Animal Biology Review

• Volume increases faster than surface area.
• Epithelium lines a surface.
• Connective tissue is the tissue type of blood.

How a Thermostat Works

• It uses negative feedback when the temperature is too low.
• The controlled condition is temperature.
• The receptor is a thermometer.
• The control center is a thermostat that sends information to the effector if the temperature is too low.
• The effector is a heater.
• The effector responds to instructions to cause a change in a negative feedback loop.
• Mastication is the process of chewing and it happens in the oral cavity.
• Food passes through the digestive tract of a rabbit twice.
• Boyle's Law relates pressure to volume.
• When the diaphragm contracts, it moves downward, increasing the volume of the thoracic cavity and the lungs.
• As the volume of the lungs increases, the pressure inside the lungs decreases.
• Atmospheric pressure remains relatively constant.
• During inhalation, when the lung pressure becomes lower than atmospheric pressure, air moves into the lungs to equalize the pressure.
• As the diaphragm contracts and the volume of the lungs increases, the pressure inside the lungs becomes lower than the atmospheric pressure.
• This causes air to move into the lungs from the atmosphere, a process known as inhalation.

Features of the Animal Kingdom:

• Multicellularity, with many complex bodies and tissue structures is a feature.
• Heterotrophy features obtaining energy and organic molecules by ingesting other organisms.
• Active movement includes moving more rapidly and in more complex ways.
• Diversity of form and size ranges from microscopic to enormous.
• Most animals exhibit sexual reproduction, with offspring passing through developmental stages.
• Morphology of animals is determined by developmental cues in a determined/fixed body plan.

Complex Tissue Structure:

• Animals lack cell walls.
• They feature unique intracellular communication via gap junctions.

Types of Animal Tissues:

• Connective tissues have cells embedded in an extracellular matrix like bone or cartilage.
• Epithelial tissues cover, line, protect, and secrete.
• Nervous tissue coordinates movement and maintains homeostasis.
• Muscle tissue powers locomotion.

Animal Reproduction and Development:

• Most animals are diploids (2n).
• Somatic cells are diploid.
• Gametes are haploid.
• Most reproduced sexually, where haploid egg and sperm unite (fertilization or syngamy) to form a diploid zygote.
• This distinguishes them from fungi, many protists, and prokaryotes.

Exceptions to Sexual Reproduction:

• Asexual phases in several groups like cnidarians and flatworms sometimes occur.
• Social insect males are often haploid.
• Budding and fragmentation is present in hydra and sea anemones.
• Parthenogenesis happens via haplodiploidy.
• Unfertilized eggs become males (haploid).
• Fertilized eggs become females (diploid).
• Parthenogenesis is found in some vertebrates and insects.
• Pros/cons include the potential buildup of deleterious mutations, but there is often no need to find mates.

Early Development After Zygote Forms:

• Cleavage: A series of mitotic cell divisions.
• After three divisions, an 8-cell stage is reached.
• Cells continue to divide and rearrange.
• Blastula: a 6 to 32-cell hollow "ball".
• Blastocoel is the internal cavity.
• Gastrulation forms a gastrula.
• Invagination forms the blastopore and archenteron (embryonic gut).
• Gastrulation establishes ectoderm (outer), endoderm (inner), and often mesoderm (middle) germ layers.

Features Used to Classify Animals:

• Symmetry
• Number of tissue layers
• Origin of mouth and anus
• Body plan and cavities

Animal Characterization - Based on Body Symmetry:

• Asymmetrical animals have no symmetry (e.g., Porifera/sponges).
• Radial symmetry involves arrangement around a central axis (e.g., jellyfish, comb jellies).
• They have oral vs. aboral sides.
• It suits encountering the environment from any direction, which is good for stationary or planktonic lifestyles.
• Bilateral symmetry divides the body into right and left halves (e.g., most animals).
• It allows for cephalization (concentration of sense organs in the head).
• It suits moving forward.

Animal Characterization - Based on Embryological Development:

• Parazoa ('beside' animals) have no true tissues or symmetry (e.g., sponges – Phylum Porifera).
• Eumetazoa ('true' animals) have distinct tissues & symmetry.

