Unit 4 Flashcards
T/F
Embryology is the study of prenatal development
True
T/F
There are three primary germ layers in an embryo
True
T/F
Amnion is the transparent sac that develops from epiblast. It fills with amniotic fluid that protects the embryo from trauma, infections, and temperature fluctuations and is only penetrated by the umbilical cord.
True
T/F
Tubal pregnancy is a synonym for ectopic pregnancies
True
T/F
Monozygotic twins form when one egg is fertilized (one zygote) but the embryoblast later divides into two. These individuals are genetically identical, of the same sex, and nearly identical in appearance.
True
T/F
A blastocyst is a solid sphere made up of three layers (trophoblast, embryoblast, and blastocoel).
False
It is a hollow sphere
T/F
During fetal blood circulation, blood bypasses the lung going directly from the right atrium to the left atrium via a hole in the “interventricular septum”
False
It is the interatrial septum
T/F
Sexual reproduction entails the union of two gonads to form a zygote.
False
T/F
An egg must be fertilized within 36-48 hours of ovulation, if it is to survive.
False
Must be fertilized within 12-24 hours
T/F
From puberty through adulthood, reproductive function is regulated by hormonal links between the hypothalamus and pituitary gland only.
False
VERIFY
T/F
Pregnancy is divided into three trimesters, composed of 4 month intervals
False
At 16 days old an embryo consists of three primary germ layers. Which of the choices below are the correct terms for the three primary germ layers?
- Mesoderm
- Endoderm
- Ectoderm
- Hectoderm
- A-C
A-C
Polyspermy is the act of
- An egg being fertilized by one sperm
- A sperm fertilizing an egg with no genetic material
- An egg being fertilized by a defected sperm
- A sperm fertilizing 2 or more eggs
- An egg being fertilized by two or more sperm
An egg being fertilized by two or more sperm
Mitotic divisions that occur in the first 3 days while the conceptus migrates down uterine tube is known as ____________.
- Cleavage
- Zygote
- Fertilization
- Embryogensis
- Implantation
- Cleavage
The nervous system is derived from the _______________ germ layer.
- Ectoderm
- Fectoderm
- Mesoderm
- Endoderm
- Ectoderm
Which of the following is not considered a preembryonic stage?
- Implosion
- Cleavage
- Implantation
- Embryogenesis
- Implosion
The bladder and glands of the respiratory system is derived from the _______________ germ layer.
- Ectoderm
- Fectoderm
- Mesoderm
- Endoderm
Endoderm
Cartilage, blood and the skeletal system is derived from the _______________ germ layer.
- Ectoderm
- Fectoderm
- Mesoderm
- Endoderm
Mesoderm
During neonates transitional period
- Their heart and respiratory rates increase; body temperature falls
- The physical activity declines and baby sleeps for about 3 hours
- They often gags on mucus and debris in the pharynx
- All of the above
All of the above
What is the function of syncytiotophoblast?
- Grows into the uterus like little roots
- Closes the embryoblast
- To maintain in contact with the endometrium
- To force the blastocyst to divide.
- Grows into the uterus like little roots
By the end of 5 weeks during embryonic folding and organogenesis the thoracic cavity has subdivided into the ______________.
- Pleural cavity
- Pericardial cavity
- Mediastinum cavity
- Pleural and mediastinum cavities
- Pericardial and pleural cavities
Pericardial and pleural cavities
Allantois is a type of embryonic membrane that begins as an outpocketing of the yolk sac. It will become ________.
- Part of the urinary bladder
- A testis
- Part of the large intestine
- Internal umbilical cord
Part of the urinary bladder
Blastocyst is a hallow ball that forms during the preembryonic stage of pregnancy. This ball is three layer, which of the following is not a layer of a blastocyst?
- Blastocoels
- Blastomere
- Trophoblast
- Embryoblast
Blastomere
Which of the follow is not true about “dizygotic” twins?
