Exam I Flashcards
1
Q
How does anatomy differ from physiology? How does this contribute to the way we learn and study anatomy?
A
Anatomy is the study of structure, examining relationships between parts of the body and individual organ structure. Physiology studies function of specific organs, systems, etc.
2
Q
What are the sub-disciplines and subdivisions of the study of microscopic and gross anatomy.
A
microscopic-> histology
gross anatomy-> comparative (within or among species), functional (how structures work), abnormal or diseased (pathology)
3
Q
Name the structural organizations of the human body aka the 11 organ systems.
A
- integumentary (skin)
- skeletal (bones)
- muscular
- nervous
- endocrine
- cardiovascular
- lymphatic
- respiratory
- digestive
- urinary
- reproductive
4
Q
What is the difference between clinical and general anatomy?
A
Clinical combines structure, function, organization, and relationships together to diagnose and keep the patient healthy. General anatomy deals with all of the above in order to understand anatomy. Clinical is applied and general is understanding the concept
5
Q
What are the historical milestones in the understanding of anatomy and the prominent individuals who helped achieve these milestones.
A
Hippocrates- “father of medicine,” thought about what a physician should do
Aristotle- studied anatomy of animals and compared the anatomical similarities of organisms, thought about variation between organisms
Herophilus and Erasistratus- performed first systemic dissections on cadavers and living criminals, sensory and motor systems, relationship between central and peripheral nervous systems.
Galen- wrote treatises on human anatomy, promoted the idea that blood not air ran through vessels
Da Vinci- viewed the human body as one of the greatest works of nature and should be studied.
Versalius- “father of anatomy,” published 3 anatomical works
6
Q
What does the integumentary system do in an organism?
A
provides protection, regulates body temp, synthesizes vitamin D, sensory receptors, prevents water loss
7
Q
What does the skeletal system do?
A
Makes blood cells (hemapotoesis), provides support and structure, stores calcium and phosphorous, allows body movement
8
Q
What does the muscular system do?
A
stores protein, creates heat due to friction, produces body movement
9
Q
What does the nervous system do?
A
regulates body movement, responds to sensory stimuli, controls all bodily functions, responsible for consciousness, intelligence and memory
10
Q
What does the endocrine system do?
A
Secretes hormones to regulate functions such as metabolism, growth, reproductive functions, chemical levels in the body, etc
11
Q
What does the cardiovascular system do?
A
pumps blood through the vessels to distribute oxygen, nutrients, hormones, and pick up waste products
12
Q
What does the lymphatic system do?
A
transports and filters lymph and filters interstitial fluids
13
Q
What does the respiratory system do?
A
responsible for exchange of gases between lungs and blood and sustains intra-abdominal pressure
14
Q
What does the digestive system do?
A
responsible for chemically breaking down food and expels waste
15
Q
What does the urinary system do?
A
filters blood and removes waste, expelling waste via urine
16
Q
What do each of the reproductive systems do?
A
Male- produces sperm and male hormones (testosterone)
Female- site of fertilization of oocyte, site of growth and development of fetus, produce female hormone, and oocytes
17
Q
Gametogenesis
A
the formation of the gametes (oocyte and sperm)
- half the original amount of DNA
- spermatogenesis or oogenesis
18
Q
Aneuploidy
A
an abnormal assortment of chromosomes
19
Q
Crossover
A
aka independent assortment occurs during meiosis I when homologous chromosomes pair up and exchange DNA
20
Q
Spermatogenesis
A
Spermatogonia(diploid) first replicates itself, so one copy completes meiosis and the other is a copy remains to redo the same process. The spermatocytes undergo meiosis and make 4 spermatids. The spermatids then undergo spermiogenesis where they grow a tail, get an acrosome, and lose much of the cytoplasm.
21
Q
R-selection vs K-selection
A
R= species prone to numerous reproduction at low cost per individual offspring
K= species expend a high amount of energy per individual offspring
22
Q
Oogenesis
A
Only one ovum is produced per meiotic cycle. Oogonia begin meiosis in the ovary and form primary oocytes prior to birth. They are arrested at prophase I until puberty and then one secondary oocyte is ovulated from the ovary per month, but is arrested in metaphase II until fertilization. the ovaries may switch sides per month. If the secondary oocyte is not fertilized after 24 hrs it then degenerates.
23
Q
Nondisjunction
A
occurs when the chromosome do not sort properly during meiosis.
-leads to abnormal chromosome numbers (can have too many or too few copies of the chromosomes.
