords** - bands of parenchyma & stroma lying b/w sinusoids
39
What are the 3 classes of Hematopoietic GFs?
Colongy-stimulating factors
Erythropoietin and Thrombopoietin
Cytokines (interleukins)
40
Unique Cardiac Muscle Characteristics
**Intercalated Discs** (gap junctions)
Mononucleated
**Central Nuclei**
41
Smooth Muscle Characteristics
**Mononucleated**
**No sarcomere arragement**
**Gap junctions**
42
Skeletal Muscle Characteristics
Striated, Peripheral Nuclei
Multinucleated = syncytium
Sarcomere arrangement, "all-or-none"
Each fiber innervated via single motor axon
**3 Myofiber Types** - I, IIA, IIB
43
What are the characteristics of Myofiber Type I?
**Slow, continuous contractions = high mito**
**NADH rich = high Oxidative Phosph = Strong staining for oxidative enzymes** (darkest)
**Dark/Red fibers**
44
Characteristics of Myofiber Type IIA?
Intermediate staining
Both aerobic and anaerobic respiration
**Faster than Type I**
**Fatigue Resistance**
45
Characteristics of Myofiber Type IIB?
**Fastest = therefore fatigue faster**
Stain Light for oxidative enzymes
Anearobic respiration for ATP
**Light/White fibers**
46
Components of the troponin-tropomyosin-actin complex
(thick and thin filament)
**Thick Filament**: Myosin - 2 heads = Actin, ATP, & light chain binding sites, 2 tails = one maintains stability, other stabilizes head
**Thin Filament:** G actin
**Troponin**: T.I.C.
**T** = binds tropomyosin
**I** = inhibits actin/myosin binding
**C** = binds Ca2+
47
Tropomyosin
2 alpha-helical polypeptides twisted around one another and sits in b/w two actin filaments
48
Location and function of T tubules
Between A and I bands
**Electrochemical Coupling** occurs
AP along sarcolemma and contraction
49
Sarcoplasmic Reticulum location and function
Contain **Cisternae** - sequester Ca2+ ions
Next to T-tubules
**Equivalent to RER**
50
Function of basal lamina in skeletal muscle
Connects muscle fibers and helps distribute the force of contraction
51
Characteristics of Satellite Cells
Attach to myotubes **before** basal lamina is laid down
Generally **quiescent**
Function as **stem cells**
Become mitotic in times of stress -\> HGF binds C-Met receptor
Gives rise to **myogenic precursor cells** - replaces damaged cells (differentiates into muscle fibers)
52
Function of the Neuromuscular Spindle
sensory receptors within the **belly of a muscle** that **primarily detect changes in the length of this muscle**. They **convey length information to the central nervous system via sensory neurons.**
53
Regions of the Neuromuscular spindle
**Sensory Region**
**Contractile Region**
**Alpha motor neurons = extrafusal fibers**
**Gamma motor neurons = intrafusal fibers**
Primary and Secondary afferent fibers
**GI BILL=** gamma = intrafusial
54
What are the components of intercalated discs in cardiac muscle? (3)
**Gap Junctions** - along longitudinal section
**Macula Adherins (desmosomes)** - adhere intermediate filaments/desmin to adjacent muscle cells (transverse component)
**Fascia Aderendentes** - anchors actin filaments of sarcomeres (transverse component)
**LGBT**
Longitudinal = gap junction
Transverse = Adherins & Aderendentes
55
What is the source and function of ANP?
Source: **cardiac muscle cells in atria**
Function: **Regulate fluid electrolyte balance**
**Relax vascular smooth muscle** (reducing blood volume and pressure) = release stimulated via atrial stretch = cleavage of prohormone into active product
56
Describe function and structure of caveolae (and lipid rafts)
Caveolin bind **cholesterol** in lipid rafts (cell membrane depressions involved in fluid and electrolye transport where pinocytotic vesicles form) and initiates formation of **caveolae** which are vesicles that detach and participate in vesicular trafficking (which transport Ca2+ from extracellular fluids to SR of smooth muscle)
57
Layers of the perichondrium?