- Form from two eggs being fertilized at the same time by two different sperms
- No more or less genetically similar than any other siblings
- Implant separately in the uterine wall and each forms its own placenta
- Genetically identical, of the same sex, and nearly identical in appearance
- Account for about two-thirds of twins
Genetically identical, of the same sex, and nearly identical in appearance
Having an extra chromosome produces a triple set is commonly known as ___.
- Nondisjuction
- Monosomy
- Sampling
- Trisomy
- Nullisomy
Trisomy
Gonads begin to develop ______________.
- 2 to 3 weeks after fertilization
- 5 to 6 weeks after fertilization
- 8 to 9 weeks after fertilization
- 20 to 24 weeks after fertilization
- At birth
5 to 6 weeks after fertilization (VERIFY)
The cessation of menstruation is called ______________
- Menopause
- Climacteric
- Atresia
- Puberty
- Menstrual
Menopause
The morula stage happens when the conceptus arrives to the uterus, this usually happens within ______ hours.
- 12
- 24
- 36
- 48
- 72
72
During gestation the conceptus is nourished in three different, overlapping ways which of the following is not a nutrient pathway?
- Uterine milk
- Trophoblastic nutrition
- Placental nutrition
- Umbilical milk
Umbilical milk
The umbilical cord is formed of_____
- Two umbilical arteries
- One umbilical vein
- Two shunts
- Two umbilical arteries and one umbilical vein
- One umbilical vein two shunts
Two umbilical arteries and one umbilical vein
The three primary germ layers of an embryo consist of all the following except:
- Ectoderm
- Fectoderm
- Endoderm
- Mesoderm
Fectoderm
Vast majority of sperm do not make it to egg because they
- Are destroyed by vaginal acid or drain out of vagina
- Are fail to penetrate the mucus of the cervical canal
- Are destroyed by leukocytes in the uterus
- Half of the sperm go up wrong uterine tube
- All of the above
All of the above
The fetus has several shunts to help with blood circulation, the ___________ allows for blood to bypass the pulmonary circuit moving directly from the right atrium to the left atrium.
- Umbilical placental circuit
- Ductus arteriosus
- Foramen ovale
- Ductus venosus
Foramen ovale
The preembryonic stage has three major processes it undergoes during the first 16 days of development. These major processes include all of the following expect:
- Implantation
- Burrowing
- Cleavage
- Embryogenesis
- All of the above
Burrowing
The fetus has several shunts to help with blood circulation; the ___________ allows blood to flow directly from the pulmonary trunk to the aorta.
- Umbilical placental circuit
- Ductus arteriosus
- Foramen ovale
- Ductus venosus
Ductus arteriosus
Stretching of uterus increases OT release, causes contractions, causing more stretching of uterus, etc. until delivery. This is an example of ________ feedback.
- Positive
- Negative
Positive
The fetus has several shunts to help with blood circulation, the ___________ allows for Placental blood to bypasses the liver and flow into the inferior vena cava (IVC).
- Umbilical placental circuit
- Ductus arteriosus
- Foramen ovale
- Ductus venosus
Ductus venosus
Which of the following statements is not true concerning a neonate’s transitional period?
- It’s the first 6 to 8 hours of life
- Heart and respiratory rates decrease; body temperature rise
- Their physical activity declines and baby sleeps for about 3 hours; second period of activity, baby often gags on mucus and debris in the pharynx; baby sleeps again and becomes more stable
- They settle into a cycle of waking every 3 to 4 hours to feed
Heart and respiratory rates decrease; body temperature rise
Infants born before 7 months tend to suffer from
- Immature liver
- Digestive issues
- Thermoregulatory
- Infant respiratory distress syndrome (IRDS)
- All of the above
All of the above
Alcohol, nicotine, diagnostic x-rays, microorganisms are considered _______ and can lead to ________.
- Teratology; birth defects
- Congenital anomalies; birth defects
- Deformities; anomalies
- Teratogens; teratology
- Teratogens; birth defects
Teratogens; birth defects
Sickle cell is an inheritable ______________ disease.
