The Integument: List the embryonic germ layers that the epidermis and dermis are derived from (be specific for the dermis). (2 points) Dermis is derived from the mesoderm. It is made up of layers of cells that originate from the bottom most layer called the stratum basale, which is constantly undergoing mitosis. The epidermis is derived from the ectoderm. The development of hair, feathers, teeth, and scales all depend on the same structure. What is it called? (2 points) Dermal papilla How do reptile scales differ from fish scales? (2 points) A reptiles scales are in the epidermis of the skin whereas a fish’s scales are in the dermis of the skin which is located underneath the epidermis. All reptilian scales have a dermal papilla underlying the epidermal part. Compare and contrast rhino horns, antlers, and giraffe horns in terms of contributions by the epidermis and dermis. (4 points) Horns are composed of a bony core covered with a sheath of keratin. Unlike antlers, horns are never branched. Rhino horns differ from true horns because their horns have no core or sheath. They are made up of many epidermal cells and bundles of dermal papillae, extensions of the dermis. Cells from each papilla form a horny fiber similar to thick hair. These fibers are not true hairs. True hair grows from follicles that extend into the dermis, whereas rhino horns grow from dermal papillae which extend up into the horn. Giraffe horns are paired, short, and permanent bony processes that are covered with skin and hair. They differ from other horns in that they do not project from the frontal bones, but lie over the sutures between the frontal and parietal bones. Antlers are not formed in the epidermis and do not consist of keratin but are... ... middle of paper ... ...rdle is attached to the axial skeleton. (5 points) The fins of fish have some basic structures in common. What are the two sets of skeletal elements that comprise the basic fish fin? What kind of paired fin has: 1) both preaxial and postaxial elements, 2) only preaxial elements? (4 points) Two sets of skeletal elements that make up the basic fish fin are Archipterygial and Metapterygial fins. The archipterygial has both preaxis and postaxial elements. Metapterygial has only preaxial elements. How do artiodactyls differ from perissodactyls? (2 points) The Artiodactyls are even-toed ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in odd-toed ungulates called perissodactyls. Perissodactyls have an odd number of toes and the middle toe on each hoof is usually larger than its neighbors.
...ons in the size and distribution of the major collagen fibrils of the dermis. J Invest Dermatol. 108(3):241-7 [PubMed: 9036918] Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/9036918
Pachycephalosaurians, thick-skulled dinosaurs such as the Stegoceras and the Pachycephalosaurus. (1) Ceratopsians and Pachycephalosaurs are closely related in their characteristics. Ceratopsians processed a saddle-shaped boney frill that extended from the skull to the neck and typically had horns over the nose and eyes. The most popular was the triceratops, which could reach over 26 feet and weigh in excess of twelve metric tons. Their frills served two major functions.
The full scientific classification of the giraffe is Animalia Chordata Mammalia Artiodactyla Ruminantia Pecora Giraffidea Giraffa camelopardalis. There were at one time seven species in the genus Giraffa but today only one is still extant: camelopardalis, (Mitchell and Skinner, 2010). Because the modern giraffe does not have any other extant species within its genus, it is helpful to look the phylogenetic tree from a broader perspective. Going beyond the level of genus, the giraffe belong to the family Giraffidea. This family, though, is very small, as it only contains two different extant genera: Giraffa and Okapia, (Lerner and Lerner, 2008) Okapia, or the okapi, represents the closest living relative to the giraffe, and the two are very similar both morphologically and molecularly. The two animals can trace their ancestry back from the “gelocid ancestral assemblage” 20-25 million years to the family Palaeomeridae. From the palaeomerycids arose the Antilocaprinae from the subfamily Dromomerycinae, and two subfamilies of giraffids, the Climacoceratidae and Canthumerycidae. (...
The second layer of the skin is called the dermis and is also known as the middle layer. The dermis is what holds the body together. The dermis has layers to it as well as the epidermis. There are two layers to the dermis, the papillary layer and the reticular layer. The cells of the dermis are fibroblast, macrophages, mast cells, and scattered white blood cells (wbc’s). the dermis is richly supplied with nerve fibers and BV;s. dermal BV’s is also a part of the integumentary system, dermal BV,s have converging and diverging vessels that ar...
Mojetta wrote about prehistoric sharks, and the history of these creatures. According to Angelo Mojetta, author of Sharks, Cladoselache genus, one of the first prehistoric sharks, was buried in sediment that kept it preserved. Unlike other sharks, Cladoselache genus had a circle of tiny plates around it’s eyes for protection against it’s victim’s attempts to fight back. These sharks lived over 400 million years ago. Sharks of the past could mostly be identified by their teeth, because shark’s bodies are made of cartilage. Another shark that was focused on was called, Stethacanthus. This shark had a very unique look. Stethacanthus had a brush like decoration on the top of it’s head, and an extra fin like part that had the same bristle like decorations on it. These characteristics were thought to be used as suction cups, to hitch rides from larger fish. One of the most famous sharks that looks like an over...