**Fibrous perichondrium -** source of fibroblasts, outermost
**Chondrogenic perichondrium -** chondroblasts and oteoprogenitor cells, innermost layer
58
What are the cells of cartilage and where are they located?
Located in **lacunae**
**Chondroblasts -** cartilage-forming cells
**Chondrocytes -** cartilage maintaining
59
What does the ECM of cartilage contain?
**Amorphous ground substance**
**Type II Collagen (besides Fibrocartilage = Type I)**
**Hyaluronic acid**
**GAGs - chondroitin sulfate, keratan sulfate, heparin sulfate**
Territorial and Inter-territorial matrix
Isogenous groups
60
How are chondrocytes arranged in elastic cartilage, fibrocartilage and hyaline cartilage?
Elastic = **Singly**
Fibrocartilage = **Sparsly**
Hyaline = **Many Isogenous groups**
61
What is unique about Fibrocartilage?
Contains **Type I Collagen** rather than Type II
is **NOT** surrounded by perichondrium
62
What is the primary regulator for bone turnover? What do low and high amounts signify?
**PTH**
[high] - PTH binds osteoblast
Osteoblast stimulated to synthesize **M-CSF & RANKL**
M-CSF binds to **M-CSFr** on **monocyte** which diff into **MO** which expresses **RANK** which binds **RANKL** which couples together osteoblast & MO = immature osteoclast
[low] - **bone formation** = Osteoblast syn. **Osteoprotegerin** which **blocks RANKL** (no binding of RANK) = osteoblast activity
63
What occurs during high [PTH] and low [PTH]?
High = high osteoclast activity = **Bone Breakdown/killing = Osteoblast releases osteoclast-differentiation factors** (eroded bone & fibrosis = osteitis fibrosis)
Low = high osteoblast activity = **Bone Formation**
64
What are the major protein products of osteoblasts?
Type I Collagen
Osteocalcin
Osteonectin
Osteopontin
Osteoprotegerin
RANKL
65
Steps in intramembranous bone development
**Mesenchymal Aggregation** (Wnt, Shh, FGF, TGF-beta)
**Osteoblasts**
Secrete osteoid, trapped blasts = **Blastema**
Trapped blasts - **Osteocytes** = **Syncytium**
**Mineralization via Ca2+ ions**
Epithelial covering secreting osteoid: **Type I + Non-collagen proteins**
Primary ossification center = **Trabecula**, fusion = **spongy bone**
**Woven Bone w/ crazy collagen fibers**
**Aligned fibers = Lamellar =** encircle vessels = **Haversian System**
**Hypertrophic Chondrocytes = Endothelial GF**
Blood vessels break thru perich. bringing in Osteoprogenitor cells, apoptosis of hypertrophic cartilage cells = **calcified matrix strands**
Above used by blasts to deposit Osteoid then calcified
Appositional growth occurring; perichondrium = periosteum
66
What are the Zones in the growth plate/epiphyseal plate?
Zone of Proliferation
zone of hyper trophy
zone of calcification
67
FAG Proteins
Fibrinogen
Albumin
Globulin
Fibrinogen - **Clotting**, target for thrombin made in liver
Albumin - major protein component in blood, made in liver
Globulin - Immunoglobulin
68
What are the hematopoietic GFs? (3)
Colony Stimulating Factors
Erythropoietin and Thrombopoietin
Cytokines
69
Characteristics of a stem cell niche
Area of a tissue that provides a specific **microenvironment**, in which stem cells are present in an undifferentiated and self-renewable state. **Cells of the stem-cell niche interact with the stem cells to maintain them or promote their differentiation.**
70
Stroma of Bone Marrow
The framework/background for growth/development of blood cells
**Fibroblasts, adipose tissue, endothelial cells**
Synthesizes and secretes Hematopoietic GFs
**S**troma = **S**ecretes
71
Parenchyma of Bone Marrow
Various lineages of hematopoietic cells in different stages of differentiation
**P**ara = different...differentiation
72
Sinusoids in Bone Marrow
Endothelial-lined spaces that connect arterial and venous vessels
Provides access for mature blood cells to move into circulation
73
Hematopoietic cords of Bone Marrow
Bands of parenchyma and stroma lying b/w sinusoids
74
What are the components of bone marrow histology? SHSP
Sinusoids
Hematopoietic cords
Stroma
Parenchyma
75
What are the 3 major CFUs?
