Anatomy Study Guide PDF

**Anatomy (Study of Body Structures)** 1. **Gross Anatomy:** Study of large structures visible to the naked eye (e.g., organs). - **Systemic Anatomy:** Study by systems (e.g., nervous, muscular). - **Regional Anatomy:** Study by body regions (e.g., head, abdomen)....

**Anatomy (Study of Body Structures)** 1. **Gross Anatomy:** Study of large structures visible to the naked eye (e.g., organs). - **Systemic Anatomy:** Study by systems (e.g., nervous, muscular). - **Regional Anatomy:** Study by body regions (e.g., head, abdomen). 2. **Microscopic Anatomy:** Study of smaller structures using a microscope. 3. **Developmental Anatomy:** Study of body development from fertilization (Embryology). 4. **Surface Anatomy:** Study of visible or palpable anatomical features. 5. **Comparative Anatomy:** Comparing anatomy across species. 6. **Radiographic Anatomy:** Study via imaging (e.g., X-rays). 7. **Pathology Anatomy:** Study of anatomical changes due to disease. **Physiology (Study of Body Functions)** 1. **Goal:** Understand body responses to stimuli and how it maintains homeostasis (balance). 2. **Human Physiology:** Study of the human body\'s function. 3. **Cellular & Systemic Physiology:** Focus on cellular and organ system functions. **Six Levels of Body Organization:** 1. **Chemical Level:** Atoms and molecules. 2. **Cell Level:** Basic unit of life. 3. **Tissue Level:** Groups of similar cells (e.g., muscle, nervous). 4. **Organ Level:** Two or more tissues working together (e.g., heart). 5. **Organ System Level:** Group of organs with a common function (e.g., digestive system). 6. **Organism Level:** The human body as a whole. **Key Body Functions:** - **Metabolism:** Sum of all chemical reactions (breaking down and building up processes). - **Responsiveness:** Ability to respond to environmental changes. - **Movement:** Motion at various levels (cellular, organ). - **Growth:** Increase in size or cell number. - **Differentiation:** Cells become specialized. - **Reproduction:** Creation of new cells or individuals. **Homeostasis:** - **Definition:** The body\'s ability to maintain stable internal conditions. - **Negative Feedback:** Reverses changes (e.g., blood pressure regulation). - **Positive Feedback:** Reinforces changes (e.g., childbirth). **Body Fluids:** - **Intracellular Fluid (ICF):** Inside cells. - **Extracellular Fluid (ECF):** Outside cells (includes blood plasma, lymph, etc.). **Body Cavities:** 1. **Dorsal Cavity:** Contains brain and spinal cord. 2. **Ventral Cavity:** Contains thoracic (heart, lungs) and abdominopelvic cavities (digestive organs, reproductive system). **Medical Imaging Techniques:** - **X-rays, CT scans, Endoscopy, Radionuclide Scanning.** **Key Notes on Special Senses** **1. General vs. Special Senses:** - **General Senses**: Somatic (tactile, thermal, pain, proprioception) and visceral sensations, found throughout the body, simple structures. - **Special Senses**: Smell, taste, vision, hearing, and equilibrium, localized in the head, anatomically distinct, complex neural pathways. **Vision:** - **Accessory Structures**: Extraocular muscles, palpebra (eyelids), conjunctiva, lacrimal glands, and ducts. - **Lacrimal Apparatus**: Produces/drains tears. - **Flow of Tears**: Lacrimal gland → ducts → superior/inferior lacrimal canal → lacrimal sac → nasolacrimal duct → nasal cavity. - **Eyeball Layers**: - **Fibrous Tunic**: Outer layer (sclera, cornea). - **Vascular Tunic**: Middle layer (choroid, ciliary body, iris). - **Nervous Tunic**: Inner layer (retina). - **Photoreceptors**: - **Rods**: Detect light, more abundant in peripheral retina. - **Cones**: Detect color, concentrated in central retina. **Eye Chambers**: - **Aqueous Humor**: Supports avascular lens/cornea, maintains intraocular pressure (IOP). - **Glaucoma**: Blocked flow or overproduction leads to increased eye pressure. **Hearing (Audition):** - **Three Main Regions**: - **External Ear**: Collects sound (auricle, auditory canal). - **Middle Ear**: Amplifies sound (ossicles: malleus, incus, stapes). - **Inner Ear**: Converts sound to neural signals (cochlea for hearing, vestibular apparatus for balance). - **Inner Ear