Symmetry and Germ Layers:

• Radiata (diploblasts) have two germ layers (ectoderm, endoderm), radial symmetry (e.g., cnidarians, ctenophores).
• Bilateria (triploblasts) have three germ layers (ectoderm, mesoderm, endoderm), bilateral symmetry (most animals).
• Endoderm is the inner lining of the digestive tract, trachea, and lungs.
• Mesoderm makes up muscle, bone, cartilage, blood, and visceral organs.
• Ectoderm becomes the outer body epithelium and central nervous system.

Body Cavity (Coelom) Classification:

• Acoelomates have no body cavity (e.g., flatworms).
• Pseudocoelomates have a "false" body cavity (e.g., nematodes).
• Coelomates have a true body cavity lined with mesoderm (most animals).

Early Animal Evolution:

• Eumetazoa ('true animals') have differentiated tissues (e.g., sponge choanocyte cells).
• Parazoa have no true tissues (e.g., sponges – Porifera).
• Both groups evolved from a common ancestor resembling modern choanoflagellates.

Precambrian & Cambrian Periods:

• Ediacaran Period (635–543 mya):
• Ediacaran biota evolved from protists.
• Choanoflagellates resemble sponge choanocytes.
• Cambrian Period (542–488 mya):
• "Cambrian Explosion" saw a rapid evolution of many animal phyla.
• Rise in O2 levels and ocean calcium levels occurred.
• Predator-prey dynamics and genetic innovations (Hox genes).

Post-Cambrian Period:

• Cretaceous-Paleogene (Tertiary) Boundary (~66 mya):
• A meteorite impact and volcanic activity lead to severe climate change.
• Extinction of many species opened niches that lead to Mammal & bird radiation.
• Sponges have no symmetry.
• Eumetazoa has Radial or Bilateral symmetry.
• Small, unicellular organisms rely on diffusion for nutrients. Size, Shape, and Metabolism:
• Surface area-to-volume ratio limits cell size so larger organisms have more cells, but not larger cells.

Body Planes & Cavities:

• The Sagittal Plane divides into right and left portions.
• The Midsagittal Plane divides into equal right and left halves.
• The Frontal Plane separates front and back.
• The Transverse Plane divides upper and lower portions.

Four Main Types of Animal Tissues:

• Epithelial tissue lines cavities, open spaces, and surfaces.
• Connective tissue provides support and connects tissues.
• Muscle tissue generates movement.
• Nervous tissue sends electrical signals.

Squamous Epithelial:

• It is avascular with a:
  • Simple: one layer of flat cells (Ex. lungs).
  • Stratified: multiple layers so the cell shape is based on the top layer of cells
• It is protective since multiple layers (Ex. esophagus).
• It is avascular.
• It is simple: look like rings, a single layer of cube-shaped cells, look at the nuclei, very very round (Ex. Thyroid gland).
• It is avascular with a simple single layer of cells, look at the outer layer, and has connective tissue.
• Oval-shaped cells are stretched out in a:
  • Microvilli: fuzzy surface at the top, they are in charge of absorption, there to increase surface area. (Ex: Kidneys, intestines)
  • Goblet cells: single-cell glands that produce mucus.

Pseudostratified Ciliated Columnar Epithelial:

• It is avascular, looks like it's stratified (multiple layers of cells) BUT every cell is connected to a basement membrane. SO, only one layer of cells with Goblet cells. (Ex: Trachea).
  • Cillia: is for movement , move the mucus back up to be swallowed and digested, longer than microvilli.
  • Consists of cells (fibroblasts) embedded in a non-cellular matrix.
  • Is usually composed of a ground substance, usually containing some combination of collagen, elastic, or reticular fibers used to connect different tissues or give the body structure (blood has unique functions).
  • Fibroblast: build/make fibers (“-blast” means to make something).
  • Adipocyte: an adipose cell, for long-term energy storage, normally in living tissue and filled with lipids so the nucleus will be pushed over to the side, and provide texture and insolation, and looks similar to lung tissue so look at the nuclei.

