33.1: Animal Form and Function
Animals vary in form and function. From a sponge to a worm to a goat, an organism has a distinct body plan that limits its size and shape. Animals’ bodies are also designed to interact with their environments, whether in the deep sea, a rainforest canopy, or the desert. Therefore, a large amount of information about the structure of an organism's body (anatomy) and the function of its cells, tissues and organs (physiology) can be learned by studying that organism's environment.
Which type of animal maintains a constant internal body temperature?
The symmetry found in animals that move swiftly is ________.
What term describes the condition of a desert mouse that lowers its metabolic rate and “sleeps” during the hot day?
- normal sleep pattern
A plane that divides an animal into equal right and left portions is ________.
A plane that divides an animal into dorsal and ventral portions is ________.
The pleural cavity is a part of which cavity?
- dorsal cavity
- thoracic cavity
- abdominal cavity
- pericardial cavity
How does diffusion limit the size of an organism? How is this counteracted?
Diffusion is effective over a very short distance. If a cell exceeds this distance in its size, the center of the cell cannot get adequate nutrients nor can it expel enough waste to survive. To compensate for this, cells can loosely adhere to each other in a liquid medium, or develop into multi-celled organisms that use circulatory and respiratory systems to deliver nutrients and remove wastes.
What is the relationship between BMR and body size? Why?
Basal Metabolic Rate is an expression of the metabolic processes that occur to maintain an individual’s functioning and body temperature. Smaller bodied animals have a relatively large surface area compared to a much larger animal. The large animal’s large surface area leads to increased heat loss that the animal must compensate for, resulting in a higher BMR. A small animal, having less relative surface area, does not lose as much heat and has a correspondingly lower BMR.
33.2: Animal Primary Tissues
The tissues of multicellular, complex animals are four primary types: epithelial, connective, muscle, and nervous. Recall that tissues are groups of similar cells group of similar cells carrying out related functions. These tissues combine to form organs—like the skin or kidney—that have specific, specialized functions within the body. Organs are organized into organ systems to perform functions.
[link] Which of the following statements about types of epithelial cells is false?
- Simple columnar epithelial cells line the tissue of the lung.
- Simple cuboidal epithelial cells are involved in the filtering of blood in the kidney.
- Pseudostratisfied columnar epithilia occur in a single layer, but the arrangement of nuclei makes it appear that more than one layer is present.
- Transitional epithelia change in thickness depending on how full the bladder is.
Which type of epithelial cell is best adapted to aid diffusion?
Which type of epithelial cell is found in glands?
Which type of epithelial cell is found in the urinary bladder?
Which type of connective tissue has the most fibers?
- loose connective tissue
- fibrous connective tissue
Which type of connective tissue has a mineralized different matrix?
- loose connective tissue
- fibrous connective tissue
The cell found in bone that breaks it down is called an ________.
The cell found in bone that makes the bone is called an ________.
Plasma is the ________.
- fibers in blood
- matrix of blood
- cell that phagocytizes bacteria
- cell fragment found in the tissue
The type of muscle cell under voluntary control is the ________.
- smooth muscle
- skeletal muscle
- cardiac muscle
- visceral muscle
The part of a neuron that contains the nucleus is the
- cell body
How can squamous epithelia both facilitate diffusion and prevent damage from abrasion?
Squamous epithelia can be either simple or stratified. As a single layer of cells, it presents a very thin epithelia that minimally inhibits diffusion. As a stratified epithelia, the surface cells can be sloughed off and the cells in deeper layers protect the underlying tissues from damage.
What are the similarities between cartilage and bone?
Both contain cells other than the traditional fibroblast. Both have cells that lodge in spaces within the tissue called lacunae. Both collagen and elastic fibers are found in bone and cartilage. Both tissues participate in vertebrate skeletal development and formation.
Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis (“steady state”). These changes might be in the level of glucose or calcium in blood or in external temperatures. Homeostasis means to maintain dynamic equilibrium in the body. It is dynamic because it is constantly adjusting to the changes that the body’s systems encounter. It is equilibrium because body functions are kept within specific ranges.
When faced with a sudden drop in environmental temperature, an endothermic animal will:
- experience a drop in its body temperature
- wait to see if it goes lower
- increase muscle activity to generate heat
- add fur or fat to increase insulation
Which is an example of negative feedback?
- lowering of blood glucose after a meal
- blood clotting after an injury
- lactation during nursing
- uterine contractions during labor
Which method of heat exchange occurs during direct contact between the source and animal?
The body’s thermostat is located in the ________.
- homeostatic receptor
- vasodilation center
Why are negative feedback loops used to control body homeostasis?
An adjustment to a change in the internal or external environment requires a change in the direction of the stimulus. A negative feedback loop accomplishes this, while a positive feedback loop would continue the stimulus and result in harm to the animal.
Why is a fever a “good thing” during a bacterial infection?
Mammalian enzymes increase activity to the point of denaturation, increasing the chemical activity of the cells involved. Bacterial enzymes have a specific temperature for their most efficient activity and are inhibited at either higher or lower temperatures. Fever results in an increase in the destruction of the invading bacteria by increasing the effectiveness of body defenses and an inhibiting bacterial metabolism.
How is a condition such as diabetes a good example of the failure of a set point in humans?
Diabetes is often associated with a lack in production of insulin. Without insulin, blood glucose levels go up after a meal, but never go back down to normal levels.