Endocrine, Cardiovascular, and Nervous Systems: Study Guide for Anatomy & Physiology

Endocrine System

Overview of Endocrine Glands and Hormones

The endocrine system consists of glands that secrete hormones directly into the bloodstream to regulate various bodily functions. Each gland produces specific hormones that target organs and tissues.

• Pituitary Gland

  • Anterior Pituitary (Adenohypophysis):

    • Hormones: GH (Growth Hormone), TSH (Thyroid Stimulating Hormone), FSH (Follicle Stimulating Hormone), LH (Luteinizing Hormone), PRL (Prolactin), ACTH (Adrenocorticotropic Hormone)

    • Functions: Growth, metabolism, reproductive system regulation, lactation, stress response

  • Posterior Pituitary (Neurohypophysis):

    • Hormones: ADH (Antidiuretic Hormone), Oxytocin

    • Functions: Water balance, uterine contractions, milk ejection

• Pineal Gland

  • Hormone: Melatonin

  • Function: Regulates sleep-wake cycles

• Thyroid Gland

  • Hormones: T3 (Triiodothyronine), T4 (Thyroxine), Calcitonin

  • Functions: Metabolism, calcium regulation

• Parathyroid Glands

  • Hormone: PTH (Parathyroid Hormone)

  • Function: Increases blood calcium levels

• Adrenal Glands

  • Adrenal Cortex: Produces corticosteroids (e.g., cortisol, aldosterone)

  • Adrenal Medulla: Produces catecholamines (e.g., epinephrine, norepinephrine)

  • Functions: Stress response, blood pressure regulation, metabolism

• Pancreas

  • Hormones: Insulin, Glucagon

  • Functions: Regulates blood glucose levels

• Gonads

  • Ovaries: Estrogen, Progesterone

  • Testes: Testosterone

  • Functions: Sexual development, reproduction

Example: The thyroid gland releases T3 and T4 to regulate metabolism; calcitonin lowers blood calcium levels.

Cardiovascular System

Blood and Blood Vessels

The cardiovascular system transports nutrients, gases, hormones, and waste products throughout the body. It consists of the heart, blood, and blood vessels.

• Blood Components

  • Red Blood Cells (RBCs): Carry oxygen

  • White Blood Cells (WBCs): Immune defense

  • Platelets: Blood clotting

  • Plasma: Liquid component containing proteins, nutrients, hormones

• Blood Vessels

  • Arteries: Carry blood away from the heart

  • Veins: Carry blood toward the heart

  • Capillaries: Exchange of gases and nutrients

Example: The aorta is the largest artery, distributing oxygenated blood from the heart to the body.

Major Arteries and Veins

Major arteries and veins are responsible for the distribution and return of blood throughout the body.

• Arteries (examples):

  • Brachiocephalic trunk

  • Left common carotid

  • Left subclavian

  • Renal artery

  • Femoral artery

• Veins (examples):

  • Jugular vein

  • Superior and inferior vena cava

  • Renal vein

  • Femoral vein

Example: The jugular vein returns deoxygenated blood from the head to the heart.

Nervous System

Central and Peripheral Nervous Systems

The nervous system is divided into the central nervous system (CNS) and peripheral nervous system (PNS). The CNS includes the brain and spinal cord, while the PNS consists of nerves and ganglia outside the CNS.

• CNS: Brain and spinal cord; processes and integrates information

• PNS: Sensory and motor neurons; transmits signals to and from the CNS

Example: The spinal cord transmits sensory and motor information between the body and brain.

Autonomic Nervous System

The autonomic nervous system (ANS) regulates involuntary functions such as heart rate, digestion, and respiratory rate. It is divided into sympathetic and parasympathetic divisions.

• Sympathetic Division: Prepares the body for 'fight or flight' responses

• Parasympathetic Division: Promotes 'rest and digest' activities

Example: Sympathetic stimulation increases heart rate; parasympathetic stimulation decreases it.

Cranial Nerves

Cranial nerves are twelve pairs of nerves that emerge directly from the brain and control sensory and motor functions of the head and neck.

• Examples:

  • CN II (Optic): Vision

  • CN V (Trigeminal): Sensation in the face, chewing

  • CN X (Vagus): Parasympathetic control of heart, lungs, digestive tract

Example: The vagus nerve regulates heart rate and digestive processes.

Blood and Immune System

White Blood Cells (WBCs) and Their Functions

White blood cells are essential for immune defense. They are classified into several types, each with specific functions.

Type	Function
Neutrophils	Phagocytosis of bacteria
Lymphocytes	Antibody production, immune memory
Monocytes	Phagocytosis, antigen presentation
Eosinophils	Defense against parasites, allergic reactions
Basophils	Release histamine, inflammation

Example: Lymphocytes are crucial for adaptive immunity and antibody production.

Additional Topics

Spinal Cord and Reflexes

The spinal cord is a major pathway for information traveling between the brain and body. It also mediates reflex actions.

• Reflex Arc: The neural pathway involved in a reflex action

• Purpose: Provides rapid, involuntary responses to stimuli

Example: The knee-jerk reflex is mediated by the spinal cord without brain involvement.

Common Pathologies

Diseases and disorders can affect the endocrine, cardiovascular, and nervous systems.

• Diabetes Mellitus: Caused by insufficient insulin production or response

• Hypertension: High blood pressure, often related to cardiovascular or endocrine dysfunction

• Multiple Sclerosis: Autoimmune disease affecting the CNS

Example: Diabetes results in elevated blood glucose due to lack of insulin.

Key Equations and Concepts

• Blood Pressure: $\text{BP} = \text{CO} \times \text{TPR}$ Where BP = blood pressure, CO = cardiac output, TPR = total peripheral resistance

• Cardiac Output: $\text{CO} = \text{HR} \times \text{SV}$ Where CO = cardiac output, HR = heart rate, SV = stroke volume

Example: Increased heart rate or stroke volume raises cardiac output and blood pressure.

Summary Table: Major Endocrine Glands and Hormones

Gland	Hormone(s)	Main Function
Pituitary	GH, TSH, FSH, LH, PRL, ACTH, ADH, Oxytocin	Growth, metabolism, reproduction, water balance
Thyroid	T3, T4, Calcitonin	Metabolism, calcium regulation
Parathyroid	PTH	Increase blood calcium
Adrenal	Cortisol, Aldosterone, Epinephrine	Stress response, blood pressure
Pancreas	Insulin, Glucagon	Blood glucose regulation
Gonads	Estrogen, Progesterone, Testosterone	Sexual development, reproduction

Additional info: Some content was expanded for clarity and completeness, including definitions, examples, and equations relevant to the listed topics.