Anatomy and Physiology PDF

**1.1 Definition of Anatomy and Physiology; Various Suffixes and Prefixes Used in Anatomy and Physiology** - **Anatomy**: The branch of biology concerned with the study of the structure of organisms and their parts. Anatomy examines the physical structure of the body. - **Physiology**:...

**1.1 Definition of Anatomy and Physiology; Various Suffixes and Prefixes Used in Anatomy and Physiology** - **Anatomy**: The branch of biology concerned with the study of the structure of organisms and their parts. Anatomy examines the physical structure of the body. - **Physiology**: The branch of biology that deals with the normal functions of living organisms and their parts. Physiology focuses on how the body and its systems work. - **Suffixes**: - **-itis**: Inflammation (e.g., gastritis) - **-ectomy**: Removal (e.g., appendectomy) - **-osis**: Condition or disease (e.g., neurosis) - **-ology**: Study of (e.g., cardiology) - **-logy**: Study of (e.g., biology) - **Prefixes**: - **Hyper-**: Excessive (e.g., hypertension) - **Hypo-**: Below normal (e.g., hypoglycemia) - **Sub-**: Under or below (e.g., subcutaneous) - **Trans-**: Across or through (e.g., transdermal) **1.2 Definition of Different Terminologies Used in Various Systems** - **Cardiovascular System**: The system responsible for the circulation of blood and lymph through the body. Key terms include heart, arteries, veins, and capillaries. - **Respiratory System**: The system responsible for breathing and gas exchange. Key terms include lungs, bronchi, alveoli, and diaphragm. - **Digestive System**: The system that breaks down food into nutrients. Key terms include stomach, intestines, liver, and pancreas. - **Nervous System**: The system that controls bodily functions and processes sensory information. Key terms include brain, spinal cord, nerves, and neurons. - **Musculoskeletal System**: The system that provides structure and support through bones and muscles. Key terms include bones, muscles, tendons, and ligaments. **1.3 Main Cavities: Cranial, Thoracic, Abdominal, and Pelvic** - **Cranial Cavity**: Contains the brain and is protected by the skull. - **Thoracic Cavity**: Contains the heart and lungs, bounded by the rib cage and diaphragm. - **Abdominal Cavity**: Contains digestive organs such as the stomach, intestines, liver, and kidneys. - **Pelvic Cavity**: Contains reproductive organs, bladder, and rectum, and is bordered by the pelvis. **1.4 Anatomical Position of the Body** - **Anterior (Ventral)**: Front of the body. - **Posterior (Dorsal)**: Back of the body. - **Superior**: Above or closer to the head. - **Inferior**: Below or closer to the feet. - **Proximal**: Closer to the point of origin or attachment. - **Distal**: Further from the point of origin or attachment. - **Dorsal**: Pertaining to the back. - **Ventral**: Pertaining to the front or belly side. - **Palmer**: Pertaining to the palm of the hand. - **Lateral**: Away from the midline of the body. - **Medial**: Toward the midline of the body. - **Supine**: Lying on the back. - **Prone**: Lying on the stomach. **1.5 Range of Motion** - **Flexion**: Decreasing the angle between body parts (e.g., bending the elbow). - **Extension**: Increasing the angle between body parts (e.g., straightening the elbow). - **Abduction**: Moving a limb away from the midline of the body (e.g., lifting the arm sideways). - **Adduction**: Moving a limb toward the midline of the body (e.g., lowering the arm to the side). - **Rotation**: Turning a body part around its axis (e.g., turning the head). - **Circumduction**: Circular movement of a limb (e.g., moving the arm in a circular motion). - **Supination**: Rotating the forearm so the palm faces up or forward. - **Pronation**: Rotating the forearm so the palm faces down or backward. - **Opposition**: Movement of the thumb to touch the fingertips. **2.1 The Structure and Functions of Human Cells** - **Structure**: - **Cell Membrane**: The outer boundary of the cell, controlling what enters and leaves the cell. It's composed of a phospholipid bilayer with embedded proteins. - **Nucleus**: Contains the cell\'s genetic material (DNA) and is involved in regulating activities such as growth and metabolism. It has a nuclear envelope, nucleolus, and chromatin. - **Cytoplasm**: A jelly-like substance within the cell membrane that contains organelles and is the site for most cellular processes. - **Organelles**: - **Mitochondria**: Known as the \"powerhouse\" of the cell, they generate ATP through cellular respiration. - **Ribosomes**: Sites of protein synthesis. - **Endoplasmic Reticulum (ER)**: - **Rough ER**: Studded with ribosomes and involved in protein synthesis and modification. - **Smooth ER**: Involved in lipid synthesis and detoxification. - **Golgi Apparatus**: Modifies, sorts, and packages proteins and lipids for transport. - **Lysosomes**: Contain digestive enzymes to break down waste materials and cellular debris. - **Peroxisomes**: Break down fatty acids and produce hydrogen peroxide. - **Cytoskeleton**: A network of fibers (microfilaments, intermediate filaments, and microtubules) that provides structural support and aids in cell movement. - **Functions**: - **Metabolism**: Chemical reactions occurring within the cell to maintain life, including energy production, growth, and repair. - **Protein Synthesis**: The process of creating proteins necessary for cellular functions. - **Reproduction**: Cells replicate through mitosis or meiosis to produce new cells or gametes. - **Transport**: Movement of substances in and out of the cell via passive or active transport mechanisms. **2.2 Cell Division: Mitosis and Meiosis** - **Mitosis**: - **Purpose**: Produces two identical daughter cells from a single parent cell, used for growth, repair, and asexual reproduction. - **Phases**: - **Prophase**: Chromosomes condense, and the nuclear envelope dissolves. - **Metaphase**: Chromosomes line up at the cell\'s equator. - **Anaphase**: Chromosomes are pulled apart to opposite poles of the cell. - **Telophase**: Nuclear envelopes reform around the chromosomes, which de-condense. - **Cytokinesis**: Division of the cytoplasm, resulting in two separate cells. - **Meiosis**: - **Purpose**: Produces four genetically unique daughter cells (gametes) from a single parent cell, essential for sexual reproduction. - **Phases**: - **Meiosis I**: Reduces chromosome number by half. - **Prophase I**: Chromosomes condense, homologous chromosomes pair up and exchange genetic material (crossing over). - **Metaphase I**: Homologous chromosome pairs line up at the cell\'s equator. - **Anaphase I**: Homologous chromosomes are pulled to opposite poles. - **Telophase I**: Two cells form, each with half the original chromosome number. - **Meiosis II**: Similar to mitosis, separates sister chromatids. - **Prophase II**: Chromosomes condense, and a new spindle apparatus forms. - **Metaphase II**: Chromosomes line up at the cell\'s equator. - **Anaphase II**: Sister chromatids are separated and pulled to opposite poles. - **Telophase II**: Nuclear envelopes reform, resulting in four genetically distinct haploid cells. **2.3 The Structure and Function of Tissues** - **Epithelial Tissue**: - **Structure**: Cells are tightly packed in layers or sheets. - **Functions**: Protects surfaces, absorbs nutrients, secretes substances, and forms barriers (e.g., skin, lining of organs). - **Connective Tissue**: - **Structure**: Cells are scattered within an extracellular matrix (can be fluid, gel-like, or solid). - **Functions**: Supports, binds, and protects tissues and organs (e.g., bone, blood, adipose tissue). - **Muscular Tissue**: - **Structure**: Cells are long and thin (muscle fibers) and can be striated or non-striated. - **Functions**: Facilitates movement (e.g., skeletal