A&P II: Exam 4

Choose the answer choice described in the following statement. Wavelike smooth muscle contractions that move foodstuffs through the alimentary tube.

Peristalsis

The chemical and mechanical processes of food breakdown are called ________.

digestion

The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task?

villi, and microvilli

Choose the answer choice described in the following statement. Process by which simpler chemical units pass through the lumen of the gastrointestinal tract into the blood or lymph.

Absorption

Which of the following is least involved in the mechanical breakdown of food, digestion, or absorption?

the esophagus

The function of the hepatic portal circulation is to ________.

collect absorbed nutrients for metabolic processing in the liver

You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?

amylase

Outline the flow of food through the digestive tract from the mouth to the anus.

Mouth -> Pharynx -> Esophagus -> Stomach -> Small Intestine -> Duodenum -> Jejunum -> ileum -> Large Intestine -> Cecum -> Ascending Colon -> Transverse Colon -> Descending Colon -> Sigmoid Colon -> Rectum -> Anus

Describe the nerve supply to the digestive tract.

The digestive tract is supplied by both intrinsic and extrinsic nerves. The intrinsic nerve supply, also known as the enteric nervous system, includes the submucosal and myenteric plexuses, which regulate local activities such as secretion and muscle contraction. The extrinsic nerve supply comes from the autonomic nervous system: parasympathetic nerves, which is primarily the vagus nerve, enhance digestive activity, while sympathetic nerves inhibit it.

Describe the role of the pancrease, liver and gallbladder in digestion.

The pancreas secretes digestive enzymes l(amylase, lipase, and proteases) into the small intestine to break down carbohydrates, fats, and proteins. It also releases bicarbonate to neutralize stomach acid. The liver produces bile, which emulsifies fats to aid in their digestion and absorption. The gallbladder stores and concentrates bile, releasing it into the small intestine when fats are present.

Proximal convoluted tubule is_______.

Site at which most of the tubular reabsorption occurs

Glomerulus is ______.

Site of filtrate formation

Peritubular capillaries are________.

Blood supply that directly receives substances from the tubular cells

Collecting duct is___________.

Site that drains the distal convoluted tubule

The path urine takes after it is formed until it leaves the body is the urethra, urinary bladder, and finally the ureter.

false

The entire responsibility for urine formation lies with the nephron.

true

The collecting duct is impermeable to water in the presence of ADH.

false

State the 4 organs of the urinary system and their functions.

The 4 organs of the urinary system and their functions:

1. Kidneys – Filter blood to remove waste products and form urine. They also regulate electrolyte balance, blood pressure, and pH.

2. Ureters – Transport urine from the kidneys to the urinary bladder through peristaltic movements.

3. Urinary Bladder – Temporarily stores urine until it is ready to be excreted.

4. Urethra – Conducts urine from the bladder to the outside of the body during urination.

State the vessel that feeds blood into and the vessel that sends blood out of the glomerulus.

The afferent arteriole feeds blood into the glomerulus.
The efferent arteriole carries blood out of the glomerulus.

State the structures (in order) that urine flows through as it goes from the renal pyramid to the ureter.

1. Renal pyramid

2. Minor calyx

3. Major calyx

4. Renal pelvis

5. Ureter

Role of Liver?

Produces and secretes bile into the small intestine and gallbladder

Role of Gallbladder?

Stores bile produced by the liver, concentrates bile and releases it into the small intestine

Role of Pancreas?

Secretes pancreatic juice which contains enzymes that breakdown carbohydrates, lipids, proteins and nucleic acids.

Explain the role of amylases in digestion.

Break down carbohydrates

Explain the role of proteases in digestion.

Break down proteins

Explain the role of lipases in digestion.

Break down fats

What are the 4 macromolecules and their respective building blocks?

• Carbs → Monosaccharides

• Proteins → Amino acids

• Lipids → Fatty acids

• Nucleic acids → Nucleotides

Of the alimentary canal organs, which two play the biggest role in digestion?

Small intestine and stomach

Of the alimentary canal organs, which plays the biggest role in absorption?

Small intestine

What is the function of the digestive system? (3)

• Break down food

• Release nutrients from food

• Absorb nutrients

Proximal convoluted tubule is_______.

Site at which most of the tubular reabsorption occurs

Glomerulus is ______.

Site of filtrate formation

Peritubular capillaries are________.

Blood supply that directly receives substances from the tubular cells

Collecting duct is___________.

Site that drains the distal convoluted tubule

True or False

The path urine takes after it is formed until it leaves the body is the urethra, urinary bladder,
and finally the ureter.

