BIOL Exam 1

Anatomy

The study of the structures of organisms

Physiology

The study of the functions of the structures of organisms

Homeostasis

The maintenance of the internal environment in a relatively stable state. It is a dynamic process involving continuous internal adjustments to compensate for external changes

Requirements for Individual Animal Cells

Must be surrounded by an aqueous solution for osmotic balance

Tissue

A group of cells with the same structure and function

Organ

A structure that integrates two or more different tissues to carry out a specific function (e.g.

Organ System (Body System)

Coordinates the activities of two or more organs to carry out a major body function such as movement

Factors Determining Tissue Structure and Function

Properties of individual cells

Anchoring Junctions

Cell junctions that form button-like spots or belts

Tight Junctions

Cell junctions that seal spaces between cells

Gap Junctions

Open channels between cells in the same tissue

Four Basic Animal Tissue Types

Epithelial

Epithelial Tissue Function

Protection

Epithelial Tissue Surfaces

Apical surface: The outer surface

Simple Epithelium

Epithelium formed by a single layer of cells.

Stratified Epithelium

Epithelium formed by multiple cell layers.

Squamous Cells

Flattened cell shapes within an epithelium.

Cuboidal Cells

Cube-shaped cell shapes within an epithelium.

Columnar Cells

Elongated cell shapes within an epithelium.

Simple Squamous Epithelium

A layer of flattened cells found in blood vessel walls and air sacs of the lungs. Its function is diffusion.

Stratified Squamous Epithelium

Several layers of flattened cells found in the skin and surfaces subject to abrasion (e.g.

Cuboidal Epithelium

A layer of cube-like cells (which may have microvilli) found in glands and tubular parts of nephrons in kidneys. Its function is secretion and absorption.

Columnar Epithelium

A layer of tall

Epithelial Stem Cells

Undifferentiated cells found in the basal layer of the skin (and in adults in the brain

Exocrine Glands

Glands connected to the epithelium by a duct

Endocrine Glands

Ductless glands that release hormones

Connective Tissue Function

Supports other body tissues

Extracellular Matrix (ECM)

The nonliving material secreted by the cells of connective tissue. Its type and quantity determine the mechanical properties of the connective tissue

Loose Connective Tissue

Consists of sparsely distributed fibroblast cells surrounded by an open network of collagen and other glycoprotein fibers. It supports epithelia

Dense Connective Tissue

Has sparsely distributed fibroblasts among dense masses of collagen and elastin fibers arranged in highly ordered

Cartilage

Consists of sparsely distributed chondrocytes surrounded by networks of collagen fibers embedded in a tough

Bone

Forms the skeleton

Osteon

The structural unit of bone

Adipose Tissue

Contains large

Blood

The major transport vehicle of the body

Erythrocytes

Red blood cells

Leukocytes

White blood cells

Platelets

Membrane-bound fragments of specialized blood cells that participate in blood clotting.

Muscle Tissue

Consists of cells with the ability to contract (shorten) due to the interaction of actin and myosin proteins. It moves body limbs

Skeletal Muscle

Attached by tendons to the skeleton

Cardiac Muscle

Striated muscle that contracts spontaneously (involuntarily). Its cells are short and branched

Smooth Muscle

Found in the walls of tubes and cavities (e.g.

Nervous Tissue

Contains nerve cells (neurons) that serve as lines of communication and control

Neuron

A nerve cell consisting of a cell body

Extracellular Fluid (ECF)

The fluid that supplies nutrients and oxygen to cells and eliminates wastes in multicellular organisms. It has two components: plasma (fluid portion of blood) and interstitial fluid (fluid surrounding cells).

Regulator (Homeostatic Control)

An animal that maintains factors of its internal environment in a relatively constant state (e.g.

Conformer (Homeostatic Control)

An animal whose internal environment matches the external environment (e.g.

Negative Feedback Control

A homeostatic mechanism that cancels the system responsible for the initial response

Positive Feedback Mechanism

A mechanism that intensifies or adds to a change in the internal or external environment. These are not as common as negative feedback because they do not result in homeostasis (e.g.

Acclimatization

A temporary change in a physiological process that occurs during the life of an animal in response to natural alterations in environmental conditions.

Acclimation

A change in a set point that occurs artificially in a laboratory setting.

The Endocrine System
Hormone

A regulatory chemical secreted into extracellular fluid and carried by the blood. It can act at a distance from its source and must be complex enough to convey regulatory information and stable enough to resist destruction.

Neurohormone

A regulatory chemical released from neurons that travels in the blood

Paracrine Regulators

Signaling molecules that do not travel in the blood

they allow cells of an organ to regulate each other.