muscle for voluntary movement, cardiac muscle for heart contractions, smooth muscle for involuntary movements). - **Nervous Tissue**: - **Structure**: Composed of neurons (nerve cells) and supporting cells (neuroglia). - **Functions**: Transmits electrical signals throughout the body, coordinating and regulating bodily functions. **2.4 Structure and Functions of Membranes, Glands, and Cartilage** - **Membranes**: - **Structure**: Thin layers of tissue covering surfaces, organs, and cavities. - **Types**: - **Mucous Membranes**: Line body cavities that open to the outside (e.g., digestive tract). - **Serous Membranes**: Line body cavities not open to the outside (e.g., thoracic and abdominal cavities). - **Synovial Membranes**: Line joints and produce synovial fluid for lubrication. - **Cutaneous Membranes**: Skin, covering the external body surface. - **Glands**: - **Structure**: Cells or organs that secrete substances. - **Types**: - **Exocrine Glands**: Secrete substances into ducts (e.g., sweat glands, salivary glands). - **Endocrine Glands**: Secrete hormones directly into the bloodstream (e.g., thyroid gland, adrenal glands). - **Cartilage**: - **Structure**: Flexible connective tissue with a dense matrix of collagen and elastic fibers. - **Types**: - **Hyaline Cartilage**: Provides support with some flexibility (e.g., in the nose, trachea, and at the ends of long bones). - **Elastic Cartilage**: Provides flexibility and strength (e.g., in the outer ear). - **Fibrocartilage**: Provides strong support and resists compression (e.g., intervertebral discs, menisci). **3.1 Body Fluid and Electrolytes** - **Fluid and Electrolyte Distribution**: - **Intracellular Fluid (ICF)**: The fluid within cells, accounting for about 60% of the body's total fluid. - **Extracellular Fluid (ECF)**: The fluid outside cells, including interstitial fluid (between cells), intravascular fluid (in blood vessels), and transcellular fluid (e.g., cerebrospinal fluid, synovial fluid). It makes up about 40% of the body's total fluid. - **Important Functions of Body Fluid**: - **Transport**: Delivers nutrients, hormones, and oxygen to cells, and removes waste products. - **Regulation of Temperature**: Helps maintain body temperature through sweating and evaporation. - **Lubrication**: Reduces friction between body parts and facilitates movement (e.g., synovial fluid in joints). - **Cellular Function**: Maintains cell shape, size, and function through osmotic balance. - **Body Fluid and Electrolyte Balance**: - **Fluid Balance**: Maintained by intake (drinks, food) and output (urine, sweat, respiration). The balance is regulated by mechanisms such as thirst, renal function, and hormonal control (e.g., antidiuretic hormone). - **Electrolyte Balance**: Maintained through intake (diet), absorption, and excretion. Key electrolytes include sodium, potassium, calcium, magnesium, chloride, and bicarbonate. - **Importance of Fluid and Electrolyte Balance in Health**: - Essential for maintaining blood pressure, nerve function, muscle function, and overall cellular homeostasis. Imbalances can lead to conditions such as dehydration, edema, or electrolyte disturbances, affecting various body systems. **3.2 Acid-Base Balance** - **Definition of Acid and Base**: - **Acid**: A substance that donates hydrogen ions (H+) in solution (e.g., hydrochloric acid). - **Base**: A substance that accepts hydrogen ions (H+) or donates hydroxide ions (OH-) in solution (e.g., sodium hydroxide). - **Mechanisms to Maintain Acid-Base Balance**: - **Respiratory System**: Regulates pH by adjusting the rate and depth of breathing to alter carbon dioxide (CO2) levels. Increased CO2 leads to acidosis, while decreased CO2 leads to alkalosis. - **Urinary System**: Excretes hydrogen ions and reabsorbs bicarbonate (HCO3-) to regulate pH. The kidneys can adjust the pH of urine to balance blood pH. - **Buffer Mechanism**: Immediate response to pH changes involves buffer systems in the blood, such as: - **Bicarbonate Buffer System**: Combines with excess H+ to form carbonic acid, which can be converted to CO2 and exhaled. - **Hemoglobin Buffer System**: Hemoglobin binds to H+ in red blood cells. - **Protein Buffers**: Proteins in cells and blood act as buffers by binding or releasing H+. **3.3 Fluid and Electrolyte Imbalances** - **Conditions Related to Fluid and Electrolyte Imbalance**: - **Dehydration/Overhydration**: - **Dehydration**: Loss of water and electrolytes; can result from vomiting, diarrhea, or inadequate intake. - **Overhydration**: Excess water intake; can lead to dilution of electrolytes. - **Hypo/Hyperkalemia**: - **Hypokalemia**: Low potassium levels, leading to muscle weakness, arrhythmias. - **Hyperkalemia**: High potassium levels, leading to potential cardiac issues. - **Hypo/Hypernatremia**: - **Hyponatremia**: Low sodium levels, causing swelling of cells. - **Hypernatremia**: High sodium levels, leading to dehydration of cells. - **Hypo/Hypercalcemia**: - **Hypocalcemia**: Low calcium levels, affecting muscle and nerve function. - **Hypercalcemia**: High calcium levels, causing bone pain, kidney stones. - **Hypo/Hypermagnesemia**: - **Hypomagnesemia**: Low magnesium levels, leading to muscle cramps and neurological symptoms. - **Hypermagnesemia**: High magnesium levels, causing cardiovascular and neuromuscular issues. - **Ways of Replacement**: - **Oral Rehydration Therapy**: Solution of water, electrolytes, and glucose to treat dehydration. - **Naso-gastric Feeding**: Involves inserting a tube through the nose into the stomach for nutrient and fluid intake. - **Intravenous Therapy**: Administers fluids and electrolytes directly into the bloodstream. - **Types of Rehydration Solutions**: - **Hypertonic**: Higher solute concentration than blood, used to draw fluid into the bloodstream. - **Hypotonic**: Lower solute concentration than blood, used to hydrate cells. - **Isotonic**: Equal solute concentration as blood, used to maintain fluid balance. **4.1 Circulatory System** - **Structure and Functions of the Heart**: - **Structure**: The heart is a four-chambered organ with two atria (upper chambers) and two ventricles (lower chambers). It has four valves: tricuspid, pulmonary, mitral, and aortic. - **Functions**: Pumps blood throughout the body, delivering oxygen and nutrients while removing carbon dioxide and waste products. It maintains blood pressure and regulates blood flow. - **Cardiac Cycle**: - **Phases**: - **Diastole**: The heart relaxes and fills with blood. The atria contract to push blood into the ventricles. - **Systole**: The ventricles contract to eject blood into the pulmonary artery and aorta. The atria refill with blood from the veins. - **Conduction System**: - **Components**: - **Sinoatrial (SA) Node**: The natural pacemaker of the heart that initiates the heartbeat. - **Atrioventricular (AV) Node**: Delays the impulse before transmitting it to the ventricles. - **Bundle of His**: Transmits impulses from the AV node to the ventricles. - **Purkinje Fibers**: Spread impulses throughout the ventricles, causing them to contract. - **Heart Sounds**: - **First Heart Sound (S1)**: \"Lub\" -- Closure of the mitral and tricuspid valves. - **Second Heart Sound (S2)**: \"Dub\" -- Closure of the aortic and pulmonary valves. - **Additional Sounds**: May indicate abnormal heart function, such as murmurs or gallops. - **Normal Blood Flow**: - Blood flows from the body into the right atrium, through the tricuspid valve to the right ventricle, then to the lungs via the pulmonary artery. Oxygenated blood returns to the left atrium, passes through the mitral valve to the left ventricle, and is pumped out to the body through the aorta. - **Blood**: - **Composition of Blood**: - **Cells**: - **Red Blood Cells (Erythrocytes)**: Carry oxygen from the lungs