Understanding Hormones and the Reproductive System
Glands are organs that produce hormones. The hypophysis is a gland that regulates all the other glands and depends on the activity of our brain.
Hormones, which are produced by glands, are chemical substances that act on the cells, changing the metabolism of the target organ.
Each hormone has a target organ, which is an organ of a group of tissues that responds to the hormone.
Types of Receptors
- Mechanoreceptors: Capture mechanical energy.
- Thermoreceptors: Capture thermal energy.
- Chemoreceptors: Capture
Nutrition and Food Science: A Comprehensive Guide to Nutrients
Nutrition and Food Science
What is Nutrition?
Nutrition science is the study of foods and nutrients, and their actions, interactions, and balance in relation to health and disease. It also encompasses the social, economic, cultural, and psychological impacts of food. Nutrition can be viewed as an involuntary process that begins after food intake, providing energy, building and repairing body structures, and regulating metabolic processes.
What is Food?
Food comprises any substances that provide the
Read MoreOverview of Osteology, Arthrology, and Myology
ITEM 3. OVERVIEW OF OSTEOLOGY
Classification of Bones
- Long Bones: Typical of limbs, their length reflects both the speed and power of motion. One axis predominates over the other two. They are subject to great traction. Their tubular shaft with a central medullary cavity widens (metaphysis) towards the expanded articular ends (epiphysis), which have separate ossification centers and are often multiple.
- Short Bones: Characterized by no axis predominating over the others. They are subject to compressive
Fish Breeding and Larval Rearing
Fish Breeding
Ovoviviparous vs. Viviparous
Fertilization, as with viviparous fish, is internal for ovoviviparous fish. However, the eggs are retained within the female until hatching. The developing fish are nourished by the egg yolk, not directly from the mother.
In viviparous fishes, fertilization is also internal. Unlike ovoviviparous fish, each embryo receives nutrients directly from the mother’s body, not from an egg reserve. These fish give birth to fully formed offspring.
Internal Fertilization
Fertilization
Read MoreBird Embryology: From Egg to Chick – Segmentation, Blastula & Gastrulation
Bird Embryology: From Egg to Chick
A. Fertilization and Egg Formation
After ovulation, the egg travels through the oviduct, where fertilization occurs. Glands in the oviduct secrete albumin, forming the egg white. The egg’s twisting journey through the oviduct’s spiral folds creates the chalazae, which hold the yolk in place. Shell membranes and the calcareous shell are also added during this process. The egg then enters the cloaca and is laid. This entire process takes approximately 16 to 20 hours.
Read MoreReptile Reproduction: From Snakes to Crocodiles
– Sexual dimorphism is very pronounced and difficult to distinguish males from females. The adult male is slightly smaller than the female, but has the longest tail and voluminous. Sometimes there are differences in the arrangement of the scales. In most cases the male has more plates and less ventral subcaudal.
Fertilization is internal in all reptiles
A) male reproductive organs
The male reproductive tract of snakes, has two hemipenis located at the base of the tail, ventral level, remaining