Notes, summaries, assignments, exams, and problems for Biology

Major Arteries of the Human Body

• Aorta: Extends from the left ventricle of the heart down to the abdomen.
• Carotid Artery: Located on the left and right sides of the neck.
• Subclavian Artery: Positioned underneath the clavicle.
• Pulmonary Artery: Located at the base of the heart's right ventricle.
• Coronary Artery: Supplies the heart muscle.
• Axillary Artery: Located in the armpit region.
• Brachial Artery: Located in the forearm.
• Posterior Tibial Artery: Located behind the tibia.

The Lymphatic System

The lymphatic system is responsible for the removal of interstitial fluid from tissues, the absorption and transport of fatty acids and fats (as chyle) from the digestive system, and the transport of white blood cells to and from lymph nodes and bones.

Lymphatic

Skeletal Class II and Class III Malocclusions

Causes of skeletal malocclusions include:

• Class II: Hypertrophic maxilla or retrognathic mandible.
• Class III: Hypoplastic maxilla or prognathic mandible.

Functional appliances are typically utilized between ages 11–14 for boys and 10–13 for girls to address Class II issues. Transverse dimension features include compression, crossbite, scissor bite, and midline deviation.

Intramembranous Bone Formation

1. Osteoblasts produce osteoid tissue.
2. Cells and blood vessels become encased.
3. Osteoid tissue is produced by membrane cells.
4. Osteoid calcifies.
5. Essential membrane covers the bone, alongside an internal membrane.

Moyers Method for Mixed Dentition

The Moyers method is used during interarch relationship analysis... Continue reading "Orthodontic Diagnosis and Treatment Planning Essentials" »

What is a Tissue?

A tissue is an aggregate of connected cells that have a similar origin, structure, and function and cooperate to perform a certain function.

Epithelial Tissue

Epithelial tissue covers the body and organ surfaces, lines body cavities, and forms glands. It is involved with protection, absorption, and excretion.

It is made of one or more layers of cells arranged without spaces between them. They can be different shapes—such as flat, prismatic, or cubic—and be arranged in one or more different layers.

Functions of Epithelial Tissue

Epithelia line or cover your body surface, your organs, and all your body cavities, such as your digestive tract, your lungs, blood vessels, and bladder to protect them. Quite often, they perform other... Continue reading "Human Body Tissues: Types and Functions" »

Cooking Techniques

Moist-Heat Techniques

Methods in which heat is conducted to foods by water or other liquid or by steam:

• Simmer: To cook in water or other liquid that is bubbling gently (85-96°C). Similar to poaching, the only difference is the time.
• Steam: To cook by direct contact with steam.
• Boil: To cook in water or other liquid that is bubbling rapidly, about 100°C at sea level and at normal pressure.
• Poach: To cook gently in water or other liquid that is hot but not actually bubbling (71-82°C).
• Blanch: To cook an item partially and very briefly in boiling water or in hot fat. Usually a pre-preparation technique, as to loosen peels of vegetables, fruits, and nuts, to partially cook French fries or other foods before service, to prepare for

Nervous System Fundamentals

• Nervous System Function: Control and communication.
• Autonomic Nervous System: Regulates internal organs.
• Central Nervous System (CNS): Controls most functions of the body and mind (brain and spinal cord).
• Peripheral Nervous System: Connects the CNS to limbs and organs (cranial and spinal nerves).

Brain and Spinal Structures

• Cerebrum: Senses, thoughts, and movements (frontal, parietal, temporal, occipital lobes).
• Cerebellum: Balance, coordination, and speech (anterior lobe, posterior lobe, primary fissure).
• Diencephalon (Thalamus): Processes sensory and motor signals.
• Diencephalon (Hypothalamus): Links the nervous system to the endocrine system.
• Medulla Oblongata: Controls breathing, swallowing, and heart rate.
• Pons: Connects

Human Receptors and Nervous System

Receptors: Structures that human beings use to detect stimuli.

Interoceptors

Collect information about the body’s internal conditions. Located in the internal environment.

Exteroceptors

Provide information from the body’s outside environment. Located on the surface of the body.

Proprioceptors

Inform about the relative position and condition of each of the body’s muscles. Found in the inner ear’s vestibule and locomotive system.

Eyes/Sight

Detect light stimuli. Photoreceptors

Ears/Hearing

Detect sound waves (Mechanoreceptors) and proprioception.

Nose/Smell

Detect substances dissolved in the air. Chemoreceptors

Mouth/Taste

Detects substances dissolved in liquids found in the oral cavity. Chemoreceptors

Skin/Touch

Detects... Continue reading "Human Receptors and Nervous System: An Overview" »

1. Telomerase is a ribonucleoprotein complex that consists of telomerase RNA (which contains several tandem hexanucleotide repeats complementary to the telomere repeats in the substrate) and a reverse transcriptase. This complex is able to synthesize telomeric repetitive DNA sequences at the end of linear DNA molecules. Telomerase RNA binds to the DNA strand, and complementary dNTPs are incorporated into newly synthesized, extended DNA strands by reverse transcriptase. Thus, dNTPs must also have been present during step 1 of the TRAP assay (step 1).

2. The PCR reaction mixture also contained a heat-resistant DNA polymerase (Taq polymerase).

3. Sample 3 contained cell extract isolated from immortal cells. In the presence of the telomerase, products... Continue reading "Telomerase Activity in Immortalized Cells" »

Blood Composition and Functions

Cells live immersed in a medium that provides them with all the nutrients they need. They also secrete the waste products released during metabolism into this medium. In multicellular organisms like humans, this medium is called the internal milieu and is made up of the interstitial plasma, a fluid found in the space between the cells. The interstitial plasma is renewed thanks to the blood, which continuously circulates around the whole body, providing nutrients and taking away waste products.

What is Blood?

Blood is a viscous fluid with a salty taste that flows inside the vessels that make up the circulatory system.

Blood Components

Blood is made up of cells suspended in a liquid called blood plasma.

• Blood plasma

Understanding Cells: Structure, Functions, and Types

The cell is the smallest unit of a living organism that can carry out vital functions: nutrition, interaction, and reproduction.

Essential Cell Components

All cells possess a plasma membrane, cytoplasm, and DNA.

• Plasma Membrane: This is a very thin and stretchy cover that separates a cell from its environment. Its primary function is to regulate the movement of substances in and out of the cell. It also detects environmental stimuli and allows cells to communicate.
• Cytoplasm: This is the substance contained inside the cell, in which the cell organelles are found. Metabolic processes occur within the cytoplasm.
• Genetic Material (DNA): A complex chemical substance that contains the information needed

Oparin’s Theory of the Origin of Life

1. The primitive atmosphere was made up of gases: ammonia, water vapor, methane, and hydrogen.
2. The energy for the first chemical reactions to occur came from volcanic eruptions, radiation from the sun, and storms.
3. The temperature of the Earth fell, so the water vapor condensed and formed seas.
4. Organic molecules, synthesized by the reactions, accumulated in the water and joined together to form bigger molecules.
5. Coacervates were structures formed by organic molecules insulated from the water.
6. The first cell appeared when the coacervates started to reproduce.

The Endosymbiotic Theory

The Endosymbiotic Theory of Margulis explains the appearance of the first eukaryotic living things from the symbiotic relationships... Continue reading "Origins of Life and Biological Evidence for Evolution" »