to tissues and carbon dioxide back to the lungs. - **White Blood Cells (Leukocytes)**: Involved in immune response and fighting infection. - **Platelets (Thrombocytes)**: Aid in blood clotting. - **Plasma**: The liquid component of blood, composed of water, electrolytes, proteins (e.g., albumin, globulins), hormones, and waste products. - **Coagulation Factors**: Proteins in plasma that help in blood clotting (e.g., fibrinogen, prothrombin). - **Functions of Blood**: - **Transportation**: Carries oxygen, nutrients, hormones, and waste products. - **Regulation**: Maintains body temperature, pH balance, and fluid volume. - **Protection**: Defends against disease through immune cells and antibodies, and prevents blood loss through clotting. - **Blood Grouping and Rhesus Factor**: - **Blood Groups**: A, B, AB, and O, determined by the presence or absence of antigens (A and B) on red blood cells. - **Rhesus Factor (Rh)**: Positive or negative based on the presence of the Rh antigen on red blood cells. **4.2 Blood Vessels** - **Structure and Function of Blood Vessels**: - **Arteries**: Carry oxygenated blood away from the heart (except for the pulmonary arteries). Have thick, elastic walls to handle high pressure. - **Veins**: Return deoxygenated blood to the heart (except for the pulmonary veins). Have thinner walls and valves to prevent backflow. - **Capillaries**: Microscopic vessels where exchange of gases, nutrients, and waste occurs between blood and tissues. Have thin walls to facilitate diffusion. - **Main Blood Vessels and Their Branches**: - **Aorta**: The largest artery, branching into the ascending aorta, aortic arch, and descending aorta. - **Major Veins**: Superior and inferior vena cava return deoxygenated blood to the right atrium. - **Common Arteries and Veins**: Include carotid arteries, subclavian arteries, renal arteries, and corresponding veins. - **Blood Pressure**: - **Definition**: The force exerted by blood on the walls of blood vessels. - **Measurement**: Systolic (pressure during ventricular contraction) over diastolic (pressure during ventricular relaxation). - **Pulse**: - **Definition**: The rhythmic expansion and contraction of arteries as blood is pumped through them. - **Measurement Sites**: Commonly measured at the wrist (radial pulse) or neck (carotid pulse). **4.3 Different Kinds of Circulation** - **Pulmonary Circulation**: - **Pathway**: Blood flows from the right ventricle through the pulmonary arteries to the lungs for oxygenation and returns to the left atrium via the pulmonary veins. - **Systemic Circulation**: - **Pathway**: Oxygenated blood flows from the left ventricle through the aorta to the body's tissues and returns deoxygenated blood to the right atrium. - **Portal Circulation**: - **Pathway**: Blood flows from the gastrointestinal tract and spleen through the hepatic portal vein to the liver for processing before returning to the heart. - **Fetal Circulation**: - **Pathway**: In the fetus, blood bypasses the lungs (which are not yet functioning) through structures like the ductus arteriosus and foramen ovale, connecting the umbilical cord to the placenta for oxygenation and nutrient exchange. **5.1 Structure and Function of the Lymphatic System** - **Structure**: - **Lymphatic Vessels**: A network of vessels that transport lymph, a clear fluid containing lymphocytes, throughout the body. They include lymphatic capillaries, collecting vessels, lymph nodes, and lymphatic ducts. - **Lymph**: A clear fluid that originates from interstitial fluid, containing lymphocytes, proteins, fats, and cellular debris. - **Lymphatic Ducts**: - **Right Lymphatic Duct**: Drains lymph from the right upper body into the right subclavian vein. - **Thoracic Duct**: Drains lymph from the rest of the body into the left subclavian vein. - **Function**: - **Fluid Recovery**: Collects excess interstitial fluid and returns it to the bloodstream, preventing fluid accumulation (edema). - **Immune Response**: Filters lymph through lymph nodes where immune cells can respond to pathogens. - **Fat Absorption**: Absorbs dietary fats from the small intestine and transports them to the bloodstream. **5.2 Lymphatic Vessels** - **Structure**: - **Lymphatic Capillaries**: Tiny, thin-walled vessels located throughout tissues that absorb interstitial fluid. - **Larger Lymphatic Vessels**: Have valves to prevent backflow and transport lymph towards lymph nodes and ducts. - **Lymphatic Nodes**: Filter lymph and house immune cells. - **Function**: - **Transport**: Carry lymph from tissues to lymph nodes and eventually to the bloodstream. - **Filter**: Lymphatic vessels, especially in nodes, filter out pathogens and debris from lymph before it re-enters the bloodstream. **5.3 Lymphatic Organs and Tissue** - **Lymph Nodes**: - **Structure**: Small, bean-shaped structures distributed along lymphatic vessels. They have an outer cortex and an inner medulla. - **Function**: Filter lymph, trapping pathogens and foreign particles. Contain lymphocytes and macrophages that initiate immune responses. - **Spleen**: - **Structure**: The largest lymphatic organ located in the upper left abdomen. It has a red pulp (filters blood) and white pulp (immune function). - **Function**: Filters blood, removes old or damaged red blood cells, stores blood components, and initiates immune responses to bloodborne pathogens. - **Thymus**: - **Structure**: A bilobed organ located behind the sternum. - **Function**: Matures T lymphocytes (T cells), crucial for adaptive immunity. It is most active during childhood and shrinks with age. - **Tonsils/Peyer's Patches**: - **Tonsils**: Located at the throat and the base of the tongue, these structures trap and neutralize pathogens entering through the mouth or nose. - **Peyer's Patches**: Aggregates of lymphoid tissue in the ileum of the small intestine. They monitor intestinal bacteria populations and prevent the growth of pathogenic bacteria. - **Immunoglobulins and Their Types**: - **Immunoglobulins (Ig)**: Antibodies produced by B cells that recognize and bind to specific antigens. - **IgG**: The most abundant antibody in blood and extracellular fluid. Provides long-term immunity and crosses the placenta. - **IgA**: Found in mucosal areas (e.g., saliva, tears) and protects body surfaces exposed to foreign substances. - **IgM**: The first antibody produced in response to an infection. Found in blood and lymphatic fluid. - **IgE**: Associated with allergic reactions and defense against parasitic infections. - **IgD**: Found on the surface of B cells and involved in initiating immune responses. **6.1 Types, Structure, and Functions of Muscles** - **Types of Muscles**: - **Voluntary Muscles**: - **Structure**: Striated appearance with long, cylindrical fibers. - **Function**: Controlled consciously by the somatic nervous system. Includes skeletal muscles that move bones and facilitate locomotion and posture. - **Involuntary Muscles**: - **Structure**: Non-striated appearance with spindle-shaped cells. - **Function**: Controlled unconsciously by the autonomic nervous system. Includes smooth muscles found in walls of internal organs and blood vessels, responsible for movements such as peristalsis and vasoconstriction. - **Cardiac Muscle**: - **Structure**: Striated appearance with branched, interconnected fibers. Contains intercalated discs that facilitate synchronized contraction. - **Function**: Involuntary muscle found only in the heart. Pumps blood throughout the circulatory system and maintains heart rhythm. - **General Muscle Structure**: - **Muscle Fibers (Cells)**: The basic contractile units of muscle tissue. - **Myofibrils**: Long, thread-like structures within muscle fibers containing actin and myosin filaments. - **Sarcomeres**: The functional units of muscle contraction, defined