Anatomy and Physiology Midterms PDF

INTRODUCTION to Anatomy and Physiology Anatomical and Directional Terms and Body Planes Anatomy describes the structure and location of the Anatomical position different components of an organism to provide a is the standard position that we use as...

INTRODUCTION to Anatomy and Physiology Anatomical and Directional Terms and Body Planes Anatomy describes the structure and location of the Anatomical position different components of an organism to provide a is the standard position that we use as a reference framework for understanding. It comes from the Greek point for all anatomical descriptions, locations, and root words "ana" and "tomy" which literally mean "to cut directions. apart". Observation of the external structures of the f we stand on our heads, our skull is still human body is the first step in anatomy. When a body is considered to be superior to our torso, not inferior dissected, its structures are cut apart in order to observe to it, even though in actuality we are “upside the physical attributes and their relationships to one down.” Furthermore, a person is supine when lying another. Human anatomy studies the way that every part face up and prone when lying face downward. of a human, from molecules to bones, interacts to form a functional whole. *Specializations of Anatomy: ◦ Microscopic Anatomy focuses on the structures which are very small and can only be observed and analyzed with the assistance of a microscope. This includes cytology, the study of cells and histology, the study of tissues. As the technology of microscopes has advanced, anatomists have been able to observe smaller and smaller structures of the Why is Anatomical Position important? body, from slices of large structures like the heart, to the The standard anatomical position is agreed upon by three-dimensional structures of large molecules in the the international medical community. body. A body that is lying down is described as either ◦ Gross Anatomy or Macroscopic Anatomy focuses on prone or supine. These terms are sometimes used in larger structures can readily be seen, manipulated, describing the position of the body during specific measured, and weighed. physical examinations or surgical procedures. ▪ Prone describes a face-down orientation What is Physiology? ▪ Supine describes a face up orientation. Human physiology is about the function of the structures. It is the scientific study of the chemistry and physics of the structures of the body and the ways in which they work together to support the functions of life. Much of the study of physiology centers on the body’s tendency toward maintaining a steady internal conditions or homeostasis. Directional term describes the location of a specific body part with respect to a different body part. Thus, different directional terms can be used to describe the position of a given body part depending on what we are comparing it to. Superior or cranial - toward the head end of the body; upper ▪ Example: The hand is part of the superior extremity. Inferior or caudal - away from the head; lower ▪ Example: The foot is part of the inferior extremity Anterior or ventral - front ▪ Example: The kneecap is located on the anterior side of the leg. Posterior or dorsal - back ▪ Example: The shoulder blades are located on the posterior side of the body. Medial - toward the midline of the body ▪ Example: The middle toe is located at the medial side of the foot. Lateral - away from the midline of the body ▪ Example: The little toe is located at the lateral side of the foot. Proximal - toward or nearest the trunk or the point of origin of a part ▪ Example: The proximal end of the femur joins with the pelvic bone. Distal - away from or farthest from the trunk or the point or origin of a part ▪ Example: The hand is located at the distal end of the forearm. Superficial- towards the surface ▪ Example: The skin is superficial to the muscles Deep -towards the core ▪ Example: Bones in an appendage are located deeper than the muscles - - 2 Basic Position Prone describes a face-down orientation Supine describes a face up orientation Anatomical terms is a list of terms that concern with the anatomy of the human body. It gathers the terms that pertain to the anatomical regions and specific structures, planes, directions and body *The point of the origin is the shoulders and the trunk is the chest part movements. The figure below will give you the different anatomical terms that you need to know. Be familiar with these terms since they will be useful in understanding the next part of the module. Body Planes A section is a two-dimensional surface of a three- dimensional structure that has been cut. Body sections can be correctly interpreted, only if the viewer understands the plane along which the section was made. Body Plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine: ◦ Sagittal plane is the plane that divides the body or an organ vertically into right and left sections. ▪ Midsagittal or Median Plane. If the plane runs directly down the middle of the body, dividing the body into equal left and right sections. ▪ Parasagittal Plane. If the plane divides the body into unequal right and left sections ◦ Frontal plane or Coronal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. ◦ Transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sec tions. Body Organization 1. Body Cavities - hollow spaces within the human body that contain internal organs. The Dorsal Cavity: located toward the back of the body, is divided into the cranial cavity (which holds the brain) and vertebral or spinal cavity (which holds the spinal cord). The Ventral Cavity: located toward the front of the body, is divided into abdominopelvic cavity and thoracic cavity by the diaphragm. The abdominopelvic cavity is subdivided into abdominal cavity (which holds liver, gallbladder, stomach, pancreas, spleen, kidney, small and large intestines) and the pelvic cavity (which holds the urinary bladder and reproductive organs). Coelom or Body Cavity. It is a fluid-filled space inside the A serous membrane (also referred to a serosa) is body that holds and protects internal organs. It allows for one of the thin membranes that cover the walls and significant changes in the size and shape of the organs as organs in the thoracic and abdominopelvic cavities. It they perform their functions. For example, the lungs, heart, provides additional protection to the viscera (organs) stomach, and intestines can expand and contract without they enclose by reducing friction that could lead to distorting other tissues or disrupting the activity