Unit 4: Homeostasis

Homework Guidelines

• Pre-read notes and textbook.
• Answer assigned homework questions.
• Submit at the start of assigned classes.
• Answers should be detailed, accurate, and grammatically correct.
• No late submissions or plagiarism.

Homework Questions by Section

• 8.1 (p.348): Questions 2 (6A), 9 (2A), 10 (5I)
• 8.2 (p.362): Questions 9 (5I), 11 (2I)
• 9.1 (p.395): Questions 3 (3I), 11 (2I)
• 9.2 (p.403): Questions 6 (2A), 10 (2I)
• 9.3 (p.413): Questions 4 (3A), 9 (8A)
• 9.4 (p.425): Questions 6 (2I), 11 (2I)
• 10.1 (p.448): Questions 5 (2I), 10 (2I)
• 10.2 (p.455): Questions 10 (4A), 11 (2I)
• 10.3 (p.465): Questions 4 (3A), 5 (4I)

8.1: Human Body Systems and Homeostasis

Learning Goals

• Purpose of homeostasis for survival.
• Negative and positive feedback systems.
• Role of different body systems in survival.

Body Systems in Homeostasis

• Circulatory System: Material transport.
• Immune System: Disease protection.
• Digestive System: Nutrient absorption.
• Respiratory System: Gas exchange.
• Excretory System: Waste removal.
• Nervous System: Response to stimuli.
• Endocrine System: Hormone secretion.

Homeostasis

• Maintains stable internal environment (dynamic equilibrium).
• Necessary for organ and system function.

Feedback Systems

• Negative Feedback: Stimulus reduction (e.g., iris control).
• Positive Feedback: Stimulus amplification (e.g., childbirth).

8.2: Nervous System Structures and Processes

Learning Goals

• Parts and functions of the nervous system.
• Neuron structure and function.
• Reflex arcs.
• Neuron action steps.
• Signal transmission between neurons.

Nervous System Overview

• CNS: Brain and spinal cord.
• PNS: Nerves connecting CNS.
• Autonomic: Involuntary control.
• Somatic: Voluntary control.

Neuron Function

• Specialized for information transmission.
• Supported by glial cells (e.g., Schwann cell).
• Sensory Neurons: Sense organ signals.
• Motor Neurons: CNS to muscle signals.
• Interneurons: Connect sensory and motor neurons.

Reflex Arcs

• Automatic response before brain processing.
• Examples: Blushing, yawning, blinking, etc.

Nerve Impulse Transmission

• Resting Potential: High K+ inside, Na+ outside.
• Action Potential: Depolarization and repolarization.
• Synapse: Neurotransmitter-mediated signal transfer.
• Neurotransmitters: Acetylcholine, dopamine, serotonin, etc.

9.1: Endocrine System Glands and Hormones

Learning Goals

• Compare nervous and endocrine systems.
• Steroid vs non-steroid hormones.
• Major endocrine glands.

Hormones

• Chemical messengers in blood.
• Exocrine Gland: Hormones through ducts (e.g., sweat).
• Endocrine Gland: Hormones directly into blood.

Hormone Types

• Steroid Hormones: Lipid-based, enter cells (e.g., cortisol).
• Non-Steroid Hormones: Protein-based, membrane-binding (e.g., insulin).

9.2: Hormonal Regulation of Growth and Metabolism

Learning Goals

• Pituitary gland (master gland).
• Anterior/posterior lobe hormones.
• Thyroid gland function and metabolism.
• Calcium regulation by thyroid and parathyroid glands.

Pituitary Gland

• Anterior: TSH, FSH, LH, ACTH, HGH, prolactin.
• Posterior: Stores ADH and oxytocin.

Thyroid Gland

• Regulates metabolic rate via thyroxine.
• Hyperthyroidism vs hypothyroidism.
• Calcium regulation via calcitonin and PTH.

9.3: Stress Response and Blood Sugar Regulation

Learning Goals

• Adrenal gland structure and function.
• Pancreas role in glucose regulation.
• Diabetes types.

Adrenal Glands

• Medulla: Fight or flight response.
• Cortex: Long-term stress response.

Blood Sugar Regulation

• Insulin: Lowers blood sugar.
• Glucagon: Raises blood sugar.

Diabetes

• Type 1: Insulin absence.
• Type 2: Insulin resistance.

9.4: Reproductive System Hormonal Regulation

Learning Goals

• Hormonal roles in male and female cycles.

Male Reproductive Cycle

• Continuous sperm production.
• Hormones: GnRH, LH, FSH, testosterone.

Female Reproductive Cycles

• Periodic egg release.
• Hormones: GnRH, LH, FSH, estrogen, progesterone.

10.1: Excretory System Overview

Learning Goals

• Excretory system functions.
• Kidney and nephron identification.

Functions

• Waste removal, osmoregulation, pH balance.
• Hormone secretion and vitamin D activation.

Kidney Structure

• Cortex: Upper nephron parts.
• Medulla: Loop of Henle.
• Pelvis: Urine collection.

10.2: Urine Formation in Nephron

Learning Goals

• Urine formation process.

Nephron Process

1. Filtration at Bowman's capsule.
2. Reabsorption in proximal tubule.
3. Water reabsorption in loop of Henle.
4. Distal tubule adjustments.
5. Concentration in collecting duct.

10.3: Excretory System Functions and Disorders

Learning Goals

• ADH and aldosterone effects on urine.
• Blood pH regulation.

Hormonal Effects

• ADH: Water reabsorption.
• Aldosterone: Salt and water balance.

Blood pH Regulation

• Via kidney filtration and respiratory system.
• Carbonic acid buffer system.