24
Q
Risks of older moms
A
- higher incidences of chromosomal abnormalities
- primary cause is maternal chromosomal nondisjunction
25
Offspring of older men
- chromosomal aberrations and mutations occur during germ cell maturation
- may have decreased fertility, increased risks of birth defects, cancer, and schizophrenia
26
Teratogens
external agents that produce developmental malformations
27
Why do teratogens cause varying effects?
1. Conc and time of teratogen delivery
2. timing of exposure during development
3. variation in susceptibility due to genetic variation
4. synergistic interactions between the teratogen and other compounds
28
corona radiata
the outer protective layer of the ovum
29
zona pellucida
inner protective layer of ovum composed of glycoproteins that help sperm find the egg
30
What and where does fertilization occur?
Fertilization occurs in the ampulla (lateral third of the fallopian tube) when the sperm enters the egg and the two pronuclei fuse becoming diploid again. Cleavage begins. To prevent another sperm from entering the egg the zona pellucida changes the resting potential of the membrane and destroys the receptors the sperm attach to.
31
What are the three stages of embryological development and when do they occur?
pre-embryonic period (0-2 weeks when zygote becomes spherical multicellular structure)
embryonic period (3-8 weeks when major organs begin forming)
fetal (9 -38 weeks fetus continues to grow and organs become more complex)
32
Describe the major events of embryogenesis.
cleavage- division of zygote and formation of blastocyst
gastrulation- formation of germ layers (endo/exo/mesoderm)
organogenesis- germ layers differentiate and give rise to major organs
33
morula
a solid ball of cells resulting from division of a fertilized ovum
34
blastocyst
contains the inner cell mass(ICM) that will eventually forms the embryo. Composed trophoblast and embryoblast. The zona pellucida begins to dissipate.
35
trophoblast
the germ layer that will eventually form the placenta
36
embryoblast
the germ layer in the blastocyst that will eventually form the fetus
37
Differentiate between the three types of twinning discussed in class.
1. The blastocyst cleaves early and two separate fetuses and chorion and created in the uterus.
2. The ICM splits within the same blastocyst and two fetuses are created within the same chorion. One fetus may take a majority of the nutrients.
3. The ICM divides incompletely forming conjoined twins sharing the same chorion.
38
Implantation
This occurs after the first week when the blastocyst enters the uterus and the zona pellucida begins to break down. The blastocyst begins to bury within the endometrium and implants itself to receive mother's nutrients.
39
What is an ectopic pregnancy?
This occurs when an ovum implants outside of the uterus. Can be pre-disposed by inflammation and/or scarring of the uterine tubes.
40
What are the two layers of the embryoblast?
epiblast and hypoblast
41
What are the two layers of the trophoblast?
cytotrophoblast and synctiotrophoblast
42
What is the role of human chorionic gonadotropin during pregnancy?
hCG is secreted by the blastocyst. This signals to the ovary to continue secreting progesterone and estrogen to maintain the pregnancy. Can detect levels between 22-24 days after fertilization.
43
What is the function of the synctiotrophoblast?
It is the outer cell lines that invades the endometrium, penetrating the mother's blood vessels. Acts as one big cell, so there won't be an immune reaction.
44
What is the function of the cytotrophoblast?
Extends villi into the syntiotrophoblast.
45
What is the extraembryonic mesoderm and what does it give rise to?
This is a new layer of cells that arises during week 3 of development from the epiblast and yolk sac. Found between inner lining of cytotrophoblast and yolk sac and continues to separate the embryo from surrounding uterine tissue. Important in forming placenta. It gives rise to skeletal muscle and body wall (somatic) and viscera (splanchnic)
46
What are the trophoblastic lacunae?
cavities located in the syncytiotrophoblast that supplies the fetus with nutrients and oxygen from mother's blood.
47
What are the primary villi in the cytotrophoblast?
These will form the capillary networks that will supply the fetus with blood from the mother.
48
What is the fetus' contribution to the placenta? The mother's?
fetus- chorion
| mother- endometrial lining
49
What can an ultrasound detect during the first trimester of pregnancy?
- baby's age
- look for problems such as ectopic pregnancy
- determine heart rate
- look for multiple pregnancies
- identify problems of the uterus, cervix, placenta, and ovaries
50
What is Gestational Trophoblastic Disease (GTD)?
a group of neoplasms that arises from fetal tissue invading the maternal host. Tumors are composed of trophoblastic tissue. Highly responsive to chemotherapy (90% success rate)
51
What major developments occur during the embryonic stage of development?
- 2D disc turns into 3D cylinder
- all major body systems are formed
- folding of the embryo
- craniocaudal folding- CNS
- lateral folding- amnion/body wall
52
What is the significance of the primitive streak?
