Week 1 Flashcards
(361 cards)
1
Q
Which is the largest chromosome? The smallest?
A
- Largest is chromosome 1
- Smallest: Chromosome 21
2
Q
In what stage of the cell cycle is Karyotyping performed?
What drug is applied to stop the cell cycle in this phase?
What is the action of this drug?
A
- Metaphase
- Colchicine
- Colchicine is used because it stops the microtubule formation
3
Q
What is Giemsa used for?
A
Used to stain chromosomes during karyotyping
4
Q
What is FISH?
What is it used for?
A
- FISH: Fluorescence In Situ Hybridization
- Labels a specific chromosome using hybridization with a fluorescent probe. Can be used to detect Trisomy 21, or deletions such as region of 15q that is missing in Prader-Willi Syndrome
5
Q
What does “dic” stand for in cytogenetics ?
A
Dic: dicentric
6
Q
What does “inv” stand for in cytogenetics?
A
Inv: inversion
7
Q
What does “t” stand for in cytogenetics?
A
Translocation
8
Q
A normal individual chromosome set is condsidered:
A
A normal individual is a disomy: 46, XX or 46 XY
9
Q
Describe acrocentric vs metacentric?
A
Compare the evenness of the centromere between p and q arms
Metacentric: even placement of centromere between p and q arm
Acrocentric: uneven placement of centromere such that p arm are only satellites
10
Q
What does “dup” stand for in cytogenetics?
A
“dup” : duplication
11
Q
What is mosaicism?
A
Some cells are wild type while some are mutant type all occurring WITHIN the same cell
12
Q
T/F: Aneuploidy means there is one less chromosome present than normal
A
False, aneuploidy is ANY deviation of chromosome set that differs from the wild type. This can be monosomy or trisomy etc.
13
Q
This chromosomal abnormality has the highest rate of spontaneous abortions
A
Trisomy chromosomal abnormalities incur the highest incidence of spontaneous abortions
14
Q
There are 7 common physical features of Down’s Syndrome including:
1. Oblique palpebral fissures:
2. Flat ___________ _____________
3. Low set ears
4. ____________ ___________
5. Epicanthal folds:
6. Brushfield spots:
7. Simian crease:
A
- Oblique palpebral fissures: slanting of the eyes
- Flat nasal bridge
- Low set ears
- Protruding Tongue
- Epicanthal folds: skin fold of the eye that covers the inner corner of the eye
- Brushfield spots: small white, gray spots that appear in the iris
- Simian crease: transverse crease across the palm
15
Q
List three common associated conditions in patients with Trisomy 21
A
- Hypothyroidism
- Congenital heart disease-ventricular septal defects, atrioventricular septal
- GI-duodental atresia
16
Q
Causes of trisomy 21 include non-disjunction associated with maternal age. 4% are due to Robertsonian translocations. What is Robertsonian translocation?
A
Its a form of translocation wherein the long long arms of a chromosome fuse together are create uneven chromosomes
17
Q
- What is another name for Edward Syndrome?
- List 3 associated symptoms
A
- Edward Syndrome = Trisomy 18
- Patients may have prominent occiput and receded jaw. Clenched fists where 2nd & 5th digits overlap the 3rd and 4th. Prominent calcanei also known as Rocker-bottom feet
18
Q
What is another name for Trisomy 18?
What chromosome abnormality is it?
A
Edward Syndrome
Trisomy of Cr 18
19
Q
What is another name for Trisomy 13?
A
Patau syndrome
20
Q
- What is Patau syndrome?
- List 4 symptoms assocaited with this condition.
A
- Patau syndrome = Trisomy 13
- Severe mental retardation, severe heart and urogenital defects. Microencephaly and cleft lip/palate. Polydactyly
21
Q
What is the death incidence from Trisomy 18 compared to Trisomy 13?
A
Trisomy 18: death within 1 yr
Trisomy 13: death within 6 mo
22
Q
- What is Klinefelter syndrome?
- Describe some characteristics of this disorder
A
- Klinefelter syndrome is XXY
- Male hypogonadism with tall stature and gynecomastia
Lack of secondary male characteristics
Lack of Testosterone that causes elevated FSH & LH
Gynecomastia and mental retardation
23
Q
What is an associated symptoms of XYY syndrome?
What is causes this triploidy?
A
- Increased growth velocity from early childhood and tall in final height
- XXY syndrome caused by nondisjunction of meiosis II wherein some sperm cells have an extra copy of Y chromosome
24
Q
What causes Triple X Syndrome?
What are some defining features?
A
- Triple X syndrome is caused by oocyte or sperm containing an extra copy of X chromosome due to nondisjunction
- Unusually tall, learning difficulties, decreased muscle tone, seizures, or kidney problems; normal fertility
25
What is Turner Syndrome?
What are some characterizing features of this disorder in infancy?
- 45 total chromosomes, only 1 X chromosome
- Infancy develop lymph edema in extremities
- Cystic hygroma of neck followed by webbing of neck
- Short stature
26
1. What are some general disorders associated with Turner syndrome?
2. What about characterizing features that are more prominent in adolescence/adulthood?
1. 50% of patients develop hypothyroidism. Congenital heart defects.
2. Short stature, streak ovaries, failure to develop secondary sex characteristics-no breasts due to low estrogen
27
What are streak ovaries?
- Nonfunctional ovaries that do not secrete estrogen resulting in amenorrhea & accelerated loss of oocytes
- Increased risk for Germ cell tumors
28
Reciprocal and Robertsonian are both types of ______________________________.
Robertsonian and Reciprocal are both types of translocation
29
Describe the difference between Reciprocal and Robertsonian translocation
Reciprocal: translocation wherein genetic material is exchanged between two chromosomes in a *balanced* manner such that negative repercussions are not normally found. Places offspring at risk of inheriting unbalanced chromosomal material
Robertsonian: More common. Occurring in acrocentric chromosomes, wherein there is loss of short arms of two chromosomes and fusion of long arms.
30
Why is Robertsonian translocation considered balanced if there is loss of chromosome?
Robertsonian translocation occurs on acrocentric chromosomes wherein the p arm is lost. In acrocentric chromosomes the p arm is so small there is no genetic material housed and thus no genetic material to loose in the first place
31
What causes Cri-du-chat syndrome?
What are some characteristics of this disorder (4)?
1. Terminal deletion of the p arm of chromosome 5 resulting in monosomy 5p
2. Cry of the cat in infants. Mental retardation, microcephaly with wide set eyes, cardiac defects incld. ventricular septal defects and atrial septal defects
32
What causes Williams syndrome?
What are some characteristics of the disorder (5)?
1. Deletion on the 7th chromosome q arm
2. Hypothyroidism, hypercalcemia, developmental delay, intellectual disability, cardiac defects
33
What is another name for DiGeorge syndrome?
Velocardiofacial syndrome
34
What is Velocardiofacial syndrome?
What causes it?
Velocardiofacial syndrome = DiGeorge Syndrome due to 22 q deletion inherited Autosomal Dominant (or new mutation)
Resulting in cranial facial anomalies, mental retardation and heart defects
35
What does the acronym CATCH 22 used in regard to?
C - cardiac defects
A - Abnormal facies
T - Thymic hypoplasia
C - Cleft lip/palate
H - Hypocalcemia from defective parathyroid glands
For deletions of Chromosome 22, DiGeorge Syndrome
36
What about Turner syndrome makes people affected short in stature?
SHOX gene
37
What is the SRY gene?
- Gene on the Y chromosome that determines sex of offspring
38
What gene on the Y chromosome determines sex of offspring after fertilization? How does it work?
SRY gene encodes a product that blocks the action of DAX1. In the absence of DAX1, cells are able to differentiate into Sertoli cells and secrete MIF inhibiting factor = male phenotype
39
What causes XX male syndrome?
