Blood and Reproductive Systems Practice Flashcards

Comprehensive practice flashcards covering Chapter 14 (Blood) and Chapter 22 (Reproductive Systems) based on lecture notes.

What is the average blood volume of an adult?

The average blood volume of an adult is $5\,\text{liters}$.

What percentage of blood by weight is composed of formed elements versus plasma?

Formed elements compose $45\%$ of blood by weight, while plasma composes $55\%$ by weight.

What is the name of the large primitive stem cell from which all blood cells are formed?

All blood cells are formed from a hemocytoblast (hematopoietic stem cell).

Where does blood cell production (hematopoiesis) occur in the embryo, fetus, and adult?

In the embryo, hematopoiesis occurs in the yolk sac; in the fetus, it occurs in the liver and spleen; and in adults, it occurs in red bone marrow.

What are the primary physical characteristics and method of ATP production for mature erythrocytes?

Mature red blood cells are tiny ($7.5\,\mu\text{m}$ diameter), biconcave disks that lack nuclei and produce ATP strictly through glycolysis.

What is the average red blood cell count (RCC) in a healthy individual?

The average RCC is $4\,\text{million}$ to $6\,\text{million}$ RBCs/$\text{mm}^3$ of blood.

What hormone controls red blood cell production, and which organs secrete it?

Erythropoietin controls RBC production, and it is produced and secreted by special cells in the kidney and liver in response to low blood oxygen.

What is the average lifespan of a red blood cell, and how are worn RBCs destroyed?

The average lifespan is $120\,\text{days}$, and worn RBCs are destroyed by macrophages in the liver and spleen.

What are the five types of white blood cells and their normal percentage ranges in blood?

Neutrophils ($54\%-62\%$), Eosinophils ($1\%-3\%$), Basophils ($<1\%$), Monocytes ($3\%-9\%$), and Lymphocytes ($5\%-33\%$).

Which leukocyte is the largest in size, and what is it called when it enters body tissues?

Monocytes are the largest leukocytes ($12-20\,\mu\text{m}$ in diameter) and are called macrophages when they enter body tissues.

What do the terms leukocytosis and leukopenia signify regarding white blood cell counts?

Leukocytosis signifies a white blood cell count greater than $10,000\,\text{WBCs/mm}^3$, whereas leukopenia signifies a count less than $5,000\,\text{WBCs/mm}^3$.

From what giant cells are blood platelets derived, and what is the normal platelet count?

Platelets are fragments of giant cells called megakaryocytes, and the normal count is $130,000-360,000\,\text{platelets/mm}^3$ of blood.

What are the three major plasma proteins and their main functions?

Albumin maintains cellular osmotic pressure and transports fatty acids; globulins act as antibodies; and fibrinogen functions in blood clotting. All three are produced in the liver.

What are the three step-by-step mechanisms involved in hemostasis in order?

1. Blood Vessel Spasm (vasospasm)
2. Platelet Plug Formation
3. Blood Coagulation

What distinguishes the starting condition of the extrinsic clotting mechanism from the intrinsic clotting mechanism?

The extrinsic mechanism starts when blood contacts damaged tissue outside a blood vessel (a break in the vessel wall), while the intrinsic mechanism starts when blood contacts a foreign substance without a break in the vessel wall.

How do a thrombus, an embolus, and an embolism differ?

A thrombus is an abnormal clot formed in an intact vessel; an embolus is a floating, detached clot; and an embolism occurs when an embolus gets lodged in a small blood vessel, obstructing blood flow.

Which blood type is considered the universal donor, and which is the universal recipient?

Type O blood is the universal donor because its RBCs lack A and B antigens. Type AB blood is the universal recipient because it produces neither anti-A nor anti-B antibodies.

What causes erythroblastosis fetalis (hemolytic disease of the newborn)?

It occurs when an Rh-negative mother previously sensitized to Rh-positive blood conceives a second Rh-positive fetus, causing her anti-Rh antibodies to cross the placenta and hemolyze the fetus's red blood cells.

What are the chromosome counts for human diploid somatic cells versus haploid gametes?

Human somatic cells are diploid ($2n = 46$ chromosomes), while human sex cells or gametes are haploid ($n = 23$ chromosomes).

What are the roles of spermatogenic cells and sustentacular (Sertoli) cells in the seminiferous tubules?

Spermatogenic cells give rise to sperm cells, whereas sustentacular (Sertoli) cells support and nourish the spermatogenic cells.

What structural components make up a mature sperm cell?