Hair is considered one of the components of the integumentary system, along with the skin, nails, glands and nerves. Mammalian hair has many functions including protection from environmental factors and the ability to disperse sweat gland products such as pheromones. Almost every part of the human body is covered by hair except for the palms, hands and bottoms of the feet. On average, every person has about five million hairs; each of these hairs is born from a follicle or tiny tube-like structure that grows into the dermis layer of the skin. Oftentimes this follicle even reaches the subcutaneous layer, which is made of fat and connective tissue. (UXL Complete Health Research, 2001)
The integumentary system is composed of the skin and the structures related to the skin, which include the hair, the finger nails, the sensory receptors and the glands (Shier, Butler, & Lewis, 2009). This system has an important function since it provides protection to the body, helps to maintain body temperature, and contains sensory receptors (p.117). The skin has essential function such as regulating homeostasis and body temperature, also delaying the loss of water from deeper tissues, storing sensory receptor, synthesizing biomechanical, and discharging waste from the body (p.117). The skin has two layers: the epidermis (outer layer) and the dermis (inner layer) (p.117). There is also a subcutaneous layer or hypodermis (p.117). According to Shier, Butler, and Lewis 2009 “as its name indicates, this layer is beneath the skin and not a true layer of the skin” (p.117). This layer has the blood vessels that supply the skin (p.117).
The skeletal system frames our entire bodies and protects our fragile inner organs. We have two major types of bone in our body: compact bone and spongy bone. Compact bone is dense and looks smooth, while spongy bone is comprised of small needle-like pieces of bone with lots of open spaces. Our body contains 206 bones. The skeleton is separated into axial and appendicular sections. The axial skeleton includes the bones in the longitudinal axis of our body. The appendicular skeleton consists of the limbs and girdles of the body, such as our arms and shoulders. There are four different classifications of bone, determined by their shape. Long bones are shafts with ‘heads’ on both sides. Our limbs contain mostly long bones. Short bones
Throughout time, one theory has remained constant in terms of why giraffes developed longer necks. The idea, which was presented by Charles Darwin states quite simply that giraffes selected for longer necks in order to reach the food that was higher off the ground during the dry season. No one has ever challenged that idea until 1996. Initially, Gould argued that "the story-the giraffe evolved its long neck in competition to reach scare foliage-is supported by no evidence" (18). That's when two scientists, Robert Simmons and Lou Scheepers made the claim that necks evolved for a very different reason: sexual selection. Within this paper, information will be presented that argues both for and against the theories made by Darwin and Simmons and Scheepers.
Epitheral tissues develop in the embryo from all three layers. Connective tissues and muscle tissues all derive from mesoderm. Ectoderm gives rise to nervous tissue.
Balaban and Bobick (2008) state that skin has several different functions and that these functions are significant. The outer skin cells are lifeless and keratinized which makes the skin waterproof. Skin also functions as a barricade against things such as abrasions as well as bacteria and viruses. Skin helps in the regulation of body temperature and contains receptors that receive the sensations of touch, vibration, pain, and temperature. Balaban and Bobick (2008) also state that, “Skin is a tissue membrane which consists of layers of epithelial and connective tissues” (p.42). Epidermis is the outer layer of the skins epithelial tissue and dermis is the inner layer of the connective tissue and a basement membrane separates the two layers. The appendages of the skin include sebaceous glands, sudoriferous glands, hair, and nails (Dr. Grass, 2013). Balaban and Bobick (2008) state that, “Scientists estimate there are between 50 and 100 trillion cells in the human body” (p. 27). Cells are constantly dying and new cells are always replacing them. These are normal functions of the skin, but skin functions can be altered during the diseased state.
The skin is made up of three layers; epidermis, dermis, and subcutaneous layer. The epidermis layer contains stem cells. Stem cells regenerate new skin if the
To begin we will look at the integumentary system and its entire multitude of functions. The main components of the integumentary system are the skin, hair, nails, glands and nerves. For the purpose of this paper we will focus mainly on the levels of the skin and their functions. While the integumentary
The morphology of whale sharks is mostly similar to aquatic fish species, but many specific traits help differentiate them from the rest. Whale sharks are the largest fish in the world and can reach a size of around 20 meters (Martins, C., and C. Knickle). This is often compared to the size of a school bus. The shark has a very large transverse mouth. They have 5 very large gill slits and have a larger first dorsal fin compared to the second one (Whale Shark). They have a distinctive spotted “checkerboard” pattern with stripes (Martins, C., and C. Knickle). It is not exactly known why they have this specific body marking. It is believed that the body markings act as a camouflage. The strange thing about whale sharks is that they have 300 rows of teeth that play no role in feeding (Martins, C., and C. Knickle).
... At the age of six months, a giraffe’s coat turns dark brown and white. They drink their mother’s milk and they like to eat grass too. When they are one year old, their horns are thick, their hooves are big, and they are so tall that they can reach the top of some trees.