All derived from **Myeloid SCs = Pluripotent**
**Colony Stimulating Factors** - G-CSF, M-CSF, SFC (stem cell factor)
**Erythropoietin and Thrombopoietin**
**Cytokines**
76
What do Erythroid CFUs give rise to? Cellular lineage
**Proerythroblast** **via Erythropoietin**
"**P**ro**BPOR**Eos"
Oreos are Pro for high BP
**Pro**erythroblast - mitotic
**Basophilic** erythroblast - mitotic, blue
**Poly**chromatophilic - mitotic
Orthochromatic
Reticulocytes - **circulation (blue; RER remnants, nucleus lost)**
Erythrocyte - **circulation**
77
What do Megakaryocyte CFUs give rise to?
Megakaryocytoblast via **Thrombopoietin**
**MMP -** mighty muthafuckn problems
Megakaryocytoblast
Megakaryocyte (big nucleus) - remain in stroma bc too large
**Platelet - circulation**
78
What do Basophilic and Eosinophil CFUs give rise to? Lineage?
**Myeloblast; Bands** will make her dance
**MProMMetaBandE/B**
**M**r. **Pro M**ighty **Meta Band E/B**
Myeloblast - **mitotic**
Promyelocyte - **mitotic**
Myelocyte - **mitotic**
Metamyelocyte
Band Cell - **Circulation**
Eosinophil/Basophil
79
Colony CFUs clinical relevance
After patients undergo radiation, may develop **neutropenia (low neutrophils), GM-CSF/G-CSFs** used during **radiation/chemo therapy**
80
Erythropoietin Clinical relevance
Erythropoietin is released in **polycythemia** (high RBC); sometimes due to smoking or tetralogy of fallot - HARMFUL
Produced in kidney during hypoxia = **decrease oxygen saturation**
81
Thrombopoietin Clinical Usage
None
82
Cytokines Clinical Use
Primarily Interleukins
Signaling pathways
Mediate cellular quiescence, apoptosis, proliferation, differentiation
83
What do Eosinophil CFUs give rise to? Lineage?
**Myeloblast**
MPMetaBE
Bands Will make her dance
84
Lineage of Granulocyte-CFU
SAME AS BASOPHIL AND ESINOPHIL
**MProMM**eta**B**and**N**
Myeloblast - **mitotic, no granules**
Promyelocyte - **mitotic, primary granules, red/magenta**
Myelocyte - **mitotic, primary & specific granules**
Metamyelocyte
Band cell - **circulation**
Neutrophil - **circulation**
85
What do Granulocyte-Macrophage CFUs give rise to? Lineage?
Neutrophils via **G-CSF**
and
Monoblasts via **M-CSF**
86
Hierarchichal Structure of skeletal muscle
Muscle **Fasicle** surrounded by **Epimysium** (bundle of myofibers)
**Perimysium** in between Fasicles (fibroblasts & Type I)
**MyoFiber** w/ **Sarcolemma** surrouned by **Endomysium** (bundle of myofibrils) **Basal Lamina**
**Myofibril with sarcomeres**
87
Thick Filament components
Myosin; dimeric protein w/ two heads and two tails
**Myosin Head -** actin, ATP, light chain binding region
**Light chain stabilizes myosin head**
**Myosin Tail** - 2 tails; maintains stability of myosin II
88
Which components of the sarcomere move during contraction?
