Endocrine and Muscle Physiology Quiz

Organic Molecules

• Organic molecules are the building blocks of life
• Carbohydrates are a readily available energy source for the body.
• General structure: Carbon : 2 * Hydrogen : Oxygen
• Monosaccharides are single-chain or single-ring structures, with pentose (5 carbon) and hexose (6 carbon) sugars being the most important in the body.
• Disaccharides form when two monosaccharides join via dehydration synthesis
• Polysaccharides are large, insoluble molecules, ideal for storage. Starch is a plant storage carbohydrate, and glycogen is an animal storage carbohydrate.
• Lipids insulate body organs, build cell membranes, and provide stored energy.
• Triglycerides are made of 1 glycerol and 3 fatty acids.
• Phospholipids have a phosphate-containing group, and are a chief component of cell membranes.
• Steroids are flat molecules with interlocking 4 hydrocarbon rings.

Proteins

• Proteins are the body's primary structural material and have many functions.
• The primary protein structure is a linear sequence of amino acids.
• Secondary protein structures include alpha-helix and beta-sheet.
• Tertiary structure: when secondary structures fold upon one another to produce a ball-like globular structure.
• Quaternary structure: proteins that consist of more than one polypeptide chain.
• Types of proteins include fibrous proteins (structural support) and globular proteins (functional).
• Example fibrous proteins include collagen.
• Globular proteins include enzymes that help regulate biochemical reactions.

Cells

• Cells are the fundamental structural and functional units of living organisms.
• Plasma membrane: the outer boundary of the cell, acting as a selective barrier.
• Phospholipid layer: Forms the basic structure of the membrane, with hydrophilic heads facing the water and hydrophobic tails facing away from the water.
• Membrane proteins: some are constitutive (part of the membrane) while others are inducible (moving/changing positions)
• Cytoplasm: the intracellular fluid containing organelles.
• Nucleus: controls cellular activities; encloses chromatin (genetic information).
• Mitochondria: a powerplant; double membrane, with own DNA; contains ribosomes.
• Ribosomes: involved in protein synthesis. Some are bound to the ER to synthesize proteins to be secreted, and others are free in the cytosol.
• Endoplasmic Reticulum: network of membranes
• Rough ER: associated with ribosomes, important for protein synthesis
• Smooth ER: no ribosomes, involved in lipid metabolism, steroid hormone synthesis, drug detoxification
• Golgi apparatus: processes, packages, and ships proteins and lipids.
• Lysosomes: Contain digestive enzymes, essential for breaking down material.
• Cytoskeleton: Network of rods & accessory proteins that provides the cell with support and shape.
• Centrosome & centrioles: cell center that help in cell division
• Extracellular material: substances outside cells that contribute to body mass (e.g., body fluids, cellular secretions, extracellular matrix)
• Cell junctions: Structures that connect cells (e.g., tight junctions, desmosomes, gap junctions).

Cell Cycle

• Cell cycle = period of cell formation to cell division. Involves three substages (G1, S, G2), followed by mitosis (prophase, metaphase, anaphase and telophase) and cytokinesis.

DNA (Deoxyribonucleic Acid)

• Nucleotide is the basic unit of DNA
• DNA is a double-helix molecule consisting of paired bases (adenine-thymine, guanine-cytosine).
• DNA replication involves copying the DNA molecule to create two identical copies of a DNA molecule.

Transcription & Translation

• Transcription is the process by which the information encoded in DNA is copied into a molecule of RNA -> messengerRNA(mRNA).
• mRNA leaves the nucleus and travel to ribosomes -> Translation
• Translation is the process in which mRNA is used to create protein. The transfer RNA(tRNA) molecules carry amino acids to the ribosomes, where they are assembled according to the sequence of codons in mRNA.
• Initiaton: tRNA subunit binds to mRNA to produce a functional ribosome.
• Elongation: rRNA/mRNA complex move along
• Termination: end codon is reached, water is added to break the peptide chain, and the polypeptide is released.