False

True or False

The entire responsibility for urine formation lies with the nephron.

True

True or False

The collecting duct is impermeable to water in the presence of ADH.

False

State the 4 organs of the urinary system and their functions.

1. Ureters-transport urine from kidneys to bladder

2. Urinary bladder-temporary storage reservoir for urine

3. Urethra-transports urine out of the body

4. Kidney-maintains body’s internal environment and forms urine

Whats the function of the Ureters?

Transport urine from kidneys to bladder

Whats the function of the Urinary Bladder?

Temporary storage reservoir for urine

Whats the function of the Urethra?

Transports urine out of the body

Whats the function of the Kidneys?

Maintains body’s internal environment and forms urine

State the vessel that feeds blood into and the vessel that sends blood out of the glomerulus.

Into-afferent arteriole
Out of-efferent arteriole

What vessel feeds blood into the Glomerulus?

Afferent Arteriole

What vessel sends blood out of the Glomerulus?

Efferent Arteriole

State the structures (in order) that urine flows through as it goes from the renal pyramid to the
ureter.

Renal pyramid→ Minor Calyx→ Major Calyx→ Renal Pelvis → Ureter

Which region of the nephron plays the biggest role in reabsorption?

Proximal convoluted tubule (PCT)

Which region of the nephron plays the biggest role in secretion?

Distal convoluted tubule (DCT)

Describe how the anatomy of the renal corpuscle structures allows for blood filtration.

Renal corpuscle = Glomerulus + Bowman’s capsule

If glucose is found in the urine, would this be concerning?

Yes, it’s an indicator of diabetes

If a large amount of proteins is found in the urine, would this be concerning?

Yes, it’s an indicator of glomerulus damage

State the 4 organs of the urinary system and their functions.,

Ureters → transport urine from kidneys to bladder;

Urinary bladder → temporary urine storage;

Urethra → transports urine out;

Kidneys → filter blood, produce urine

What are the 3 regions of the internal kidney?

Renal cortex, renal medulla, renal pelvis

State the vessel that feeds blood into and the vessel that sends blood out of the glomerulus

Into → afferent arteriole; Out of → efferent arteriole

Label A in the kidney image

Afferent Arteriole

What is B labeled as in the kidney?

Efferent Arteriole

What is C labeled as in the kidney?

Bowman’s Capsule

What is D labeled as in the kidney?

Proximal Convoluted Tubule

What is E labeled as in the kidney?

Loop of Henle (nephron loop)

What is the glomerulus composed of and what is its function?

Capillaries with fenestrated epithelium (leaky) → allows glomerular filtration

Where does the filtrate go after leaving the glomerulus?

Bowman’s capsule → proximal convoluted tubule (PCT)

What is the function of the proximal convoluted tubule (PCT)?

Tubular reabsorption and secretion of solutes (Na+, Cl-, glucose)

What parts of the nephron reabsorb water?

PCT, loop of Henle, DCT, collecting ducts

What parts of the nephron are under hormonal control for reabsorption?

Distal convoluted tubule (DCT), collecting duct

State the hormones involved in absorption regulation and their roles

ADH → inserts aquaporins, ↑water reabsorption; Aldosterone → ↑Na+ & water reabsorption, K+ loss; ANP → ↓blood Na+; PTH → ↑Ca2+ reabsorption in DCT

True or False

The amount of testosterone and sperm produced by the testes is dependent on the influence of FSH alone.

False

True or False

Ovarian follicles contain mature eggs.

False

True or False

The corpus luteum secretes progesterone.

True

Which of the following hormones controls the release of anterior pituitary gonadotropins?

GnRH

If gametes were diploid like somatic cells, how many chromosomes would the zygote contain?

Twice the diploid number, and with every succeeding generation, the chromosome number would continue to double and normal development could not occur.

Which of the following is true of testosterone?

Testosterone is produced by the Leydig cells

During the secretory phase of the menstrual cycle, ________ reaches its highest levels.

Progesterone

Folliculogenesis and Oogenesis are interrelated processes that are both part of the ovarian cycle. Explain one way that the 2 processes are connected.

Folliculogenesis and oogenesis are connected because the developing follicle supports and nurtures the maturing oocyte (egg) inside it. As the follicle grows and develops during folliculogenesis, it provides the necessary environment and hormonal signals for the oocyte to resume meiosis and continue its development. Without folliculogenesis, oogenesis could not successfully occur.

Describe the process of spermatogenesis.