**HI**!!!
A band - myosin; thick
I band - actin thin filaments
89
Thin Filament Components
G Actin
2 polymers in alpha helix w/ (+) end connected to Zdisc and (-) end towards H band
**Troponin**
**Tropomyosin**
90
Alpha Actinin
Attaches thin filaments to Z line
91
Alpha-beta Crystallin
Heat shock protein that protects desmin from mechanical stress
92
Desmin Intermediate Filaments
Surrounds Z-line and extends into each sarcomere
## Footnote
**Links myofibrils laterally and to sarcolemma**
93
Dystrophin
Links alpha-actinin/desmin complex to cytoplasmic side of sarcolemma
**Anchors actin to sarcolemme**
Reinforces sarcolemma during muscle contractions
94
Dystroglycan complex
**Links dystrophin (ICM) to laminin-2 (ECM)**
95
Nebulin
**A**ct right for the **N**ubian Queen
Template to regulate length of **actin** filament
Extends from Z disk to end of actin filament
96
Plectin
Binds desmin filaments
97
Titin
**Connects ends of thick filaments to Z line**
Extends from Z disk to H band
Provides myosin w/ elasticity, large fibrous protein
98
Function & Characteristics of Satellite cells
**Attach to myotubes before basal lamina is laid down**
Generally quiescent
Function as stem cells
Become mitotic in times of stress
**C-Met receptor binds HGF**
Gives rise to **myogenic precursor cells** which **replace damaged muscle by proliferating, fusing, and differentiation into skeletal muscle fibers**
99
What is a common unique characterstics of both cardiac and smooth muscle cells?
Both contain **gap junctions**
and are **mononucleated**
100
Common characterstic between skeletal and cardiac muscle cells
Sarcomere arrangement
101
Explain the contractile apparatus of smooth muscle, what are the differences b/w that and skeletal?
Plasma membrane dense bodies and cytoplasmic dense bodies bind actin-myosin bundles which zig-zig thru cell
Contain **Dense bodies rather than Z lines** which connect actin filaments together and to cell membrane - alpha actinin
**Caveolae and lipid rafts** contain the **pinocytic vesicles** that detach and participate in vesicular traffiking
102
What type of cells are within the ventricular/epemdyma zone and intermediate zone? What do they contain?
Pseudostratified epithelium
Ventricular Zone - ventricular cells
Intermediate zone - apoptosis of excess neurons
103
What does the cortical plate contain (mantle layer)?
Postmitotic neurons
Future gray matter; cell bodies, dendrites, unmyelinated axons
104
What does the marginal layer contain?
Axons
Future white matter; myelinated axons
105
What is the origin of neuroblasts and what do they give rise to?
Derived from **Neuroepithelial cells from embryonic neuroectoderm**
Give rise to **neurons of the CNS (brain and spinal cord)**
106
Where are glial cells derived from?
Cortical plate
107
Cell Body Characteristics of a motor neuron
Nucleus
Nissl bodies w/ RER & free ribosomes
Mitochondria
Microtubules & Neurofilaments
Lipofucsin granules that accumulate w/ age (old neurons)
ligand gated channels and local potentials
108
Dendrite Characteristics
Conduct impulses (local potentials)
Nissle substance
Mitochondria
No Golgi body
Dendritic spines w/ increase SA for contact
Ligand gated channels and local potentials
109
2 major differences of neuron cell bodies and dendrites
Cell body contains the nucleus
Cell body has Golgi structures
110
Axon Hillock and Axon Characteristics
Hillock - site for origin of axon
NO NISSL SUBSTANCE
**AP generation**
Axon - v.g. channels
Mitochondria and microtubules
**Lacks RER, ribosomes, Golgi**
Terminates in branching **telodendrites** which contain synaptic vesicles & related proteins and form presynaptic membranes
111
What are the three ways to classify motor neurons?
Axon length
Function
Number of Processes
112
How do you classify neurons according to function?
**Sensory -** afferent
**Interneuron -** processes information within CNS between sensory and motor
**Motor -** efferet, somatic and autonomic; **skeletal muscles, cardiac and smooth muscles** (sym. and parasymp.)
113
How do you classify neurons according to the numbers of processes? 3
**Bipolar** - single axon extends from either side of cell body giving off multiple dendrites **Special Sensory =** eye, olfactory, auditory, vestibular
**Multipolar -** single axon giving off multpile dendrites
**Pseudounipolar -** single axon extends from cell body and shortly bifurcates into a central and peripheral process w/ dendrites in periphery
**Sensory ganglia of cranial & spinal nerves**
114
How do you classify neurons according to axon length?