- Dominant
- Autosomal
- Recessive
- Co-dominant
VERIFY
Recessive
Neurotransmitters
- What releases them
- What do they do
- Released from neurons to travel across synaptic cleft to second cell
What are hormones
- Chemical messengers that travel in the bloodstream to other tissues and organs
What are endocrine glands
- Organs that are traditional sources of hormones
Describe exocrine glands
- Have ducts carry secretion to an epithelial surface or the mucosa of the digestive tract: “external secretions”
- Extracellular effects (food digestion)
Endocrine gland characteristics
- No ducts
- Contain dense, fenestrated capillary networks which allow easy uptake of hormones into bloodstream
- “Internal secretions”
- Intracellular effects such as altering target cell metabolism
Liver cells
- Defy rigid classification
- Rreleases hormones, releases bile into ducts, releases albumin and blood-clotting factors into blood (not hormones)
What is the pituitary gland suspended from?
Hypothalamus; by a stalk called infundibulum
Location & size of pituitary gland
- Housed in sella turcica of sphenoid bone
- Size and shape of kidney bean
What is the pituitary gland composed of?
- 2 structures with independent origins and separate functions
- Adenohypophysis (anterior pituitary): Arises from hypophyseal pouch (outgrowth of pharynx)
- Neurohypophysis (posterior pituitary): Down-growth from brain
Oxytocin (OT)
- What is it
- What does it do
- Posterior pituitary hormone
- Surge of hormone released during sexual arousal and orgasm
- Stimulate uterine contractions and propulsion of semen
- Promotes feelings of sexual satisfaction and emotional bonding between partners
- Stimulates labor contractions during childbirth
- Stimulates flow of milk during lactation
- Promotes emotional bonding between lactating mother and infant
Control of pituitary secretion
Positive feedback
- Stretching of uterus increases OT release
- Causes contractions, causing more stretching of uterus, etc. until delivery
Pineal gland
- Where is it
- What happens after age 7
- What does it do?
- Attached to roof of third ventricle beneath the posterior end of corpus callosum
- After age 7, it undergoes involution (shrinkage)
- Down 75% by end of puberty
- Tiny mass of shrunken tissue in adults
-
Synthesizes melatonin from serotonin during the night
- Fluctuates seasonally with changes in day length
- May synchronize physiological function with 24-hour circadian rhythms of daylight and darkness
Seasonal affective disorder (SAD)
- Symptoms
- Treatment
- Occurs in winter or northern climates
- Symptoms
- depression
- sleepiness
- irritability
- carbohydrate craving
- 2-3 hours of exposure to bright light each day reduces the melatonin levels and the symptoms (phototherapy)
List the 3 pancreatic islets
- Glucagon
- Insulin
- Somatostatin
Glucagon
- What is it secreted by
- When is it released
- Secreted by A or alpha (a) cells
- Released between meals when blood glucose concentration is falling
Insulin
- What is it secreted by
- When is it released
- What does it stimulate? What does insufficiency cause?
- Secreted by B or beta (b) cells
- Secreted during and after meal when glucose and amino acid blood levels are rising
- Stimulates cells to absorb these nutrients and store or metabolize them lowering blood glucose levels
- Insufficiency or inaction is cause of diabetes mellitus
Somatostatin
- What is it secreted by
- When is it released
- What does it do
- Secreted by D or delta (d) cells
- Partially suppresses secretion of glucagon and insulin
- Inhibits nutrient digestion and absorption which prolongs absorption of nutrients
General adaptation syndrome (GAS)
- What does it react to?
- What does it involve?
- List the 3 stages
- Consistent way the body reacts to stress
- Typically involves elevated levels of epinephrine and glucocorticoids (especially cortisol)
- Occurs in three stages
- Alarm reaction
- Stage of resistance
- Stage of exhaustion
Alarm reaction
- Describe
- What is it mediated by
- What levels does it increase?
