Question

8. Describe the anatomical structure of the female breasts (mammary glands) accessory organs of reproduction. as 9. When does ovulation occur? 10. Name and explain the four phases of the human sexual response. Fetal Development 1. Contrast mitosis and meiosis. 2, How does the female have an influence on which sperm fertilizes the mature ovum? 3. Describe the events that take place during transport of the zygote through the fallopian tube. 4. Explain the differences between the chorion and the amnion. 5. What are the functions of amniotic fluid?

Answer 1

Ans) 8) The breast is the tissue overlying the chest (pectoral) muscles. Women's breasts are made of specialized tissue that produces milk (glandular tissue) as well as fatty tissue. The amount of fat determines the size of the breast.

- The milk-producing part of the breast is organized into 15 to 20 sections, called lobes. Within each lobe are smaller structures, called lobules, where milk is produced. The milk travels through a network of tiny tubes called ducts. The ducts connect and come together into larger ducts, which eventually exit the skin in the nipple. The dark area of skin surrounding the nipple is called the areola.

- Connective tissue and ligaments provide support to the breast and give it its shape. Nerves provide sensation to the breast. The breast also contains blood vessels, lymph vessels, and lymph nodes.

9) Ovulation is the release of eggs from the ovaries. In humans, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized by sperm.

10) The sexual response cycle refers to the sequence of physical and emotional changes that occur as a person becomes sexually aroused and participates in sexually stimulating activities, including intercourse and masturbation. Knowing how your body responds during each phase of the cycle can enhance your relationship and help you pinpoint the cause of any sexual problems.

Phases of the sexual response cycle:
Sexual Response Cycle
The sexual response cycle has four phases: excitement, plateau, orgasm, and resolution. Both men and women experience these phases, although the timing usually is different. For example, it is unlikely that both partners will reach orgasm at the same time. In addition, the intensity of the response and the time spent in each phase varies from person to person. Understanding these differences may help partners better understand one another's bodies and responses, and enhance the sexual experience.

Phase 1: Excitement
General characteristics of the excitement phase, which can last from a few minutes to several hours, include the following:

Muscle tension increases.
Heart rate quickens and breathing is accelerated.
Skin may become flushed (blotches of redness appear on the chest and back).
Nipples become hardened or erect.
Blood flow to the genitals increases, resulting in swelling of the woman's clitores and labia minora (inner lips), and erection of the man's penis.
Vaginal lubrication begins.
The woman's breasts become fuller and the vaginel walls begin to swell.
The man's testicles swell, his scrotem tightens, and he begins secreting a lubricating liquid.

Phase 2: Plateau
General characteristics of the plateau phase, which extends to the brink of orgasm, include the following:

The changes begun in phase 1 are intensified.
The vagine continues to swell from increased blood flow, and the vaginel walls turn a dark purple.
The woman's clitores becomes highly sensitive (may even be painful to touch) and retracts under the clitorel hood to avoid direct stimulation from the penes.
The man's testicles are withdrawn up into the scrotem.
Breathing, heart rate, and blood pressure contihanges that occur as a person becomes sexually aroused and participates in sexually stimulating activities, including intercourse and masturbation.

Phase 3: Orgasm
The orgasm is the climax of the sexual response cycle. It is the shortest of the phases and generally lasts only a few seconds. General characteristics of this phase include the following:

Involuntary muscle contractions begin.
Blood pressure, heart rate, and breathing are at their highest rates, with a rapid intake of oxygen.
Muscles in the feet spasm.
There is a sudden, forceful release of sexual tension.
In women, the muscles of the vagine contract. The uterus also undergoes rhythmic contractions.
In men, rhythmic contractions of the muscles at the base of the penes result in the ejaculation of semen.
A rash, or "sex flush" may appear over the entire body.

Phase 4: Resolution
During resolution, the body slowly returns to its normal level of functioning, and swelled and erect body parts return to their previous size and color. This phase is marked by a general sense of well-being, enhanced intimacy and, often, fatigue. Some women are capable of a rapid return to the orgasm phase with further sexual stimulation and may experience multiple orgasms. Men need recovery time after orgasm, called a refractory period, during which they cannot reach orgasm again. The duration of the refractory period varies among men and usually lengthens with advancing age.

Fetal development:

1) There are two major differences between mitosis and meiosis. First, meiosis involves not one, but two cell divisions. Second, meiosis leads to the production of germ cells, which are cells that give rise to gametes. Germ cells are different from somatic cells in a critical way.

- Mitosis consists of one stage whereas meiosis consists of two stages. Mitosis produces diploid cells (46 chromosomes) whereas meiosis produces haploid cells (23 chromosomes). Mitosis produces two identical daughter cells whereas meiosis produces four genetically different daughter cells.