**Golgi Type I** - **long axons** that leave grey matter of which they part
**Golgi Type II -** neurons with **short axons** which ramify thru grey matter
115
Define Nerve
Bundle of **axons** in the **PNS**
116
Define Ganglion
**Cell body** and **dendrite aggregates** in the **PNS**
117
Define tract
Bundle of **axons** in the **CNS**
118
Define nucleus (neuronal)
**Cell body** and **dendrite aggregates** in the **CNS**
119
List the layers of a neuron
**Epineurium** - covers entire nerve (supplied by blood and lymphatic vessels) **Type I & fibroblasts**
**Perineurium -** covers bundles of axons/fasiscles within nerve **Dense CT**
**Endoneurium -** surrounds individual fascicles and Schwann cells **Thin layer of reticular CT, Type III** (receptors and ion channels)
120
Define Anterograde and what protein does it utilize?
Movement from **cell body toward distal end of axon**
**Kinesin**
Slow; 1-6mm/day SCa; microtubules, neurofilaments (slow component a) SCb (**enzymes, actin, clathrin**)
Intermediate; 50-100mm/day **(mito.)**
Fast; 400mm/day **(NTs, Synaptic vesicles)**
121
Define Retrograde Movement, what protein does it involve and what does it carry?
Movement from **Axon toward the cell body**
**Dynein**
Endocytosed materials and recycled proteins
100-300mm/day
122
List the Glial Cells (5)
Astrocytes
Ependymal
Microglia
Oligodendrites
Schwann cells
123
Astrocytes; origin, location, function, major characteristics
**CNS**
Functions: structural support, **blood brain barrier = exchange of nutrients & metabolites b/w blood and neurons** (**pediceles**; feet on pia mater and blood vessels)
Potassium sink, uptake/metabolism of NTs
**Fibrous Astrocyte -** white matter
**Protoplasmic Astrocyte -** grey matter
124
What are the components of the blood brain barrier?
Continous basal lamina of endothelial capillaries
End feet of astrocytes
Tight Junctions
125
Microglia; origin, location, function, major characteristics
**Macrophages**
Derived from **BM as MO precursors**
Phagocytic in PNS, Hyperactivated = neurodegenerative diseases
126
Schwann Cells; origin, location, function, major characteristics
PNS
Can also surround unmyelinated axons
One cell myelinates a **single axon** at a time
127
Oligodendrites; origin, location, function, major characteristics
**CNS**
**Satellite cells in grey matter**
Myelinates **serveral axons** at a time in the CNS
128
Ependymal Cells; origin, location, function, major characteristics
Function in **transport**
Ciliated cuboid cells; lines ventricles and central canal of spinal cord
Contain **Tanycytes** - cells in the 3rd ventricle that place end feet on blood vessels
Satellite cells = insulators for protection derived from neural crest
129
Describe the process of myelination in the PNS
Schwann cell plasma membrane wraps around axon.
Schwann cell cytoplasm is “squeezed” out, leaving behind concentric layers of membranes.
130
Define External mesaxon
Also known as the outer point of fusion
Creates the **intraperiod line** which is an **electron dense line** (extracellular spaces)
Close but non-fused outer leaflefts
131
Define Internal Mesaxon
Also known as the inner point of fusion
**Major dense line** are the inner leaflefts with cytoplasmic space remnants with CLOSE opposition; thinner line
132
Define Intraperiod dense lines
The line thats created by the external mesaxon/outer point of fusion
Non-fused; electron dense line
133
Define Major dense line
Formed from the internal mesaxon/inner point of fusion containing cytoplasmic space remnants
Thinner line than the intraperiod line
134
Define Schmidt-Lanterman clefts (incisures)
Residual areas of cytoplasm within the major dense lines
Contain **tight junctions** and **Connexin 32**
135
Define MPZ
Myelin Protein Zero
**PNS**
Synthesized by schwann cells and interacts w/ one another to **stabilize apposed plasma membranes as homotetramers**
Intracellular tail contains a signaling function
136
Define MBP
Myelin Basic Protein
Located in **Both CNS and PNS**
137
Define PLP
Proteolipid Protein
In CNS protein which stabilizes adjacent stacks of membranes **of oligodendrites**
138
Differences b/w CNS and PNS myelin
_CNS_
contain **astrocyte end foot** in Node of Ranvier
Cytoplasmic processes of adjacent oligos **DO NOT interdigitate**
_PNS_
Cytoplasmic processes of adjacent cells **interdigitate with tight junctions**
139
List major differences between presynaptic membrane and postsynaptic membrane
_Presynaptic:_ **(signal delivery)**
V.g. Ca2+ channels
Synaptic vesicles; synapsins
_Postsynaptic:_ **(signal response)**
NT receptors; ligand gated
EPP
Local potential
140
What are the 6 types of synapses?