- future axis of the embryo (orients the development) -> buccopharyngeal membrane
- marks beginning of gastrulation
- a split primitive steak could result in conjoined twins
- cells migrate through the primitive streak after elongation and add to the ventral side
53
What happens during the proliferation of the 2D embryo or the formation of the three germ layers?
Epiblast cells travel through the primitive streak and spread through the hypoblast creating the mesoderm, ectoderm, and endoderm. All these germ cells are derived from the epiblast.
54
What happens when the primitive streak does not regress?
Sacrococcygeal tetroma- remnant of primitive streak, contains all three germ layer derivative, so can contain every kind of tissue. Very common tumor and can be removed in utero if too big and causing strain on heart.
55
What is caudal dysplasia?
- germ layer disorder (mesoderm migration disturbed)
- possible cause is maternal diabetes
- total or partial failure of development of the lower vertebrae, including sacrum, which results in abnormalities of the lower extremities (spine, gastrointestinal, urinary, and kidneys)
- aka sacral agenesis, sacral regression, caudal aplasia, caudal regression sequence, sirenomelia
56
Ethics of embryo experimentation.
-argument that embryo experimentation is permissible until the formation of the primitive streak (about 14 days). Then the embryo is considered a unique human being. Many countries require that the zygote must be placed in utero within 14 days.
57
Functions of the notochord.
- structure: rigid axis which embryo develops
- skeletal: foundation for the vertebral column, forms part of intervertebral disc
- induction: will bring about the future nervous system
58
How is the notochord formed?
- formed from the primitive streak, forms in mesoderm
- chordamesoderm
- replaces the primitive streak
59
What condition forms from remnants of the notochord?
- chordoma: primary malignant bone cancer in the spine or the skull base. Affects men more than women between ages 49-69. 7 years after diagnosis, treatment involves chemo and surgery.
- clival chordoma: tumor in skull base grow through dura. Can be debulked through endonasal approach.
60
Induction of the neural tube (neurulation)
Neural plate overlies the notochord, so notochord produces signaling cells that elicit a response in the overlying ectoderm to begin neurulation. Neural plate folds up and breaks away from ectoderm.
- the ectoderm will differentiate into the epithelial and neural ectoderm
61
What is the definition of induction and how does this apply to the formation of the embryo?
-when one set of cells/tissues causes another set of cells/tissues to change their fate. This applies to the notochord inducing the neural plate to change into the neural tube
62
Neural crest cells
cells sloughed off by the notochord and utilized in many different tissues such as melanocytes
63
What are the three derivatives of the ectoderm?
epithelial/surface ectoderm: epidermis, hair, nails, tooth enamel, cutaneous glands, mammory glands, anterior pituitary, lens of eye, inner ear, sensory nasal epithelium
neuroecroderm
- neural tube: CNS, pineal body, retina, posterior pituitary
- neural crest: sensory ganglia, PNS, autonomic ganglia, Schwann cells, autonomic ganglia, pigment cells, pharyngeal arch cartilage, components of eye, skull, teeth, and skin
64
What is Ectodermal dysplasia?
-a group of 150 heritable disorders that affect the ectoderm. Must have at least two of the symptoms of ED
65
What are the neurocristopathies that were discussed in class?
-neural crest disorders
Piebaldism: disease of melanocyte development characterized by congenital white forelock and multiple hypopigmented or depigmented areas
albinism: autosomal recessive, eye problems common including nystagmus, strabismus, and light sensitivity. Causes nystagmus bc fovea fails to develop, but rest of eye does. Neural connections between retina and brain are altered.
vitiligo: autoimmune disorder that destroys melanocytes, possibly autosomal dominant or environmental factors
66
What are the three early brain segmentations (4 weeks) and what will they become?
prosencephalon- forebrain
mesencephalon- midbrain
rhombencephalon- hindbrain
67
What are the segmentation of the brain at 5 weeks and what are their brain derivatives? What are the 4 week derivatives?
telencephalon- cerebrum (prosencephalon)
diencephalon- epithalamus, thalamus, and hypothalamus (pros)
mesencephalon- cerebral peduncles, superior and inferior colliculi (me)
metencephalon- pons and cerebellum (rhomb)
myelencephalon- medulla oblongata (rhomb)
68
What condition is caused by the cranial neurophore not closing?