by the area between two Z-lines. - **Endomysium**: Connective tissue surrounding individual muscle fibers. - **Perimysium**: Connective tissue surrounding bundles of muscle fibers (fascicles). - **Epimysium**: Connective tissue surrounding the entire muscle. **6.2 Principal Skeletal Muscles** - **Muscles of the Face, Neck, Trunk, Shoulder, and Upper Limb**: - **Face**: - **Orbicularis Oculi**: Closes the eyelids. - **Orbicularis Oris**: Closes and protrudes the lips. - **Masseter**: Elevates the mandible (jaw). - **Neck**: - **Sternocleidomastoid**: Rotates and flexes the head. - **Trapezius**: Elevates, retracts, and rotates the scapula. - **Trunk**: - **Rectus Abdominis**: Flexes the vertebral column. - **External Obliques**: Rotates and laterally flexes the trunk. - **Latissimus Dorsi**: Extends, adducts, and medially rotates the arm. - **Shoulder**: - **Deltoid**: Abducts the arm. - **Rotator Cuff Muscles (Supraspinatus, Infraspinatus, Teres Minor, Subscapularis)**: Stabilize and move the shoulder joint. - **Upper Limb**: - **Biceps Brachii**: Flexes the elbow and supinates the forearm. - **Triceps Brachii**: Extends the elbow. - **Brachioradialis**: Flexes the forearm at the elbow. - **Muscles of the Hip and Lower Limb**: - **Hip**: - **Iliopsoas**: Flexes the thigh at the hip joint. - **Gluteus Maximus**: Extends and laterally rotates the thigh. - **Thigh**: - **Quadriceps Femoris**: Extends the knee. - **Hamstrings (Biceps Femoris, Semitendinosus, Semimembranosus)**: Flex the knee and extend the thigh. - **Leg**: - **Gastrocnemius**: Plantarflexes the foot and flexes the knee. - **Tibialis Anterior**: Dorsiflexes and inverts the foot. - **Pelvic Floor**: - **Levator Ani**: Supports pelvic organs and maintains continence. - **Coccygeus**: Supports the pelvic floor and aids in coccygeal support. - **Action of the Muscles in Relation to Force**: - **Agonist (Prime Mover)**: The primary muscle responsible for a movement. - **Antagonist**: Muscle that opposes the action of the agonist. - **Synergist**: Assists the agonist in performing the movement. - **Fixator**: Stabilizes the origin of the agonist muscle to enable efficient movement. **7.1 Definition: Bone, Joint** - **Bone**: - **Definition**: A rigid organ that constitutes part of the vertebrate skeleton. Bones provide support, protection, and structure to the body and facilitate movement. - **Composition**: Bone tissue is composed of an extracellular matrix of collagen fibers and mineralized salts (mainly calcium phosphate), along with cells such as osteocytes, osteoblasts, and osteoclasts. - **Joint**: - **Definition**: A connection between two or more bones. Joints enable movement and provide stability to the skeletal structure. - **Types**: Joints are classified based on their structure and function, including fixed, cartilaginous, and synovial joints. **7.2 Development of Bone** - **Bone Development**: - **Osteogenesis**: The process of bone formation. - **Intramembranous Ossification**: Bone develops directly from mesenchymal tissue (e.g., flat bones of the skull). - **Endochondral Ossification**: Bone forms by replacing hyaline cartilage (e.g., long bones). - **Bone Growth**: - **Appositional Growth**: Increase in bone thickness due to the addition of new bone tissue. - **Interstitial Growth**: Increase in bone length during childhood and adolescence. **7.3 Sutures and Fontanelles** - **Sutures**: - **Definition**: Immovable joints between the bones of the skull, held together by fibrous connective tissue. - **Examples**: Coronal suture, sagittal suture, lambdoid suture, and squamous suture. - **Fontanelles**: - **Definition**: Soft spots on an infant's skull where the bones have not yet fused. They allow for growth of the brain and skull during early development. - **Types**: Anterior fontanelle (frontal), posterior fontanelle (occipital), sphenoidal, and mastoid fontanelles. **7.4 Types and Function of Bones** - **Types of Bones**: - **Long Bones**: Longer than they are wide; provide support and facilitate movement (e.g., femur, humerus). - **Short Bones**: Cube-shaped; provide stability and support (e.g., carpals, tarsals). - **Flat Bones**: Thin and flat; protect organs and provide surface area for muscle attachment (e.g., skull, ribs). - **Irregular Bones**: Complex shapes; protect internal organs (e.g., vertebrae, pelvic bones). - **Sesamoid Bones**: Embedded within tendons; protect tendons from wear and tear (e.g., patella). **7.5 Classification of Skeleton** - **Axial Skeleton**: - **Components**: Skull, vertebral column, rib cage. - **Function**: Supports the head, neck, and trunk, and protects the brain, spinal cord, and thoracic organs. - **Appendicular Skeleton**: - **Components**: Limbs (arms and legs) and girdles (pectoral and pelvic girdles). - **Function**: Facilitates movement and supports limbs. **7.6 Types and Function of Joints** - **Types of Joints**: - **Fixed (Synarthroses)**: Immovable joints (e.g., sutures of the skull). - **Cartilaginous (Amphiarthroses)**: Slightly movable joints (e.g., intervertebral discs, pubic symphysis). - **Synovial (Diarthroses)**: Freely movable joints with a fluid-filled cavity (e.g., knee, shoulder). - **Mechanism of Joint Movement and Relation to Lever Principles**: - **Lever Principles**: Joints act as fulcrums, bones as levers, and muscles provide the force. Types of levers: - **First-Class Lever**: Fulcrum between effort and load (e.g., head on neck). - **Second-Class Lever**: Load between fulcrum and effort (e.g., calf raise). - **Third-Class Lever**: Effort between fulcrum and load (e.g., bicep curl). **7.7 Types/Structure/Functions of Teeth** - **Types of Teeth**: - **Temporary (Deciduous)**: The first set of teeth, which are eventually replaced by permanent teeth. Typically, 20 in number. - **Permanent**: The second set of teeth, which replace temporary teeth. Typically, 32 in number. - **Structure of Teeth**: - **Crown**: Visible part of the tooth covered with enamel. - **Root**: Embedded in the jawbone, anchoring the tooth. - **Enamel**: Hard, outer layer that protects the tooth. - **Dentin**: Underneath enamel, provides structural support. - **Pulp**: Soft tissue inside the tooth containing nerves and blood vessels. - **Functions of Teeth**: - **Mastication**: Breaking down food into smaller particles for digestion. - **Speech**: Assists in pronunciation and articulation of sounds. - **Aesthetics**: Contributes to facial appearance and smile. **7.8 Types of Movement of Bones (1 hr)** - **Types of Sinuses**: - **Frontal Sinus**: Located in the forehead region. - **Sphenoid Sinus**: Located within the sphenoid bone, behind the eyes. - **Ethmoid Sinus**: Located between the eyes, in the ethmoid bone. - **Maxillary Sinus**: Located in the cheeks, below the eyes. - **Disorders** (Introduction Only): - **Osteoporosis**: A condition characterized by weakened bones and increased fracture risk. - **Rickets**: A childhood disorder caused by vitamin D deficiency, leading to bone deformities. - **Osteomalacia**: Softening of bones in adults due to vitamin D deficiency. - **Osteomyelitis**: Infection of the bone. - **Paget's Disease**: A disorder characterized by abnormal bone remodeling. - **Bone Tumors**: Abnormal growths within bone tissue (e.g., osteosarcoma). - **Arthritis**: Inflammation of joints, causing pain and stiffness (e.g., osteoarthritis, rheumatoid arthritis). - **Carpal Tunnel Syndrome**: Compression of the median nerve in the wrist, causing pain and numbness. - **Fracture**: - **Definition**: A break or crack in a bone. - **Types**: Simple (closed), compound (open), comminuted (shattered), greenstick (incomplete), and more. **8.1 Structure and Function of Different Parts of Respiratory Organs (1 hr)** - **Nose and Nasal Cavity**: - **Structure**: External nose (nasal