XX male syndrome are phenotypic males with small testes but with no intra-abdominal Mullerian tissue. Sterile caused by SRY gene translocation to the *X CHROMOSOME*
40
What is Swyer S?
What causes it?
- XY gonadal dysgenesis wherein the person is externally female with streak gonads; has uterus and cervix but no breasts
- Loss of Function mutations in SRY gene
41
This genetic disorder of sex development would cause what repercussions?
Androgen insensitive S in 46, XY where there is a decrease in androgen receptors
- No uterus, breasts present
42
This genetic disorder of sex development would cause what repercussions?
Leydig cell agenesis 46, XY with decreased luteinizing hormone receptors
- No uterus present, breasts present
43
What 2 features do the follow disorders all have in common
1. Turner Syndrome, 45 X
2. Swyer's Syndrome, 46 XY
3. ____________________ _______________________ S in 46, XY
4. _______________ ________________ ________________________ 46, XY
5. 17-α-hydroxylase deficiency 46, XY
3. Androgen insensitive S in 46, XY
4. Leydig cell agenesis 46, XY
All are genetic disorders of sex development and all have no ovaries present or loss of ovarian function early in life
44
Define: Locus
Location of a certain gene
45
Define: Allele
Variations of a gene, i.e. Gene A vs. Gene B
46
Define: genotype
Allele A + Allele B = Genotype
The code which allele you have either normal or mutated
47
What is Colchicine?
Microtubule inhibitor during cell cycle in metaphase meiosis I
48
In what phase of meiosis is Karyotyping performed? Why?
- They are in their "X" position
- In Meiosis I, metaphase
49
What is the recurrence rate for autosomal recessive disorders?
25%
50
What is the chance of the first child of a couple being a carrier in an autosomal recessive disorder? What is the chance the *next* child will be a carrier in an autosomal recessive disorder?
- 66% chance the born, 1st child is carrier
- 50% chance the *next* born child is a carrier
51
In a family pedigree, what can you assume if the condition affects males and females equally?
If both males and females are affected equally in a family pedigree then this is not an X-linked disorder
52
If a family pedigree, the disorder skips a generation, what can you assume about the genetic inheritance pattern?
If skip a generation = recessive disorder
53
If in a family pedigree, the disorder affects only men, what can you assume about the inheritance pattern?
If only affects men = Y linked dominant
54
Why do Mitochondrial genetic disorder affect ALL offspring?
Because Mom's mitochondria are in all oocytes and therefore given to ALL offspring
55
What are two parameters that normally indicate the genetic inheritance pattern is autosomal recessive?
Male and Females affected equally and only seen in 1 generation = Autosomal recessive
56
Define: variable expression
Have the genotype of the mutation, should have the disease & do have the disease. BUT at variable severity
57
The following disorders are all inherited via:
1. Familial Hypercholesterolemia
2. Huntington Disease
3. Myotonic dystrophy
Autosomal dominant inheritance: Familial Hypercholesterolemia, Huntington disease, Myotonic Dystrophy (MD)
58
The following disorders are all inherited via:
Neurofibromatosis Type 1
Marfan Syndrome
Acute intermittent porphyria
Autosomal Dominant Inheritance: Neurofibromatosis Type 1 (NF1), Marfan syndrome (MFS), Acute intermittent porphyria (AIP)
59
The following disorders are all inherited via:
Achondroplasia (Ach)
Myotonic Dysrophy (MD)
Autosomal dominant inheritance
60
Describe 3 characterizing features of the autosomal __________________ disorder, Neurofibromatosis Type 1
1. Fleshy tumor growths known as neurofibromas
2. Flat pigmented skin lesions, cafe-au-lait spots
3. Lish nodules-benign tumors of the iris of the eye
Inherited via autosomal dominant
61
1. What disorder are Cafe-au-Liat spots associated with?
2. Describe these spots
1. Cafe-au-Liat spots are flat irregular pigmented spots of the skin
2. They are associated with Neurofibromatosis Type I disorder
62
What mutation causes Neurofibromatosis Type I?
Explain how this impacts cells.
1. Mutation in NF1 gene that normally codes for GAP protein is not coded
2. The GAP protein is what controls RAS activation, such that if this protein is not coded, RAS is not turned off
63
Define: Incomplete Penetrance
Have genetic mutation of a particular disease, should have the disease but DO NOT HAVE THE DISEASE
64
What is Pleiotropy?
Give an example
- If have genotype change, have phenotype chance, but that gene can cause multiple phenotypic effects
- Ex. Marfan's syndrome causes problems in connective tissue. Since connective tissue is found all over the body, there are wide spread effects from 1 type of genetic mutation
65
The following disorders are inherited via what type of genetic inheritance
1. Sickle Cell Disease
2. Cystic Fibrosis
Sickle Cell disease & Cystic Fibrosis are all inherited via Autosomal recessive
66
The following disorders are inherited via what type of genetic inheritance
1. Phenylketonuria
2. Tay-Sachs Disease
PKY and TSD (Tay-Sachs Disease) are inherited via Autosomal recessive inheritance
67
Describe a pedigree exhibiting Pseudodominance
If an individual who is homozygous for an autosomal recessive disorder marries a carrier of the same disorder, their children have a 1 in 2 chance of being affected
68
In X-linked recessive inheritance patterns, males are much more likely to be affected compared to females due to hemizygous. What is hemizygous?
Hemizygous refers to the fact that men only have 1 X chromosome compared to Females who have 2 X chromosomes
69
"Obviously, a Female Will Often Give Her Boys Her X-Linked Disorders" is an acronym for X-linked __________________ disorders. List them
X-Linked Recessive Disorders
1. Ornithine Transcarbamylase deficiency
2. Fabry disease
3. Wiskott-Aldrich syndrome
4. Ocular albinism
5. G6PD Deficiency
6. Hunter syndrome
7. Hemophilia A & B
8. Lesch-Nyhan syndrome
9. Duchenne Muscular Dystrophy
70
How does X chromosome inactivation come about?
What physical feature can determine which is X chromosome is inactivated?
1. X chromosome inactivation occurs via methylation such that the DNA is inaccessible for use
2. Barr bodies can be visualized under the microsome during interphase of cells
71
Females have 2 copies of X chromosome. Such that they usually require two copes of a mutation to express a disease. If this is the case, how do some females express X-linked recessive mutations?
By random chance, some females will inactivate the normal allele and thus express the mutant allele via X chromosome inactivation.
72
Females have 2 copies of X chromosome. Such that they usually require two copes of a mutation to express a disease. In females who do express X-linked recessive mutations, compare their disease state compared to hemizygous males.
Because females have 2 X chromosomes, often times only 1 mutant allele, their disease state is normally milder
Since males are hemizygous, meaning they only have 1 X chromosome, their disease state will be worse than females in the same situation
73
List three X linked dominant inherited disorders
1. Fragile X syndrome
2. Rett Syndrome (RTT)
3. X-linked hypophosphatemia
74
What is Skewed inheritance?
When some but *not all* cell inactivate Male/Female X chromosomes preferentially
75
What type of inheritance transmits only to sons, never to daughters?
Y linked inheritance disorders since only male sex have Y
76
What is holandric inheritance?
Y linked inheritance pattern
77
What are pseudoautosomal regions?
Genes that can exchange regularly between X & Y chromosomes
78
Describe how pleiotropy, expressivity, and penetrance all behave in NF1 disorder & what they mean
In Neurofibromatosis Type I
- Penetrance is 100% (complete penetrance) which means all persons with the mutation have the disorder
- Expressivity is varied because some may only have cafe-au-lait spots, freckles on the axillary skin, and Lisch nodules while other have life-threatening benign tumors etc.
- Since mutation of NF1 gene impacts GAP protein, the effects are widespread and through out the body affecting eye, skin etc.
79
What do RET genes code for?
RTK proteins
80
What type of genetic inheritance is often fatal?
Homozygous dominant mutations
81
What is Locus heterogeneity?
