BI 342 Final Study Questions

A set of 55 flashcards for reviewing key concepts from the BI 342 lecture notes on the autonomic nervous system and reproductive systems.

What is the function of the autonomic nervous system (ANS)? How is it different from the somatic nervous system (SNS) anatomically?

The ANS controls involuntary bodily functions; anatomically, the SNS involves a single motor neuron from the CNS to skeletal muscle, while the ANS involves a two-neuron chain.

What brain structure is considered the primary controller of the ANS?

The hypothalamus is considered the primary controller of the ANS due to its role in visceral control and homeostasis.

What is meant by dual innervation by the autonomic nervous system?

Dual innervation means that many visceral organs receive innervation from both the sympathetic and parasympathetic divisions, often with opposing effects.

How would you generally characterize the effects of the parasympathetic nervous system versus the sympathetic nervous system?

The parasympathetic nervous system is known as 'rest and digest,' while the sympathetic nervous system is referred to as 'fight or flight.'

What is another name for the sympathetic division of the ANS (anatomical and functional)?

Anatomical: Thoracolumbar division; Functional: Fight or flight.

What is another name for the parasympathetic division of the ANS (anatomical and functional)?

Anatomical: Craniosacral division; Functional: Rest and digest.

Where in the CNS are the preganglionic cell bodies of the sympathetic division located?

In the lateral horns of the gray matter of the thoracic and lumbar segments (T1-L2) of the spinal cord.

Where in the CNS are the preganglionic cell bodies of the parasympathetic division located?

In the brainstem nuclei of cranial nerves III, VII, IX, and X, and in the lateral horns of the gray matter in the sacral segments (S2-S4).

What are prevertebral ganglia of the sympathetic division?

Prevertebral ganglia are sympathetic ganglia that are anterior to the vertebral column and receive preganglionic fibers from the lower thoracic and lumbar splanchnic nerves.

Where are the ganglia of the sympathetic division located?

Sympathetic ganglia are located near the spinal cord in the sympathetic trunk (chain ganglia) or as prevertebral (collateral) ganglia.

Where are the ganglia of the parasympathetic division located?

Parasympathetic ganglia are located near or within the wall of the target organ.

What is the relative length of preganglionic and postganglionic neurons in the sympathetic division?

Sympathetic preganglionic neurons are short, and postganglionic neurons are long.

What is the relative length of preganglionic and postganglionic neurons in the parasympathetic division?

Parasympathetic preganglionic neurons are long, and postganglionic neurons are short.

What neurotransmitter is released by sympathetic preganglionic neurons? What type of receptor is on the postganglionic neuron?

Acetylcholine (ACh) is released; the postganglionic neuron has a nicotinic cholinergic receptor.

What neurotransmitter is released by parasympathetic preganglionic neurons? What type of receptor is on the postganglionic neuron?

Acetylcholine (ACh) is released; the postganglionic neuron has a nicotinic cholinergic receptor.

What neurotransmitter is released by most sympathetic postganglionic neurons to the effectors? What type of receptors are on the effectors?

Norepinephrine (NE) is released; the effectors have adrenergic receptors (alpha or beta).

What neurotransmitter is released by parasympathetic postganglionic neurons to the effectors? What type of receptors are on the effectors?

Acetylcholine (ACh) is released; the effectors have muscarinic cholinergic receptors.

Which cranial nerve contains most of the parasympathetic fibers of the body?

The vagus nerve (cranial nerve X) contains most of the parasympathetic fibers of the body.

What hormone do the interstitial (Leydig) cells make that stimulates spermatogenesis?

Interstitial cells make testosterone, which is required for spermatogenesis.

What is autonomic tone?

Autonomic tone is the baseline level of activity maintained by both sympathetic and parasympathetic divisions of the ANS.

What are the main functions of the male reproductive and sexual systems?

To produce, store, and deliver gametes (sperm) for reproduction and to produce male sex hormones.

