ZooLab 4 Frog Dissection

• Organs are composed of a number of tissues, and the structure and function of an organ are dependent on those tissues.
• An organ can perform a function that none of the tissues can do alone.
• The function of the bladder is to store urine and to expel it when convenient, but this function is dependent on the individual tissues making up the bladder.
• The epithelium lining the bladder helps the organ store urine by stretching while preventing urine from leaking into the internal body cavity.
• The muscles of the bladder propel the urine forward into the urethra so that it can be removed from the body.
• The functions of an organ system are dependent on its organs.
• The function of the urinary system is to produce urine, store it, and then transport it.
• The kidneys produce urine, the bladder stores it, and various tubes transport it from the kidneys to the bladder (the ureters) and out of the body (through the urethra).
• The systems of the body are divided into different categories based on its characteristics and functions such as transport of fluids throughout the body and the protection of the body, maintenance of the body, control of the body’s systems, sensory input and motor output, and reproduction.
• The cardiovascular system consists of blood, the heart, and the blood vessels that carry blood throughout the body.
• Blood transports nutrients and oxygen to interstitial fluid for the cells and removes waste molecules, excreted by cells, from the interstitial fluid.
• The lymphatic system consists of lymphatic vessels, lymph, lymph nodes, and other lymphatic organs.
• Lymphatic vessels absorb fat from the digestive system and collect excess interstitial fluid, which is returned to the blood in the cardiovascular system.
• The frog's sex can be determined by looking at the hand digits, or fingers, on its forelegs.
• A male frog usually has thick pads on its "thumbs," which is one external difference between the sexes.
• Male frogs are usually smaller than female frogs.
• To locate and identify the external features of the head, find the mouth, external nares, tympani, eyes, and nictitating membranes.
• To determine the sex of a frog, cut the hinges of the mouth and open it wide.
• Use a probe to help find each part: the vomerine teeth, the maxillary teeth, the internal nares, the tongue, the openings to the Eustachian tubes, the esophagus, the pharynx, and the slit-like glottis.
• Locate the opening to the frog’s cloaca, located between the hind legs, and use forceps to lift the skin and use scissors to cut along the center of the body from the cloaca to the lip.
• Turn back the skin, cut toward the side at each leg, and pin the skin flat.
• Examine the dorsal and ventral sides of the frog, notice its color, and count the number of toes present.
• Measure your frog from the tip of the head to the end of the frog’s backbone (exclude the measure of the legs).
• Feel the frog’s skin, record the structure, and locate the following using a probe: a nictating membrane, attached to the bottom of the eye; a tympanic membrane, a circular structure behind the eyes; a tongue, near the mouth and remove; an esophagus, a tube in the center of the mouth, toward the back which leads to the stomach; Eustachian tubes, an opening close to the angles of the jaw one on each side; a glottis, before the esophagus, a slit opening behind the tongue; vomerine teeth, found on the roof of the mouth; maxillary teeth, found around the edge of the mouth; nostrils/nares, tiny op
• Pry the frog's mouth open and use scissors to cut the angles of the frog's jaws open, cut deeply so that the frog's mouth opens wide enough to view the structures inside.
• Locate the tongue and play with it, observe its attachment.
• In the center of the mouth, toward the back is a single round opening, the esophagus, this tube leads to the stomach.
• The cardiovascular and lymphatic systems are also involved in the protection of the body against disease.
• The digestive system consists of the organs along the digestive tract, together with associated organs, including the teeth, salivary glands, liver, and pancreas.
• The digestive system receives food and digests it into nutrient molecules, which then enter the blood.
• The nervous system consists of the brain, the spinal cord, and associated nerves.
• The nerves conduct nerve impulses from receptors to the brain and spinal cord.
• The nerves also conduct nerve impulses from the brain and spinal cord to the muscles and glands, allowing us to respond to both external and internal stimuli.
• Sensory receptors and sense organs are sometimes considered a part of the nervous system.
• The endocrine system consists of the hormonal glands, such as the thyroid and adrenal glands, which secrete hormones, chemicals that serve as messengers between body parts.
• Both the nervous and endocrine systems coordinate and regulate the functions of the body’s other systems.
• The nervous system tends to cause quick responses in the body, while the body’s responses to hormones released by the endocrine system tend to last much longer.
• The endocrine system also helps maintain the proper functioning of the male and female reproductive organs.
• The integumentary system consists of the skin and its accessory structures.
• The sensory receptors in the skin, and in organs such as the eyes and ears, respond to specific external stimuli and communicate with the brain and spinal cord by way of nerve fibers.