bones, cartilage), internal nasal cavity divided by the nasal septum. - **Function**: Filters, warms, and moistens inhaled air. Contains olfactory receptors for smell. - **Sinuses**: - **Structure**: Air-filled cavities in the skull (frontal, sphenoid, ethmoid, maxillary). - **Function**: Lighten the weight of the skull, enhance voice resonance, and produce mucus. - **Pharynx**: - **Structure**: Muscular tube divided into nasopharynx, oropharynx, and laryngopharynx. - **Function**: Passage for air and food; involved in speech production. - **Larynx**: - **Structure**: Voice box located below the pharynx. Contains vocal cords. - **Function**: Produces sound (phonation), protects the trachea against food aspiration, and provides a passage for air. - **Trachea**: - **Structure**: A rigid, tube-like structure extending from the larynx to the bronchi. - **Function**: Provides a clear airway for air to enter and exit the lungs; lined with ciliated epithelium to trap debris. - **Lungs**: - **Structure**: Paired organs within the thoracic cavity, consisting of lobes (three in the right lung, two in the left). - **Function**: Site of gas exchange; oxygenates blood and removes carbon dioxide. - **Bronchi and Bronchioles**: - **Structure**: The trachea branches into the right and left main bronchi, which further divide into secondary and tertiary bronchi, eventually leading to bronchioles. - **Function**: Distribute air to the alveoli; bronchioles control airflow to different parts of the lung. - **Alveoli**: - **Structure**: Tiny air sacs at the end of the bronchioles. - **Function**: Site of gas exchange between air and blood. Surrounded by capillaries where oxygen and carbon dioxide are exchanged. **8.2 Respiratory Muscles: Intercostals Muscle and Diaphragm (2 hrs)** - **Intercostal Muscles**: - **Structure**: Muscles located between the ribs (external and internal intercostals). - **Function**: Aid in expanding and contracting the thoracic cavity during breathing. External intercostals assist in inhalation by elevating the ribs, while internal intercostals help with exhalation by depressing the ribs. - **Diaphragm**: - **Structure**: A dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. - **Function**: Primary muscle of respiration. Contracts to increase the volume of the thoracic cavity and draw air into the lungs; relaxes to decrease thoracic volume and expel air. **8.3 Physiology of Respiration (2 hrs)** - **External Respiration**: - **Definition**: The exchange of gases between the alveoli and the blood in the pulmonary capillaries. Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli. - **Internal Respiration**: - **Definition**: The exchange of gases between the blood and the body\'s tissues. Oxygen moves from the blood into the tissues, and carbon dioxide moves from the tissues into the blood. - **Exchange of Gases**: - **Mechanism**: Occurs via diffusion. Oxygen diffuses from areas of higher concentration (alveoli or blood) to lower concentration (blood or tissues), and carbon dioxide diffuses in the opposite direction. - **Respiration in Relation to Boyle's Law**: - **Boyle's Law**: States that the pressure of a gas is inversely proportional to its volume (P1V1 = P2V2). During inhalation, the diaphragm and intercostal muscles expand the thoracic cavity, increasing lung volume and decreasing pressure, causing air to flow into the lungs. During exhalation, the volume decreases, increasing pressure and pushing air out of the lungs. **8.4 Capacity of Lung (2 hrs)** - **Tidal Volume (TV)**: - **Definition**: The amount of air inhaled or exhaled during normal breathing (approximately 500 mL). - **Inspiratory Reserve Volume (IRV)**: - **Definition**: The maximum amount of air that can be inhaled after a normal inspiration (approximately 3000 mL). - **Inspiratory Capacity (IC)**: - **Definition**: The total amount of air that can be inhaled after a normal exhalation (TV + IRV, approximately 3500 mL). - **Functional Residual Capacity (FRC)**: - **Definition**: The amount of air remaining in the lungs after a normal exhalation (ERV + RV, approximately 2500 mL). - **Expiratory Reserve Volume (ERV)**: - **Definition**: The maximum amount of air that can be exhaled after a normal expiration (approximately 1200 mL). - **Residual Volume (RV)**: - **Definition**: The amount of air remaining in the lungs after a maximal exhalation (approximately 1200 mL). - **Vital Capacity (VC)**: - **Definition**: The total amount of air that can be exhaled after a maximal inhalation (TV + IRV + ERV, approximately 4500 mL). This outline should help guide your study of the respiratory system. Adjust time spent based on your familiarity with each topic and your study needs. **9.1 Definition (1 hr)** - **Digestion**: - **Definition**: The process by which food is broken down into smaller, absorbable components. This involves both mechanical processes (e.g., chewing) and chemical processes (e.g., enzymatic breakdown). - **Digestive System**: - **Definition**: A complex system of organs and glands responsible for processing food, extracting nutrients, and expelling waste. It includes the digestive tract (alimentary canal) and accessory organs. **9.2 Structure and Function of Digestive Organs (2 hrs)** - **Mouth**: - **Structure**: Includes the oral cavity, teeth, and tongue. - **Function**: Mechanical digestion (chewing) and chemical digestion (enzymes in saliva). The tongue helps in mixing food and forming the bolus. - **Esophagus**: - **Structure**: A muscular tube connecting the mouth to the stomach. - **Function**: Transports food and liquids from the mouth to the stomach through peristaltic movements. - **Stomach**: - **Structure**: A hollow organ with a lining of gastric mucosa, which includes gastric glands. - **Function**: Performs mechanical and chemical digestion. Secretes gastric acid and digestive enzymes to break down proteins and kill pathogens. Converts food into chyme. - **Small Intestine**: - **Structure**: Composed of three parts: duodenum, jejunum, and ileum. Lined with villi and microvilli. - **Function**: Completes digestion and absorbs nutrients into the bloodstream. The duodenum receives bile and pancreatic juices, while the jejunum and ileum are primarily involved in absorption. - **Large Intestine**: - **Structure**: Includes the cecum, colon (ascending, transverse, descending, and sigmoid), and rectum. - **Function**: Absorbs water and electrolytes from indigestible food residues, forming feces. Houses beneficial gut bacteria and helps in the formation of fecal matter. - **Rectum**: - **Structure**: The final section of the large intestine, ending at the anus. - **Function**: Stores feces until elimination. Signals the need for defecation. - **Anus**: - **Structure**: The opening at the end of the digestive tract. - **Function**: Controls the expulsion of feces through sphincter muscles. **9.3 Structure and Function of Accessory Organs (2 hrs)** - **Salivary Glands**: - **Structure**: Pairs of glands include parotid, submandibular, and sublingual. - **Function**: Produce saliva which contains enzymes (e.g., amylase) that begin carbohydrate digestion. Lubricates food for easier swallowing. - **Pancreas**: - **Structure**: An elongated gland located behind the stomach. - **Function**: Produces digestive enzymes (e.g., lipase, protease, amylase) and bicarbonate to neutralize stomach acid. Also has endocrine functions, producing insulin and glucagon to regulate blood glucose levels. - **Liver**: - **Structure**: A large organ located in the upper right abdomen. - **Function**: Produces bile, which aids in fat digestion and absorption. Processes nutrients absorbed from the small intestine, detoxifies harmful substances, and stores vitamins and minerals. - **Biliary Duct**: - **Structure**: Includes the hepatic