Anencephaly or craniorachischisis- brain not encased by skull
69
Iniencephaly
-extreme retoflexion of the head, short and almost absent neck, hyperextended spine, facial skin is fused to the chest and neck is directly fused to back
70
Encephalocele
- cranium bifida: cranial defect with herniation of the intercranial contents (common in occipital region)
- meningoencephalocele: contains meninges and brain
meningohydroencephalocele: contains meninges, brain, and ventricular system
- less common anterior
71
Arnold-Chiari malformation
-herniation of cerebellar vermis or tonsils through the foramen magnum blocking the flow of CSF
72
Spina bifida
-caused by failure of the caudal neuropore to close
-spinal cord is normal, but failure of vertebral arches to unite, characterized by hair in the area
-can cause urinary/bowel dysfunction, range of locomotor difficulties, and reduced sensation
+ spina bifida: failure of neural arches to form
+ s.b. occulta: arches absent, tube normal
+ s.b. meningocele: dura and anarchnoid mater protrude
+ s.b. meningomyelocele: neural tissue also protrudes, aka s.b. cystica
73
What are the genetic and dietary effects on neural tube disorders?
-daily intake of 0.4mg of folic acid will decrease prevalence NTD, such as congenital heart conditions
-prevents 70% of NTD
-may be caused by metabolism rather than dietary (transformation of homocysteine to methionine)
+increased homocysteine prevents closure of neuropore
-also associated with choline, B12, methylations metabolisms
74
What is a Triple Marker Screen test?
measures levels of alpha-fetoprotein, hCG, and estriol
- AFP is increased in NTD and decreased in trisomy 21 and 18
- hCG is increased in trisomy 21 and decreased in trisomy 18
- estriol decreased in trisomy 21 and 18
75
What are the components of the placenta?
Mother -> decidua:
- decidua basalis- portion of endometrium underlying implantation site
- decidua capsularis- portion overlying implantation site and separating from uterine cavity
- decidua parietalis- the remaining endometrium
* capsularis and parietalis fuse to form one structure, cap is lost as embryo grows
Embryo -> chorion:
-chorion fondosum(chorionic plate)- area where villi develop
76
Structure of chorionic villi
- primary villi are solid outgrowths of cytotrophoblast that protrude into syntiontrophoblast
- secondary villi have a loose connective tissue core that grows into the primary villi during week 3 of development
- tertiary villi contain the embryonic blood vessels -> these connect up with vessels that develop in the chorion and connecting stalk (umbilical) and begin circulating embryonic blood
77
Function of chorionic villi
- allows diffusion of oxygen and nutrients from the maternal side to the villi and the fetal capillaries
- diffuses carbon dioxide and other waste products through the capillaries to the maternal blood through the intervillous spaces
78
What do the umbilical vein and artery carry?
vein: contains oxygen and nutrient rich blood
artery: contains deoxygenated, nutrient depleted blood from the fetus to the placenta
79
How does the oxygen diffuse from the mother's blood to the fetus'?
Fetal blood has a higher affinity for oxygen, so the oxygen will be more likely to diffuse across to the fetal vessels
80
What are some characteristics of the placental membrane?
- not a strict barrier
- variety of substances cross freely (beneficial or harmful)
- some substances cannot cross the barrier such as HIV
81
What are some beneficial and harmful substances that can cross the membrane?
beneficial: O2, CO2, glucose, free fatty acids, vitamins
harmful: rubella, measles, herpes, cytomegalovirus, varicella, polimyelitis
Cat D: some antibiotics, Valium, Librium, Xanax, Lithium
Cat X(never give to a pregnant woman): thalidomide (affects limb growth), warfarin, isotretinoin, nicotine, alcohol, phenytoin
82
Isotretoin and Rogain
- used to treat acne and is bad for pregnancy because it is a vitamin A derivative, but causes severe side effects
- Rogain treats baldness and uses a vitamin A derivative
83
What causes Erythroblastosis fetalis?
- Rh- mother carries a Rh+ baby, the first pregnancy is unaffected. During birth the blood is mixed and the mother develops antibodies against the Rh factor, so she carries a second Rh+ baby then her antibodies will attack the RBCs. This can also cause brain damage and severe adema (hydrops fetalis). This can be remedied using the Rhogam shot. Babies affected may have:
- anemia
- edema
- enlarged liver or spleen
- hydrops
- newborn jaundice
84
Chorionic villus sampling
- test for familial genetic disorders
- can complete during the first trimester (earlier than amniocentesis)
- can also get a karyotype the next day
- more dangerous than an amnio
85
What is Wharton's jelly and where is it found? And why would it be banked?
Wharton's jelly is found in the umbilical cord and is a connective tissue that increases in volume to assist closure of placental blood vessels. Matrix cells from the jelly have been identified as a potential source of stem cells. Families tend to bank these stem cells to help cure diseases (so far 80 diseases have been treated)
86
Why is there only one umbilical vein?