Spermatogenesis is the process by which sperm are produced in the seminiferous tubules of the testes. It begins with spermatogonia, which are stem cells that divide by mitosis. Some spermatogonia differentiate into primary spermatocytes. These primary spermatocytes undergo meiosis I to form two secondary spermatocytes. Each secondary spermatocyte undergoes meiosis II to produce two spermatids. Finally, spermatids mature into spermatozoa (sperm cells) through a process called spermiogenesis.

What structure of the male reproductive system undergoes surgery during a vasectomy and how does this lead to surgical sterilization?

During a vasectomy, the vas deferens is cut and sealed. The vas deferens is the tube that carries sperm from the epididymis to the urethra. By cutting the vas deferens, sperm can no longer be transported out of the body during ejaculation, leading to sterilization because sperm are absent from the semen.

Compare and contrast mitosis and meiosis in terms of number of cells produced, ploidy, and cell identity.

• Mitosis → 2 cells, diploid, identical

• Meiosis → 4 cells, haploid, non-identical

How may cells does Mitosis create, whats their ploidy, and cell identity?

2 cells, diploid, identical

How many cells does Meiosis produce, whats their ploidy, and cell identity?

4 cells, haploid, non-identical

Describe the process of spermatogenesis.

• Spermatogenesis occurs in the testes (seminiferous tubules).

• Begins with spermatogonia (diploid stem cells) dividing by mitosis.

• Primary spermatocytes (diploid) undergo meiosis I → two secondary spermatocytes (haploid).

• Secondary spermatocytes undergo meiosis II → four spermatids (haploid).

• Spermatids mature into sperm (spermatozoa) through spermiogenesis.

How does cutting and sealing the vas deferens (vasectomy) result in surgical sterilization?

Blocks the path sperm takes to exit the male reproductive system.

Explain the roles of the hypothalamus, anterior pituitary, Sertoli cells, Leydig cells, GnRH, FSH, LH, testosterone, ABP, and inhibin in testosterone regulation.

1. Hypothalamus → releases GnRH (gonadotropin-releasing hormone)
   ↓

2. Anterior pituitary → releases FSH and LH
   ↓

3. LH → stimulates Leydig cells → produce testosterone
   ↓

4. FSH → stimulates Sertoli cells → produce ABP (androgen-binding protein) → helps concentrate testosterone in seminiferous tubules
   ↓

5. Sertoli cells → release inhibin → negative feedback to anterior pituitary to decrease FSH
   ↓

6. Testosterone → negative feedback to hypothalamus and anterior pituitary → lowers GnRH and LH release

What are the male gonads and their function?

Testes → Produce sperm

What are the female gonads and their function?

ovaries → produce oocytes

What are the male and female gonads and their functions?

Male: testes → produce sperm; Female: ovaries → produce oocytes

Trace the path sperm travels after production in seminiferous tubules

Straight tubule → rete testis → efferent ductules → epididymis → vas deferens → penis

Describe the process of spermatogenesis

Spermatogonial stem cell → mitosis → primary spermatocyte → meiosis I → secondary spermatocytes → meiosis II → spermatids → spermiogenesis → spermatozoa (sperm)

Where is semen made and what does it consist of?

Seminal vesicles, prostate, bulbourethral glands → sperm + seminal vesicle secretions + prostate fluid + bulbourethral fluid

Explain the endocrine regulation of testosterone

Hypothalamus → GnRH → anterior pituitary → LH & FSH → LH → Leydig cells → testosterone; FSH → Sertoli cells → ABP → binds testosterone; Negative feedback: testosterone → ↓GnRH, LH, FSH; inhibin → ↓FSH

What are the three layers of the uterus wall?

Perimetrium, myometrium, endometrium

Describe the process of oogenesis

Ovarian stem cells → mitosis → primary oocytes (before birth) → puberty → meiosis I → secondary oocyte + polar body → if fertilized → meiosis II → haploid ovum → zygote

What are the six stages of folliculogenesis?

1. Primordial follicle;

2. Primary follicle (granulosa cells);

3. Secondary follicle (theca + granulosa cells);

4. Tertiary follicle (antrum forms);

5. Ovulating follicle (oocyte released);

6. Corpus luteum

Describe the hormonal regulation of ovulation.

"Hypothalamus → GnRH → anterior pituitary → LH, FSH → LH, FSH → follicle maturation → estrogen → estrogen → ↑GnRH, LH, FSH → LH surge → ovulation"

What are the three phases of the menstrual cycle and hormone changes?,

1. Menses → low estrogen & progesterone;

2. Proliferative → ↑estrogen;

3. Secretory → ↑progesterone