Mutation at different loci can cause the same disease
82
What is allelic heterogeneity?
Different mutation at the same locus can cause the same disease
83
This disorder is a common cause of visual impairment due to photoreceptor degeneration associated with abnormal pigment distribution in the retina. It has _____ loci associated with this disorder.
Retinitis pigmentosa exhibits locus heterogeneity with 80 loci associated
RP
84
This is a disorder where in the skin and other connective tissues may be excessively elastic or fragile because of an underlying defect of collagen structure, may have AD, AR, or X-linked. More than ____ different loci associated with the disorder meaning it displays
Ehlers-Danlos exhibits locus heterogeneity with more than 10 loci associated with EDS
85
What type of genetic heterogeneity does congenital hearing loss display?
Locus heterogeneity in that more than 90 different loci are associated with this disorder
86
The RET gene displays ___________________ _____________________ such that different mutant alleles of RET result in different clinical presentations.
Give 3 examples
Allele heterogeneity, RET codes for Receptor Tyrosine Kinase
1. Certain mutations can dominantly inherited failure of development of colonic ganglia leading to defective colonic motility and severe chronic constipation (Hirschsprung disease)
2. Mutations on this gene can result in dominantly inherited cancer of the thyroid and adrenal glands, multiple endocrine neoplasia
3. A third group of mutation in RET causes both Hirschsprung disease and MEN in the same individuals
87
At what rib level is the Sternal angle?
2nd ribs
88
What structures comprise the thoracic wall?
- Thoracic cage
- Intercostal muscles
- Skin, subcutaneous tissue, muscles, and fascia on the anterolateral aspect
- Mammary glands of the breasts
89
Describe the floor of the thoracic cavity
Deeply invaginated inferiorly by the viscera of the abdominal cavity
90
What is the primary muscle of respiration?
Diaphragm
91
Describe the three types of ribs
1. True: 1st-7th ribs that attach directly to the sternum
2. False: 8th, 9th, and usually 10th which their cartilage are connected to the cartilage of the rib above them; connection with the sternum is indirect
3. Floating: Sometimes 10th, but always 11th & 12th, these do not connect even indirectly with the sternum. End in the posterior abdominal musculature
92
Which ribs are considered "true ribs"? Why?
1st through 7th are true ribs because they attach to the sternum via costal cartilage
93
Which ribs are considered "false ribs"?
8th 9th & usually the 10th are considered false ribs because their cartilage are connected to the cartilage of the rib above them-the connection to the sternum is indirect
94
Which ribs are considered "Floating ribs"?
The 11th & 12th ribs are always considered floating and sometimes the 10th too. This is because they do not connect to the sternum in any manner. Rather they end in the posterior abdominal musculature
95
What vertebrae is associated with the inferior thoracic aperture?
T12
96
What are the borders of the thoracic outlet?
Describe very generally what thoracic outlet syndrome is
1. Thoracic Outlet bordered by: Scapula, clavicle, 1st rib
2. Disorders that occur due to compression of structures (brachial plexus, subclavian artery, subclavian vein) that transverse the confined space between the clavicle and first rib
97
List three anatomical variations that could contribute to thoracic outlet syndrome
1. Cervical rib
2. Abnormal first rib
3. Tight scalene muscles
98
Adson's Test, Roos Test, Wright's test can all be performed to diagnose:
Adson's Test, Roos Test, Wright's test can all be performed for diagnosis of Thoracic Outlet Syndrome
99
The esophagus and Vagus nerves pass through the _____________________ _________________________ in the inferior _____________ ________________. While the aorta and thoracic duct pass through the _____________ _______________.
The esophagus and Vagus nerves pass through the esophageal hiatus in the inferior thoracic aperture. While the aorta and thoracic duct pass through the aortic hiatus.
100
How do you name the intercostal spaces?
- Spaces are named according to the rib forming the superior border of the space
- i.e. the 4th intercostal space lies between ribs 4 & 5
101
What is the subcostal space?
The space below the 12th rib that does not lie between ribs
102
T/F: The intercostal space has two sets of intercostal blood vessels and nerves, main and collateral where Main run in the costal groove & Collateral run along the superior border of the rib below
True
103
What is the difference between costochondral and interchondral joints?
- Costochondral are where the ribs and costal cartilages meet
- Interchondral joints are where two costal cartilages come together in false ribs
104
How many pairs of internal intercostals and how many pairs of external intercostal muscles?
Both have 11 pairs
105
Describe the arrangement of the internal vs external intercostal muscles
- The internal intercostals run deep to and at right angles to the external intercostals
- Internal are slightly weaker than external
106
T/F: Subcostal muscles AKA internal intercostal muscles. Therefore they are found deep to external intercostal muscles and run at right angles to the external
- False, subcostal muscles are varied in size and shape and are found in the lower thoracic wall
- They cross 1 or Two intercostal spaces and run in the *same* direction as internal intercostal muscles almost blending in with them
107
Where is the herpes zoster resident?
Herpes zoster caused by VZV is resident in a dorsal root ganglion. When activated ,the herpes virus is transported along the axon to the skin, its expression follows the dermatome of the spinal nerve
108
Where can you find intercostal neurovascular bundles? Describe their arrangement
- Intercostal NVB are found between the internal and innermost intercostal muscles in the costal groove.
- Arranged from superior to inferior as vein, artery, nerve = VAN
109
Which neuro/vascular structures of the intercostal region are most vulnerable structures? Why?
- Intercostal nerves and posterior intercostal arteries are vulnerable structures
- They are not fully covered by ribs
110
What is a thoracentesis and where is it performed?
- Thoracentesis is needle aspiration used to remove blood or pus from the pleural cavity
- Performed in 8th, 9th, or 10th intercostal space
111
Describe the orientation of the phrenic and vagus nerve in the thoracic cavity.
- Phrenic is anterior to the lung
- Vagus is posterior to the lung
112
T/F: Quiet inspiration and expiration is passive and requires little to no muscle action
True
113
Plantar fasciitis is inflammation of ________ _____________ and caused by an overuse mechanism. The pain is most severe:
Point tenderness is located:
- Plantar fasciitis is an inflammation of the plantar aponeurosis
- The pain is most severe after sitting and getting out of bed but dissipates after 5-10 minutes of activity
- Point tenderness is located at the proximal attachment of the aponeurosis to the medial calcaneus
114
From where does the plantar aponeurosis arise?
Calcaneus
115
What nerve divides in the foot to supply the motor innervation to the majority of foot muscles? From where did that nerve arise?
- Tibial nerve divides posterior to the medial malleolus to Lateral and Medial N
- Tibial nerve is a division of the Sciatic Nerve
116
After the tibial nerve divides into the medial and lateral plantar nerve posterior to the ____________ _____________ it branches again:
- Tibial nerve divides into the medial and lateral plantar nerve posterior to the medial malleolus
- Lateral nerve divides into the superficial and deep branch
117
List the 3 most superficial muscles of the plantar foot from lateral to medial
From Lateral to Medial:
ABductor digiti minimi
Flexor digitorum brevis
ABductor hallucis
118
Compare the insertion of the flexor digitorum brevis vs ABductor digiti minimi and ABductor hallucis
- Flexor digitorum brevis inserts on the distal phalanx
- ABductor digiti minimi and ABductor digiti hallucis insert on the lateral & medial aspect of the proxmial phalanx
119
1. List the two muscles found in layer 2 of the plantar foot
2. Describe their arrangement
- Lumbricals
- Quadratus plantae
- Quadratus plantae inserts on the tendon of Flexor Digitorum Longus with the Lumbricals between the tendons of Flexor Digitorum Longus
120
List the three muscles that comprise the third layer of the plantar foot from later to medial most
Lateral to Medial most
1. Flexor digiti minimi
2. ADductor hallucis (Transverse & Oblique head)
3. Flexor hallucis brevis
121
How many interossei are dorsal?