**Axosomatic** - axon terminal synapses w/ neuron cell body
**Axoaxonic** - terminal synapses w/ another axon terminal
**Axodendritic** - terminal synapses w/ a dendrite
**Axospinous** - terminal synapses w/ a dendritic spine
**Excitatory** - contain a more (+) EPP (closer to threshold)
**Inhibitory** - has a more (-) ERR (further from threshold)
141
List the layers of the meninges
**DAP**
Epidural Space
Dura Mater - encases brain
Subdural Space
Arachnoid Mater
Sub Arachnoid Space - **CSF circulation**
Pia Mater - directly lines brain and spinal cord
142
Arachnoid Characteristics
Connect to pia mater via **arachnoid trabeculae**
Contain **Arachnoid villi** (CSF enters; arachnoid barrier cells) that extend out to venous sinus allowing CSF flow from subarachnoid space into dural sinuses
Blood does not flow from venous sinus to subarach. space
143
Define choroid plexus
Produces 80-90% of CSF
Contain **Ependymal cells**
144
Sensory (dorsal root) ganglia characteristics
Capsule of CT = epineurium
**Pseudounipolar neurons** within capsule
**Myelinated**
**Satellite cells**
145
Autonomic Ganglia Characteristics
Capsule of epineurium
Clustered **multipolar neurons**
Myelinated postganglionic axons
Satellite cells
146
List the 3 layers of the eye (tunics; outer to inner)
Outer: **Sclera & Cornea**
Middle: **Choroid, Ciliary Body, & Iris**
Inner: **Retina**
147
Components of the **S**c**LE**ra (SLE)
**Sclera Proper** - tendon for muscle attachment
**Lamina cribrosa** - pass thru optic nerve fibers
**Episclera Layer** - vascular, attaches eyelid lining to sclera, loose collagen and elastic fibers
148
Components of the **C**ornea
Triple C Boobs Do (it for me)
**Corneal Epithelium** - stratified non-k squamous
**Corneal stroma -** thickest portion
**Corneal Endothelium -** single layer of squamous
**Bowman's membrane -** acellular
**Descemets Membrane -** acellular
Triple **C B**oobs, **D**o it for me
149
Function of aqueous humor
Maintains pressure needed to inflate the eye and provide nutrition for central cornea and lens
150
What is the pathway of aqueous humor?
Posterior to Anterior chamber
Major escape route from ciliary body = **Canal of Schlemm,** where it reaches the sclera and is drained by veins and lymphatics
151
Location of the anterior and posterior chambers?
Anterior **(ACL)**: between the **lens** and the **cornea**
Posterior **(PIL)**: between the **iris** and the **lens**
152
Location of the iris? Layers?
