BCC Bioscience Image Library is a media file repository of images and video clips made available to educators and students in the biological sciences. The resources are created by faculty, staff and students of Berkshire Community College and are licensed under Creative Commons 0. This means all content is free, with no restrictions on how the material may be used, reused, adapted or modified for any purposes, without restriction under copyright or database law.

This project was partially funded by a $20,000,000 grant awarded by the U.S. Department of Labor’s Employment and Training Administration, Grant # TC-26450-14-60-A-25. The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The U.S. Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.

If you have any questions contact professor Faye Reynolds at: freynold@berkshirecc.edu

BCC Bioscience Image Library is a media file repository of images and video clips made available to educators and students in the biological sciences. The resources are created by faculty, staff and students of Berkshire Community College and are licensed under Creative Commons 0. This means all content is free, with no restrictions on how the material may be used, reused, adapted or modified for any purposes, without restriction under copyright or database law.

This project was partially funded by a $20,000,000 grant awarded by the U.S. Department of Labor’s Employment and Training Administration, Grant # TC-26450-14-60-A-25. The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The U.S. Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.

If you have any questions contact professor Faye Reynolds at: freynold@berkshirecc.edu

Oogenesis is the process of producing the female gametes, the Ovum, from the primordial germ cells. The majority of the steps in oogenesis, up to the point of producing primary oocytes, occur pre-natally. Therefore, females are born with all of the Primary Oocytes that they will ever have as primary oocytes do not divide further.

The ToxMSDT program is providing 6 case study learning modules to toxicology curious students, professionals and the general public.

This Open Educational Resources site will complement textbooks and lectures with obvious information gaps. An extension of regular learning content. For example, you can accompany the text with multimedia materials such as videos. By presenting information in multiple formats, students can more easily learn the material being taught.

Thermoregulation is the ability of an endothermic organism to maintain a relatively constant body temperature, despite fluctuations in temperature of the external environment. This is a vital part of homeostasis.

The cervix can be palpated transrectally and forms a sphincter controlling access to the uterus.The anatomy of the cervical canal is adapted to suit a particular pattern of reproduction and its composition will alter under the influence of reproductive hormones. Not only does it respond to the fluctuation in oestrodiol during the oestrous cycle, but is responsive to prostaglandins and oxytocin in order to 'soften' for parturition.

The Blood Brain Barrier refers to the mechanisms in place around the microvasculature of the brain to ensure optimal neural functioning. Endothelial cells are the structural basis of the blood brain barrier and are joined by tight cellular junctions formed by the transmembrane proteins the occludins and the claudins.

The adrenal glands are paired bodies lying cranial to the kidneys within the retroperitoneal space. The glands consist of two layers; the cortex and medulla.

Different hormones, neurotransmitters and reflexes are involved in the complicated process of feeding in animals. Secretions and motility of the gastrointestinal tract are stimulated and carefully regulated by numerous factors, including environmental stimuli and the presence of food in different parts of the gastrointestinal tract from the oral cavity right through to the intestines. When a harmful substance is ingested the body acts to eliminate it in different ways to prevent the animal becoming ill, for example, through vomiting and diarrhoea. If one or more of the pathways in controlling feeding is damaged or inhibited, then problems such as obesity occurs.

Sexual differentiaton by default follows a pathways for development of female internal and external genitalia, requiring no active intervention. Endocrine activity of the testes, production of Androgens by Leydig cells and Mullerian Inhibiting hormone (MIH) by Sertoli cells, is required for sexual differentiation to be diverted down the male genitalia development pathway.

The oesophagus (or gullet) is a muscular tube which transports food from the pharynx to the stomach. A bolus of food is passed down the oesophagus by peristalsis. The oesophagus is divided into cervical, thoracic and abdominal sections.

The intestines occupy the caudal part of the body. They contact the reproductive organs and the gizzard. The small intestine is long and relatively uniform in shape and size. There is no demarcation between the jejunum and the ileum.

The mammary gland is a modified sweat gland that nourishes the young. It consists of the mamma and the teat. Undeveloped in both the male and female at birth, the female mammary gland begins to develop as a secondary sex characteristic at puberty.

The midbrain or mesencephalon represents the connection between the brain stem and the higher centres of the brain and is involved in most body systems including sleep/consciousness, vision, hearing and temperature regulation.

Prior to birth the foetus is not capable of respiratory function and thus relies on the maternal circulation to carry out gas, nutrient and waste exchange. The foetal and maternal blood never mix, instead they interface at the placenta. Consequently the liver and the lungs are non-functional, and a series of shunts exist in the foetal circulation so that these organs are almost completely by-passed.

The term 'implantation' is often used to describe the attachment of the placental membranes to the endometrium in most animals. True implantation is a phenomenon in rodents and humans in which the conceptus 'buries' itself in the uterine endometrium. The conceptus temporarily disappears beneath the surface. In most other species, the conceptus does not truly implant, but attaches to the endometrial surface and remains in the luminal compartment.

The mediastinum divides the thoracic cage into two halves. It extends from the Spine to the Sternum and contains many structures including blood vessels, nerves, oesophagus, trachea and heart.

Osmosis is the passive movement of water across a semi permeable membrane. It occurs in the opposite direction to diffusion of ions. Water moves from a region of low solute concentration and therefore high water concentration to a region of high solute concentration and low water concentration.

Neurotransmitters are chemicals that are used to relay, amplify and modulate signals between neurones and cells. They can be classified into two main groups; small-molecule transmitters (SMT) and neuropeptides.