Hyaline(means waxy/glossy) cartilage:

• The most abundant cartilage in the body,Ex makes up the rings of the trachea with: Chondrocytes cartilage cells: located in the lacunae
  • Dense Regular Connective Tissue: cells with matrix in between and filled with collagen fibers, arranged in nice, parallel layers which gives the tissue strength when pulled. (Ex: tenlonds/ligaments) (THIS IS THE ONLY THING THAT SURFACE AREA INCREASES FASTER). Aereolar: looks like a bunch of strings (fibers), tissue glue; holds other tissues together, not a lot of cells, mostly cells that we see are fibroblasts and the really big fibers are collagen where the thin fibers are elaston fibers to provide stretch such as around blood vessels to connect muscles. Spongy bone is always internal, has no Haversion canal in the center so you don't have osteons because it has layers and osteocytes and the matrix in between the bone is very hard (osteoblast). Muscle Tissue: is for movement.

Skeletal:

• On the skeleton and tongue, moves your skeleton, the only type that is consciously controlled. Very long cells are arranged in a parallel fashion and have multi-nuclei. It is conformed from the fusion of many cells.
• Nuclei are peripheral - pushed to the sides, thus being striated.
• Cardiac: is striated and makes very fine lines.
  • Only in the cardiac muscle of the heart it has branching cells each with one nucleus, and has striations.
  • Where one cell meets another there are intercalated disks only cardiac muscle has them.
  • Smooth: is smooth, the cells are located everywhere, have no striations and has a smooth appearance and are spindle-shaped wider in the center where the nucleus is and then tapers off at the ends.

Nervous Tissue:

• Neurons: send electrical messages but cannot divide and do not get repaired (repair only happens in the peripheral nervous system).
  • The dendrites: tell how a neuron receives messages.
• Neuroglia: for support and nourishment of neurons, can divide.

Homeostasis/Thermoregulation:

• Homeostasis: aims to keep internal conditions around a set point. - If conditions stray too far from the set point homeostatic mechanisms kick in.

• Negative feedback loops (reverses): The set point can potentially change over time (alteration).. - Though homeostasis will still work towards a new set point, much more common (Ex: Fever). - Counteracts any internal changes (reverses the direction of the change). - Most biological systems are on negative feedback and can include Temperature, Glucose, pH, and/or Blood Calcium. - Acclimatization: changes in one organ system to maintain a set point in another organ system such as when one climbs tall mountains and one's Kidneys produce EPO. Positive feedback loop (build): Maintains and potentially strengthens the response to a stimulus, Not many biological systems are on positive feedback Ex: Childbirth, Platelet plug formation. Must maintain a relatively constant internal temperature to keep enzymes working and avoid denaturation.

• Thermoregulatory: control by the hypothalamus.

• Temperature: is maintained in several different ways as heat can be exchanged by four mechanisms:

  • Radiation.
  • Convection: transfer of heat through liquid or gas.
  • Conduction: heat transfer by direct contact.
  • Evaporation: sweat evaporates from your skin.

• Digestion:

  • Herbivores: animals whose primary food source is Plant-based along with being known as primary consumers.
    • Carnivores: are animals that eat other animals:
      • Obligate is when carnivores are those that rely entirely on animal flesh to obtain their nutrients.
      • Facultative is when carnivores are those that also eat non-animal food in addition to animal food, but generally do best, eating animals.

• Omnivores: animals that eat both plant- and animal-derived food and they do well eating either.

Digestive Tracts:

• Incomplete: single opening = Gastrovascular cavity.
• Food: enters through the mouth and muscular pharynx.
• Wastes: exit through the mouth and muscular pharynx as it lacks specialized parts.
• Complete: two openings = Alimentary canal in this instance, food enters through the mouth and wastes exit through the anus.
• Tongue:
  • Mastication: keeps food between the teeth during chewing.
  • Deglutition: Aids in swallowing.
• Teeth:
  • Mastication: chewing increases the surface area of food, allowing enzymes to act more efficiently.

Salivary Glands:

• Parotid, Submandibular, and Sublingual all produce:
  • Saliva: the substance that moistens food to form a bolus and contains digestive enzymes.
    • Lingual Lipase: digests fats, but is not active until in the stomach.
    • Salivary Amylase: breaks down starches into disaccharides.

