Human Biology: Metabolism, Respiration, and Circulation
Metabolism
Metabolism encompasses all the chemical processes within a living organism. It’s broadly divided into two categories:
- Anabolism: The synthesis or construction of matter.
- Catabolism: The degradation of matter.
Gas Exchange
Gas exchange occurs in the lungs, specifically within the alveoli. Oxygen from the air diffuses into the blood, while carbon dioxide diffuses from the blood into the air. This exchange is driven by simple diffusion. Pulmonary ventilation, the process of air entering and exiting
Read MoreEndocrine System Overview: Glands, Hormones, and Functions
Endocrine System Overview
Hypothalamus
Located in the brain below the thalamus, the hypothalamus acts as the main integration center between the nervous and endocrine systems. It controls the autonomic nervous system and regulates vital functions such as body temperature, thirst, hunger, and emotional responses like fear and anger.
Pituitary Gland
A pea-sized structure (1.5 cm in diameter) situated in the sella turcica of the sphenoid bone, the pituitary gland connects to the hypothalamus via the infundibulum.
Read MoreKidney Structure and Function
Renal Structure
The kidneys are bean-shaped organs located in the back of the abdomen, behind the peritoneum, on each side of the spinal column. They measure about 12 x 6 x 3 cm and weigh between 130 and 150 g. The final product is urine, excreted through the urinary system.
Urine produced by the kidneys is collected in the renal pelvis, flows through the ureters into the bladder, and exits through the urethra.
The functional unit is the nephron. Each kidney contains 600,000 to >1,000,000 nephrons.
Read MoreGenetics Fundamentals: Mendel to Modern Concepts
Mendel’s Pea Plant Experiments
Mendel chose pea plants because they were:
- Fast-growing plants
- Found in a large number of varieties
- Flowers can be easily pollinated artificially
- Study features are found in pairs, not intermediates (e.g., yellow or green peas, no blending)
Key Genetic Terms
Dominant Character:
- Appears in the first generation when crossing two pure species. Notated with capital letters.
- Determined by a dominant gene, which is always expressed when present.
Recessive Character:
- Traits that “skip”
Neuroanatomy Essentials: Brain Structures and Functions
1. Point Vanity
A. The reticular formation is a group of neurons extending from the diencephalon, brainstem to the upper cervical spinal cord.
B. The reticular formation broadly influences the cerebral cortex, controlling consciousness, sleep, and wakefulness.
C. The precentral gyrus is the primary motor area.
D. The neostriatum comprises the caudate nucleus and putamen.
E. The thalamus processes sensations of touch, pressure, pain, and temperature as crude or protopathic.
2. Diencephalon Assertions
A.
Read MoreEvolution of Immunology: From Pasteur to Modern Vaccines
Understanding the Immune System’s Organization
Scientific research over many years has led to our understanding of the immune system’s organization and function (Supplementary reference text).
Louis Pasteur (1822 – 1895)
The 17th and 18th-century disease concept suggested that diseases were inherent from birth. This changed after 1870 with Louis Pasteur, Robert Koch, and others who identified infectious agents. Pasteur showed that acquired immunity could be induced by immunization with attenuated pathogens.
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