- starts out with two, but typically the right vein regresses and is completely obliterated during the second month of development. The left vein remains and continues delivering blood to the fetus.
- occasionally the right vein will stick around and become the only umbilical vein (persistent right umbilical vein)
87
What is a velamentous cord and why is this dangerous?
the blood vessels travel abnormally along the placenta and pass through the amniochorionic membrane before reaching the placenta. These vessels are more exposed to trauma during the birth process. Watch then HR and oxygen levels.
88
Where can the placenta implant and what are some clinical conditions to consider with this?
The placenta can implant anywhere in uterus.
-placenta previa: implantation of the placenta over the cervical os (tie the placenta shut until ready for delivery there will be bleeding)
-placenta accreta: the placental roots grow too deeply into the muscularis
-placenta increta: the placenta invades through the muscle of the uterus
-placenta percreta: placenta pushes through the uterine wall and invades into another organ, like bladder
-
89
How is the placenta like an endocrine organ?
- synthesizes fatty acids, cholesterol, and glycogen
- nutrients, oxygen, and some immunoglobins and removes waste
- most hormones are synthesized in the synctiotrophoblast
- hCG: induces the corpus luteum to secrete progesterone
- chorionic somatomammotropin aka human placental lactogen
- growth hormone of fetus and lipolysis of fats
90
What are the functions of estrogen and progesterone in maintaining pregnancy?
progesterone- maintains endometrial lining during pregnancy, suppresses contractility of smooth muscle
estrogen- stimulates enlargement of mammary gland
91
What is placental calcification and what clinical condition is associated with this?
- sign of placental aging, a response to cell death and diminished blood circulation in regions of the placenta, similar to patterns seen in aging tissue (calcium hydroxyapatite)
- smoking could be a risk factor
lithopedion: the fetus is too large to be reabsorbed, so it calcifies
92
What are the functions of amniotic fluid?
- symmetrical external development
- allows free movement of fetus
- acts as barrier against infection
- permits normal fetal lung development
- prevents adherence of embryo/fetus
- helps maintain homeostasis
93
What is the clinical condition where a fetus develops in low volumes of amniotic fluid?
oligohydramnios- associated with renal agenesis and obstructive uropathy, complications: pulmonary hypoplasia and limb defects
Potter syndrome: pulmonary hypoplasia
94
What is the clinical condition associated with a high volume of amniotic fluid?
-associated with CNS abnormalities and esophageal atresia (a closing of the tube due to the overgrowth of epithelial tissue). Baby swallows amniotic fluid reducing the amount in cavity, so something prevents this from occurring.
95
What is amniotic band syndrome?
-occurs when there are tears in the amnion that detach and surround the fetus. The fetus adheres to the amnion, which can form a ring around appendages and cause constriction or amputations.
96
What are the two ways that blood vessels form in the embryo?
vasculogenesis- arise from coalescence of hemangioblasts which arise from blood islands (primitive stem cells) -> larger vessels
angiogenesis: vessel formation from branches of existing vessels (smaller vessels)
97
Outline which organs make the developing fetus' RBCs and when this occurs.
First trimester: yolk sac, aorta-gonad-mesonephros (AGM), blood, liver
*AGM will colonize the liver
Second and third trimester: thymus, liver, bone marrow
98
What are the functions of the spinal cord? Structure?
Below the medulla and terminates with the phylum terminalus. The functions include a pathway for sensory and motor functions and responses for reflexes. Has some functional independence from the brain.
99
Briefly describe the formation of the spinal cord.
- develops from ectoderm as a neural plate
- neural groove forms in neural plate
- as groove formation progresses, a neural tube is formed
100
Differentiate between the alar plate and basal plate.
Alar plate= dorsal horn: sensory
basal plate=ventral horn: motor
101
What are the lateral horns responsible for?
visceral motor/autonomic function
102
What is the basic anatomy of the spinal cord?
- has two enlargements in the cervical and lumbar regions lumbar is closer to the thoracic region)
- long flattened cylinder
- 31 pairs of spinal nerves
103
Review fetal spinal cord and brain development.
ok
104
Why is there in difference in size between the spinal cord and the vertebral column?
The spinal cord ceases growing before the vertebral column, so the cord ends around T12-L1 in adults, but will be longer in fetuses and newborns.
105
Where is the common area for a lumbar puncture? Why is it placed here?
Common for a needle to go between L4-L5 because it is under the medullary cone and there is no risk of the needle puncturing the spinal cord. Can also do a puncture through the sacrum.
