Bio 212 Ch 40

Homeostatis

"steady state" - maintenance of internal balance. Can relate to Ph, blood glucose, temperature, etc.

...as an animal's size increases...

... an animal's metabolic rate per Kg decreases...

...as an animals size decreases...

...an animal's metabolic rate per Kg increases...

Blood

A connective tissue. Liquid extracellular matrix called plasma. Contains red and white blood cells, and platelets.

Circadian Rythm

A set of physiological changes that occur roughly every 24 hours.

Metabolic rate

Amount of energy an animal uses in a unit of time; the sum of all the energy-requiring biochemical reactions.

Positive feedback

Amplifies the stimulus.

Conformer

An animal that allows its internal condition to vary with certain external changes.

Regulator

An animal that uses internal control mechanisms to moderate internal change in the face of external fluctuation. Maintains a specific temp, ph, etc.

Loose connective tissue

Binds to epithelia and holds organs in place. Most common tissue in vertebrates.

Hypothalmus

Brain region that controls the circadian clock and thermostat.

Neurons

Consists of Dendrites, Cell bodies, and Axons. Basic unit of the nervous system.

Cartilage

Contains collagenous fibers embedded in a rubbery protein carbohydrate complex called chondritin sulfate. Strong/flexible support material.

Epithelial Tissue

Covers the outside of the body and lines organs and cavities within the body. Functions as a barrier against mechanical injury.

Four types of epithelial tissue

Cuboidal - makes up kidney tubules, various glands like thyroid and salivary. Simple Columnar - Large, brick shaped cells. Lines intestines and secretes digestive juices and absorbs nutrients. Simple Squamous - Single layer of platelike cells. Lines blood vessels and lungs, where diffusion is critical. Pseudostratified - single level of cells of varying heights. Found in mucus membranes, and potions of the respiratory tract.

Negative Feedback

Dampens the stimulus.

Fibrous connective tissue

Dense with collagenous fibers. Found in tendons and ligaments.

Cardiac muscles

Forms contractile wall of the heart. Striated like skeletal muscle, but involuntary, synchronized contractions.

Smooth muscle

Lacks striations. Found in the walls of digestive tract and other internal organs. Spindle shaped, responsible for the churning of the stomach and constriction of arteries.

Bone

Mineralized connective tissue. Created by osteoblasts.

Muscle tissue

Responsible for nearly all types of movement. Skeletal, Smooth, Cardiac.

Hormones

Signaling molecules broadcast throughout the body.

Connective Tissue

Sparse population of cells scattered through an extracellular matrix. Holds tissues and organs in place.

Skeletal Muscle

Striated muscle. Attached to bones by tendons. Responsible for voluntary movement.

Basal metabolic rate

The minimum metabolic rate of a nongrowing endotherm that is not under stress, is at rest, and has an empty stomach.

Set point

The point at which an animas body "wants" to be. Going above or below this point results in a response that brings the body back to this desired place.

Thermoregulation

The process by which animals maintain their body temperature. Can be achieved through metabolism or behavioral responses like basking in the sun or finding shade. Other animals like a desert hare, can regulate heat

Macrophages (White blood cells)

Within the extracellular matrix. Engulph foreign particles and cell debris by phagocytosis

Fibroblasts

Within the extracellular matrix. Secrete fiber proteins

Torpor

a physiological state of decreased activity and metabolism that is an adaptation for saving energy while avoiding difficult environmental conditions.

Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The ________ would have the highest total annual energy expenditure, and the ________ would have the highest energy expenditure per unit mass. a. elephant; mouse b. elephant; human c. mouse; snake d. penguin; mouse

a. elephant; mouse

Brown fat

adipose tissue with many more mitochondria than white adipose tissue. Specialized for rapid heat production and is found in infants and mammals that hibernate.

You are studying a large tropical reptile that has a high and relatively stable body temperature. How would you determine whether this animal is an endotherm or an ectotherm? a. You know from its high and stable body temperature that it must be an endotherm. b. you subject the reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm. c. You note that its environment has a high and stable temperature. Because its body temperature matches the environmental temperature, you conclude that it is an ectotherm. d. You measure the metabolic rate of the reptile, and because it is higher than that of a related species that lives in a temperate forest, you conclude that this reptile is an endotherm and its relative is an ectotherm.

b. You subject the reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with ambient ambient temperature. You conclude that it is an ectotherm.

The body tissue that consists largely of material located outside of cells is: a. epithelial tissue b. connective tissue c. muscle tissue d. nervous tissue

b. connective tissue

Compared with a smaller cell, a larger cell of the same shape has a. less surface area b. less surface area per unit of volume c. the same surface area to volume ratio d. a smaller cytoplasm to nucleus ratio

b. less surface area per unit of volume

An animals inputs of energy and materials would exceed its outputs a. if the animal is an endotherm, which must always take in more energy because of its high metabolic rate. b. if it is actively foraging for food c. if it is growing and increasing its mass d. never; homeostasis makes these energy and material budgets always balance.

c. if it is growing and increasing its mass.

Which of the following would increase the rate of heat exchange between an animal and its environment? a. feathers or fur b. vasoconstriction c. wind blowing across the body surface d. countercurrent heat exchanger

c. win blowing across the body surface

Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation? a. a marine jelly (an invertebrate) b. a snake in a temperate forest c. a desert insect d. a desert bird

d. a desert bird

Hibernation

long term torpor that is an adaptation to cold winters and food scarcity.

Adipose Tissue

specialized loose connective tissue that stores fat in adipose cells distributed throughout its matrix. Insulates the body and stores fuel.

Standard metabolic rate

the metabolic rate of an ectotherm at rest at a specific temperature and is not under stress.

Countercurrent exchange

the transfer of heat between fluids that are flowing in opposite directions. Arteries and veins flowing near each other.

Thermogenesis

varied head production. Can be accomplished by shivering, or increased metabolic activity to produce heat rather than ATP.