A mature sperm cell consists of a head (containing $23$ chromosomes and an acrosome), a body/mid-piece (containing mitochondria for ATP production), and a flagellum (tail for locomotion).

What fluids make up human semen?

Semen is composed of sperm cells (from the testes), alkaline fluids (from the prostate and seminal vesicles), fructose (from the seminal vesicles), and lubricant (from the bulbourethral glands).

What are the two structural zones of the ovary and their primary contents?

The inner medulla contains connective tissue, blood and lymph vessels, and nerves for support and nourishment. The outer cortex contains ovarian follicles covered by germinal epithelium.

Under what specific condition does a secondary oocyte undergo Meiosis II?

Meiosis II is initiated and completed if and only if the secondary oocyte is penetrated by a sperm cell.

What are the three layers that compose the uterine wall?

1. Endometrium (inner lining and site of embryo implantation)
2. Myometrium (middle layer of smooth muscle bundles)
3. Perimetrium (outer visceral covering)

Which hormone surge on Day 14 of the female reproductive cycle causes ovulation?

A surge of Luteinizing Hormone (LH) released by the anterior pituitary gland causes ovulation.

What structure secretes progesterone during Days 14-24 of the female cycle, and what is its effect on the uterus?

The corpus luteum secretes progesterone, which causes the uterine endometrium to become thick, glandular, and vascular to prepare for embryo implantation.

What happens to the corpus luteum and hormone levels if implantation does not occur by Day 24 of the female cycle?

The corpus luteum degenerates into the corpus albicans, causing a dramatic decline in progesterone and estrogen levels between Days 24 and 28.

What hormonal characteristics define menopause?

Menopause is characterized by a low concentration of estrogens alongside continuous secretion of FSH and LH.

What is the average blood volume in a healthy adult?

The average blood volume of an adult is $5\,\text{liters}$.

What percentage of blood volume is composed of formed elements versus plasma?

Formed elements (mainly red blood cells) make up $45\%$ by weight, measured as the hematocrit (HCT) or packed cell volume (PCV), while plasma makes up $55\%$ by weight.

Where does hematopoiesis occur during the embryo, fetus, and adult stages of human development?

In the embryo, hematopoiesis occurs in the yolk sac; in the fetus, it occurs in the liver and spleen; in adults, it occurs in red bone marrow.

From what common primitive cell do all blood cells originate, and what are its two main cell lineages?

All blood cells form from a hemocytoblast (hematopoietic stem cell), which gives rise to myeloid stem cells (all cells except lymphocytes) and lymphoid stem cells (lymphocytes).

What are the structural characteristics and ATP production method of mature red blood cells?

Mature RBCs are biconcave disks of $7.5\,\mu\text{m}$ diameter. They lack nuclei (anucleate) and mitochondria, producing ATP exclusively through glycolysis.

What is the normal red blood cell count (RCC) in a healthy individual?

Average RCC is $4\text{ million to }6\text{ million RBCs/mm}^3$ of blood.

How does the homeostatic negative feedback mechanism control red blood cell production?

Chemoreceptors in the kidney and liver detect low blood oxygen and release the hormone erythropoietin, which targets red bone marrow to stimulate erythropoiesis.

What is the average lifespan of a red blood cell, and how are its destruction products processed?

RBCs live an average of $120\,\text{days}$. Macrophages in the liver and spleen break hemoglobin into globin and heme. Heme iron is recycled, while the rest breaks down into biliverdin and then bilirubin for excretion.

What are the three types of granulocytes and their relative percentages in blood?

Neutrophils ($54\%\text{--}62\%$), Eosinophils ($1\%\text{--}3\%$), and Basophils ($<1\%$).

What are the functions of basophils and what are they called when they enter tissues?

Basophils release heparin to inhibit blood clotting and histamine to promote inflammation; when they leave the bloodstream and enter connective tissue, they are called mast cells.

What are the characteristics and functions of monocytes?

Monocytes make up $3\%\text{--}9\%$ of WBCs, are the largest WBC ($12\text{--}20\,\mu\text{m}$ in diameter), perform phagocytosis, and are called macrophages when they enter tissues.

What is the average total white blood cell count (WCC), and what do leukocytosis and leukopenia signify?

Normal WCC is $5,000\text{--}10,000\,\text{WBCs/mm}^3$. Leukocytosis is a count greater than $10,000\,\text{WBCs/mm}^3$ (indicating infection), and leukopenia is a count less than $5,000\,\text{WBCs/mm}^3$.

What are the three major plasma proteins and their primary functions?