106
What is a reflex?
-rapid, automatic, involuntary reaction of the muscle or gland to a stimulus.
-properties include:
+stimulus required
+rapid response that requires few neurons
+automatic response
107
What are the components of the reflex arc?
how the reflex is wired
-sensory receptor in PNS
communicates with the CNS
-ends at peripheral effector (muscle or gland) cell
108
What is an ipsilateral reflex arc? Give an example of this arc.
- when the receptor and the effector organs of the reflex are of the same side of the spinal cord
ex. when muscles contract to remove arm away from a hot surface(left arm)
109
What is a contralateral reflex arc and give an example.
- contralateral is when the sensory impulses from the receptor organ cross over through the spinal cord to activate effector organs in the opposite side of the limb
ex. when you step on a sharp object with your left foot and contract your muscles in your right to maintain balance as you remove your left foot from the object
110
What is the difference between monosynaptic and polysynaptic reflexes?
Monosynaptic:
-interneurons not involved (simple)
-ex. patellar reflex
-can also monitor and regulate skeletal muscle length
+when the stimulus results in muscle stretching, the muscle with reflexively contract
Polysynaptic:
- more complicated and involve multiple synapses involving interneurons
- there is usually a prolonged or delayed response due to the amount of neurons that accounts for the multiple components
- ex. withdrawal reflexes
111
What is an example discussed in lecture of a stretch reflex?
Golgi tendon reflex:
-prevents skeletal muscles from tensing excessively
-Golgi tendon organs are nerve endings located within tendons near a muscle-tendon junction
+activation of Golgi tendon organ signals interneurons in the spinal cord, which in turn inhibits the actions of the motor neurons (prevents overstimulation of muscle)
-associated muscle is allowed to relax, protecting the muscle and tendon from excessive tension damage
112
Compare the somatic nervous system and the autonomic nervous system.
SNS:
- voluntary control
- no ganglia involved in pathway
- sensory from general and special senses, motor to skeletal muscle
- excites using ACh
- axons are thick and myelinated
ANS:
- involuntary control two neuron pathway
- ganglia!
- sensory from general and visceral senses, motor from cardiac, smooth muscle and glands
- can excite or inhibit using ACh and norepi
- axons are thin, some myelinated, slower conduction
113
How do the sympathetic and parasympathetic systems interact?
They do not cross paths or synapse with each other. The plexuses are close to each other (para: cranial and caudal, sym: spinal via sympathetic trunk). The innervations work antagonistically on the same organ. Dual innervation which creates opposing effects on an organ or gland.
114
What are the autonomic plexes?
-cardiac plexus
+controls HR and bp, para decreases and sym incres
-pulmonary plexus
+sym induces bronchiodilation, para induces constriction and increased mucus
-esophageal plexus
+para controls swallowing reflex
-abdominal plexus
+control of digestion
-hypogastric plexus
+pelvic viscera=control of urinary, defecatory, and reproductive functions
115
What other plexi does the abdominal aorta consist of?
- celiac plexus
- superior mesenteric plexus
- inferior mesenteric plexus
116
What neurotransmitters and secreted in the sympathetic and parasympathetic systems?
Sympathetic:
- preganglionic axons: releases ACh->cholinergic
- postganglionic axons: releases NE -> adrenergic (MOST)
Parasympathetic:
-all axons secrete ACh -> cholinergic
117
What are the differences in structure between the parasympathetic and sympathetic systems?
para: a single preganglionic fiber and postganglionic
sym: branched pre and postganglionic axons, post secretes NE
118
What is an autonomic reflex? Give examples.
- ANS helps maintain homeostasis through the involuntary activity of autonomic reflexes or visceral reflexes.
ex. pupil dilation, micturition, cardiac contractions, secretion of glands, heart rate, respiratory rate, digestion,
119
How does the CNS control the ANS?
-influenced by cerebrum, hypothalamus, brainstem, and spinal cord (limbic=emotional state)
-HYPOTHALAMUS: integration and command center for autonomic functions, contains nuclei that control visceral functions for all of ANS, communicates with other CNS regions, involved in emotions
-cerebrum: conscious activities affect the ANS
brainstem; contains major ANS reflex centers
-spinal cord: contains reflex centers for urination and defecation
120
How is the sympathetic trunk anatomically situated with the spinal cord?
- preganglionic neuron cell bodies are housed in the lateral horn of the T1-L2 regions of the spinal cord
- preganglionic axons travel with the somatic motor neurons axons to exit the spinal cord and first enter the anterior roots, then the T1-L2 spinal nerves
- preganglionic axons remain with the spinal nerve for a short distance before they branch off and leave the spinal nerve
121
What structures are controlled with which portions of the sympathetic trunk?