How many interossei are plantar?
4 dorsal interossei b/t digits 3, 4, & 5
3 plantar interossei b/t digits 2, 3, 4, &5
122
4 muscles of the foot are innervated by the medial planter nerve. Name them
1. ABductor Hallucis (1st layer)
2. Flexor digitorum brevis (1st layer)
3. Medial most Lumbrical (2nd layer)
4. Flexor Hallucis Brevis (3rd layer)
123
What nerves does the Babinski reflex test?
L4, L5, S1, S2
124
What would a negative Babinski sign look like?
- Since it is NEGATIVE
- Flexion of the toes = normal response
125
1. A positive plantar reflex is also known as:
2. Is visualized as:
1. Positive planter reflex = Babinski sign
2. Lateral 4 toes FAN OUT, Great Toe DORSIFLEXES
126
Babinski sign is not an abnormal response in infants, why?
Corticospinal tracts are not fully developed in newborns which allows fanning of toes and dorsiflexion of great toe up to two years of age
127
This artery supplies the sole of the foot:
Its terminal branches pass deep to the ABductor hallucis as the ________________ & _______________ ________________ arteries.
- Posterior Tibial Artery supplies the sole of the foot
- Divides after passing the flexor retinaculum
- Medial and Lateral Plantar Arteries
128
This artery terminates by joining the deep plantar artery to form the plantar arterial arch.
- Lateral plantar artery runs with the lateral plantar nerve
- Terminates by joining the deep plantar artery to form the plantar arterial arch
129
List 3 surfaces of the heart & their corresponding heart chamber association:
1. Anterior surface AKA sternocostal surface: Right ventricle
2. Diaphragmatic surface: Left ventricle
3. Pulmonary surface (L): L ventricle
130
Blockage of which artery would lead to ischemia of the apex of the heart?
Anterior interventricular (descending) coronary A
131
What structures prevent prolapsing of the mitral and tricuspid valves?
Chorade teninae & Papillary muscles
132
T/F: The right atrioventricular valve is opened by the pull of chordae tendinae
False, The chordae tendinae and papillary muscles prevent the valves from prolapsing during systole
133
The ______________ __________ is an opening in the interatrial septum which exists in the fetus. The remnants of this structure are named: ____________ ___________
- Foramen ovale
- Fossa ovalis
134
Both the aortic and pulmonary valves are termed ______________ valves. Are their three leaflets comprising these valves named the same?
- Semilunar valves
- Pulmonary: Anterior, Left, and Right leaflet
- Aortic: Posterior, Left and Right leaflet
135
1. Where are the left and right aortic sinuses located?
2. Where are these sinuses going?
1. L & R aortic sinuses are above the aortic valve leaflets
2. The sinuses go to the coronary arteries to give the heart blood suply
136
Where is it best to hear sounds associated with the tricuspid valve?
Left 4th-5th intercostal space lateral to the sternum
137
What is the coronary sulcus?
List the structures found here.
1. Coronary sulcus is the groove that separates the atria from the ventricles
2. R & L coronary A, Circumflex A, Coronary sinus
138
Why will an injury to the MCL usually disrupt the medial meniscus?
Injury to the Medial collateral Ligament will disrupt the Medial meniscus because they are attached
139
The deltoid ligament connects the medial malleolus with what structures
Deltoid ligament connects medial malleolus with talus, navicular, calcaneous
140
This ligament connects the tibia and fibular on the anterior surface and provides support to the distal ends of these bones.
Anterior tibiofibular ligament connects the tibia and fibula
141
Compare and contrast the attachments of the anterior TALOFIBULAR and the calcaneoufibular ligament
- Ant. TALOFIBular: Attaches the lateral malleolus to the anteriorlateral talus
- Calcaneofibular Ligament: connects lateral malleolus with calcaneus
142
The anterior compartment of the leg is innervated by:
Responsible for what major action:
1. Anterior compartment of the leg is innervated by the Deep Fibular N
2. Dorsiflexes the foot
143
The __________________ is the central compartment of the thoracic cavity, located between the lungs. It houses additional vital organs such as:
- Mediastinum
- Heart, trachea, esophagus, major blood vessels
144
1. What section of the mediastinum is the heart found?
2. List the other divisions of the mediastinum
1. Heart is in inferior middle mediastinum
2. Mediastinum has Superior and Inferior divisions.
- Inferior division additionally has anterior, middle, and posterior regions
145
What are the anatomic barriers comprising the superior mediastinum?
1st rib to T4 is considered the superior mediastinum
146
What nerve runs through the middle inferior mediastinum?
Phrenic nerve on bilateral to the heart
147
The visceral layer of the serous pericardium is also referred to as:
Visceral layer of serous later of pericardium = Epidcardium
148
T/F: The first tissue see when opening the chest cavity is the parietal pericardium
False, the outermost layer seen is the fibrous pericardium.
The *parietal* pericardium is the outermost layer of the pericardial sac but is below the fibrous pericardium
149
From external most to internal most list the layers of the pericardium
External: Parietal layer of serious pericardium
Pericardial cavity
Epicardium/Viseral layer of serous pericardium
150
What separates the parietal pericardium from the epicardium?
Pericardial cavity is between the parietal pericardium and the visceral layer of the serous pericardium.
151
The ____________ pericardium is the layer that directly covers the heart, adhering to its surface. This layer receives _______________ innervation from ________________ nerves ______- ______.
The visceral pericardium receives autonomic innervation from the sympathetic nerves T1-T4
152
The __________ pericardium lines the fibrous pericardium, and it receives somatic innervation from the _____________ nerves.
The parietal pericardium lines the fibrous pericardium, and it receives somatic innervation from intercostal nerves
153
The _____________ is attached to the parietal layer of the serous pericardium internally. It is fused with the surrounding structures such as the diaphragm. It receives __________ innervation from the _________ nerve, originating from spinal cord levels ____, ____, & ______.
- The fibrous pericardium is attached to the parietal layer of the serous pericardium internally.
- It receives somatic innervation from the phrenic nerve originating from C3, C4, & C5
154
What are the barriers of the transverse sinus?
- Gap found between the arterial (aorta and pulmonary A) and venous ends (superior vena cava & pulmonary veins)
155
What is the clinical significance of the transverse sinus?
Surgeons can pass a ligature through it to temporarily stop blood circulation during surgery on the aorta or pulmonary trunk
156
The oblique sinus is located anterior to the:
Oblique sinus is located anterior to the esophagus
157
Buildup of fluid in the pericardial sac is known as:
Pericardial effusion
158
Hearing this sound during auscultation: rubbing two pieces of sandpaper together/scratching sound
Accompanied by these symptoms: Chest pain, SOB, and fever
are indicative of
Pericarditis
159
A TEE (________________ ____________) is used for visualizing:
1.
2.
TEE: Transesophageal Echocardiography
Visualzing
1. Posterior to L atrium
2. Interatrial septum to dx foramen ovale
160
_______________ _______________ can cause a condition termed, __________ ______________: that hinders the hearts ability to pump blood effectively.
pericardial effusion
Cardiac tamponade hinders the hearts ability to pump blood effectively
161
1. Where is the needle inserted during a pericardiocentesis?
2. What is a pericardiocentesis?
1. Left subcostal angle/Near 5th or 6th intercostal space near sternum
2. Draining excess of fluid from the pericardial cavity
162
Why is a pericardiocentesis performed near the 5th or 6th intercostal space near the sternum on the L side?
Allows the pericardial sac to be reach without damaging the pleurae/surrounding tissue or organs
163
At which rib level is the apex of the heart located?
5th left intercostal space at the midclavicular live
164
The right ventricle forms the ______________/______________ surface of the heart.
The right ventricle forms the anterior/sternocostal surface of the heart
165
The left atrium of the heart forms the _____________ surface of the heart.
The left atrium of the heart forms the posterior surface of the heart
166
The ___________ surface of the heart is formed by the great vessels.