What hormones are required for making gametes in males and developing male sexual characteristics?

Testosterone is the primary hormone; FSH and LH from the anterior pituitary are essential for spermatogenesis.

What is the function of semen?

Semen activates sperm motility, provides nutrients for sperm, helps transport sperm, and protects sperm by neutralizing acidity.

Which structures in the male reproductive system produce gametes?

The testes, specifically within the seminiferous tubules, are responsible for sperm production.

Which structures in the male reproductive system contribute to semen production?

The seminal vesicles, prostate gland, and bulbourethral glands contribute to semen production.

What ducts do mature sperm move through on the way out of the body (in order)?

Seminiferous tubules → Epididymis → Ductus deferens (vas deferens) → Ejaculatory duct → Urethra.

What hormones are released by the hypothalamus and anterior pituitary that control the male sexual system?

The hypothalamus releases GnRH; anterior pituitary releases FSH and LH, which bind to Sertoli and Leydig cells.

What is a mature follicle?

A mature follicle is a fluid-filled sac in the ovary that contains a fully developed oocyte ready for ovulation.

What is the corpus luteum?

The corpus luteum is a temporary endocrine structure formed from the remnants of the ovarian follicle after ovulation.

What regulates the production of testosterone in males?

Testosterone production is regulated by a negative feedback loop; rising levels inhibit GnRH and LH release.

What regulates the production of LH and FSH in males?

LH and FSH production is stimulated by GnRH and inhibited by testosterone and inhibin through negative feedback.

What is the role of inhibin in the male reproductive system?

Inhibin is secreted by Sertoli cells and primarily inhibits the release of FSH from the anterior pituitary.

What are the main functions of the female reproductive and sexual systems?

To produce gametes (ova), support fertilization and development, give birth, and produce female sex hormones.

What is the ovarian cycle?

The ovarian cycle is a series of events in the ovaries associated with the maturation of an oocyte and ovulation.

What hormones regulate the ovarian and uterine cycles? Where are they made?

GnRH (hypothalamus), FSH and LH (anterior pituitary), estrogen (ovarian follicles), progesterone (corpus luteum).

Which structures in the female reproductive system produce gametes?

The ovaries produce oocytes (ova) through oogenesis.

What ducts do ovulated eggs move through on the way out of the body?

Ovary → Fimbriae of the uterine tube → Uterine tube (fallopian tube) → Uterus.

What happens to follicles during the follicular phase of the ovarian cycle?

Primordial follicles develop into primary, secondary, and eventually mature follicles, secreting estrogen.

What anterior pituitary hormone is responsible for ovulation?

A surge of LH from the anterior pituitary triggers ovulation.

What happens to the follicle cells of the most recently ovulated oocyte?

They differentiate into the corpus luteum, which produces progesterone and some estrogen.

What are the three phases of the uterine cycle? Which phases overlap the ovarian cycle?

Menstruation, proliferative phase, and secretory phase; the proliferative phase overlaps the follicular phase.

What changes occur in the endometrium during the proliferative phase of the uterine cycle?

The functional zone thickens, and endometrial glands and arteries develop, stimulated by estrogen.

What happens during the secretory phase of the uterine cycle?

Endometrial glands secrete a glycogen-rich fluid, and blood supply increases, stimulated by progesterone.

What causes menopause?

Menopause is caused by the depletion of ovarian follicles, decreasing estrogen and progesterone production.

What hormone is released by the implanted embryo? What is its importance?

The implanted embryo releases human chorionic gonadotropin (hCG), which stimulates the corpus luteum to maintain the endometrium.

Are sperm in the lumen of the seminiferous tubule fully capable of fertilizing an egg?

No, they are immature and must undergo capacitation in the female reproductive tract.

What processes occur during oogenesis?

Mitosis increases oogonia numbers; meiosis produces a secondary oocyte and polar bodies.

Where does fertilization typically occur in the female reproductive tract?

In the ampulla of the uterine tube (fallopian tube).