Autocrine Regulators

Signaling molecules secreted by the same cell that has the receptor target.

Pheromones

Chemicals released into the environment to communicate among individuals of a single species

Four Classes of Hormones

Amine

Amine Hormones

Involved in classical endocrine and neuroendocrine signaling. Most are hydrophilic (bind to cell surface receptors) and based on tyrosine

Peptide Hormones

Involved in classical endocrine and neuroendocrine signaling. They consist of amino acid chains

Steroid Hormones

Involved in classical endocrine signaling. They are hydrophobic molecules derived from cholesterol

Fatty Acid-Derived Hormones

Involved in paracrine and autocrine regulation. They are important local regulators secreted by most cells

Lipophilic (Nonpolar) Hormones

Fat-soluble hormones (steroid and thyroid hormones) that travel on transport proteins in blood and bind to intracellular receptors

Hydrophilic (Polar) Hormones

Water-soluble hormones (all others besides steroid and thyroid) that are freely soluble in blood and bind to extracellular receptors

Amplification (Hormone Signaling)

A process in which small quantities of hormones can produce profound effects because each activated protein activates a larger number of proteins for the next step in the pathway.

Endocrine vs. Exocrine

Endocrine: Product secreted into extracellular fluid and carried in blood. Exocrine: Secrete product into a duct.

Pituitary Gland (Hypophysis)

Hangs by a stalk from the hypothalamus and consists of two parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).

Anterior Pituitary Hormones (Examples)

Thyroid Stimulating Hormone (TSH)

Tropic Hormones (Tropins)

Hormones that act on other endocrine glands. Examples include TSH

Growth Hormone (GH)

A non-tropic hormone from the anterior pituitary that stimulates cell division

Prolactin (PRL)

A non-tropic hormone from the anterior pituitary that stimulates the development of secretory cells of mammary glands and milk synthesis post-partum.

Posterior Pituitary Hormones

Anti-diuretic Hormone (ADH) and Oxytocin.

Anti-diuretic Hormone (ADH)

Stimulates kidney cells to absorb more water from urine

Oxytocin

Stimulates the ejection of milk from the mammary glands of a nursing mother

it is also present in males.

Thyroid Gland Hormones

Thyroxine (T4

Calcitonin

A peptide hormone secreted by the thyroid gland that stimulates the uptake of calcium (Ca2+) into bones

Parathyroid Hormone (PTH)

Produced by the parathyroid glands

Adrenal Medulla Hormones

Epinephrine and Norepinephrine (catecholamines)

Adrenal Cortex Hormones

Corticosteroids

Pancreatic Islets of Langerhans Hormones

Insulin (from beta cells) and Glucagon (from alpha cells)

Insulin Function

Secreted by beta cells

Glucagon Function

Secreted by alpha cells

Diabetes Mellitus Type I

Insulin-dependent diabetes

Diabetes Mellitus Type II

Noninsulin-dependent diabetes

Melatonin

A hormone secreted by the pineal gland that synchronizes various body processes to a circadian rhythm

Sex Steroids (from Gonads)

Estrogen and Progesterone ("female" hormones) and Androgens (e.g.

Ecdysone

A steroid hormone secreted by prothoracic glands in insects

Juvenile Hormone (JH)

A terpenoid secreted by the corpora allata in insects. High levels produce a larger larva during a molt

Molt-Inhibiting Hormone (MIH)

A peptide neurohormone secreted by a gland in the eye stalks of crustaceans. It inhibits ecdysone secretion when the body size is too small for a molt.

Animal Reproduction
Asexual Reproduction

A single individual gives rise to genetically identical offspring without genetic input from another individual. Advantages include preserving genetic uniformity and no energy expenditure for gametes or mate finding.

Fission (Asexual)

A mitotic mechanism where the parent separates into two or more offspring of approximately equal size (e.g.

Budding (Asexual)

A mitotic mechanism where a new individual develops while attached to the parent

Fragmentation (Asexual)

A mitotic mechanism where pieces separate from the parent's body and develop (regenerate) into new individuals (e.g.

Parthenogenesis

A form of asexual reproduction where animals produce offspring by the development of an egg without fertilization. Offspring are not genetically identical to the parent or each other because the egg is produced by meiosis.

Sexual Reproduction

Male and female parents produce offspring through the fusion of gametes (egg and sperm) generated by meiosis. Advantages include generating genetic diversity among offspring.

Gametogenesis

The cellular mechanism of sexual reproduction involving the formation of male and female gametes from germ cells located in specialized organs called gonads.

Fertilization

The union of haploid sperm and egg during sexual reproduction

Spermatogenesis

The process in males that produces four mature

Sperm Structure

Typically motile cells with a flagellum