Albumin maintains osmotic pressure and transports fatty acids; globulins function as antibodies; fibrinogen functions in blood clotting.

What are the three sequential steps of hemostasis?

1. Blood vessel spasm (vasospasm), 2. Platelet plug formation, and 3. Blood coagulation.

How does the extrinsic clotting mechanism differ from the intrinsic clotting mechanism in its trigger?

The extrinsic mechanism is triggered when blood contacts damaged tissue outside a vessel (a break in the vessel wall), while the intrinsic mechanism is triggered when blood contacts a foreign substance without a break in the vessel wall.

What final biochemical conversion occurs during blood coagulation?

Prothrombin activator and calcium ions convert prothrombin to thrombin, which then catalyzes the polymerization of soluble fibrinogen into insoluble fibrin mesh.

What are the differences between a thrombus, an embolus, and an embolism?

A thrombus is an abnormal clot forming in an unbroken vessel; an embolus is a floating, dislodged clot; an embolism occurs when an embolus gets lodged in a smaller vessel and obstructs blood flow.

Which antigens and antibodies are present in each of the four ABO blood types?

Type A has A antigen and Anti-B antibodies; Type B has B antigen and Anti-A antibodies; Type AB has both A and B antigens and neither antibody; Type O has neither antigen and both Anti-A and Anti-B antibodies.

Why is Type O considered the universal donor and Type AB the universal recipient?

Type O RBCs lack A and B antigens so they do not react with recipient antibodies; Type AB individuals do not produce Anti-A or Anti-B antibodies so they do not attack donor RBC antigens.

What causes Erythroblastosis Fetalis (Hemolytic Disease of the Newborn) and how is it prevented?

It occurs when an Rh-negative mother is sensitized by an Rh-positive fetus during a first delivery and her resulting anti-Rh antibodies cross the placenta in a subsequent pregnancy to hemolyze an Rh-positive fetus's RBCs. It is prevented by administering RhoGAM.

What are the chromosome numbers for human somatic cells versus human gametes?

Somatic cells are diploid ($2n = 46$ chromosomes), whereas gametes are haploid ($n = 23$ chromosomes).

When do the testes descend into the scrotum and what hormone stimulates this process?

The testes descend at $7\text{--}8\,\text{months}$ gestation through the inguinal canal into the scrotum, stimulated by testosterone.

What specific functions are performed by the seminiferous tubules and the interstitial cells of Leydig in the testes?

Seminiferous tubules are the site of sperm cell production, whereas interstitial cells of Leydig produce male sex hormones (androgens/testosterone).

What are the three structural regions of a mature sperm cell and their functions?

The head contains $23$ chromosomes and an acrosome with enzymes to penetrate the oocyte; the body (mid-piece) contains mitochondria to produce ATP; the flagellum provides locomotion.

What fluid contributions do the seminal vesicles, prostate gland, and bulbourethral glands make to semen?

Seminal vesicles secrete an alkaline fluid rich in fructose for sperm energy; the prostate gland secretes a milky alkaline fluid that enhances sperm motility; bulbourethral glands secrete a lubricant prior to ejaculation.

When does Meiosis II complete during female oogenesis?

Meiosis II is initiated only if a secondary oocyte is penetrated by a sperm cell, and upon completion, it produces a second polar body and a mature haploid ovum.

What are the three layers of the uterine wall and their descriptions?

The endometrium is the inner lining and site of embryo implantation; the myometrium consists of smooth muscle bundles forming the bulk of the uterus; the perimetrium is the visceral outer covering.

What are the actions of Follicle Stimulating Hormone (FSH) during Days 0 to 14 of the female reproductive cycle?

FSH stimulates a primary oocyte to enlarge and undergo Meiosis I, causes follicular cells to multiply into granulosa cells, forms the zona pellucida, antrum, and corona radiata, and induces the follicle to secrete estrogen.

What causes ovulation on Day 14 of the female reproductive cycle, and what does the burst follicle become?

A surge of Luteinizing Hormone (LH) from the anterior pituitary causes ovulation, and the remnants of the burst follicle transform into the corpus luteum.

What is the role of progesterone secreted by the corpus luteum between Days 14 and 24?

Progesterone targets the uterine endometrium to prepare it for embryo implantation by making it thick, glandular, and vascular.

What occurs in the female reproductive cycle if embryo implantation does not occur by Day 24?

The corpus luteum degenerates into the corpus albicans, causing estrogen and progesterone levels to drop rapidly from Days 24 to 28, which triggers menstruation and stimulates the release of GnRH and FSH on Day 0 to start a new cycle.