duct, cystic duct, and common bile duct. - **Function**: Transports bile from the liver and gallbladder to the duodenum. **9.4 Types/Structure/Functions of Teeth (1 hr)** - **Temporary (Deciduous)**: - **Structure**: The first set of teeth that typically includes 20 teeth (8 incisors, 4 canines, 8 molars). - **Function**: Aid in chewing and speech development in children. These are eventually replaced by permanent teeth. - **Permanent**: - **Structure**: The second set of teeth, typically including 32 teeth (8 incisors, 4 canines, 8 premolars, 12 molars including 4 wisdom teeth). - **Function**: Permanent teeth perform the same functions as temporary teeth but are intended to last throughout adulthood. **9.5 Functions of Digestive System (1 hr)** - **Digestion**: Breakdown of food into smaller, absorbable components. - **Absorption**: Uptake of nutrients into the bloodstream or lymphatic system from the digestive tract. - **Elimination**: Removal of indigestible substances and waste products from the body through defecation. - **Metabolism**: Conversion of nutrients into energy and building blocks for cellular processes. **9.6 Physiology of Digestion** - **Overview**: The digestive process involves multiple stages including ingestion, propulsion, mechanical and chemical digestion, absorption, and elimination. - **Ingestion**: Taking in food through the mouth. - **Propulsion**: Movement of food through the digestive tract via swallowing (voluntary) and peristalsis (involuntary contractions). - **Mechanical Digestion**: Physical breakdown of food into smaller pieces (e.g., chewing, churning in the stomach). - **Chemical Digestion**: Enzymatic breakdown of complex molecules into simpler ones (e.g., proteins into amino acids, carbohydrates into sugars). - **Absorption**: Transport of nutrients from the digestive tract into the bloodstream or lymphatic system, primarily occurring in the small intestine. - **Elimination**: Expulsion of indigestible substances and waste products from the body via the rectum and anus. **10.1 Structure and Function of Organs Related to the Urinary System (1 hr)** - **Kidney**: - **Structure**: Paired organs located in the lower back, shaped like beans. Each kidney has an outer cortex, an inner medulla, and renal pelvis. - **Function**: Filters blood to remove waste products and excess substances, regulates blood pressure, electrolyte balance, and acid-base balance. Produces urine which is then excreted. - **Ureter**: - **Structure**: Tubular structures that extend from the renal pelvis to the urinary bladder. They are about 25-30 cm long. - **Function**: Transports urine from the kidneys to the urinary bladder through peristaltic movements. - **Urinary Bladder**: - **Structure**: A hollow, muscular organ located in the pelvic cavity. It has a distensible wall that allows it to expand as it fills with urine. - **Function**: Stores urine until it is expelled from the body. The bladder can hold up to 500 mL of urine comfortably. - **Urethra**: - **Structure**: A tube that extends from the urinary bladder to the exterior of the body. In males, it also serves as a passage for semen. - **Function**: Conveys urine from the bladder to the outside of the body. The length and function of the urethra differ between males and females. **10.2 Composition and Mechanism of Urine Formation (2 hrs)** - **Glomerular Filtration**: - **Definition**: The process by which blood is filtered through the glomeruli (capillary networks in the kidneys) to form a filtrate (glomerular filtrate). - **Mechanism**: Blood pressure forces water and small molecules (e.g., electrolytes, glucose, urea) from the glomerular capillaries into the Bowman\'s capsule, forming filtrate. - **Selective Reabsorption**: - **Definition**: The process by which the kidneys reabsorb necessary substances from the filtrate back into the blood. - **Mechanism**: Occurs mainly in the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting ducts. Essential nutrients, electrolytes, and water are reabsorbed, while waste products remain in the filtrate. - **Tubular Secretion**: - **Definition**: The process by which additional substances are secreted from the blood into the tubular fluid. - **Mechanism**: Occurs mainly in the distal convoluted tubule and collecting ducts. The kidneys secrete substances such as hydrogen ions, potassium, and certain drugs into the tubular fluid, contributing to the final composition of urine. **10.3 Mechanism of Micturition** - **Definition**: The process of urine expulsion from the urinary bladder. - **Mechanism**: - **Filling Phase**: The bladder fills with urine, stretching its walls. Stretch receptors in the bladder wall send signals to the brain, indicating the need to void. - **Urge to Void**: As the bladder fills and reaches a certain volume, the urge to urinate becomes strong. - **Micturition Reflex**: The detrusor muscle (bladder wall muscle) contracts, and the internal urethral sphincter (involuntary) relaxes, allowing urine to flow into the urethra. - **Voluntary Control**: The external urethral sphincter (voluntary) allows for conscious control over the timing of urination. When the external sphincter relaxes, urine is expelled through the urethra. **11.1 Introduction, Nerve, Neuroglia, Synapse, Nerve Transmission (1 hr)** - **Nerve**: - **Definition**: A bundle of axons (nerve fibers) that transmit electrical impulses throughout the body. Composed of sensory, motor, or mixed fibers. - **Neuroglia**: - **Definition**: Also known as glial cells, they provide structural and metabolic support to neurons. Types include astrocytes, microglia, oligodendrocytes (CNS), and Schwann cells (PNS). - **Synapse**: - **Definition**: A junction between two neurons or a neuron and another cell (e.g., muscle, gland) where nerve impulses are transmitted. - **Nerve Transmission**: - Involves the propagation of an action potential along a neuron and the release of neurotransmitters at synapses to transmit signals to other neurons or target cells. **11.2 Types of Nerves (1 hr)** - **Sensory (Afferent) Nerves**: Carry impulses from sensory receptors to the central nervous system (CNS). - **Motor (Efferent) Nerves**: Transmit impulses from the CNS to muscles or glands. - **Mixed Nerves**: Contain both sensory and motor fibers, allowing two-way communication. **11.3 Mechanism of Stimuli Transmission (1 hr)** - **Stimuli Transmission**: - **Mechanism**: Involves the generation of an action potential when a stimulus alters the resting membrane potential of a neuron. The impulse travels along the neuron and across synapses through neurotransmitter release, transmitting the signal to adjacent neurons, muscles, or glands. **11.4 The Central Nervous System (CNS) (2 hrs)** - **Covering Membranes (Meninges)**: - Three protective layers: dura mater (outermost), arachnoid mater (middle), and pia mater (innermost). - **Cerebrum**: - **Structure**: The largest part of the brain, divided into two hemispheres. Consists of four lobes (frontal, parietal, temporal, occipital). - **Function**: Responsible for higher brain functions, including sensory perception, voluntary motor actions, reasoning, learning, memory, and emotions. - **Midbrain**: - **Structure**: Part of the brainstem located between the diencephalon and the pons. - **Function**: Involved in visual and auditory processing and motor control. - **Cerebellum**: - **Structure**: Located at the back of the brain, beneath the occipital lobes. - **Function**: Coordinates voluntary movements, balance, posture, and motor learning. - **Brainstem**: - **Structure**: Consists of the midbrain, pons, and medulla oblongata. - **Function**: Controls basic life functions such as heart rate, breathing, and sleep cycles. - **Ventricles**: - **Structure**: Four interconnected cavities within the