- Initial response
- Mediated by norepinephrine from the sympathetic nervous system and epinephrine from the adrenal medulla
- Prepares body to fight or flight
- Stored glycogen is consumed
- Increases aldosterone and angiotensin levels
- Angiotensin helps raise blood pressure
- Aldosterone promotes sodium and water conservation
Stage of resistance
- What does it do?
- What is this stage dominated by?
- Provides alternate fuels for metabolism
- Stage dominated by cortisol
Cortisol
- What stage applies to cortisol
- Describe its effect
- Adverse effects of excessive cortisol
- Stage of resistance
- Has glucose-sparing effect which inhibits protein synthesis leaving free amino acids for gluconeogenesis
- Adverse effects of excessive cortisol
- depresses immune function
- increases susceptibility to infection and ulcers
- lymphoid tissues atrophy, antibody levels drop, and wounds heal poorly
ACTH
- What stage is it associated with
- What is it secreted by
- What does it do
- Stage of resistance
- Pituitary secretes an increase in ACTH
- Stimulates the adrenal cortex to secrete cortisol and other glucocorticoids
- Promotes the breakdown of fat and protein into glycerol, fatty acids, and amino acids, for gluconeogenesis
Stage of exhaustion
- Describe
- When stress continues for several months, and fat reserves are gone, homeostasis is overwhelmed
- protein breakdown & muscle wasting
- loss of glucose homeostasis because adrenal cortex stops producing glucocorticoids
- aldosterone promotes water retention and hypertension
- death results from heart & kidney infection or overwhelming infection
Comparison of the Nervous & Endocrine Systems: internal communication
- Nervous: both electrical and chemical
- Endocrine: only chemical
Comparison of the Nervous & Endocrine Systems: speed and persistence of response
- Nervous: reacts quickly (1 to 10 ms), stops quickly
- Endocrine: reacts slowly (hormones release in seconds or days), effect may continue for weeks
Comparison of the Nervous & Endocrine Systems: adaptation to long-term stimuli
- Nervous: response declines (adapts quickly)
- Endocrine: response persists (adapts slowly)
Comparison of the Nervous & Endocrine Systems: area of effect
- Nervous: targeted and specific (one organ)
- Endocrine: general, widespread effects (many organs)
Chemicals that function as both hormones & neurotransmitters in nervous and endocrine systems (list)
- Antidiuretic hormone
- Cholecystokinin
- Dopamine
- Norepinephrine
- Thyrotropin-releasing hormone
What are target organs or cells
- Organs or cells that have receptors for a hormone and can respond to it
How does the female body try to prevent polyspermy?
- List and describe
-
Fast block
- binding of sperm to the egg opens Na+ channels in the egg membrane
- inflow of Na+ depolarizes the membrane and inhibits the attachment of any more sperm
-
Slow block
- involves secretory granules and cortical granules, just below membrane
- sperm penetration releases an inflow of Ca2+
- secretion swells with water, pushing remaining sperm away
- creates an impenetrable fertilization membrane between the egg and the zona pellucida
Where are the 2 umbilical arteries found in the umbilical cord formed from?
Internal iliac arteries
T/F
Exocrine glands have no ducts, and contains dense fenestrated capillary networks which allow easy uptake of hormones into bloodstream.
False
T/F
Target organs or cells are those organs or cells that have receptors for a hormone but is unable to respond to it.
False
T/F
Both the nervous system and the endocrine system serve for external communication.