Tissues

• Tissues are groups of cells that are similar in structure and function.
• Epithelial tissue covers body surfaces and lines cavities.
• Connective tissue supports, connects, and separates different tissues. It is made of ground substance (cellular matrix) and connective tissue fibers and cells.
• Muscle tissue is responsible for movement.
• Nervous tissue is responsible for communication. It is composed of neurons that transmit impulses and neuroglia that support the neurons.

Human development

• Spermatogenesis: produces male gametes (sperm).
• Oogenesis: produces female gametes (ova). Involves meiosis -> one ovum with 23 chromosomes.
• Meiosis: type of cell division -> reductional division.
• Fertilization: joins a sperm to an ovum to form a zygote (initiating embryonic development)

Embryonic development.

• Stages include cleavage (multiple mitotic divisions)
• Blastocyst formation
• Implantation in the uterus
• Gastrulation

Covering, Support and Movement of the Body

• The integumentary system consists of skin, hair and nails.
• Epidermis: outermost protective layer
• Dermis: beneath epidermis, contains connective tissue, including nerve endings.
• Hypodermis: fatty tissue that anchors skin to underlying tissue.
• Bone tissue is connective tissue that forms a skeleton.
• Hyaline, elastic and fibrocartilage are different types of cartilage.
• Bones are organ structures, composed of different tissue types (e.g., compact bone, spongy bone).
• Skeletal muscles are responsible for body movements.

Muscles and Muscle Tissues

• Muscle tissues contain specialized muscle cells (muscle fibers) that contract to cause body motion.
• Types include skeletal muscles (voluntary), cardiac muscles (involuntary) and smooth muscles (involuntary).
• Muscle fibers contain myofibrils which are organized into repeating units called sarcomeres.
• Basic components include sarcomeres, A bands, H zones and M lines, I bands, Z discs and myofilaments.
• Myofilaments include thick (myosin) and thin (actin) filaments whose relative positions change to cause contraction
• Sliding filament model: Mechanism of skeletal muscle contraction, based on the sliding of thin filaments (actin) past thick filaments (myosin) to shorten the sarcomere.

Regulation and Integration of the Body

• The nervous system is divided into two components – Central nervous system (CNS) and Peripheral Nervous system (PNS).
• Neurons are specialized cells that transmit electrical signals.
• Neuroglia are support cells
• Types include astrocytes; microglia; ependymal cells; oligodendrocytes; satellite cells and schwann cells.
• Different types of neurons include sensory (afferent); motor (efferent); and interneurons.
• Different neurotransmitters carry signals between neurons.
• The human brain is divided into four major areas – cerebral hemispheres, diencephalon, brainstem and cerebellum.
• Cerebral cortex is the outermost layer of the cerebral hemispheres. Includes primary and association areas.

The Respiratory System

• The respiratory system's main function is to facilitate gas exchange.
• The respiratory system's organs include the nose, pharynx, larynx, trachea, bronchi and lungs (alveoli).
• Different respiratory structures ensure the air's warming and filtration, as well as voice production.

The Cardiovascular System

• The cardiovascular system circulates blood to deliver oxygen and nutrients and carry waste away.
• The heart is a four chambered pump driving blood flow.
• Blood vessels include arteries, veins, capillaries.

The Digestive System

• Intake, propulsion, digestion & absorption, defecation are major functions of the digestive system.
• Main parts include the mouth, pharynx, oesophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, appendix, colon, rectum); The accessory digestive organs include salivary glands, liver, pancreas, gallbladder
• These organs aid in mechanical and chemical digestion.

The Endocrine System

• The endocrine system uses chemical messengers called hormones. It regulates cellular and/or tissue function.
• The endocrine glands include the pituitary gland (anterior and posterior lobes), thyroid gland, parathyroid glands, adrenal glands; pancreas, ovaries, testes, others.
• These glands secrete hormones to regulate blood glucose levels; stress response; calcium balance & other essential functions.

The Immune System

• The Immune system is composed of organs like thymus, spleen, lymph nodes and bone marrow. It is involved in both innate and adaptive immune responses, with both physical and cellular responses.

Test your knowledge on smooth muscle contraction, heart muscle physiology, and the roles of various hormones in metabolism and reproduction. This quiz covers essential concepts of muscle function, hormone secretion, and feedback mechanisms crucial for understanding human physiology.