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Question 1

What must spermatozoa undergo to fertilize the oocyte?

Answer 1

Spermatozoa must undergo capacitation and the acrosome reaction to acquire the capability to fertilize the oocyte.

Question 2

Where does capacitation occur?

Answer 2

Capacitation occurs in the uterine tube.

Question 3

What happens during capacitation?

Answer 3

Glycoprotein coat and seminal plasma proteins are removed from the plasma membrane that overlies the acrosomal region of the spermatozoa.

Question 4

What is the acrosome reaction?

Answer 4

The acrosome reaction occurs after binding of spermatozoa to the zona pellucida, culminating in the release of enzymes needed to penetrate the zona pellucida.

Question 5

What are the phases of oocyte penetration?

Answer 5

Phase 1: Spermatozoa pass through corona radiata barrier.

Phase 2: One or more spermatozoa penetrate zona pellucida.

Phase 3: Fusion of oocyte and sperm cell membranes.

Question 6

What happens immediately after a sperm enters the oocyte?

Answer 6

The zona pellucida and oocyte membrane become impenetrable to other spermatozoa.

Question 7

What occurs after fertilization regarding the oocyte?

Answer 7

The oocyte finishes its 2nd meiotic division and forms the female pronucleus.

Question 8

What happens to the sperm after it penetrates the oocyte?

Answer 8

The head of the sperm separates from the tail, which detaches and degenerates.

Question 9

What forms the male pronucleus?

Answer 9

The sperm nucleus becomes swollen and forms the male pronucleus.

Question 10

What must each pronucleus do during fertilization?

Answer 10

Each pronucleus must replicate its DNA.

Question 11

What are the results of fertilization?

Answer 11

Restoration of the diploid number of chromosomes, determination of chromosomal sex, and initiation of cleavage.

Question 12

What happens if fertilization does not occur?

Answer 12

The menstrual phase begins, shedding the spongy and compact endometrial layers while the basal layer remains to regenerate.

Question 13

What is observed in the two-cell stage immediately after ovulation?

Answer 13

The oocyte shows the spindle of the 2nd meiotic division.

Question 14

What happens in the two-cell stage after a spermatozoon penetrates the oocyte?

Answer 14

The chromosomes of the oocyte are arranged in a vesicular nucleus, the female pronucleus.

Question 15

What occurs during the two-cell stage regarding DNA?

Answer 15

Male and female pronuclei replicate their DNA.

Question 16

What happens to chromosomes during the two-cell stage?

Answer 16

Chromosomes become arranged on the spindle in the equator of the zygote.

Question 17

What occurs after the completion of the first mitotic division of the zygote?

Answer 17

Two cells are produced.

Question 18

What is cleavage?

Answer 18

Cleavage is a series of mitotic divisions that results in an increase in cells (blastomeres) which become smaller with each division.

Question 19

What happens after three divisions of blastomeres?

Answer 19

Blastomeres undergo compaction to become a tightly grouped ball of cells with inner and outer layers.

Question 20

When is the two-cell stage reached after fertilization?

Answer 20

The two-cell stage is reached approximately 30 hours after fertilization.

Question 21

When is the four-cell stage reached after fertilization?

Answer 21

The four-cell stage is reached at approximately 40 hours after fertilization.

Question 22

When is the 16-cell stage reached after fertilization?

Answer 22

The 16-cell stage is reached at approximately 3 days after fertilization.

Question 23

What happens during the late morula stage?

Answer 23

The late morula stage is reached at approximately 4 days, and blastomeres are surrounded by zona pellucida.

Question 24

What occurs during blastocyte formation?

Answer 24

The morula enters the uterus on the 3rd or 4th day after fertilization, and fluid begins to penetrate through the zona pellucida.

Question 25

What is formed at approximately 4.5 days during blastocyte formation?

Answer 25

A single cavity called the blastocele is formed, and the embryo is referred to as a blastocyst.

Question 26

What are the divisions of the autonomic nervous system (ANS)?

Answer 26

The ANS is classified into three divisions: Sympathetic, Parasympathetic, and Enteric.