The superior surface of the heart is formed by the great vessels
167
The __________________/__________ surface of the heart is mainly formed by the right ventricle anteriorly and left ventricle posteriorly.
The inferior/diaphragmatic surface of the heart is formed by the right ventricle anteriorly and left ventricle posteriorly
168
The right atrium has a _________ posterior wall and a ____________ anterior wall. The rough portion contains _________ muscles.
What separates the anterior & posterior wall?
- The right atrium has a smooth posterior wall
- The right atrium has a rough anterior wall.
- The rough portion contains pectinate muscles
- Crista Terminalis divides pectinate muscle and smooth surface
169
What is the sinus venarum?
- Sinus venarum = smooth surface of the posterior R atrium
170
The SVC & IVC deliver deoxygenated blood at the ____________ ______________ of the right atrium.
The SVC & IVC deliver deoxygenated blood at the Sinus Venarum-the smooth surface of the posterior wall of the R atrium
171
Describe the location of the coronary sinus of the Right Atrium
Coronary sinus opening is located between the right AV valve and inferior vena cava
172
The _________________ of _______________ acts as a delay center for electrical impulses. It contains the AV node. Describe the importance of the delay.
- Triangle of Koch
- Allows time for atrial contraction to complete before ventricular contraction begins
173
What is the difference between the Conus Arteriosus and Trabeculae Carneae in the right ventricle?
- Conus arteriosus: smooth walled outflow tract leading to the pulmonary valve
- Trabeculae Carneae: muscular ridges and projections that line the inner walls. Increase surface area for muscle attachment
174
What is the significance of the moderator band?
Where is it located?
- Found in the right Ventricle
- Plays a role in the electrical conduction system of the heart by carrying the right bundle branch
175
T/F: The left and right atrium have smooth posterior wall and rough anterior wall.
False, the Left atrium has smooth lining
The Right atrium has rough anterior wall and smooth posterior wall
176
How many pulmonary veins feed into the left atrium?
4 total, 2 superior, 2 inferior
177
The _______ ventricle features trabeculae carneae:
The ________ ventricle also features aortic vestibule:
Left ventricle
- Trabeculae carne: muscular ridges
- Aortic vestibule: smooth-wall outflow portion that transitions into the aortic valve
178
This may occur 2-7 days after MI that results in:
Rupture of papillary muscles that results in mitral valve prolapse
179
What is the Annulus Fibrosis?
Fibrous ring that serves as a arrier between the atria and ventricles that prevents the spread of electrical impulses between the chambers
- Structurally is a point of attachment for valve leaflets
- Structurally prevents over-distention
180
Mitral valve prolapse AKA mitral ___________ can cause symptoms of:
Mitral regurgitation
fatigue, SOB, and palpitation
181
What causes the semilunar valves to close?
Blood pressure in the aorta and pulmonary artery become greater than ventricular pressure
182
What produces the 2nd heart sound?
Closure of the semilunar valves
183
What produces the first heart sound?
Closure of mitral and tricuspid valve
184
1. From where do the right coronary artery arise?
2. From where do the left coronary arteries emerge?
1. Right coronary artery from R aortic sinus
2. Left coronary A from left aortic sinus
185
The coronary arteries arise from the aortic sinuses, which are:
Aortic sinuses are small dilations in the aorta situated just above the aortic valve leaflets
186
Where is the aortic valve located?
Aortic valve is located in the second intercostal space to the right of the sternal border
187
What can be heard in the second intercostal space to the right of the sternal border?
Aortic valve
188
Where is the pulmonic valve located?
Second intercostal space to the left of the sternal border
189
What can be heard in the second intercostal space to the left of the sternal border?
Pulmonic valve sound
190
Where can the tricuspid valve be auscultated?
Fourth intercostal space on Left sternal border
191
Which is easier to hear, tricuspid valve or mitral valve? Why?
Mitral valve is easier to hear as it has high intensity
192
1. Where is the “lub” sound heard?
2. Is it heard during diastole or systole?
1. Lub sound is heard where the aortic valve is located-2nd ICS, R of sternal border
2. Heard during systole
193
1. Where is “dub” sound heard?
2. Is it heard during systole or diastole?
1. “Dub” heard at the pulmonic valve-2nd ICS, L of sternal border
2. Heard during diastole
194
These murmurs occur during atrial systole when the ventricles are filling due to stenosis of the mitral and tricuspid valves. They are often described as low-pitched, rumbling sounds
Diastolic murmurs
195
1. What do systolic murmurs sound like?
2. What structural defect(s) are systolic murmurs found?
1. Higher pitched and more easily audible
2. Occur during ventricular contraction-aortic stenosis, mitral regurgitation, and ventricular septal defects
196
Which heart valves are more commonly affected by disease?
Aortic and mitral valves are more commonly affected by
197
_____________ _____________ can result in degenerative calcifications that leads to ventricular hypertrophy. This is also associated with stenosis of the ____________ valve.
- Aortic valve stenosis
- Common cause is rheumatic fever
198
______________ valve incompetence is a condition wherein this valve does not close properly. Allowing backflow of blood from the aorta to the left ventricle. This can result in:
1.
2.
- Aortic valve incompetence (prolapse)
1. Murmur
2. Collapsing pulse
199
What is the preferred view for chest XR?
Posterioranterior
200
In XR, the _________ __________ view involves positioning the patient on their side. It aids in the identification of fluid collections, like pleural effusion. How would the fluid behave/move in this position?
Can also aid in identification of air pockets, such as ______________, which would behave/move in this position?
- In XR, the lateral decubitus view: patient on their side
- Fluid would accumulate at the lower point
- Air pockets would rise to the top of the chest cavity
201
A cardiothoracic ratio greater than 0.5 indicates:
Cardiomegaly
202
The cardiac cycle begins with:
Cardiac cycle begins with diastole
203
The period of ventricular emptying is:
Systole
204
The heart beats about 70 times per minute and pumps about ____ L of blood per minute
Heart pumps about 5 L of blood per minute
205
What does the Left coronary artery supply?
- L Ventricle
- L atrium
- Anterior 2/3rd of Interventricular septum
- Some of R ventricle
- AV bundle through its perforating IV septal branches
206
What does the R coronary artery supply?
- R atrium
- R ventricle
- Posterior 1/3rd of interventricular septum
- SA Node
- AV node
207
The SA nodal artery is a branch of the ___________ coronary artery
SA nodal artery is a branch of the RIGHT coronary artery
208
The _____________ branch of the left coronary artery supplies the _____________ & _____________ aspects of the left ventricle.
The circumflex branch of the left coronary artery supplies the lateral and posterior aspects of the left ventricle
209
The ____________ _______________ (IV) branch, also known as the _________ _______________ artery, is an important vessel that originates from the ____________ coronary artery and supplies the inferior portion of the interventricular septum and part of the posterior left ventricle.
The posterior interventricular branch, also known as the posterior descending artery originates from the RIGHT coronary artery and supplies
210
The heart is considered right dominant in 70% of cases, what does right dominant mean?
Right dominant: posterior interventricular artery is a branch of the right coronary arteryy
211
The heart is considered right dominant in 70% of cases. When is it considered Left heart dominant?
When posterior interventricular artery is a branch of the LEFT coronary artery
212
What is the name of the layer that lines the chambers of the heart and covers the valves?
Endocardium
213
Which layer of the heart is comprised of muscle cells that contribute to the hearts contractile force?
Myocardium
214
What is the main venous drainage for the heart?
Coronary sinus
215
List the major cardiac veins:
1. Greater cardiac vein
2. Posterior cardiac vein
3. Middle cardiac vein
4. Small cardiac vein
216
What is found in the posterior atrioventricular groove of the heart?
Coronary sinus
217
What artery runs with the Great cardiac vein?
Where are they located?
1. GCV & Ant. Interventricular A
2. In anterior interventricular groove
218
What artery runs with the middle cardiac vein?
