biomedicine quiz 6 (wk 8 content) Flashcards
Which of the following structures will develop into the epiblast of the bilaminar disk?
Question 1 Answer
a.
trophoblast (outer cell mass)
b.
embryoblast (inner cell mass)
c.
corona radiata
d.
blastocoel
b.
embryoblast (inner cell mass)
Choose the TRUE statement re: cleavage in the early embryo:
Question 2 Answer
a.
The zona pellucida protects against premature cleavage by ensuring only one sperm fertilizes the ovum.
b.
Cleavage occurs all throughout the early embryonic phase and does not end until neurulation is complete.
c.
Cleavage does not occur until implantation has occurred.
d.
Cleavage tends to cause blastomere cells to become smaller and smaller with each cell division.
a.
The zona pellucida protects against premature cleavage by ensuring only one sperm fertilizes the ovum.
ITHINK D IS TRUE??
Choose the TRUE statement about the connecting stalk in the early embryo.
Question 3 Answer
a.
The connecting stalk develops later into the umbilical cord and is formed from extraembryonic mesoderm
b.
The connecting stalk connects the hypoblast to the epiblast and is formed from extraembryonic mesoderm
c.
The connecting stalk develops later into the umbilical cord and is formed from the intraembryonic coelom
d.
The connecting stalk connectts the hypoblast to the epiblast and is formed from the intraembryonic coelom
a.
The connecting stalk develops later into the umbilical cord and is formed from extraembryonic mesoderm
How many germ layers are found in a gastrula?
Question 4 Answer
a.
three
b.
one
c.
two
d.
four
a.
three
Which of the following is a function of the notochord?
Question 5 Answer
a.
It induces the overlying ectoderm to become the primordium of the central nervous system
b.
It directly develops into most of the sensory aspects of the spinal cord
c.
It develops into the vertebral bodies of the fetus
d.
It induces the underlying endoderm to become the primordium of the colon
a.
It induces the overlying ectoderm to become the primordium of the central nervous system
Choose the TRUE statement about spinal cord development:
Question 6 Answer
a.
The basal plate forms the ventral and lateral gray horns and has a predominantly motor function
b.
The neural crest cells form the ventral and lateral gray horns and have a predominantly sensory function
c.
The alar plate forms the white matter of the motor and sensory spinal cord tracts
d.
The sulcus limitans forms the meninges that will later surround the spinal cord
a.
The basal plate forms the ventral and lateral gray horns and has a predominantly motor function
Which of the following structures develops from the intraembryonic coelom?
Question 7 Answer
a.
The lumen of the genitourinary tract
b.
The lumen of the gastrointestinal tract
c.
The ventricles of the brain
d.
The pericardial cavity
d.
The pericardial cavity
Choose the TRUE statement regarding tail folding in the development of the embryo.
Question 8 Answer
a.
It brings the connecting stalk towards the ventral surface of the embryo.
b.
It brings the somatopleure ventrally, to form the ventral body wall.
c.
It brings the chorionic membrane ventrally, to form the decidua basalis.
d.
It brings the heart primordium towards the ventral surface of the embryo.
a.
It brings the connecting stalk towards the ventral surface of the embryo.
Lateral folding of the embryo causes the endoderm layer to be incorporated into what will become:
Question 9 Answer
a.
the midgut
b.
the sixth pharyngeal arch
c.
the hindgut
d.
the foregut
a.
the midgut
In the spinal cord, the cells of the alar plate later become:
Question 10 Answer
a.
the dorsal root ganglia
b.
the lateral gray horns
c.
the dorsal gray horns
d.
the ventral gray horns
c.
the dorsal gray horns
Choose the TRUE statement regarding the umbilical vein:
Question 11 Answer
a.
The umbilical vein is formed from the caudal portion of the dorsal aorta
b.
The umbilical vein carries blood to the heart from the umbilical vesicle
c.
The umbilical vein carries blood from the heart to the umbilical vesicle
d.
The umbilical vein carries oxygenated, nutrient-rich blood
b.
The umbilical vein carries blood to the heart from the umbilical vesicle
OURNOTES SAY UMBILICAL VEIN IS FROM TERTIARY VILLI TO HEART
AND VITELLINE VEIN WOULD BE UMBILICAL VESICLE TO HEART
GOOGLE SAYS: the umbilical vein carries newly oxygenated and nutrient-rich blood back to the fetus.
Where do red blood cells first develop in the embryo?
Question 12 Answer
a.
From the intra-embryonic vessel primordia in the gastrula
b.
From the paired heart tubes in the gastrula
c.
From the vessel primordia in the extra-embryonic mesoderm of the umbilical vesicle and allantois
d.
They are transported across the placenta from the mother’s circulation
c.
From the vessel primordia in the extra-embryonic mesoderm of the umbilical vesicle and allantois
When calcium binds to ________________, then ___________________ reveals the myosin-binding site on actin.
Question 13 Answer
a.
tropomyosin; troponin
b.
tropomyosin; actinin
c.
troponin; tropomyosin
d.
troponin; actinin
c.
troponin; tropomyosin
Choose the TRUE statement about tetany in skeletal muscle fibres:
Question 14 Answer
a.
During tetany, calcium clearance into the SR (sarcoplasmic reticulum) is inadequate to drop cytosolic calcium levels low enough to result in sarcomere relaxation.
b.
Tetany occurs when action potential frequency (number of action potentials per second) decreases below a threshold level.
c.
Although tetany can result in longer muscle contraction, it will not increase the tension in a muscle.
d.
Tetany is due to increased intracellular potassium, which activates the sarcomere.
a.
During tetany, calcium clearance into the SR (sarcoplasmic reticulum) is inadequate to drop cytosolic calcium levels low enough to result in sarcomere relaxation.
The perimysium is a connective tissue sheath that surrounds:
Question 15 Answer
a.
Many fascicles
b.
One myofibre
c.
One sarcomere
d.
One fascicle
d.
One fascicle
