Mammalian Reproduction, Sensory Systems and Conservation Terms

Mammalian Reproduction, Sensory Systems & Conservation

Lecture 16 — Reproduction II

  • Immunorejection – Maternal immune system attacking the embryo because it is genetically half paternal.
  • Choriovitelline placenta – Marsupial yolk-sac placenta with weak attachment and low efficiency.
  • Embryonic diapause – Temporary pause in embryonic development before implantation.
  • Zona pellucida – Glycoprotein coat around an oocyte or blastocyst that prevents polyspermy and offers protection.
  • Delayed fertilization
Read More

Histology Essentials: Tissue Structure and Cell Function

Histology Fundamentals and Cell Structures

Histology Definition

Histology: Microscopic examination of biological structures that are both structurally and functionally related.

Cytoplasmic Membrane Functions

Cytoplasmic Membrane: Regulates interactions between cells, acts as a mechanical barrier, and provides transport for specific molecules.

Epithelial Tissue and Glands

Epithelial Tissue Characteristics

Epithelial Tissue: Closely linked cells that form continuous sheets and resist external forces. Forms

Read More

Neurobiology, Sensory Systems, and Endocrine Regulation

Glial Cells: Support and Function

Glial cells are the other type of cell found in nervous tissue, often considered support cells. Their functions are directed at helping neurons complete communication. They typically have a higher ratio to nerve cells.

Key Glial Functions

  • Bind nerve cells and maintain the ionic milieu.
  • Modulate the rate of nerve signal propagation.
  • Modulate synaptic action by controlling the uptake of neurotransmitters.
  • Provide a scaffold for neural development.
  • Aid in recovery from neural
Read More

Invertebrate Phyla: Arthropoda, Mollusca, and Hemichordata

Phylum Arthropoda: Jointed Appendages and Exoskeletons

Phylum Arthropoda is the largest phylum in the animal kingdom, comprising more than 80% of all known species. Their hallmark is the presence of jointed appendages and a chitinous exoskeleton.

General Characters of Phylum Arthropoda

  • Level of Organization: Organ-system level.
  • Symmetry and Germ Layers: Bilaterally symmetrical, triploblastic, and metamerically segmented.
  • Exoskeleton: A hard outer covering made of chitin, which provides protection and
Read More

Fundamentals of Neuroscience: Structure and Function

Cellular Foundations of the Nervous System

Neurons: Structure and Function

Neurons are the basic units of the nervous system. They have four functional zones:

  • Input: Dendrites receive information from other cells.
  • Integration: The cell body (or soma) integrates the information it receives.
  • Conduction: A single axon conducts output information away from the cell body as an electrical impulse.
  • Output: Axon terminals at the end of the axon communicate activity to other cells.

Neuronal Shapes and Functions

Different

Read More

Ecological Principles and Environmental Change Dynamics

ADAPTATIONS

Adaptation = heritable trait ↑ fitness. Types: structural, behavioral, physiological. NS: variation→heritability→differential survival→allele freq change.
Predict adaptations by matching trait to environmental pressure.

DISTRIBUTIONS & NICHES

Patterns: random, uniform, clumped. Determined by dispersal limits, abiotic factors, biotic interactions. Fundamental niche = possible; realized = actual after competition/predation.

POPULATION GROWTH

Exponential: discrete Nt+1=λNt (λ>

Read More