Unit 3A

Morphophysiology and Development

  • The body regulates temperature in response to nervous system signals.

Human Excretory System

  • Composed of:

    • Kidneys

    • Ureters

    • Urinary bladder

    • Urethra

  • Function: kidneys filter blood and form urine, which is stored until eliminated through the urethra.

  • Structure of the kidney is illustrated on the right.

Human Digestive System

  • Digestion Starts in the Mouth:

    • Food is masticated by teeth and moistened with saliva.

    • Saliva contains enzymes that digest starches and fats.

    • The tongue helps move the bolus into the esophagus for swallowing.

  • Large Intestine Function:

    • Reabsorbs water from undigested food.

    • Stores waste until elimination.

The Stomach

  • Acidic Environment:

    • Most protein digestion occurs here.

  • Balanced Diet:

    • Comprises fruits, vegetables, grains, protein, and dairy.

Respiratory System

  • Air enters through the nasal cavity, traveling through:

    • Pharynx

    • Trachea

    • Lungs

The Heart

  • Divided into four chambers:

    • Two atria

    • Two ventricles

  • Chamber functions:

    • Right side: receives deoxygenated blood, pumps it to lungs.

    • Left side: pumps oxygenated blood to the body.

  • One-way valves separate each chamber.

Cardiac Cycle

  • Comprised of systoles and diastoles:

    • Diastole: all chambers relaxed, blood flows in.

    • Atrial systole: pushes blood into ventricles.

    • Ventricular systole: pushes blood out of the heart.

  • Arteries: Red, supply oxygenated blood.

  • Veins: Blue, return deoxygenated blood to the heart.

Endocrine Glands

  • Pituitary Gland: Located at the base of the brain.

  • Parathyroid Glands: On the posterior of the thyroid gland.

  • Adrenal Glands: Situated atop the kidneys.

  • Pancreas: Between the stomach and small intestine.

Skeleton Overview

  • Axial Skeleton: Bones of the skull, ear ossicles, hyoid bone, vertebral column, thoracic cage.

  • Appendicular Skeleton: Bones of the limbs and girdles.

Muscle Tissue Types

  • Types of Muscle Tissue:

    • Skeletal: Long, cylindrical, multi-nucleated.

    • Smooth: Short, tapered, single nucleus.

    • Cardiac: Short, branched, one or two nuclei.

  • Skeletal Muscle Fiber: Surrounded by sarcolemma, contains sarcoplasm, striated appearance due to orderly protein arrangement.

Neurons

  • Neurons have organelles: nucleus, mitochondria, plus dendrites and axons.

  • Spinal Cord: Comprised of gray matter (cell bodies) and white matter (myelinated axons).

Immune System

  • Vaccination: Smallpox vaccine derived from cowpox virus.

    • Vaccines stimulate immune response for future infections.

  • Variola Structure: Dumbbell-shaped under electron microscope, contains viral DNA.

Virus Discovery

  • Tobacco Mosaic Virus: First virus discovered, visible via electron microscopy.

  • Virus Size: Small relative to cells and organelles.

Ebola Virus Visualization

  • Visualized using scanning and transmission electron microscopes.

  • Complexity of viruses:

    • Bacteriophage T4: DNA head, tail fibers.

    • Adenovirus: Spikes for binding to host.

    • HIV: Uses glycoproteins for attachment, includes matrix proteins for stability.

    • Retrovirus: Reverse transcribes RNA genome into DNA, integrates into host DNA.

Influenza Virus Infection

  • Glycoproteins attach to host cells, leading to RNA and protein assembly for new virions.

  • Viruses cause a range of illnesses from mild to serious.

Immune Response Overview

  • Innate vs. Adaptive Immunity:

    • Innate: Physical barriers and internal defenses, general response.

    • Adaptive: Specific responses, involves white blood cells (leukocytes).

Immune Cell Features

  • Innate Response Cells: Mast cells, NK cells, monocytes, macrophages, neutrophils.

  • T and B cells: Similar appearance, differentiated by surface receptors.

B Cells and Antibodies

  • B cell receptors bind antigens.

  • Antibodies function:

    • Prevent target binding.

    • Tag pathogens for destruction.

    • Activate complement cascade.

Primary Immune Response

  • First exposure results in antibody secretion from plasma cells.

  • Memory cells lead to enhanced antibody production on re-exposure.

  • Lymphatic System: Carries lymph fluid, filtered through lymph nodes filled with lymphocytes.

HIV Reproduction

  • HIV observed budding from a lymphocyte cell.

Allergic Response

  • First exposure to allergen leads to antibody synthesis in plasma cells.

  • Secondary exposure causes mast cells to release histamines, resulting in allergy symptoms.

Unique Reproductive Strategies

  • Seahorses: Males fertilize eggs and carry developing young in a pouch.

  • Anemones: Can reproduce through fission.

  • Hydra: Budding occurs; new hydra detaches after development.

  • Coral: Reproduce through budding.

Asexual Reproduction in Sea Stars

  • Sea stars reproduce asexually via fragmentation; shed arms regenerate into new individuals.

Snail Mating

  • Many snails are hermaphrodites, capable of mating to produce numerous eggs.

Toad Reproduction

  • Males externally fertilize eggs while grasping females.

  • Oviparity: Eggs develop outside the female.

  • Ovoviviparity: Eggs develop inside the female.

  • In mammals, nutrition is from the placenta.

Fertilization and Zygote Development

  • Fertilization forms zygote.

  • Cleavage: Zygote divides rapidly.

  • Blastula Formation: Cells form a hollow ball.

Gastrulation

  • Rearrangement of cells in the blastula to form germ layers.

Male Reproductive Structure

  • Showcases male reproductive anatomy.

Female Reproductive Structure

  • Displays female reproductive anatomy.

  • Spermatogenesis: Each primary spermatocyte yields four sperm.

  • Structure of seminiferous tubule illustrated for context.

Oogenesis

  • Occurs in the outer layer of the ovary, regulated by hormones.

Hormonal Regulation of Female Reproduction

  • Ovarian and menstrual cycles regulated by hormones from the hypothalamus, pituitary, and ovaries.

  • Includes fetal development stages.

Gestation Stages

  • Shows fetal growth and development stages during pregnancy, emphasizing the role of the placenta in nutrient support in mammals.

Conclusion

  • End of content overview regarding reproductive systems and physiological processes.