```
T1-T6 -> head, upper limb, thoracic viscera
-T1-T3:head, salivary glands
-T1-T2:eye
-T4-T6: heart, lungs, esophageal
T7-T11 -> body wall, abdominal viscera
-T7-T9:stomach, liver, gallbladder, pancreas
-T10-11; appendix, colon
-T8-T10: small intestine
T12-L2(3) -> lower limb, pelvic viscera(hindgut)
-T10-L1:suprarenal gland
-T11-L1: kidney
-T12-L2(3): rectum, bladder, uterus
```
122
Where is the sympathetic trunk and what does it look like?
Lies lateral to the spinal cord that look like string and beads.
- string(axons)
- beads( sympathetic ganglia)
One sympathetic trunk ganglia corresponds/associated to one set of spinal nerves
-cervical portion is divided into three sympathetic trunk ganglia(sup, middle, and inf) instead of 8 cervical nerves
123
What do the rami do with the sympathetic trunk?
White rami:
- connects the preganglionic cells from the spinal nerve to the sympathetic trunk (entrance to sympathetic)
- myelinated
- associated with only T1-L2 spinal nerves
Grey Rami:
- carries postganglionic nerves from sympathetic trunk to spinal nerve (exit sympathetic highway)
- unmyelinated
- connect to all spinal nerves (sympathetic info that started in the thoracolmbar region can be dispersed to all parts of the body)
124
Where are sympathetic splanchnic nerves located and what are their function?
-composed of preganglionic sympathetic axons
-run anteriorly from trunk to most of viscera
-terminate in prevertebral ganglia (immediately anterior to vertebral column on anterolateral wall of aorta)
-typically cluster around major abdominal arteries
+greater thoracic splachnic nerves
+lesser thoracic splanchic nerves
+least thoracic splanchic nerves
+lumbar
+sacral
+celiac
-postganglionic axons extend away from the ganglionic neuron cell bodies and innervate many abdominal organs
125
What are the 4 sympathetic nerve pathways?
- spinal nerve
- postganglionic sympathetic nerve pathway
- splanchnic nerve pathway
- adrenal medulla pathway
126
Prevertebral ganglia
- differ from sympathetic trunk ganglia
- single structures, not paired
- anterior to vertebral column on anterior of aorta
- abdominopelvic cavity
- includes celiac, superior mesenteric, and inferior mesenteric
127
What sympathetic system appears to not synpase?
the adrenal medulla ganglia, it actually synapses in the medullary cells. Doesn't synpase in the sympathetic trunk like the other systems
128
What happens when the fight or flight response is activated?
sympathetic, in mass activation a large number of ganglionic neurons activate many effector organs
-cause a heightened sense of alertness due to stimulation of the reticular activation system
129
In general, what is the parasympathetic division?
- cooperates with sympathetic to maintain homeostasis
- craniosacral division
- concerned with conserving energy and replenishing nutrient stores
- most active when the body is at rest or digesting a meal
130
What cranial nerves are associated with the parasympathetic system and what are their corresponding ganglia?
oculomotor -> ciliary
facial -> pterypalatine and submandibular
glossopharyngeal -> otic
vagus -> no named ganglia
131
What is the oculomotor nerve responsible for?
ciliary ganglia
- pupil constriction
- ciliary muscles of lens for accommodation (near vision/reading)
132
What is the facial nerve responsible for in the parasympathetic system?
pterygopalatine
- lacrimal glad(tear production)
- nasal cavity(mucus production)
- oral cavitysaliva/mucus production)
submandibular ganglia
-submandibular and sublingual glands
133
What does the glossopharngeal nerve do in the parasympathetic system?
otic ganglia
| -parotid gland
134
What does the vagus nerve do in the parasympathetic system?
no named ganglia
- multiple terminal and intramural ganglia
- respiratory organs (decrease respiration)
- heart(decrease rate)
- bronchial passages(constricts and excites mucus production)
- esophagus(promotes swallowing and peristalsis)
- abdominal viscera(promotes digestion)
135
What nerve are all of the cranial ganglia associated with and why?
trigeminal nerve, though not directly innervating the parasympathetic ganglia it allows them to hitchhike to their final destinations in the cranium
136
What two systems is the caudal contribution of the parasympathetic system derive from?
- pelvic splanchnic nerves
| - sacral spinal nerves
137
How is the caudal portion of the parasympathetic system innervated?