Swallowing (Deglutition):

• Pharynx: Where digestive and respiratory passages come together so the soft palate closes off the nasopharynx. Epiglottis cartilage: covered with a mucus membrane that moves down to close the opening into the trachea, keeping food from air passages most of the time and taking food to the stomach by the peristalsis.
• Peristalsis rhythmic: muscle contraction to move contents in tubular organs where contracts behind the bolus of food and relax in front of the bolus of food to push it toward the stomach and through the intestines.

Stomach:

• Food becomes chyme after digested and lingual and gastric lipase are active here to turn triglycerides into monoglycerides and fatty acids that break ester bonds between glycerol and fatty acids.
• Stomach wall: has deep folds (rugae) that disappear as the stomach fills to an approximate volume of one liter because the tissue has three layers to help churn food together.
• Epithelial Lining: millions of gastric pits which drain gastric glands.
• Pepsin: hydrolytic enzyme that acts on breaking down proteins to produce peptides.
  • Pepcynigen: inactive form.
    • Pecyniden + HCL = Pepsin

HUMAN DIGESTIVE TRACT:

• Food mixed with gastric juices: becomes chyme with the junction between the stomach and small intestine controlled by a sphincter so when the sphincter relaxes, a small quantity of chyme passes into the small intestine.
• Duodenum contains:
  • First Segment: of the small intestine where liver, gallbladder, and pancreas are all attached and Chyme from the stomach enters where it mixes with secretions from the liver and pancreas.
• Liver: Produces bile, which is stored in the gallbladder.
• Bile contains bile salts: which break up fat into fat droplets via emulsification, thus helping maintain glucose concentration in blood by converting excess into glycogen.
• Pancreas:
  • Endocrine gland Produces: insulin and glucagon which control blood glucose levels.
  • Exocrine gland: Produces pancreatic juice and digestive enzymes that can break down all four classes of macromolecules like proteins, lipids, nucleic acids, carbohydrates into the duodenum and also produces bicarbonate that is important to raise the levels of pH so that the enzymes work since the chyme is very acidic.
  • Pancreatic:
    • Amylase digests starch to (disaccharides) maltose.
    • Trypsin: Digests protein to peptides.
    • Lipase: Digests fat droplets to glycerol and fatty acids. Epithelial cells: Intestine also produce enzymes known as brush border enzymes that have microvilli that complete the digestion of peptides (proteins) and sugars.

CARBOHYDRATE DIGESTION:

• Digestion: carbohydrates is performed by several enzymes.
  • Amylase and maltase: Break down starch and glycogen into glucose.
  • Sucrase and lactase: Break down sucrose (table sugar) and lactose (milk sugar).
• Gigunum: is the middle part of the small intensive which is the main site of absorption.

PROTEIN DIGESTION:

• Starts: stomach with pepsin breaking down proteins into peptides (short chains of 4-9 amino acids).
• Duodenum: trypsin, elastase, and chymotrypsin reduce peptides to smaller peptides. Brush enzymes border in combination with carboxypeptidase, dipeptidase, and aminopeptidase reduce peptides to free amino acids that are absorbable.

LIPID DIGESTION:

Begins: stomach with lingual lipase and gastric lipase. Bulk: digestion occurs in the small intestine due to pancreatic lipase.

• When is released after chyme enters the duodenum with a hormonal response,bile produced in the liver and stored in the gallbladder.
  • Bile: Aids in lipid digestion with the primary substrate being triglycerides through emulsification.

STEPS OF DIGESTION (ABSORPTION):

• Only monosaccharides can be absorbed so the mucous membrane of the small intestine has ridges and furrows, giving it a corrugated surface containing lacteals which are lymphatic capillaries that travel through the lymph before going into the blood.

• Villi: of the surface which contain smaller ridges, and microvilli greatly increasing absorptive area. Duodenum: first part of small intestine, right after the stomach, and each villus contains blood capillaries and a lymphatic capillary called a lacteal. Large Intestine is and includes:

• cecum: colon, rectum, and anal canal

• larger:in diameter and shorter in length than the small intestine and absorbs water, salts, and some vitamins.

• Cecum has a small projection - appendix

• Colon is: subdivided into ascending, transverse, descending, and sigmoid colons. - Opening to the anal canal.

  • Anus for elimination.

• Liver: Bile Production.

