Nervous, Endocrine and Reproductive System PDF

The Nervous system is the body’s communication and control center. It is responsible for detecting changes in the environment, processing information, and coordinating responses. It is divided into two main parts: 1. Central Nervous System (CNS) Components: Brain and spinal cord Function...

The Nervous system is the body’s communication and control center. It is responsible for detecting changes in the environment, processing information, and coordinating responses. It is divided into two main parts: 1. Central Nervous System (CNS) Components: Brain and spinal cord Function: Processes information, controls voluntary and involuntary actions, and serves as the center for thoughts, emotions, and memory. Brain: Controls higher functions like thinking, emotions, and memory. Spinal Cord: Transmits signals between the brain and the rest of the body. 2. Peripheral Nervous System (PNS) Components: Nerves outside the CNS (cranial and spinal nerves). Function: Connects the CNS to the rest of the body. It is further divided into: Somatic Nervous System: Controls voluntary movements (e.g., muscle movements). Autonomic Nervous System (ANS): Regulates involuntary actions (e.g., heart rate, digestion). Sympathetic Division: Activates "fight or flight" response during stress. Parasympathetic Division: Promotes "rest and digest" functions during relaxation. 3. Neuron (Nerve Cell) Structure: Cell Body: Contains the nucleus and organelles. Dendrites: Receive signals from other neurons. Axon: Transmits signals to other neurons or muscles. Function: Transmits electrical and chemical signals throughout the body. How it Works: 1. Sensory Input: Detects stimuli (via sensory organs). 2. Integration: Processes information in the CNS. 3. Motor Output: Sends responses to muscles or glands through motor neurons. Diencephalon The diencephalon is a part of the brain located between the brainstem and the cerebrum. It acts as a relay and processing center for sensory and motor information. It has three major structures: 1. Thalamus: o Location: At the top of the brainstem, inside the diencephalon. o Function: ▪ Acts as the brain's sensory relay station. It processes and transmits sensory information (except smell) to the cerebral cortex. ▪ Plays a role in regulating consciousness, alertness, and sleep. 2. Hypothalamus: o Location: Below the thalamus. o Function:  ▪ Regulates homeostasis (e.g., body temperature, hunger, thirst). 3. Epithalamus: o Location: Near the back of the diencephalon. o Function: ▪ Includes the pineal gland, which regulates sleep-wake cycles by producing melatonin. Thalamus (A Part of the Diencephalon) The thalamus is a key structure within the diencephalon and plays a significant role in sensory perception and motor control: Sensory Role: Receives signals from the eyes, ears, skin, and other sensory organs and sends them to the appropriate areas in the cerebral cortex. Motor Role: Helps coordinate motor signals by relaying them between the motor cortex and other parts of the brain. The pons is a part of the brainstem located between the medulla oblongata and the midbrain. It acts as a bridge by connecting the brain and spinal cord and coordinating communication between different parts of the brain, including the cerebellum. Functions: Helps control breathing. Involved in sleep, hearing, taste, and facial movements. Relays signals between the cerebrum and cerebellum. The medulla oblongata is the lowest part of the brainstem, located just above the spinal cord. It controls many vital, involuntary functions essential for survival. The medulla oblongata is also known as the center for respiration because it controls and regulates the breathing process. The spinal cord is divided into four main regions based on the vertebrae it passes through. Each region serves specific areas of the body: 1. Cervical Region (C1-C8) Location: Uppermost region, in the neck. Function: Controls movement and sensation in the neck, shoulders, arms, and hands. 2. Thoracic Region (T1-T12) Location: Middle back, corresponding to the chest area. Function: Controls muscles in the chest, abdomen, and parts of the back. 3. Lumbar Region (L1-L5) Location: Lower back. Function: Controls movement and sensation in the lower abdomen, hips, and legs. 4. Spinal Nerves (S1-S5) Location: Pelvic area, below the lumbar region. Function: Controls movement and sensation in the pelvis, thighs, legs, feet, and some bladder and bowel functions. The fourth region of the spinal cord, sometimes associated with the spinal nerves, refers to the sacral region, and includes the nerves that carry signals to and from the body. These nerves are divided into two types based on the direction of signal transmission: Afferent Nerves (Sensory Nerves) Carry information to the spinal cord and brain from the body. Responsible for sensing stimuli like touch, temperature, pain, and pressure. Example: Feeling the heat of a flame on your hand. Efferent Nerves (Motor Nerves) Carry instructions from the brain and spinal cord to muscles and glands. Responsible for actions like movement and glandular secretions. Example: Moving your hand away from the flame. The amygdala is a small, almond-shaped structure located deep within the brain, in the temporal lobe. It is a key part of the limbic system, which is involved in processing emotions and memories. Dopamine Secreted by: Substantia nigra, Ventral Tegmental Area (VTA) Meaning: A neurotransmitter for motivation, reward, and motor control. Endocrine System Nervous Peripheral Nervous System These are nerves linked to CNS but are located outside the brain and spinal cord. 1. Somatic Nervous System Controls all 5 senses & movements Two division: Sensory 2. Autonomic Nervous System Controls involuntary physiological processes Two division: Neurons and Motor Sympathetic and Neurons Parasympathetic Sympathetic Nervous System “Fight-or-Flight” ✓Increases Heart Rate and Blood Pressure ✓Dilates pupils ✓Stops salivation ✓Increase Blood sugar ✓Relaxes bladder (no urination) REMEMBER: “S” for Stress Parasympathetic Nervous System “Rest-and-Digest” ✓Lowers Heart Rate and Blood Pressure ✓Constricts pupils ✓Stimulates salivation ✓Bronchi constriction ✓Contracts bladder REMEMBER: “R” in paRa for Relax Reproductive System  Patrick Christopher Steptoe - A British OB-GYN, a renowned pioneer in fertility treatment - laparoscope Dr. Robert Edwards - the father of In Vitro Fertilization Louise Brown -World’s first “Test-tube baby”? (July 25, 1978) Birth Stage 1 Initial (latent) phase Begins with the onset labor Amniotic sac breaks and releases fluid Stage 2 Contraction of uterus Passing of the baby to the vagina Stage 3 Umbilical cord