IOC
Between anterior and posterior chambers, surrounds the pupil
Contains melanocytes
Inner, outer, and concentric layers contain **myofilaments**
**Inner = pigmented**
**Outer = dilater**
****_C_**oncentric = **_C_**onstrictor**
153
Contents of the Inner and Outer segments of rods and cones
Outer - **rhodopsin-containing lamellae** (foldings of cell membrane w/ photo sensitive molecules)
Inner - rods and cones w/ mito, RER, Golgi, Glycogen
154
Contents of the outer and inner nuclear layer
Outer - cell bodies of rods and cones **(1st order neurons)**
Inner - cell bodies of bipolar cells **(2nd order),** horizonal cells, amacrine cells, Mueller cells
155
Contents of the outer and inner plexiform layers
Outer - synapses b/w **axons of rods and cones** and dendrites of **bipolar neurons and horizontal cells**
Inner - synapses b/w **axons of bipolar cells** and dendrites of **ganglion cells**
156
Contents of Ganglion cell layer
Eye
Cell bodies of ganglion cells (3rd order neurons)
157
Contents of Optic nerve layer
Axons of ganglion cells
158
What are the cells of the retina? (6)
"**A Bipolar** **G**uy **H**umps **M**any **P**eople"
**Amacrine** - interneurons; connect ganglion cells & bipolar neurons
**Bipolar** - conducting neurons synapse w/ rods & cones
**Ganglion -** conducting neurons whose **axons form fibers of optic nerve**
**Horizontal -** Interneurons that interconnect rods and cones w/ each other & w/ bipolar
**Muller -** neuroglial cells extend thruout retina
**Pigmented - Synthesize** **Melanin**; Esterify Vit A
159
Define Macula lutea
Yellow region surrounding the fovea
Highest visual acuity
160
Define fovea centralis
Middle of Macula lutea
## Footnote
**Highest density of cone cells**
**Lacks rod cells & capillaries**
161
Optic disc components
**Lacks photoreceptors**
Point where ganglion cells turn into optic nerve = blind spot
162
What are the types of photoreceptors
**Rods** = **R**hodopsin as photopigment, sensitive to low-light intensity **Black & White vision,** discontinuous lamellae
**Cones** = 3 different types of **Iodopsins** as photopigment
Sensitive to high intensity light; continuous lamellae
Contain: Inner segment; Mito
Cell body; nucleus & short axon
Outer segment; cilium
Disks
163
What are the components of the lens?
"If you stare too hard, you'll tear your **ACL**"
**Anterior epithelium -** simple cuboidal, gives rise to cells that become "lens fiber"
**Capsule -** encloses lens substance, glycoproteins & type IV
**Lens Nucleus -** no nucleus & organelles, filled w/ crystalline proteins (decrease w/ age = cataracts)
164
Eyelid components
**Anterior Surface** - covered w/ skin, **Glands of Zeiss** (sebaceous glands), **Glands of Moll** (sweat glands)
**Palpebral conjunctive -** stratified columnar/squamous epi w/ goblet cells, lines inner surface of eyelids, continuous w/ bulbar conjunctiva (covers eyeball)
**Palpebral fascia - fibrous core of eyelids**; Meibomian glands (sebaceous glands not associated w/ hair follicles);
165
Components of the Outer Ear?
**EAT**
External Auditory Meatus
Auricle - hair follicles
Tympanic Membrane - ear drum, vascularized
166
Middle ear components?
Tympanic Cavity; Bones
**MIS**
**Malleus** - attaches to tympanic membrane
**Incus** - intermediate
**Stapes -** inserts into oval window
167
Inner Ear Components? (4)
**M**en **A**re **V**ery **B**oring
**Membranous Labyrinth**
**Auditory Organ** - Cochlear duct, Organ of Corti
**Vestibular Organ** - patches of sensory structures that respond to changes in position, cristae ampullaris of semicircular canals, stereocilia = w/ **afferent nerve endings**
**Bony Labyrinth** - Fluid filled w/ Na+ perilymph
Semicircular Canals
Cochlea
Scala vestibuli
Scala tympani
168
Muscles of the Middle Ear (2)
Responds to loud noises to dampen ossicle vibrations
## Footnote
**Tensor Tympani**
**Stapedius**
169
What does the Bony Labyrinth of the Inner Ear consist of?
Cochlea
Semicircular canals
Scala vestibuli
Scala tympani
170
What is the Organ of Corti? Where is it located, function?
Located in **Scala media**
Produces nerve impulses in response to sound vibrations
Sensory receptors = hair cells
