Amphibia - Biology Study Guide PDF

**Amphibia** The origins of a deadly disease that\'s killing amphibians \| Natural History Museum They are the **first terrestrial** animals. They evolved from **Sarcopterygii** (násadcoplutvovce - lobed fish) 370 million years ago. Amphibians introduction [[https://youtu.be/TiYIiQKG4NA]](https:...

**Amphibia** The origins of a deadly disease that\'s killing amphibians \| Natural History Museum They are the **first terrestrial** animals. They evolved from **Sarcopterygii** (násadcoplutvovce - lobed fish) 370 million years ago. Amphibians introduction [[https://youtu.be/TiYIiQKG4NA]](https://youtu.be/TiYIiQKG4NA) **Characteristic features:** 1. They live in water in larval stage - (tadpoles), adults live on land. 2. They are **Anamniota** - eggs are without protective membranes or shells. Eggs are laid in water. Anamniota is a group of vertebrates without amnion (the innermost of the extraembryonic membranes forming a fluid filled sac around the foetus in amniotes). It includes cyclostomes, fishes and amphibians. Gas exchange of O~2~ and CO~2~ is done through a vitelline membrane. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------  Anamniotic egg Ciencia de tronos V - Dracarys - Naukas  Comparison of an amniotic and anamniotic egg 3. They are **Tetrapoda** (have four limbs). 4. Frogs breathe by gills in larval stage, by lungs as adults. 5. Skin is smooth, wet and glandular, vascular and sometimes may be poisonous. Skin might have different pigment cells with various colours and shapes. Variation in pigmentation gene expression is associated with distinct aposematic color morphs in the poison frog Dendrobates auratus \| BMC Evolutionary Biology \| Full Text 6. They breathe **also by skin** (cutaneous respiration) 7. They are **cold-blooded**. - exotermic. 8. They have **cloaca**. Amphibia characteristics - video: [[https://youtu.be/pBbBuHV8T30]](https://youtu.be/pBbBuHV8T30) Amphibia -classifiction -- video: [[https://youtu.be/wH1wLuy2ytw]](https://youtu.be/wH1wLuy2ytw) **Skeleton:** Free Vector \| Science eduction of frog anatomy Vertebral column consists of cervical, sacral vertebrae and a **urostyle** (vertebrae are fused together forming one bone). They have just **atlas** -- one of first two cervical vertebrae in human body. They cannot turn their head around. Ulna and radius are grown together forming one bone -**radio-ulna**. Similarly tibia and fibula in lower limbs is grown together forming **tibio-fibula**. Frogs **don´t have ribs** and **diaphragm.** **Digestive system:** Mouth, buccal cavity, teeth, **long and sticky tongue**, pharynx, esophagus, stomach, liver, pancreas, gall bladder, small and large intestines, **cloaca**  **Respiratory system:** Frogs breathe by lungs and skin which must remain moist. Lungs are **not efficient** to supplement all oxygen for the body. Additional breathing organ is also **buccal cavity**. Tadpoles breathe by **gills**. Respiratory system of Frog - Online Biology Notes Respiration in frogs with the help of buccal cavity  **Circulatory system:** It is closed, the heart has **three chambers** (two atria and one ventricle), they also have a **pulmonary** and a **systemic** (body) **circulation** - double circulation (it is imperfect) and a well developed lymphatic system. **Deoxygenated blood** is coming from body to the right atrium, then to the ventricle where it is mixed with **oxygenated blood** from lungs. **Mixed blood** from the ventricle is entering lungs and also the body through the aorta. Chap 10.1 + 10.2 :Types of Circulatory System (Part 1) Flashcards \| Chegg.com Blue -- deoxygenated blood, violet -- mixed blood, red -- oxygenated blood  Evolution of the circulatory system in Vertebrata **Excretory system:** Amphibians have two **kidneys (mesonephros)**, just like humans, and those kidneys filter wastes out of the blood and combine them with water to form urine. Urine then travels from the kidneys via the **ureters** to the **bladder**, and then out through the cloaca. The **cloaca**, or vent, is an opening used for the **excretory, intestinal**, and **reproductive system** of amphibians. Urine leaves the body through the cloaca when the bladder is full. Adult frogs release nitrogenous waste in the form of **urea** and tadpoles release it in the form of **ammonia**. Urogenital System of Frogs (Labelled Diagrams) - Anatomy (Parts) and Physiology (Functions)) Excretory system in Amphibia - mesonephros type of kidneys **Nervous system :** The nervous system is basically the same as in other vertebrates, with a **central brain**, a **spinal cord**, and **peripheral nerves** throughout the body. The amphibian brain is less developed compared to that of reptiles, birds, and mammals. It consists of a **cerebrum**, **midbrain**, and **cerebellum** of similar sizes. The **olfactory lobe** is the center of the sense of smell. The cerebrum integrates behavior and learning. The **optic lobe** processes information from the eyes. The **cerebellum** is the center of muscular coordination. The **medulla oblongata** controls some organ functions, such as heart rate and respiration. The brain sends signals through the spinal cord and nerves to regulate activity in the rest of the body. The **pineal body**, known to regulate sleep patterns in humans, is thought to produce the hormones involved in **hibernation** and **estivation** in amphibians. nervous system - The vertebrate system \| Britannica **Senses:** They have a **good sight** except Gymnophiona (Červone). Eyes are covered by **nictitating membrane**. Gymnophiona and some cave newts (Caudata - mloky) are almost blind. They have a **very good hearing** to recognize partners and enemies. They have developed inner ear which receives vibrations from external **tympanic membrane** (eardrum). They have **olfactory bulbs** used to smell things and an additional **Jacobson´s organ** (vomeronasal organ) an organ of [chemoreception](https://www.britannica.com/science/chemoreception) a special cavity in the mouth to smell and feel taste. **Lateral line** is developed in larval stage in aquatic environment (tadpoles). In adult stage on land it is reduced. Gymnophiona have also a **sensory tentacle** (zmyslové tykadlo) on their head.  The nasolacrimal duct of anuran amphibians: suggestions on its functional role in vomeronasal perception - Nowack - 2010 - Journal of Anatomy - Wiley Online Library Vomeronasal organ (Jacobson´s organ) in frogs  Gymnophiona (caecilians) -- a sensory tentacle on the head **Reproduction:** They have external fertilisation or internal fertilisation, Amphibians reproduce by laying eggs in water, but the fertilization process differs based on the type of amphibian. They must lay their eggs in a suitable environment in order to reproduce. Popular habitats for egg laying include streams, plant stems, under leaves or plant life or in specially-built mud homes. The **newts** fertilization process can be external or internal. In most cases, the males excrete sperms that the female picks up and stores in her glands. She uses the stored sperm to fertilize the eggs she lays. Most **frogs fertilize externally**, with the male holding onto the female\'s back legs and emitting sperm when she begins to lay the eggs. Development is **indirect** in case of frogs. A tadpole lives in water and breathe by gills. frog and toad - Reproduction and diet \| Britannica Different ways of lying eggs in Amphibia  Life cycle of a frog **Classification of Amphibia** Amphibia are divided into three orders: **a) Anura - frogs** **b) Caudata - newts** **c) Gymnophiona -- červone (looks like a worm)** **Anura** (frogs) - in Slovakia lives 13 species of Anura: Kunka žltobruchá- Bombina variegata, **Yellow-bellied toad** Skokan zelený- Pelophylax esculentus, **Edible frog** Skokan hnedý- Rana temporaria, **Common frog** Ropucha bradavičnatá- Bufo bufo, **Common toad** Rosnička zelená- Hyla arborea, **European tree frog** Hrabavka škvrnitá- Pelobates fuscus, **Common spadefoot toad**  European Tree Frog Yellow- Bellied Toad **Caudata** (newts) Salamandra škvrnitá- Salamandra salamandra, **Salamander**  Mlok bodkovaný- Lissotriton vulgaris, **Smooth newt** Jaskyniar vodný - Proteus anguinus, **Olm** Axolotl mexický -Ambystoma mexicanum (water monster, neotenic salamander) Proteus (Jaskyniar) and Ambystoma (Axolotl) live all they life in **larval stage**, they breathe by external gills, it reproduces in this stage which is called **neoteny** (neoténia) also called [**[pedogenesis]**](http://www.dictionary.com/browse/pedogenesis) - the production of offspring by an organism in its larval or juvenile form-elimination of the adult phase of the life cycle. Biology\'s Beloved Amphibian\--the Axolotl\--Is Racing toward Extinction - Scientific American  Axolotl with external gills **Hibernation** is a state of inactivity and [metabolic](https://en.wikipedia.org/wiki/Metabolism) depression in [**endotherms**](https://en.wikipedia.org/wiki/Endotherm). Hibernation refers to a season of [heterothermy](https://en.wikipedia.org/wiki/Heterothermy) that is characterized by low body temperature, slow breathing and heart rate, and low metabolic rate. Hibernation during the [summer](https://en.wikipedia.org/wiki/Summer) months is known as **[aestivation](https://en.wikipedia.org/wiki/Aestivation).** Caudata - Wiktionary  Salamandra salamandra Gymnphiona - červoň (limbless Amphibia) Salamandra škvrnitá Amphibia protection video: [[https://youtu.be/lAe7CX5zqRQ]](https://youtu.be/lAe7CX5zqRQ) Gymnophiona video: [[https://youtu.be/xjt2TawPrpk]](https://youtu.be/xjt2TawPrpk) Caudata video: [[https://youtu.be/MjAiWnzU2aE]](https://youtu.be/MjAiWnzU2aE) Birth of a salamander video: [[https://youtu.be/SEejivHRIbE]](https://youtu.be/SEejivHRIbE) Development of a frog video: [[https://youtu.be/gmlaclb3K2o]](https://youtu.be/gmlaclb3K2o)