Movement of Hormones in Animals & Plants Packet #56 Chapter #45

Organ Systems Introduction 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 including Growth Reproduction Homeostasis

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 may Provide different responses in different tissue Provide different responses at different times during development Affect the activity or production of other hormones Provide 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 elongation Apical dominance Root initiation Fruit development

Cytokinins Cytokinins are produced in the roots Cytokinins are responsible for: - Cell division Delay of stem senescence Inhibition of apical dominance Flower development Embryo development Seed germination

Ethylene Ethylene is produced at/in: - Stem nodes Ripening fruit Damaged or senescing tissue Ethylene is responsible for: - Fruit ripening Responses to environmental stressors Seed germination Maintenance of the apical hook on seedlings Root initiation Senescence 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 dormancy Responses that occur as a result of water stress

Gibberellins Gibberellins are produced at/in: - Young leaves Shoot apical meristems Embryo in seeds Gibberellins are responsible for Seed germination Stem elongation Flowering Fruit 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 parts Endocrine glands Cells Signaling cells Target cells Tissue that secrete hormones The endocrine system, along with the nervous system, regulate an animal’s physiology

Introduction II Glands of the Endocrine System There are multiple glands utilized, in the human body, to release a variety of hormones. Figure 45.6 Page 950

Glands of the Endocrine System There are two types of glands that are utilized in the endocrine system. Exocrine glands Endocrine glands

Glands of the Endocrine System II Exocrine glands secrete substances into tube-like structures Salivary glands Mammary glands that produce milk Glands 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 45.1 Page 949

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 pituitary Posterior pituitary

Anterior Pituitary--Figure 45.7 Page 950

Posterior Pituitary--Figure 45.8 Page 951

Consequences of Endocrine Malfunction

HormoneHyposecretionHypersecretion Growth hormonePituitary dwarfismGigantism if malfunction occurs in childhood; acromegaly in adult. Thyroid hormonesCretinism (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 hormonesSpontaneous discharge of nerves; spasms; tetany; death Weak brittle bones; kidney stones InsulinDiabetes mellitusHypoglycemia Hormones of adrenal cortex Addison’s diseaseCushing’s disease

Malfunction—Growth Hormone DwarfismGigantism

Malfunction—Thyroid Hormones Myxedema Grave’s Disease (Goiter)

Malfunction—Parathyroid Hormone Brittle Bone DiseaseKidney Stones

Malfunction—Insulin DiabetesHypoglycemia

Malfunction—Adrenal Cortex

HormoneHyposecretionHypersecretion Growth hormonePituitary dwarfismGigantism if malfunction occurs in childhood; acromegaly in adult. Thyroid hormonesCretinism (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 hormonesSpontaneous discharge of nerves; spasms; tetany; death Weak brittle bones; kidney stones InsulinDiabetes mellitusHypoglycemia Hormones of adrenal cortex Addison’s diseaseCushing’s disease

Other Information

Homeostasis The maintenance of a specific physiological state in an organism.

Feedback Regulation

Hormones & Insects

Review

Review I HormonesFormPeptidesSteroidsRegulationGrowthReproductionHomeostasis

Review II Plant Hormones AuxinsCytokininsEthylene Abscisic Acid Gibberellins

Review III Glands of Endocrine System Exocrine Glands Secrete substances into tube like structures Endocrine Glands Directly secreted into extra cellular space

Review IV Glands of the Endocrine System Hypothalamus Pituitary Gland Anterior Pituitary Posterior Pituitary ThyroidParathyroidPancreasAdrenal Gland Adrenal Cortex Adrenal Medulla Pineal GlandGonads Ovary Testes