Where are they located?
1. MCV & Posterior Interventricular A
2. In posterior interventricular groove
219
What artery runs with the small cardiac vein?
Where are they located?
1. SCV & R Marginal Branch of R coronary A
2. Right border of the heart to supply & drain the R ventricular myocardium
220
What is Atherosclerosis?
Gradual buildup of lipid deposits in the inner lining (intima) of the coronary arteries
221
As coronary arteries become blocked, how does the body compensate?
What are the limitations to this?
1. Heart develops collateral blood vessels to bypass obstruction
2. These collateral channels are often not sufficient to fully meet the heart’s increased metabolic demands during activity
222
Describe referred pain coming from the heart?
Visceral structures proximal to the heart transmit via visceral afferent fibers (T1-T4) accompanying sympathetic (efferent) fibers and referred to somatic structures or areas-dermatomes T1-T4
223
List the most common sites for coronary artery occlusion
1. Left Ant Descending A
2. R coronary A
3. L circumflex A
4. Obtuse marginal A
5. Diagonal A
6. Post. Descending A
224
This procedure invovles using a catheter to pass into a stenosed coronary artery. Either flatten the plaque or use _______________ enzyme to dissolve clots in the artery. Then place stent to prevent re-narrowing or restenosis.
Percutaneous Transluminal Coronary Angioplasty
- Thrombokinase Enyme
225
Infective endocarditis is a condition caused by bacteria or fungal infection of the endocardium.
1. Which valves are most commonly affected?
2. What formations are created & what can they cause/do?
1. Mitral & aortic valves
2. Microorganisms, WBC, platelets, and fibrin accumulate on the heart valves, forming vegetations. Can enlarge and become dislodged = possible embolism. Vegetations can also impair normal function of heart valves = regurg or stenosis
226
Pulmonary artery HTN is persistent increase in mean pulmonary arterial pressure above 25 mmHg at rest.
1. Which side of the heart is affected?
2. What structure is also impacted that disrupts normal hemodynamics?
1. Elevated pressure = greater workload on R ventricle, leading to right ventricular hypertrophy = R sided heart failure
2. Inc pressure can lead to dilation of coronary sinus
227
What autonomic innervation decreases heart rate and constricts the coronary arteries?
Parasympathetic fibers from the vagus nerve decrease heart rate and constrict coronary arteries
228
What autonomic innervation decreases heart rate and constricts the coronary arteries?
Parasympathetic fibers from the vagus nerve decrease heart rate and constrict coronary arteries
229
What autonomic innervation increases the heart rate and force of contraction?
Sympathetic nerves from superior, middle, and inferior cervical and thoracic cardiac nerve
230
What is the cardiac plexus?
Where is it?
1. Network of nerves that innervate the heart, formed by the union of branches from both SNS & PNS
2. Superficial part inferior to the aortic arch and deep part situated between aortic arch and tracheal bifurcation
231
Proper function of what nervous system is crucial for maintaining normal heart rate and cardiac output & via what nerve?
Parasympathetic N fibers from Vagus N
232
What structure of the heart delays its received impulse?
What is the purpose of the delay?
1. AV node delays received impulse
2. Allows the atria to finish their contraction and ventricles to fully fill
233
Name the coronary artery which supplies this structure:
1. SA Node
2. AV node
3. AV bundle
SA & AV node are both R coronary artery
AV bundle supplied by L coronary artery
234
EKG: What is the P wave?
- Depolarization of atria in response to SA node receiving impulse
- First wave seen on EKG
235
EKG: What is the PR interval?
Delay of AV node allowing for filling ventricles
236
EKG: What is QRS complex?
Depolarization of ventricles, tiggers main pumping contractions
237
EKG: What is ST segment?
- Beginning of ventricle repolarization
- Flat portion of tracing following QRS complex
238
EKG: What is T wave?
Ventricular repolarization
239
What portion of an EKG corresponds to the S1 heart sound?
- S1 is Lub- AV valves close (mitral & tricuspid)
- RS segment of EKG where ventricles are completely contracting during systole
240
What segment of an EKG corresponds to S2 heart sound?
- S2 sound is closing of Semilunar valves
- Ending portion of T segment
241
List three things that are encoded by mitochondrial DNA
1. OXPHOS (protein for oxygen phosphorylation)
2. 22 tRNAs
3. rRNAs
242
T/F: Most the mitochondrial proteins are encoded in the mitochondria and transported to the nucleus
False, most of the mitochondrial proteins are nuclear encoded and imported into the mitochondrion
243
List three Mitochondrial genetic disorders
1. Lebers Hereditary Optic Neuropathy
2. Myoclonic epilepsy and ragged-red fiber disease
3. MELAS syndrome
244
_________ Hereditary optic neuropathy (LHON) results in bilateral loss of vision in early adulthood. What causes this disorder?
- Leber’s hereditary optic neuropathy
- Point mutation in mitochondrial NADH dehydrogenase (Complex I of the ETC)
245
_______________ epilepsy and ______________-___________ fiber disease (______) is characterized by muscle jerking and abnormal shape of mitochondria. What causes this disorder?
- Myoclonic epilepsy and Ragged-Red Fiber disease (MERRF)
- Caused by mutation in gene encoding tRNA for lysine
246
What is the difference in MERRF & MELAS syndrome aside from their different presentations?
What classifies them as similar?
- MERRF is mutation in gene coding a tRNA for Lys
- MELAS is point mutation in tRNA-Leu
- Both are mitochondrial genetic disorders
247
What are some characterizing features of MELAS syndrome?
- Mitochondrial myopathy
- Encephalopathy
- Lactic acidosis
- Stroke-like episodes
248
What is Heteroplasmy?
- Referring to mitochondrial inheritance
- In mom, not all mitochondria are mutant. So during gametogenesis, some eggs will receive more mutant mitochondria while others will receive more wild type mitochondria
- Proportion of affected mitochondria in different tissues or different individuals in a family
249
Mitochondria Genetics: what is the Threshold Effect?
- Determines what percent or what threshold of mutant mitochondria must be present for clinical expression of a disorder/sydrome
250
How does trinucleotide repeats undergoing expansion over generations impact the offspring?
- Leads to anticipation, a phenomenon wherein the disorder occurs earlier in life
- Increase severity of disease
251
What happens if there are trinucleotide repeats in an exon of mRNA?
Toxic proteins are made
252
What happens if there are trinucleotide repeats in the RNA coding regions?
Altered RNA function
253
What happens if there are trinucleotide repeats in non-coding regions (introns) of mRNA?
Reduced transcription or translation
254
In Fragile X syndrome where is the mutation found?
5’ UTR region of mRNA
255
Where are trinucleotide repeats that cause Huntington’s disease?
Within the translated region/Exon of mRNA
256
Where are the trinucleotide repeats that cause Fredreich ataxia?
Intron
257
Where are the trinucleotide repeats that cause Myotonic dystrophy?
3’ UTR of mRNA
258
_________________ ______________, associated with CAG repeats, is an adult onset neurodegenerative condition affecting mainly the basal ganglia. It is an ____________ _____________ disorder caused by:
Huntington’s disease
It is an autosomal dominant disorder caused by 39+ trinucelotide repeats in Exon 1 of Huntinton gene on chromosome 4p16.3
259
Describe symptoms of Huntington’s disease
What is the average lifespan of person dx with HD?
- Movement disorder with jerky, random, and uncontrollable movements called chorea
- Life span is 15 after onset of sx
260
What is the difference between HD and juvenile HD?
- HD have 39+ trinucleotide CAG exon repeats
- Juvenile onset HD ave 60-70 trinucleotide CAG exon repeats
261
____________ _____ syndrome is caused by expansion of CGG repeats in the 5’ UTR of FRM-1 gene. Normally, repeats are between 6-40. In those with this disorder have _________-_________ CGG repeats
Fragile X Syndrome
200-1,000 CGG repeats
262
These signs and symptoms match what disorder?