Fluids**: Perilymph and endolymph in the cochlea aid in transmitting sound. **Equilibrium:** - **Static Equilibrium**: Balance relative to gravity (saccule, utricle). - **Dynamic Equilibrium**: Balance during motion (semicircular canals). **Olfaction (Smell):** - **Olfactory Epithelium**: Contains olfactory receptors, supporting cells, basal cells. - **Pathway**: Olfactory nerves → bulbs → tract → primary olfactory area in the temporal lobe. **Gustation (Taste):** - **Five Primary Tastes**: Sour, sweet, bitter, salty, umami. - **Cranial Nerves Involved**: - **Facial Nerve (VII)**: Taste from anterior 2/3 of the tongue. - **Glossopharyngeal Nerve (IX)**: Taste from posterior 1/3. - **Vagus Nerve (X)**: Taste from throat and epiglottis. **Homeostatic Imbalances:** - **Cataracts**: Opaque lens, common with aging. - **Conjunctivitis**: Inflammation of conjunctiva (pink eye). - **Age-Related Macular Degeneration (AMD)**: Loss of central vision due to retina damage. - **Otitis Media**: Middle ear infection, common in young children. This summary covers key areas of brain development and anatomy, highlighting major structures, functions, and reflexes: **Brain Stem** - **Functions**: Controls cranial nerves, regulates heartbeat, breathing, consciousness, and reflex movements (eye, head, and trunk). - **Medulla Oblongata**: Contains vital centers for cardiovascular and respiratory control. - **Pons**: Connects brain regions, regulates sleep, and supports facial movement and balance. **Diencephalon** - **Hypothalamus**: Regulates body temperature, hunger, thirst, sleep cycles, and integrates the nervous and endocrine systems. - **Thalamus**: Relay station for sensory and motor signals, involved in alertness and pain sensation. **Cerebrum** - **Cortex**: Processes sensory information and controls motor function. Each area has specific roles: - Visual: Occipital lobe - Auditory: Temporal lobe - Gustatory (taste): Near somatosensory area - Olfactory (smell): Inferior temporal lobe **Basal Ganglia & Limbic System** - **Basal Ganglia**: Movement control and habit formation. - **Limbic System**: Includes the **amygdala** (emotion/fear processing) and **hippocampus** (memory formation). **Cranial Nerves** - Twelve nerves (I-XII) control sensory functions like smell (olfactory), vision (optic), and motor functions for eye movement (oculomotor, trochlear, abducens) and facial expression (facial nerve). **Protective Structures** - **Meninges**: Layers (dura, arachnoid, pia mater) protect the brain and spinal cord. - **Falx Cerebri & Tentorium Cerebelli**: Protective barriers separating brain regions. **CSF and Brain Blood Flow** - **Cerebrospinal Fluid (CSF)**: Protects the brain and spinal cord, regulates pressure, and removes waste. Issues in drainage lead to **hydrocephalus**. - **Brain Blood Flow**: Supplied by internal carotid and vertebral arteries, returned by jugular veins. **Spinal Cord Anatomy** - White matter (outer) carries signals, while gray matter (inner) integrates them. Major tracts include **spinothalamic** (sensory) and **corticospinal** (motor). **ANS (Autonomic Nervous System)** - **Sympathetic (\"fight or flight\")**: Increases heart rate, dilates vessels in essential organs, and decreases GI activity. - **Parasympathetic (\"rest and digest\")**: Increases digestion and relaxation (SLUDD: Salivation, Lacrimation, Urination, Digestion, Defecation). **Overview of the Nervous System** The nervous system is responsible for rapid communication in the body to maintain homeostasis. It enables behaviors, thought processes, and control of organ functions. **Key Types of Neurons:** 1. **Sensory Neurons**: Carry signals from the body to the central nervous system (CNS). 2. **Motor Neurons**: Send signals from the CNS to muscles, skin, and glands. 3. **Association Neurons (Interneurons)**: Found in the CNS, connecting sensory and motor neurons. **Main Functions of the Nervous System:** 1. **Sensory Input**: Collects information from the environment. 2. **Integration**: Processes sensory input and decides on an action. 3. **Motor Output**: Triggers muscles or glands to respond. 4. **Homeostasis**: Maintains internal balance by detecting and responding to changes. 