- preganglionic axons from the neuron cell bodies in the lateral horn contribute to the formation of the superior and inferior hypogastric plexus
- from there the axons travel to the organs and synapse with ganglia close to or in the walls of the organs
138
What is innervated by the caudal parasympathetics via the pelvis splanchnic nerves?
- distal portion of large intestine
- rectum
- most reproductive organs
- urinary bladder(contracts)
- distal ureter
- erection
139
How is the parasympathetic division different from the sympathetic?
- active during times when body is processing nutrients and conserving energy
- lack of extensive divergence in preganglionic axons preventing mass activation
- tend to be discrete and localized
- can affect one group of organs without having to "turn on" all other organs
140
What are brachial arches?
the antecedent that leads to the formation of cranial nerves and other structures
141
What are the 12 cranial nerves and their corresponding number?
```
I. olfactory
II. optic
III. oculomotor
IV. trochlear
V. trigeminal
VI. abducens
VII. facial
VIII. vestibulocochlear
IX. glossopharyngeal
X. vagus
XI. accessory
XII. hypoglossal
```
142
What is the most rostral cranial nerve? Caudal?
rostral- olfactory
| caudal- hypoglossal
143
Name the brachial arches and what nerves are derived from them.
first/mandibular- trigeminal
second/hyoid- facial
third- glossopharyngeal
fourth and sixth- vagus
144
What foramen do the cranial nerves enter?
cribiform plate- olfactory
optic canal- optic
superior orbital fissure- opthalmic division of trigeminal, abducens, oculomotor, trochlear
foramen rotundum- maxillary division of trigeminal
foramen ovale- mandibular division of trigeminal
internal acoustic meatus- facial, vestibulocochlear
jugular foramen- glossopharnygeal, vagus, accessory
hypoglossal canal- hypoglossal
145
What is the only named sympathetic nerve of concern to us?
deep petrosal
146
How do parasympathetic ganglia travel? (pre and postganglia)
- preganglionic fiber arise from nuclei in the brain stem and synapse at 4 ganglia in the head (ciliary, otic, etc)
- preganglionic are carried by III, VII, IX, X (oculomotor, facial, glossopharyngeal)
- postganglionic fibers "piggy back" on the trigeminal nerve to arrive at the structure they innervate
147
What is the component and function of the olfactory nerve?
component: special sensory
function: smell
148
What is the component and function of the optic nerve?
component: special sensory
function: to see, info to the retina
149
What are the three cranial nerves that control ocular movement?
oculomotor, abducens, and trochlear
150
What is the component and function of the oculomotor nerve?
component: somatic motor and visceral motor
functions: levetor pelpebrae superioris, superior rectus, medial rectus, inferior rectus, inferior oblique
parasympathetic supply to pupillae and ciliary muscle
151
What is the component and function of the trochlear nerve?
component: somatic motor
function: move superior oblique
152
What is the component and function of the abducens nerve?
component: somatic motor
function: move lateral rectus
153
What are the components and functions of the trigeminal nerve?
brachial motor- muscles of mastication, tensor tympani, tensor palatini, mylohyoid, ant belly of digastric
general sensory- all of face
154
What are the branches of the trigeminal nerve and their terminal branches?
opthalmic (V1) -> supraorbital
maxillary (V2) -> infraorbital
mandibular (V3) -> mental
155
What are the components and functions of the facial nerve?
brachial motor- stapeidius, stylohyoid, pot belly of digastric, facial expression
visceral motor- stimulation of lacrimal, submandibular, sublingual glands. Mucus membrane of nose
general sensory- skin around ear
special sensory- taste ant 2/3 of tongue
156
What is the component and function of the vestibulocochlear nerve?
component: special sensory
function: auditory and balance
157
What are the components and functions of the glossopharyngeal nerve?
brachial motor- stylopharyngeus
visceral motor- otic ganglia -> parotid gland
visceral sensory- carries sensation from carotid body and carotid sinus
general sensory- post tongue, skin of external ear, tympanic membrane
special sensory- taste post 1/3 of tongue
158
What are the components and functions of the vagus nerve?
brachial motor- pharynx, tongue, and larynx
visceral motor- smooth muscle, glands of pharynx and larynx, abdominal viscera
visceral sensory- larynx, trachea, stretch receptors in aorta, chemoreceptors, thoracic and abdominal viscera
general sensory- skin on back of ear and tympanic membrane, pharynx
159
What is the component and function of the accessory nerve?
component: brachial motor
function: sternocleidomastoid and trapezius
160
What is the component and function of the hypoglossal nerve?
component: somatic motor
function: intrinsic and extrinsic muscles of tongue
