Search results for: 'A Human Karyotype Preparation Animation'

Watch Later 1:13

By: HWC, Views: 3840

Blood is collected from the person being analyzed. The blood is added to a growth medium that also contains a chemical that stimulates mitosis. The cells are allowed to grow in this medium for two or three days at body temperature. Colchicine is added to arrest cell division at metaphase. T...

Watch Later 1:16

Amniocentesis and CVS Animation

By: HWC, Views: 3582

Amniocentesis and chorionic villus sampling (CVS) are prenatal diagnostic tools. In amniocentesis, which can be performed as early as 14 weeks into the gestation period. A syringe needle is inserted through the abdominal and uterine walls to withdraw some amniotic fluid. The fluid contains...

Watch Later 0:51

Interpreting a cladogram Animation

By: HWC, Views: 276

Using a cladogram to determine relative relatedness and whether the lungfish is more closely related to a human or to a trout. To determine the relative relatedness, we begin by tracing the branches from the human and the lungfish to the point where they meet. We'll call this node 1. Now...

Watch Later 1:29

Mitosis step-by-step

By: HWC, Views: 4570

During interphase, the chromosomes will be duplicated in preparation for mitosis, which divides the chromosomes, and cytokinesis, which divides the cell's cytoplasm. In early prophase, the duplicated chromosomes begin to condense. Each chromosome consists of two sister chromatids joined at the...

Watch Later 2:10

Hormonal regulation of pregnancy - weeks 17 through 38

By: HWC, Views: 6899

• Estrogens increase uterine blood flow, maintaining the endometrium during pregnancy. • High levels of estrogen and progesterone inhibit the synthesis of milk. Progesterone inhibits myometrial contractions of the uterus to prevent premature birth. • Relaxin inhibits myometrial contract...

Watch Later 1:51

Lactation and Breast Feeding

By: HWC, Views: 7471

Regulation of lactation - breast preparation • Pregnancy hormones trigger breast changes to prepare for feeding the new baby. • The amount of the hormone prolactin, essential to the initiation of lactation, increases steadily throughout pregnancy. • However, high levels of both estroge...

Watch Later 1:03

hGH (protein synthesis, growth and development)

By: HWC, Views: 7109

• Increased GHRH, a hypothalamic releasing hormone stimulated by low blood glucose, physical exertion, and increased sympathetic stimulation, stimulates the production of human growth hormone (hGH) from the somatotrophic cells of the anterior pituitary. • Human growth hormone targets cartil...

Watch Later 2:44

Introduction to Human Immunodeficiency Virus (HIV)

By: Administrator, Views: 9567

Human immunodeficiency virus gains entry into helper T cells, uses the cell DNA to replicate, interferes with normal function of the T cells, and destroys the normal cells. 1 in 10 persons with AIDS: age 50 or older. 4% of all AIDS cases: age 65 or older. AIDS’ main form of treatment: an...

Watch Later 1:45

Head and Neck Movement Animation

By: Administrator, Views: 296

Interestingly, head and neck muscles are the first ones that the baby can control. A baby can hold his head up before he can sit erect. The muscles of the head and neck perform many important tasks, including movement of the head and neck, chewing and swallowing, speech, facial expressions, an...

Search Results