brain that produce and contain cerebrospinal fluid (CSF). - **Function**: CSF cushions the brain, maintains pressure, and removes waste products. - **Spinal Cord**: - **Structure**: A cylindrical structure extending from the brainstem to the lower back, encased within the vertebral column. - **Function**: Conducts sensory and motor impulses to and from the brain and serves as a center for reflex actions. **11.5 The Peripheral Nervous System (PNS) (2 hrs)** - **Spinal Nerves**: - 31 pairs of nerves that arise from the spinal cord, responsible for transmitting sensory and motor information between the spinal cord and the body. - **Cranial Nerves**: - 12 pairs of nerves that originate from the brain and control functions related to the head, neck, and thoracic and abdominal cavities. - **Autonomic Nervous System (ANS)**: - **Structure**: Subdivided into the sympathetic and parasympathetic systems. - **Function**: Regulates involuntary body functions such as heart rate, digestion, and respiratory rate. The sympathetic system prepares the body for \"fight or flight\" responses, while the parasympathetic system promotes \"rest and digest\" activities. **11.6 Neurons (1 hr)** - **Mechanisms of Stimuli Transmission in the Nervous System**: - **Reflex Action**: A rapid, automatic response to a stimulus, bypassing the brain for immediate action through the spinal cord. - **CNS - Brain and Spinal Cord**: - **Function**: The brain processes information and coordinates complex functions. The spinal cord serves as a conduit for signals between the brain and body and facilitates reflexes. - **PNS - Spinal Cord and Cranial Nerves**: - **Function**: Connects the CNS to limbs and organs, relaying sensory and motor signals. - **ANS - Sympathetic and Parasympathetic Systems**: - **Sympathetic System**: Activates body systems for emergency situations (increases heart rate, dilates pupils). - **Parasympathetic System**: Calms the body and conserves energy (slows heart rate, increases digestion). **12.1 Female Reproductive Organs (3 hrs)** - **Structure and Functions of External Reproductive Organs**: - **Vulva**: Includes the labia majora, labia minora, clitoris, and vestibule. - **Labia Majora/Minora**: Protect the inner structures of the vulva. - **Clitoris**: Highly sensitive, plays a role in sexual arousal. - **Vestibule**: Contains the openings to the urethra and vagina. - **Structure and Functions of Internal Reproductive Organs**: - **Ovaries**: Small, almond-shaped organs that produce ova (eggs) and secrete hormones (estrogen and progesterone). - **Fallopian Tubes**: Tubes extending from the uterus to the ovaries; they transport the ovum from the ovary to the uterus and are the site of fertilization. - **Uterus**: A pear-shaped organ where the fertilized egg implants and grows into a fetus. Composed of the endometrium (inner lining), myometrium (muscular layer), and perimetrium (outer layer). - **Cervix**: The lower part of the uterus that opens into the vagina; serves as a passage for sperm and menstrual blood. - **Vagina**: A muscular canal connecting the cervix to the vulva; serves as the birth canal and the exit for menstrual flow. - **Primary and Secondary Sex Characteristics**: - **Primary**: Ovaries and other reproductive organs. - **Secondary**: Breast development, pubic and axillary hair growth, widening of hips, and onset of menstruation. - **Mechanisms**: - **Puberty**: The process of physical changes through which a child\'s body matures into an adult body capable of sexual reproduction. Triggered by hormonal signals (mainly estrogen) from the brain to the ovaries. - **Menstrual Cycle**: A monthly cycle involving the preparation of the uterus for pregnancy and the shedding of the uterine lining when pregnancy does not occur. Phases include: - **Menstrual Phase**: Shedding of the endometrial lining. - **Follicular Phase**: Growth of ovarian follicles; estrogen levels rise. - **Ovulation**: Release of a mature egg from the ovary. - **Luteal Phase**: Corpus luteum formation; progesterone prepares the uterus for potential implantation. - **Fertilization**: - **Spermatogenesis**: The process of sperm formation in the testes. - **Oogenesis**: The formation and maturation of ova in the ovaries. - **Conception**: Occurs when a sperm cell successfully fertilizes an ovum, resulting in the formation of a zygote. - **Menopause**: The natural cessation of menstruation and reproductive ability in women, typically occurring between ages 45-55, due to declining ovarian function and hormone levels. **12.2 Structure and Function of Mammary Glands (2 hrs)** - **Structure**: - Each breast contains mammary glands composed of lobules (milk-producing glands) and ducts that carry milk to the nipple. - **Areola**: The pigmented area surrounding the nipple. - **Fatty Tissue**: Surrounds the mammary glands and contributes to breast size and shape. - **Function**: - **Milk Production**: Hormones (primarily prolactin) stimulate the lobules to produce milk, while oxytocin triggers milk ejection during breastfeeding. - **Nourishment**: Provides essential nutrients and antibodies to the newborn. **12.3 Male Reproductive Organs (3 hrs)** - **Structure and Function of Male Reproductive Organs**: - **External Organs**: - **Penis**: Functions in sexual intercourse and serves as the passage for semen and urine. - **Scrotum**: A sac that holds and regulates the temperature of the testes, crucial for sperm production. - **Internal Organs**: - **Testes**: Oval-shaped organs that produce sperm (spermatogenesis) and secrete testosterone. - **Epididymis**: A coiled tube located at the back of each testis where sperm mature and are stored. - **Vas Deferens**: Ducts that transport mature sperm from the epididymis to the urethra. - **Seminal Vesicles**: Glands that produce seminal fluid, which nourishes and protects sperm. - **Prostate Gland**: Secretes a fluid that enhances sperm motility and viability. - **Urethra**: Conveys both urine and semen out of the body. - **Primary and Secondary Sex Characteristics**: - **Primary**: Testes and other reproductive organs. - **Secondary**: Deepening of the voice, facial and body hair growth, increased muscle mass, and development of the Adam\'s apple. - **Puberty**: - The period during which boys experience hormonal changes (increased testosterone), resulting in the development of secondary sexual characteristics and the ability to reproduce. **13.1 Structure and Function of Endocrine Glands and Their Hormones (2 hrs)** - **Endocrine Glands**: Ductless glands that release hormones directly into the bloodstream to regulate various bodily functions. - **Hypothalamus**: - **Structure**: Located in the brain, it connects the nervous system to the endocrine system via the pituitary gland. - **Function**: Produces hormones that regulate the pituitary gland (e.g., growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH)). - **Pituitary Gland**: - **Structure**: A small, pea-sized gland at the base of the brain. - **Function**: Often called the \"master gland,\" it secretes hormones that regulate other endocrine glands (e.g., growth hormone (GH), prolactin, adrenocorticotropic hormone (ACTH)). - **Thyroid Gland**: - **Structure**: Located in the neck, shaped like a butterfly. - **Function**: Produces hormones like thyroxine (T4) and triiodothyronine (T3) that regulate metabolism, growth, and development. - **Parathyroid Glands**: - **Structure**: Four small glands located on the back of the thyroid gland. - **Function**: Secrete parathyroid hormone (PTH), which regulates calcium and phosphate levels in the blood. - **Adrenal Glands**: - **Structure**: Located on top of each kidney; composed of the adrenal cortex (outer layer) and adrenal medulla (inner layer). - **Function**: The cortex produces corticosteroids (e.g., cortisol, aldosterone), while the medulla produces catecholamines (e.g., adrenaline, noradrenaline). - **Pancreas**: - **Structure**: Located behind the stomach. - **Function**: Produces insulin and glucagon to regulate blood glucose levels. - **Pineal Gland**: - **Structure**: Small, pea-shaped gland in the brain. - **Function**: Produces melatonin, which regulates sleep-wake cycles. - **Gonads (Ovaries and Testes)**: - **Structure**: Ovaries in females, testes in males. - **Function**: Produce sex hormones (e.g., estrogen, progesterone in females; testosterone in males) that regulate reproduction and secondary sexual characteristics. **13.2 Hormones Produced by Different Glands and Their Functions (2 hrs)** - **Hypothalamus**: Releases hormones that control the pituitary gland. - **Examples**: GHRH (stimulates growth hormone release), TRH (stimulates thyroid-stimulating hormone (TSH) release). - **Pituitary Gland**: Produces hormones that influence growth, reproduction, and metabolism. - **Anterior Pituitary Hormones**: GH (growth), TSH (thyroid function), ACTH (adrenal gland function), FSH and LH (reproductive functions), prolactin (milk production). - **Posterior Pituitary Hormones**: Oxytocin (labor contractions, milk ejection), antidiuretic hormone (ADH) (water balance). - **Thyroid Gland**: - **Thyroxine (T4) and Triiodothyronine (T3)**: Regulate metabolism, energy production, and growth. - **Calcitonin**: Lowers blood calcium levels. - **Parathyroid Glands**: - **Parathyroid Hormone (PTH)**: Increases blood calcium levels by stimulating bone resorption and increasing calcium absorption in the intestines. - **Adrenal Glands**: - **Cortex**: Produces corticosteroids. - **Cortisol**: Regulates metabolism, immune response, and stress. - **Aldosterone**: Maintains blood pressure and electrolyte balance. - **Medulla**: Produces catecholamines. - **Adrenaline/Noradrenaline**: Prepare the body for \'fight or flight\' responses. - **Pancreas**: - **Insulin**: Lowers blood glucose by facilitating cellular uptake of glucose. - **Glucagon**: Raises blood glucose by promoting the release of glucose from the liver. - **Pineal Gland**: - **Melatonin**: Regulates sleep patterns and circadian rhythms. - **Ovaries**: - **Estrogen and Progesterone**: Regulate menstrual cycle, pregnancy, and secondary sexual characteristics in females. - **Testes**: - **Testosterone**: Regulates sperm production, male secondary sexual characteristics, and libido. **13.3 Male and Female Sex Hormones (4 hrs)** - **Estrogen**: - **Produced by**: Ovaries, adrenal glands, placenta (during pregnancy). - **Functions**: - Development of female secondary sexual characteristics (breast development, hip widening). - Regulation of the menstrual cycle. - Maintenance of pregnancy. - **Progesterone**: - **Produced by**: Ovaries (corpus luteum), placenta (during pregnancy). - **Functions**: - Prepares the endometrium for implantation of a fertilized egg. - Maintains the uterine lining during pregnancy. - Regulates the menstrual cycle. - **Testosterone**: - **Produced by**: Testes (in males), adrenal glands, and ovaries (in females). - **Functions**: - Development of male secondary sexual characteristics (deepening of voice, muscle growth, facial hair). - Stimulates sperm production. - Influences libido in both males and females. - **Other Hormones**: - **Follicle-Stimulating Hormone (FSH)**: Stimulates ovarian follicle growth in females and sperm production in males. - **Luteinizing Hormone (LH)**: Triggers ovulation and development of the corpus luteum in females; stimulates testosterone production in males. - **Human Chorionic Gonadotropin (hCG)**: Produced by the placenta during pregnancy; supports the corpus luteum to maintain pregnancy. **14.1 Structure and Function of the Skin** - **Structure**: The skin is composed of three main layers: - **Epidermis**: The outermost layer, providing a barrier against pathogens and regulating water loss. - **Dermis**: Contains blood vessels, nerves, hair follicles, and glands (sweat and sebaceous), providing nourishment to the epidermis and facilitating sensory perception. - **Hypodermis (Subcutaneous layer)**: Consists mainly of fat and connective tissue, offering insulation and cushioning for the body. - **Functions**: - **Sensation**: The skin contains sensory receptors (nerve endings) that detect touch, pressure, pain, and temperature changes. - **Regulation of Body Temperature**: - **Conduction**: Transfer of heat through direct contact with other objects. - **Convection**: Transfer of heat through the movement of air or water molecules across the skin. - **Radiation**: Emission of heat in the form of infrared rays from the body. - **Excretion**: Removal of waste products such as urea, salts, and water through sweat. - **Protection**: Acts as a physical barrier against mechanical injury, pathogens, and harmful UV rays. - **Immunity**: The skin has immune cells (e.g., Langerhans cells) that detect and respond to pathogens. **14.2 Sensory Organ: Eye** - **Location of the Eye**: Situated in the bony orbits (eye sockets) of the skull. - **Structure of the Eye**: - **External Parts**: - **Sclera**: The white, protective outer layer. - **Cornea**: The transparent, dome-shaped surface that focuses light. - **Middle Layer**: - **Choroid**: Provides nourishment to the eye through blood vessels. - **Iris**: The colored part of the eye, controlling the size of the pupil and, thus, the amount of light entering the eye. - **Pupil**: The opening through which light passes. - **Inner Layer**: - **Retina**: Contains photoreceptor cells (rods and cones) that detect light and convert it into electrical signals. - **Eye Accommodation**: The ability of the lens to change shape (through the ciliary muscles) to focus light on the retina for clear vision at various distances. - **Visual Pathway**: The route taken by nerve signals from the retina to the brain\'s visual cortex via the optic nerve, where visual information is processed. **14.3 Structure and Function of the Ear (Adult and Child)** - **Location of the Ear**: On either side of the head, responsible for hearing and balance. - **Structure of the Ear**: - **Outer Ear**: - **Pinna (Auricle)**: The visible part that collects sound waves. - **Ear Canal**: Channels sound toward the eardrum. - **Middle Ear**: - **Tympanic Membrane (Eardrum)**: Vibrates in response to sound waves. - **Ossicles**: Three small bones (malleus, incus, stapes) that amplify vibrations and transmit them to the inner ear. - **Inner Ear**: - **Cochlea**: A spiral-shaped organ that converts vibrations into electrical signals for hearing. - **Semicircular Canals**: Involved in maintaining balance. - **Function of the Ear**: Responsible for hearing (by converting sound waves into electrical signals sent to the brain) and maintaining balance (through the semicircular canals). **14.4 Nose and Throat: Structure and Function (Review from Respiratory System)** - **Nose**: - **Structure**: Consists of the external nostrils, nasal cavity, and sinuses lined with mucous membranes and cilia. - **Function**: Filters, warms, and humidifies inhaled air; contains olfactory receptors for the sense of smell. - **Throat (Pharynx)**: - **Structure**: A muscular tube extending from the nasal cavity to the larynx and esophagus. - **Function**: Passageway for air (to the larynx) and food (to the esophagus); plays a role in vocalization. **14.5 Tongue: Structure and Function (Review from Digestive System)** - **Structure**: A muscular organ covered with mucous membrane, containing taste buds (papillae) and sensory receptors. - **Function**: Aids in chewing, swallowing, and speech; taste perception through the detection of flavors (sweet, salty, sour, bitter, umami). 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