Question 27

What does the autonomic nervous system (ANS) conduct?

Answer 27

The ANS conducts involuntary impulses to smooth muscle, cardiac muscle, and glandular epithelium.

Question 28

What are visceral motor neurons?

Answer 28

Visceral motor neurons are the neurons of the ANS that are frequently accompanied by visceral sensory neurons.

Question 29

Where are the cell bodies of first neurons (preganglionic fibers) located?

Answer 29

The cell bodies of first neurons are located in the CNS nuclei.

Question 30

Where are the cell bodies of second neurons (postganglionic fibers) located?

Answer 30

The cell bodies of second neurons are located in the autonomic ganglia outside the CNS.

Question 31

Where are the presynaptic neurons of the sympathetic division located?

Answer 31

The presynaptic neurons are located in the thoracic and upper lumbar portions of the spinal cord (T1 to L2).

Question 32

What do presynaptic neurons of the sympathetic division send?

Answer 32

They send axons from the thoracic and upper lumbar spinal cord to the vertebral and paravertebral ganglia.

Question 33

What do paravertebral ganglia contain?

Answer 33

Paravertebral ganglia contain the cell bodies of the postsynaptic effector neurons of the sympathetic division.

Question 34

Where are the presynaptic neurons of the parasympathetic division located?

Answer 34

The presynaptic neurons are located in the brain stem and sacral spinal cord.

Question 35

Where do presynaptic parasympathetic neurons send axons?

Answer 35

They send axons to visceral ganglia.

Question 36

What are ganglia?

Answer 36

Ganglia are collections of neuron cell bodies outside the CNS.

Question 37

What are the two types of ganglia?

Answer 37

1. Sensory ganglia 2. Autonomic ganglia (Sympathetic or parasympathetic)

Question 38

Where are spinal ganglia located?

Answer 38

Spinal ganglia are attached to spinal nerves and located in intervertebral foramina.

Question 39

Where are autonomic ganglia located?

Answer 39

Autonomic ganglia occupy sites near the spinal cord and in the walls of, or close to, some viscera.

Question 40

What are sympathetic ganglia?

Answer 40

Sympathetic ganglia are in the sympathetic chain of paravertebral ganglia and in prevertebral ganglia.

Question 41

Where are parasympathetic ganglia typically found?

Answer 41

Parasympathetic ganglia are found in the walls of, or near to, the organs they affect.

Question 42

What do sympathetic ganglia receive?

Answer 42

Sympathetic ganglia receive axons of presynaptic cells whose soma is within the CNS.

Question 43

Where are cell bodies of sympathetic postganglionic neurons generally grouped?

Answer 43

They are grouped into discrete ganglia located at some distance from the target tissue.

Question 44

What do axons of preganglionic sympathetic neurons do?

Answer 44

They branch in the periphery and synapse on many postganglionic neurons.

Question 45

What envelops sympathetic ganglia?

Answer 45

These ganglia are enveloped by a collagenous connective tissue capsule.

Question 46

What is the internal organization of sympathetic ganglia like?

Answer 46

The arrangement of cell bodies appears to be haphazard and contains numerous fibroblasts and Schwann cells.

Question 47

What do satellite cells do in ganglia?

Answer 47

Satellite cells surround and support the perikarya in ganglia by providing electrical insulation.

Question 48

What conveys CNS influence over digestive system activities?

Answer 48

CNS influence is conveyed by sympathetic and parasympathetic pathways.

Question 49

What allows the digestive tract to perform basic reflexive functions independently?

Answer 49

The gut wall is equipped with an intrinsic network of neurons termed the enteric nervous system.

Question 50

What is the enteric nervous system regarded as?

Answer 50

The enteric nervous system is regarded as the third division of the autonomic nervous system.

Question 51

How many neurons are estimated to be in the enteric nervous system?

Answer 51

It is estimated to comprise roughly 100 million neurons.

Question 52

What types of neurons are found in the enteric nervous system?

Answer 52

Sensory neurons, interneurons, and motor neurons.