  • Bile emulsifies lipids: making them more soluble in water for enzymatic action.

• Gallbladder:

  • Bile storage: stores bile produced by the liver.

• Pancreas:

  • Duodenum: Part of the small intestine where the liver and gallbladder connect to the pancreas.
  • pH Regulation: Makes the small intestine more alkaline.
    • Enzyme Production: Produces enzymes that break down carbohydrates, lipids, proteins, and nucleic acids.

Digestive Systems in Different Animals:

• Carnivores - Dentition: Pointed incisors and enlarged canines for tearing flesh; jagged molars for tearing. Herbivores - Dentition: Sharp incisors for tearing leaves; large, flat molars for grinding plant material.
• Omnivores - Dentition: Combination of chisel-shaped incisors, pointed canines, and flat molars for a varied diet.

Birds:

• Crop: Stores food, as part of Gl tract.
• Proventriculus: Contains digestive enzymes.
• Gizzard: Mechanical digestion with grinding action.
• Cloaca: One opening to excrete urine and feces
• Ruminants: are known as cows and goats and have four stomachs so they feature:
• Rumen and Reticulum: Contains prokaryotes and protists/ or microbes in to digest cellulose fiber. Omasum: Removes water. Abomasum: Enzymes produced by the animal and involved in the digestion of food by a process known as:
  • Regurgitation: Chewing cud for further breakdown.

Monogastric Systems:

• Humans: Single stomach, small and large intestines, small cecum.
• Rabbits: digest food twice when food takes a path where a large cecum is used for fermentation, and cecotropes are re-ingested for additional nutrition.

NUTRITION (CARBOHYDRATES):

• Carbohydrates: present in food in the form of sugars, starch, and fiber.
  • Monosaccharides: the most basic unit of carbohydrates and include elements like: - Glucose - Fructose - Disaccharides: complex carbohydrates that can be further broken down: - Lactose (milk sugar) - Sucrose (table sugar) - Polysaccharides are the most basic unit to build and include elements like: - Plants: stores glucose as starch and cellulose. - Animals: store glucose as glycogen

NUTRITION & PROTEINS:

• Adequate protein formation requires 20 different types of amino acids where Adults require 8 essential amino acids from the diet and children require 9 as a bare requirements, luckily some foods, such as meat, milk, and eggs, provide all 20 amino acids known as complete proteins due to their full constitution while vegetables supply one or more essential amino acids but are deficient in at least one and thus vegetarians should combine plant products to provide all the essential amino acids also kids need Arginine.

NUTRITION & LIPIDS:

Fat: from the oils and cholesterol that are essential for the storage and activity of fat-soluble vitamins A, D, E, and K to provide energy at nine calories per gram and where in general:

• fat storage is essential to protect internal organs and help insulate against cold temperatures and can come in the form of saturated fats where:
  • they are solids at room temperature.
  • they usually come from animals.
  • they are found in butter and meats which are marbled red meats and bacon.
  • palm oil and coconut oil are high in saturated fats. Fat soluble vitamins:
• Vitamin A: promotes eye health and helps form and maintain healthy skin, teeth, and bones.
  • Vitamin D helps the body absorb calcium, maintains strong bones.
    • Vitamin E: is an antioxidant and boosts immune function.
    • Vitamin K: aids in blood clotting.

NUTRITION AND VITAMINS:

• soluble: should be taken with food, can overdose because they are stored in fat while water-soluble vitamin B helps the body produce energy and influence growth and development and vitamin C boosts immune functioning, fights skin aging as a antioxidant.

Minerals:

• is the definition of providing inorganic which are essential nutrients that must be obtained from food.
• Function: Help in structure and regulation and act as co-factors such as those found in the bones that are a product of calcium or teeth.
• Dogfish Shark:
  • Teeth: Specialized for grasping and tearing prey.
    • Liver Prod: a large mount of oil that is aiding in buoyancy.
    • Spiral: Intestine Increases surface area for absorption to compensate for a shorter digestive track. - Bullfrog Adapt: Digestive System for swallowing prey whole. - Fetal Pig: Digestive System Closely resembles humans. - TGE is contagious in Pigs

