Movement of Hormones in Animals

& PlantsPacket #56

Chapter #45

Organ SystemsIntroduction

An organ system, also known as a biological system, is a group of organs that work together to perform a certain task.

In mammals, a subsection of Kingdom Animalia, there are common systems.

However, in plants, there is no need for multiple systems because of their simple makeup compared to animals.

In both plants, and animals, hormones are produced and there is a need for a system to move those hormones around the organism.

Hormones

Definition & Function

A hormone is an organic compound, normally in the form of a steroid or a peptide, that travels from one area of the organism, to another, in order to carry a specified function.

Hormones regulate physiological activities includingGrowthReproductionHomeostasis

Flashback

At the cellular level, there are different ways in which a signal, can be received and decoded to carry out a specific process/procedure.How are steroid hormones processed at the cellular

level? Signal transduction pathways.

Plant Hormones

Introduction

A plant hormone mayProvide different responses in different tissueProvide different responses at different times during

developmentAffect the activity or production of other hormonesProvide a different response depending on the

concentration.

Auxins

Auxins are produced at the shoot apical meristem, young leaves and seeds

Auxins are responsible for: -Stem elongationApical dominanceRoot initiationFruit development

Cytokinins

Cytokinins are produced in the roots

Cytokinins are responsible for: -Cell divisionDelay of stem senescence Inhibition of apical dominanceFlower developmentEmbryo developmentSeed germination

Ethylene

Ethylene is produced at/in: -Stem nodesRipening fruitDamaged or senescing tissue

Ethylene is responsible for: -Fruit ripeningResponses to environmental stressorsSeed germinationMaintenance of the apical hook on seedlingsRoot initiationSenescence and abscission in leaves and flowers.

Abscisic Acid

Abscisic acid is produced in almost all cells that contain plastids.

Abscisic acid is responsible for: -Seed dormancyResponses that occur as a result of water stress

Gibberellins

Gibberellins are produced at/in: -Young leavesShoot apical meristemsEmbryo in seeds

Gibberellins are responsible forSeed germinationStem elongationFloweringFruit development

Other Plant Hormones

Brassinosteroids

Salicylic acid

Systemin

Oligosaccharins

Jasmonates

Plant Hormones

Plants do not have glands that produce hormones.

However, various tissue, found in the plant, produce hormones.

Hormones, that are not used in the tissue that it was produced in, are transported to other regions.May be transported via vascular tissue

Animal Hormones

Introduction

The endocrine system consists of three main partsEndocrine glandsCells

Signaling cells Target cells

Tissue that secrete hormones

The endocrine system, along with the nervous system, regulate an animal’s physiology

Introduction IIGlands of the

Endocrine System

There are multiple glands utilized, in the human body, to release a variety of hormones.

Figure 45.6Page 950

Glands of the Endocrine System

There are two types of glands that are utilized in the endocrine system.Exocrine glandsEndocrine glands

Glands of the Endocrine System II

Exocrine glands secrete substances into tube-like structuresSalivary glandsMammary glands that produce milkGlands in the stomach that produce stomach acid

Endocrine glands secrete substances directly into extra-cellular space.Substance moves via diffusion

Glands of the Endocrine System & Their Functions

Introduction

There are multiple glands that make-up the endocrine system. These glands include the: - Hypothalamus Pituitary gland

Anterior pituitary gland Posterior pituitary gland

Thyroid gland Parathyroid gland Pancreas Adrenal gland

Adrenal cortex Adrenal medulla

Pineal gland Gonads

Ovary Testes

Table 45.1Page 949

Table 45.1Page 949

Hypothalamus

Hypothalamus

The hypothalamus is the region of the brain that contains the control center for many autonomic nervous system functions.

However, the hypothalamus forms a complex interaction with the pituitary gland and makes up an essential part of the endocrine system.

Hypothalamus

The hormones released as a result of activity with the hypothalamus regulates the secretion of hormones from the anterior pituitary gland.

Pituitary Gland

Introduction

The pituitary gland, which is regulated by the hypothalamus, controls the activities of several other endocrine glands and is considered to be the master gland.

The pituitary gland is divided into two regions: -Anterior pituitaryPosterior pituitary

Anterior Pituitary--Figure 45.7Page 950

Posterior Pituitary--Figure 45.8Page 951

Consequences of Endocrine Malfunction

Hormone Hyposecretion Hypersecretion

Growth hormone Pituitary dwarfism Gigantism if malfunction occurs in childhood; acromegaly in adult.

Thyroid hormones Cretinism (in children); myxedema, a condition of pronounced adult hypothroidism; dietary iodine deficiency leads to hyposecretion and goiter

Hyperthyroidism; increased metabolic rate, nervousness, irritability; goiter, can be caused by Grave’s disease

Parathyroid hormones

Spontaneous discharge of nerves; spasms; tetany; death

Weak brittle bones; kidney stones

Insulin Diabetes mellitus Hypoglycemia

Hormones of adrenal cortex

Addison’s disease Cushing’s disease

Malfunction—Growth Hormone

Dwarfism Gigantism

Malfunction—Thyroid Hormones

MyxedemaGrave’s Disease

(Goiter)

Malfunction—Parathyroid Hormone

Brittle Bone Disease Kidney Stones

Malfunction—Insulin

Diabetes Hypoglycemia

Malfunction—Adrenal Cortex

Hormone Hyposecretion Hypersecretion

Growth hormone Pituitary dwarfism Gigantism if malfunction occurs in childhood; acromegaly in adult.

Thyroid hormones Cretinism (in children); myxedema, a condition of pronounced adult hypothroidism; dietary iodine deficiency leads to hyposecretion and goiter

Hyperthyroidism; increased metabolic rate, nervousness, irritability; goiter, can be caused by Grave’s disease

Parathyroid hormones

Spontaneous discharge of nerves; spasms; tetany; death

Weak brittle bones; kidney stones

Insulin Diabetes mellitus Hypoglycemia

Hormones of adrenal cortex

Addison’s disease Cushing’s disease

Other Information

Homeostasis

The maintenance of a specific physiological state in an organism.

Feedback Regulation

Hormones & Insects

Review

Review I

Review II

Review III

Review IV