False
Compare and contrast the nervous system and endocrine system in regards to communication about body stimuli
- Both serve for internal communication
-
Nervous system
- affects both electrical and chemical communication
- reacts quickly and stops quickly
- adapts quickly
- affects a targeted/specific organ
-
Endocrine system
- serves only chemical communication
- reacts slowly, and its effects may continue for weeks
- adapts slowly
- affects general, widespread organs (more than 1)
-
Nervous system
All of the following chemicals function as both hormones and neurotransmitters except
- Dopamine
- Oxytocin
- Norepinephine
- Cholecystokinin
- All of the above
b. Oxytocin
Chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ, often a considerable distance away are know as __________
VERIFY (HW 10)
Hormones
General adaptation syndrome (GAS) is a consistent way the body reacts to stress; typically involves elevated levels of epinephrine and glucocorticoids (especially cortisol). Which of the following is not a stage of GAS?
- Alarm reaction
- Stage of adaptation
- Stage of resistance
- Stage of exhaustion
Stage of adaptation
Somatostatin is secreted by
- Alpha cells
- Beta cells
- Delta cells
- No answer text provided
Delta cells
What does the hypothalamus secrete?
Corticotropin-releasing hormone
T/F
Exocrine glands have no ducts, and contains dense fenestrated capillary networks, which allows easy uptake of hormones into the bloodstream
False
T/F
Exocrine glands have ducts, and carry secretion to an epithelial surface or the mucosa of the digestive tract.
True
T/F
The pituitary gland is composed of two parts anterior (adenohypophysis) and posterior (neurohypophysis).
True
Hormones are
- Pores in the cell membrane that allows signaling molecules, nutrients, and electrolytes to move from cell to cell.
- Released from neurons to travel across synaptic clefts to a second cell
- Secreted into tissue fluid to affect nearby cells
- Chemical messages that travels in the bloodstream to other tissues and organs
- Chemical messages that travels in the bloodstream to other tissues and organs
Neurotransmitters are
- Pores in the cell membrane that allow signaling molecules, nutrients, and electrolytes to move from cell to cell
- Released from neurons to travel across synaptic clefts to a second cell
- Secreted into tissue fluids to affect nearby cells
- Chemical messages that travel in the bloodstream to other tissues and organs
- Released from neurons to travel across synaptic clefts to a second cell
Which system is responsible for external communication, nervous or endocrine?
Nervous system
This system is responsible for internal and external communications. The endocrine is limited to internal communications.
What 2 structures with independent origins and separate functions compose the pituitary gland?
-
Adenohypophysis (anterior pituitary)
- Arises from hypophyseal pouch (outgrowth of pharynx)
-
Neurohypophysis (posterior pituitary)
- Downgrowth from brain
What 3 systems does the thymus play a role in?
- Endocrine
- Immune
- Lymphatic
What is the largest endocrine gland?
Thyroid gland
What is the thyroid gland composed of?
- 2 lobes; and
- Isthmus below the larynx
Thyroid follicles
- What are they
- What do they contain
- Sacs that compose most of thyroid
- Contain protein-rich colloid
Follicular cells
Simple cuboidal epithelium that line thyroid follicles
Parathyroid glands
- 4 glands partially embedded in posterior surface of thyroid gland
The ___ is an endocrine gland and has several endocrine functions
- Pancreas
- Parathyroid gland
- Thyroid gland
- All the above
- All the above
T/F
The endocrine system is involved in the adaptation of stress
True
Hyposecretion disorder
- What is it
- Inadequate hormone release
- Tumor or lesion destroys gland or interferes with its ability to receive signals from another gland
- Head trauma affects pituitary gland’s ability to secrete ADH
- Diabetes insipidus: chronic polyuria
- Head trauma affects pituitary gland’s ability to secrete ADH
- Autoantibodies fail to distinguish person’s own gland from foreign matter
Acromegaly disorder
Thickening of bones and soft tissues in adults, especially in hands, feet, and face
Heterozygous & homozygous gene distribution
- Heteorzygous: one dominant and one recessive gene (ie Bb)
- Homozygous: either two dominant or two recessive genes (ie BB or bb)
Recessive vs dominant genes
- Recessive are the “weaker” genes, and need two (homozygous) genes in order to be visible
- Dominant genes are the “stronger” genes
What is used to visualize gene distribution options
Punnett square