zoology lec

• Integumentary System


  Consists mainly of the skin, hair, nails, and exocrine glands, the integumentary system covers and protects other parts of the body. In humans, it makes up about 60% of body weight making it the largest organ system in the human body.
• Integumentary System


  • Helps in the synthesis of Vitamin D
  • Regulation of body heat
  • Excretion of substances such as sweat and oil
  • Sensory reception
  • Gas exchange
• Animals have evolved diverse means of locomotion
• Means of animal locomotion

  • Swimming
  • Walking, hopping, or running
  • Burrowing or crawling
  • Flight
• Musculo-Skeletal System


  Skeletons provide body support, movement by working with muscles, and protection of internal organs
• Types of skeletons


  • Hydrostatic skeleton (e.g. in worms and cnidarians)
  • Exoskeleton (e.g. chitinous in some in arthropods, and calcareous mollusks)
  • Endoskeleton (e.g. cartilaginous or ossified in vertebrates, and spicules in sponges)
• Muscle fibers


  Are cells, consist of bundles of myofibrils
• Myofibrils


  Contain overlapping thick (myosin) filaments and thin (actin) filaments
• Types of Muscle Tissue

  • Skeletal
  • Smooth
  • Cardiac
• Each muscle cell has its own contractile apparatus
• Animals must exchange materials with the environment. This is aided by the circulation of blood that transports materials throughout the body.
• Materials transported by the circulatory system

  • Food and wastes via the digestive system
  • Gases via the respiratory system
  • Metabolic waste via the excretory system
• Open Circulatory System


  Blood leaves vessels and flows among tissues

  
• Closed Circulatory System


  Blood flows through a continuous network of vessels

  
• Circulatory paths


  • Pulmonary circuit - blood flows from the heart to the lungs and back
  • Systemic circuit - blood flows from the heart to the body tissues and back

  
• Inhalation is always active, exhalation is usually passive, exhalation becomes active when you attempt to expel more air
• Types of animal diet

  • Herbivores that feeds on plant
  • Meat-eating carnivores
  • Omnivores that eat both plants and other animals
• Food processing


  1. Ingestion

  2. Digestion

  3. Absorption

  4. Elimination

  
• Ingestion


  There are four ways on how animals can ingest their food: suspension feeding, substrate feeding, fluid feeding, and bulk feeding
• Ruminants have four chambered stomach to aid in the digestion of plant materials. The four compartments are called the rumen, reticulum, omasum, and abomasum.
• Osmoregulation


  Maintains the constant osmotic pressure in the fluids of an organism via the regulation of water and salt concentration

  
• Types of osmoregulation


  • Osmoconformers - have the same internal solute concentration as seawater
  • Osmoregulators - control their solute concentrations

  
• Nitrogen-containing metabolic waste products

  • Ammonia
  • Urea
  • Uric acid
  • Nucleic acids
  • Amino acids
  • Proteins
• Roles of the urinary system

  1. Filtration

  2. Reabsorption

  3. Secretion

  4. Excretion
• Innate immunity


  Set of inborn, fixed general defenses against infection
• Adaptive immunity


  Set of immune defenses tailored to specific pathogens encountered by an organism during its lifetime
• Lymphocytes


  • B cells - secrete antibodies, mount the humoral immune response
  • T cells - attack cells infected with bacteria or viruses, cell-mediated immune response
• Nervous system


  Obtains sensory information, processes sensory information, sends commands to effector cells (muscles) that carry out appropriate responses
• Diversity of animal nervous systems
• Endocrine system


  Consists of glands that produce hormones regulating the metabolism, growth and development, tissue function, sexual function, and reproduction
• Hormone signaling


  1. Reception of hormone via a receptor protein

  2. Signal transduction

  3. Response within target cells
• Asexual reproduction results in the generation of genetically identical offspring
• Asexual reproduction methods


  • Budding
  • Fission
  • Fragmentation/regeneration
• Sexual reproduction involves the fusion of gametes from two parents, resulting in genetic variation among offspring
• Glycogen storage in alpha cells of pancreas

  1. Declining blood glucose level (e.g., after skipping a meal) stimulates pancreas to release glucagon into the blood

  2. Liver breaks down glycogen and releases glucose to the blood

  3. Blood glucose level rises to set point; stimulus for glucagon release diminishes
• Glycogen breakdown and glucose release

  1. Declining blood glucose level (e.g., after skipping a meal) stimulates pancreas to release glucagon into the blood

  2. Liver breaks down glycogen and releases glucose to the blood

  3. Blood glucose level rises to set point; stimulus for glucagon release diminishes
• Asexual reproduction


  • One parent produces genetically identical offspring
  • Very rapid reproduction
  • Can proceed via budding, fission, or fragmentation/regeneration
• Sexual reproduction


  • Involves the fusion of gametes from two parents
  • Results in genetic variation among offspring
  • Increased reproductive success in changing environments
• External fertilization


  Eggs and sperm are discharged near each other (many fish and amphibian species)
• Internal fertilization


  Sperm is deposited in or near the female reproductive tract (some fish and amphibian species, nearly all terrestrial animals)