- Prominent forehead, large jaw, large ears
- Macroorchidism (abnormally large testes) in post-pubertal males
- Mental retardation in 80% of patients
- Joint laxity
- Behavioral problems
Fragile X syndrome
263
There are two types of myotonic dystrophy. MD 1 & MD2. Describe the cause of type I
Caused by CTG repeats in 3’ UTR of DMPK gene
DMPK is a gene for myotonic dystrophy protein kinase
264
List some signs/symptoms of myotonic dystrophy
- Muscle wasting: face, neck, distal muscles
- Myotonia: inability to relax following muscle contraction
- Frontal balding
- Testicular atrophy
265
____________ ____________ is an autosomal recessive disorder caused by expanded GAA triplet:
Friedreich Ataxia
- Expanded GAA triplet repeats in the first intron of FXN gene
- This gene codes for protein Frataxin (iron binding protein in mitochondria)
266
Describe Anticipation
In some autosomal dominant disorders, onset of disease occurs at an earlier age in offspring
- Or the disease occurs with increasing severity in subsequent generation
267
What causes the increase in trinucleotide repeats over generations
During meiosis there is unequal crossover causing each generation to have more repeats
268
What two dysmorphic syndromes are associated with genomic imprinting?
Prader-Willi
Angelman syndromes
269
What is genomic imprinting?
Methylation is the imprint applied to certain DNA sequences in their passage through gametogenesis
270
What is Uniparental Disomy?
- Uniparental disomy is when the inherited chromosomes came from the SAME parent
- Was trisomy but then one of the chromosomes was lost and left only chromosomes from one parent
271
What is uniparental isodisomy?
If an individual inherits two copies of the same homolog from one parent through an error in meiosis II
272
What is the difference between uniparental isodisomy and uniparental heterodisomy?
- Isodisomy: error in Meiosis II
- Hetero Disomy: error in Meiosis I
273
What is the major cause of Prader-Willi syndrome?
Interstitial deletion of the proximal portion of the long arm of paternal chromosome 15
274
This disorder is caused by interstitial deletion of proximal portion of Q arm of paternal chromosome 15. There is a delineation in the symptoms during infancy:
And Childhood+:
Prader-Willi Syndrome
- Infancy: hypotonic, slow weight gain
- Childhood: Hyperphagia, obesity, short statue, hypogonadism, learning difficult y
275
What is the difference between the cause of Angleman syndrome and Prader-Willi?
Angleman: interstitial deletion of chromosome 15 in MATERNAL homolog
Prader-Willi: interstitial deletion of chromosome 15 in PATERNAL homolog
276
T/F: While less frequent, Maternal/Paternal uniparental disomy can cause Angleman syndrome/Prader-Willi
True
277
What are some characteristics of Angleman syndrome?
- Movement and balance disorder
- Speech deficits
- Laughter (happy puppet)
- Seizures
278
Describe what genetic concept allowed an unaffected father to have two children with osteogenesis imperfecta with different partners.
- Father had germline mosaicism
- Some, not all, of his germ cells had mutation in collagen gene that causes OA
- Mosaicism allow father to not have the disorder
279
List three diseases that have complete penetrance?
What does this mean?
Means, that if the person has the genotype for the disorder they will 100% of the time have phenotypic effects
- NF1
- OI
- MFS (Marfans Syndrome)
280
Name two disorders with incomplete penetrance?
What is incomplete penetrance?
- HD (Huntington’s Disease @ 40%)
- Retinoblastoma (90%)
Means that if the person has this genotype, they may or may not display the phenotype.
281
Define: Natural selection
Increase the frequency of genes that promote survival or fertility and reduce the frequencies of genes that reduce fitness
282
What does balanced polymorphism relate to?
- Relates to natural selection and that both homozygous wild type and homozygous mutant individuals are subjected to selection for what provides the greatest fitness
283
Define: Genetic drift
- Gene frequency change caused by finite population size
- usually occurring in small populations
- Helps explain why small isolated populations have higher incidence of a certain genotype
284
What is the Founder effect? What does it relate to?
- The frequency of the recessive allele is low in the initial larger population
- When move to smaller population with heterozygous genotype, the frequency is the recessive allele is higher in this population
- Contributes to Genetic drift
285
Describe a situation that shows Gene flow
The frequency of sickle cell D is lower in black Americans in part because of gene flow from neighboring populations that do not carry the disease causing mutation; in addition, the heterozygote advantage for sickle cell mutation has disappeared b/c of malaria has been rare in N. America
286
Which vessels have larger tunica media? Arteries or Veins? Why?
- Tunica media is the muscular & elastic portion of vessel layers
- Arteries need to have ability to distend and recoil in response of ventricular contraction and to help propel blood through circulation
287
What category of artery actually penetrates the tissue it is supplying?
Arterioles
288
Describe Tunica Adventitia & where it is found
- TA is found on the outermost portion of arteries etc.
- Connective tissue containing blood vessels, nerves, macrophages
289
Describe the variation in Tunica Media in Large/Elastic A vs. Medium/Muscular A vs. Arterioles
Large/Elastic A: thick layer to help support the varied pressure coming from ventricular contraction
Medium/Muscular: Fewer elastic fibers
Arterioles: few layers of smooth muscle
290
Describe the ANS innervation for arteries & arterioles
Direct inn. By Sympathetic only
291
Describe ANS innervation of Coronary arteries
Coronary A inn. By SNS & PNS
- α1 = vasoconstriction
- sympathetic activation of adrenal medulla = release of norepi/epi
292
Describe the anatomy of a capillary compared to arteriole
- Capillary does not have tunica adventitia or tunica media - Have endothelium and basal lamination that are often en enveloped by pericytes
293
What is the approximate diameter of a capillary?
About the size of a erythrocyte
294
Describe the different categories of capillaries
- Continuous, non-fenestrated: no gaps in endothelial cells - Fenestrated: pores in cell membrane or b/t endothelial cells -Sinusoid: large gaps in basement membrane & b/t endothelial cells
295
Where are continuous, non fenestrated capillaries found? Why?
CNS b/c movement of substances in and out of the blood/brain barrier is VERY controlled mechanism
296
Where are continuous, non fenestrated capillaries found? Why?
CNS b/c movement of substances in and out of the blood/brain barrier is VERY controlled mechanism
297
Where are fenestrated capillaries found? Describe them.
Majority of capillaries are fenestrated. Pores in cell membrane or between endothelial cells that allow direct passage b/t blood contents and tissue externally to capillary
298
Where might you find sinusoid capillaries? What are sinusoid capillaries?
- Sinusoid capillaries are found in liver, spleen, bone marrow, erectile tissue - Have large gaps in basement membrane and between endothelial cells that lead to large blood-filled spaces within certain tissues or ograns
299
Describe the mechanism of movement in fenestrated capillaries
Pinocytosis & Diffusion
300
Describe the movement in continuous non-fenestrated capillaries
Have transmembrane protein transports at both surfaces of the cell membrane or use tight junctions to regulate movement in and out
301
What are the purpose of precapillary sphincters? Where are they found?
Found at proximal ends of capillaries that can constric and reduce blood flow into capillaries. Serve to reduce flow to functionally less active tissues & mediate heat conservation-maintain heat body core in certain situations
302
What are the purpose of precapillary sphincters? Where are they found?
Found at proximal ends of capillaries that can constric and reduce blood flow into capillaries. Serve to reduce flow to functionally less active tissues & mediate heat conservation-maintain heat body core in certain situations
303
What is the purpose of A-V shunts? Where are they found?
- Force movement of blood through capillaries by being constricted by smooth muscle such that the blood is forced to go through capillaries. Also can be used in response to increased demand for blood flow or heat dissipation. -Found proximal to arterioles & venules where they connect via capillary
304
What is diapedesis?