TGE (Transmissible Gastroenteritis): A highly contagious viral disease affecting the digestive system of pigs that breaks down the villi which has effects that will show:

• Severe Diarrhea as PIGS will eventually starves too death without its intestinal villi.
• Respiratory and Circulatory System Functions:
• The main is to take in and allow and or enable the
• Delivery of oxygen to cells and remove carbon dioxide within.
• Oxygen is required to maintain cell functioning.
• Gas: change is essential for aerobic respiratIons which requires
  • energy as carbon dioxide is used as a waste as part of creating the cellular environment.
• Gas exchange in multicellular Organasms
• Gas is required in multicellular organisms to maintain a circulatory system for efficient delivery of gases and waste removal.

Oxygen System and pressure:

• The pressure is dependent on each other to maintain that gas exchanges still occurs.
• All cells require oxygen as the cells are cellular respiration.
• One: of the major physiological challenges facing all multicellular animals is obtaining sufficient.

Gas Exchange between Blood Systems:

• In vertebra is where gases must diffuse into the aqueous as they form respiratoritory system membranes and depend:

  • Diffusion is passive: driven only by the difference in 02 and CO2 concentrations on the two sides of the membranes and how the the relation to the diffusion of plasma membranes. -High 02 needs to move into the blood .

• High CO2: is where the blood needs to move into the alveoli. Diffusion will occurs in at that site with:

  • A Mechanism that is d to pressures from the gases:

• External system that diffusions oxygen and out carbon dioxide and has two capillary systems:

• inter Alveoli

Fick's Law of Diffusion:

• Rate is Dependent on several main process:
• Diffusion constant requires a surface area which involves the process:

Factors Alveoli:

• Surface Area Largely increased due at time of the blood flow change.

• The gradient will greatly effect the differencial process.

• The distance that is related diffusion must be at a certain length maintain its the rate. There has to be adaptations inside different Organasms to maintain the system with:

• Rely on different diffusion.

• May not need a circulatory system and can rely directly upon the diffusion of gases that: - Amphibians: Use skin, lungs, and oral cavity for gas exchange.

• Has a system that maintains their blood pressure.

• -- Fishes Use Gills on their countercurrent system with:

• gills the the increase surface area for diffusion.

• Move water: into the mouth through the gills out of the fish, mouth and through the gill cover.

Mammals and terrestrial:

• Land Animals Use lungs in ways to evaporate some water in the air:
• The animal have lungs to increase surface area in there lung tissues and there must be different adaptations such as sea level.
• Calculations are used to maintain a total pressures must be created for total effect as pressure or volume occurs which maintain in place the the whole organism. They have some type of breathing mechanisms that use the most of the oxygen molecules to create a healthy lifestyle in all living Organisms. The mountain effects which creates a oxygen molecules to create a health problems, therefore some Climbers in the environment needs oxygen to survive the blood levels. There such of oxygen system involves many systems:
• Such how lungs maintain the alveoli.
• The ventilation works in the area between the thorax .
  • Exhalation: The Diaphragm relaxes, decreasing volume, and increasing pressure to bifurcates into the right and left bronchi which enter each lung which further subdivide into bronchioles. - The bronchioles maintain cartilage and are surrounded by smooth muscles that produces negative pressures draws air in for to maintain volume.
• Bird Respiratory System.
  • Unidirectional Flow moves air effectively.
  • Gas exchange in the ovuloli system between the different lungs and that needs the partial pressures .

Hemoglobin

Each chain has a associated that has hema group that:

• binds in lungs to oxygen and helps loads.

• Effect is can affects the pH and the system that is made.

• CO2 the carbon does it can be the opposite of oxyhemoglobin due to this can shift between environment conditions.

• Oxygen and carbon effects are maintain in that order to maintain.

• Interverbate system are very important factors where they are and what organism they maintain for example sponges a and cnidarians.

• The circulatory system helps water. Vertebreates

Circulatory Systems:

• The main differences come from the numbers and chambers and what are: Amphibians: Advent of lungs which come from second pumping circuit, or double

This quiz reviews basic animal biology, covering topics from tissue types and the digestive system to feedback loops and gas exchange. It tests understanding of animal characteristics, organ systems, and basic biological principles. It also explores the relationship between pressure and volume.