5. **Mental Activity**: Controls consciousness, memory, and thinking. **Divisions of the Nervous System:** - **Central Nervous System (CNS)**: Includes the brain and spinal cord. - **Peripheral Nervous System (PNS)**: Everything outside the CNS. - **Somatic Nervous System (SNS)**: Voluntary control of movements via skeletal muscles. - **Autonomic Nervous System (ANS)**: Involuntary processes like heart rate, digestion, and respiration. - **Enteric Nervous System (ENS)**: Controls functions of the gastrointestinal (GI) tract. **Action Potentials and Neurotransmitters:** - **Action Potential**: The nerve signal sent for long-distance communication, which is an all-or-nothing response. - **Neurotransmitters**: Chemicals that transmit signals across neurons, with some being excitatory (stimulate) and others inhibitory (calm). **Neuron Classifications:** 1. **Multipolar Neurons**: Have multiple dendrites and one axon; mainly motor neurons. 2. **Bipolar Neurons**: One dendrite and one axon; involved in senses like sight and smell. 3. **Unipolar Neurons**: Single process; mainly sensory neurons, conveying touch and stretching. **Neuron Fiber Types:** 1. **A Fibers**: Large and fast, transmitting touch and pressure sensations. 2. **B Fibers**: Medium-sized, involved in sensory and autonomic signals. 3. **C Fibers**: Small and slow, transmitting unmyelinated sensory and autonomic signals. Here are the **key notes** for the cardiovascular system: **Heart Overview** - The heart is a **muscular organ** that pumps **5L of blood per minute**. - Located in the **pericardial cavity**, it is surrounded by the **pericardium**: - **Fibrous pericardium** (outer layer) - **Serous pericardium**: Includes the **parietal** and **visceral (epicardium)** layers. **Layers of the Heart Wall** 1. **Epicardium**: Outer surface. 2. **Myocardium**: Thick muscular middle layer. 3. **Endocardium**: Smooth inner surface. **Chambers of the Heart** - **4 chambers**: Right/Left atria (upper) and ventricles (lower). - **Atria**: Receives blood and functions as reservoirs. - **Ventricles**: Pump blood to the lungs (right) or the rest of the body (left). **Heart Circulations** - **Pulmonary circulation**: Right heart pumps blood to the lungs. - **Systemic circulation**: Left heart pumps blood to the body. **Heart Valves** - **Atrioventricular (AV) valves**: Right (tricuspid) and left (bicuspid/mitral) valves allow blood flow from atria to ventricles. - **Semilunar valves**: Aortic and pulmonary valves prevent backflow into the ventricles. **Cardiac Conduction System** - **Autorhythmicity**: Cardiac cells can generate their own action potential. - Pathway includes: - **Sinoatrial (SA) node**: Heart\'s pacemaker. - **Atrioventricular (AV) node**, **AV bundle**, **bundle branches**, and **Purkinje fibers**: Spread the electrical signal. **Cardiac Cycle Phases** 1. **Atrial diastole**: Blood passively flows into atria and ventricles. 2. **Atrial systole**: Atria contract to fill ventricles. 3. **Isovolumetric contraction**: Ventricles contract; AV valves close. 4. **Ventricular systole**: Ventricles pump blood into arteries. 5. **Isovolumetric relaxation**: Ventricles relax, semilunar valves close. **Cardiac Output (CO)** - **Stroke volume (SV)**: Volume of blood ejected per heartbeat. - Formula: **SV = EDV - ESV**. - **Cardiac Output**: Blood volume pumped per minute. - Formula: **CO = HR x SV**. **Blood Components** - **Plasma**: 55% of blood, mostly water (91%) with proteins (Globulins, Albumin, Fibrinogen). - **Buffy coat**: WBCs and platelets. - **RBCs**: Carry oxygen, lifespan of 120 days. **Hemostasis (Blood Clotting)** - Steps to stop bleeding: 1. **Vascular spasm** (vasoconstriction). 2. **Platelet plug** formation. 3. **Coagulation** (blood clotting via fibrin). **Blood Disorders** - **Anemia**: Low RBCs/hemoglobin. - **Polycythemia**: Excess RBCs. - **Thrombocytopenia**: Low platelets; risk of bleeding. - **Hemophilia**: Lack of clotting factors; prolonged bleeding. - **Leukemias**: High WBCs, often related to cancers. **Blood Pressure** - **Systolic BP**: Pressure during ventricular contraction. - **Diastolic BP**: Pressure during ventricular relaxation.