Receptor mediated process of moving cells across endothelium via chemical signals in capillaries
305
Why do veins not have as much elastic fiber compared to arteries?
- While they need to stretch, they do not need to recoil like arteries need to recoil after stretching
306
Compare & contrast the contents of myocardium vs. epicardium
- Epicardium (innermost) has electrical conducting system -Myocardium has blood vessels, nerves, branches of electrical conducting system
307
What are the metabolic energy sources for cardiac muscles? What significance does this have?
- Primarily metabolize fatty acids but can also use glycogen stores - Since cardiac muscle requires so much E needs to have a special reserve/separate metabolite dedicated to its Energy source
308
How does the structure of cardiac muscle differ from skeletal muscle?
- Cardiac muscle branches - Intercalated discs separate cells -Skeletal muscle continuous - Both are striated
309
What is the function of the innermost intercostal muscles?
Forced expiration
310
What are the bony landmarks that define the superior thoracic aperture?
- Thoracic inlet
- 1st rib
- Manubrium
311
What structures pass through the superior thoracic aperture
- Trachea, esophagus
- Common carotid arteries, subclavian arteries, internal jugular veins, brachiocephalic veins
- Vagus nerves, phrenic nerves, recurrent laryngeal nerve, outflow to three cervical sympathetic ganglia
- Thoracic and right lymphatic duct
312
What are the structures of the Inferior thoracic aperture
- IVC
- Esophagus
- Vagus N
- Aorta
- Thoracic duct
313
What are the boundaries of the inferior thoracic aperture
- Xiphisternal joint
- Costal margin
- 11th & 12th pair of ribs
314
The external intercostal muscles:
Active inspiration
315
The internal costal muscles action:
Forced expiration
316
What are the levatores costarum?
- Located on the back of the ribs
- T1-T12
- Elevate ribs
317
Describe the “pump-handle” movements of the ribs during respiration
Increases anterior posterior movement of the ribs
318
Describe the “pump-handle” movements of the ribs during respiration
Increases anterior posterior movement of the ribs
319
Describe the “bucket-handle” movements of the ribs during respiration
Increases transverse dimension of the ribs during expiration
320
What is the main muscle involved in quiet inspiration?
Diaphragm
321
What nerve provides sensory innervation to the parietal pleura
Somatic afferent fibers
322
Ventral rami of T___-T___ give rise to the following branch(es).
Ventral rami of T1-T11 give rise to the intercostal N
323
Ventral rami of T___-T___ give rise to the following branch(es).
Ventral rami of T1-T11 give rise to the intercostal N
324
List the branches of the intercostal N
- Ant. Cutaenous Sternal N
- Collateral Ns
- Lateral Cutaneous N
- Somatic afferent
325
Aside from the diaphragm, w hat does the phrenic N innervate?
Pericardium, Plura
Motor, SNS, Sensory inn
326
Aside from the diaphragm, w hat does the phrenic N innervate?
Pericardium, Plura
Motor, SNS, Sensory inn
327
The larynx is innervated by the ____________ _____________ N which is a branch of the ____________ N.
The larynx is innervated by the recurrent laryngeal N that is a branch of the Vagus N
328
The visceral plura is innervated by:
Compared to the parietal pleura that is innervated by:
Visceral pleura: ANS, not nociceptive
Parietal: Somatic Afferent N
329
What type of tissue are cardiac valves?
- Loose & Dense connective tissue
- Some elastic tissue
330
Compare histological structure of heart valves to their function
- Dense CT has lots of collagen and elastic fibers that provide Durability and Flexibility
- Loose CT has lots of ground substance that provides shock-absorption and reduces vibration caused by valves closing
331
In what layer of the artery wall do aneurysms exist? What impacts does this have on the other artery layers
- Form in Tunica media
- Causes tunica medial to push/put pressure into tunica intima
332
Where do aneurysms tend to form?
At branch points of arteries
333
What are arteriovenous malformation?
- Failure to form capillary beds
- Arteries/arterioles entangled with veins/venules
334
Describe how Arteriorvenous Malformations can occur throughout life?
- They can form gradually and are compensated for by other vessels/capillaries
335
Describe the disease process of atherosclerosis
1. RF: HTN, microbes, etc.
2. WBC cross epithelium to respond to tissue changes in the artery wall
3. Microphages phagocytose lipids & other material, but become bloated and appear as “foam cells.” Extracellular debris can also accumulate
4. Smooth muscle cells proliferate to surround the plaque. Reduces chance of a rupture into the artery lumen
5. Narrow lumen diameter
336
Describe the disease process of atherosclerosis
1. RF: HTN, microbes, etc.
2. WBC cross epithelium to respond to tissue changes in the artery wall
3. Microphages phagocytose lipids & other material, but become bloated and appear as “foam cells.” Extracellular debris can also accumulate
4. Smooth muscle cells proliferate to surround the plaque. Reduces chance of a rupture into the artery lumen
5. Narrow lumen diameter
337
Define ischemia
Ischemia: general term for a period of lack of blood flow or some flow but not enough O2 to maintain normal cellular function
338
Define ischemia
Ischemia: general term for a period of lack of blood flow or some flow but not enough O2 to maintain normal cellular function
339
Define Infarct
Infarct: Focal area of tissue damage created by prolonged period of ischemia. Brief ischemia may not cause permanent damage
340
How long can cardiac muscles undergo ischemia before there is permanent loss of cardiac cells? How are the cells repaired in this state?
- Ischemia longer than 20 minutes generally produces permanent loss of some cardiac muscle cells
- The cells are permanently lost and replaced by connective tissue (scar tissue)
341
Infective endocarditis is highly suspected. How many sets of blood cultures and how many ML of blood should you obtain prior of initiation of ABX therapy?
3 sets of blood culture over 1 hour perior, > 10 mL
342
What strain of Staph is always considered + in blood culture & never considered contaminant?
Staph Aureus always considered + infection
343
Why is there a shift from older populations having endocarditis to now younger generations also getting endocarditis
Rise in use of drugs which vasoconstrict and cause damage to vessels
344
What are the parameters for prescribing ABX prior to dental procedures?
- Cyanotic Heart Disease
- Valve replacement
- Previous endocarditis
345
What is the most common cause of bacterial endocarditis
Staph aureus
346
What is the most common cause of bacterial endocarditis
Staph aureus
347
What other places can infective endocarditis impact?
- *Kidney* majro
- Spleen
- GI/Colon
- Roth spots of the eye
- Legs
- Knuckles
348
What does Duke Criteria discern?
The criteria to determine if patient has endocarditis
349
What does PWID stand for?
People Who Inject Drugs
350
What does CIED stand for?
Cardiac Implantable Electronic Device
351
T/F: Cardiac valves are not highly vascularized
True
352
The presence of this bacteria on blood culture indicates the need for finding an abscess
Staphylococcus lugdunensis
353
The presence of this bacteria indicates the need for colonoscopy, why?
- Streptococcus gallolyticus (bovis)
- 25% of time indicates presence of colon lesion/growth
354
Eikenella corrodens are bacteria found:
Bacteria found in oral cavity
355
Which is the more sensitive imaging for finding vegetation in valves in suspected endocarditis, TEE or TTE?
TEE is more sensitive to find Vegetation in the valve
356
What is the first/main indication to pursue valve replacement? What is the second indication to pursue valve replacement?
1. Congestive Heart Failure
2. Persistent bacteremia
357
How do you determine for presence of Bartonella bacteria?
Serology
358
Why are splinter hemmorages not automatically indicative of infective endocarditis?
Splinter hemorrhage can be caused by psoriasis
359
FISH is a genetic testing choice to observe:
Chromosomal abnormalities
360
What is pulse pressure equivalent to?
Systolic P - Diastolic P
Stroke volume & arterial compliance
361
What is pulse pressure equivalent to?
Systolic P - Diastolic P
Stroke volume & arterial compliance