of nearby inflammation of the organs. organs. There are two largest human body cavities: Dorsal REMEMBER: and Ventral. These are subdivided into smaller cavities. ▪ Parietal membrane lines the walls of the body ◦ Ventral cavity - which includes the: cavity ▪ Abdominopelvic cavity which is subdivided into: ▪ Visceral membrane covers the organs (the ▪ Abdominal cavity which houses the organs of the viscera) and is therefore in direct contact with the digestive system organ. ▪ Pelvic cavity which houses the organs for reproduction ▪ Serous Fluid is a fluid that fills the space (like uterus and ovary) and excretion (like the urinary between the parietal and visceral membranes. This bladder) and portions of the digestive tract (like the pelvic cushions and reduces friction on internal organs when colon, and rectum) they move, such as when the lungs inflate or the ▪ Thoracic cavity enclosed by the ribcage is subdivided heart beats. into: ▪ Pericardial cavity which lies within the mediastinum, a There are three serous cavities and their space between the right and left pleural cavities. It encloses associated membranes in humans: the heart, thymus and portions of the esophagus and ◦ Pleura is the serous membrane that encloses the trachea, and other structures pleural cavity surrounding the lungs. ▪ Pleural cavity which encloses the lungs ▪ Parietal Pleura is a membrane that lines the Dorsal cavity which includes the: pleural cavity Cranial Cavity which houses the brain ad the sense organs ▪ Visceral Pleura is a membrane that covers the Spinal Cavity which houses the spinal cord and the nerves lungs ◦ Pericardium is the serous membrane that encloses NOTE: the pericardial cavity surrounding the heart. ▪ The brain and spinal cord make up a continuous, ▪ Parietal Pericardium is the membrane that lines uninterrupted structure, the cranial and spinal cavities that the pericardial cavity house them are also continuous. The brain and spinal cord ▪ Visceral Pericardium is the membrane that covers are also protected by the bones of the skull and vertebral the heart column and by cerebrospinal fluid, a colorless fluid produced ◦ Peritoneum is the serous membrane that encloses by the brain, which cushions the brain and spinal cord within the peritoneal cavity surrounding several organs in the posterior (dorsal) cavity. the abdominopelvic cavity.  ▪ Parietal Peritoneum refers to the membrane that lines the peritoneal cavity ▪ Visceral Peritoneum refers to the membrane that covers the abdominal organs ▪ Peritoneal Cavity is the potential space between these two layers. It is filled with a small amount of slippery serous fluid that allows the two layers to slide freely over each other. ▪ Mesentery is often used to refer to a double layer of visceral peritoneum. There are generally blood vessels, nerves, and other structures between these layers. The space between the two layers is technically outside of the peritoneal sac, and thus not in the peritoneal cavity. Membranes of the dorsal cavity is collectively known as meninges. These are the membranes that envelop and protect the central nervous system which includes the brain and spinal cord. The three meninges are: dura, pia and arachnoid mater ◦ Dura mater. It is the thick, outer most membrane that is closest to the skull and vertebrae ◦ Arachnoid mater. It is the thin, transparent membrane which is the middle layer of the membranes ◦ Pia mater. It is a thin and delicate membrane that envelope and firmly adheres to the surface of the brain and spinal cord, following all of the brain's contours. It is pierced by blood vessels to the brain and spinal cord, and its capillaries nourish the brain. Cerebrospinal fluid. It is a clear, colorless body fluid found in the brain and spinal cord located between the arachnoid mater and the pia mater. It acts as a lubrication between surrounding bones and the brain and spinal cord and as a cushion, dulling the force by distributing its impact.  Body Membranes - tissue linings of the body cavities and coverings of internal organs. Parietal Membrane - lining of the body cavity (e.g. parietal pleural membrane lines the pleural cavity) Visceral Membrane - covering of internal organ (e.g. visceral pleural membrane lines the surface of the lungs 11 Organ Systems 1. Integumentary, Skeletal, Muscular, Nervous, Endocrine, Digestive, Respiratory, Circulatory, Lymphatic, Urinary and Reproductive Systems. 2. The reproductive system is mainly involved in transmitting genetic information From one generation to another, while the remaining 10 organ systems are important in maintaining homeostasis. 3. These 11 Organ Systems may be classified by their functions: Protection - Integumentary System Membranes Support and Movement - Skeletal and Muscular Serous Membranes Systems Membrane that lines the body cavities Parietal Membrane Integration and Coordination - Nervous and Endocrine Lines the inner wall of the body cavity Systems Visceral Membrane - covers and protects the internal organs Processing and Transport - Digestive, Respiratory, Serous Fluid - Lubricating fluid Circulatory, Lymphatic and Urinary Systems Common Terms Reproduction and Development - Reproductive abdomina: region between thorax and pelvis antebrachial: the forearm antecubital: the front of elbow axillary: the armpit brachial: the upper arm celiac: the abdomen cephalic: the head cervical: the neck costal: the ribs cubital: the elbow femoral: the thigh gluteal: the buttock lumbar: the lower back Medical Imaging Techniques that are essential for diagnosing a wide range of disorders. Conventional Radiography = X-rays pass through the body and expose on X-ray film, producing a negative image called a roentgenogram. Computed Tomography Scanning (CT) or computerized axial tomography (CAT) = X-rays pass through the body, tissues absorb small amounts of radiation depending on their densities and the absorption is indicated on a monitor. Effective for tumor, kidney stones, gallstones, etc. Magnetic Resonance Imaging (MRI) = Magnetism is applied to MRI the human body, and the response of atoms’ nuclei in a tissue will produce a computerized image, Hydrogen ion nuclei is most popular. Ultrasound (US) = high-frequency sound waves are applied to body, When sound waves make contact with an object, certain amount of sound bounces back and be detected as image called sonogram. HOMEOSTASIS ◦ Stimulus is any disruption to the internal environment Homeostasis is one of human's survival needs which enable usually resulting from changes in external conditions. Generally, the stimulus indicates that the value of the variable has them to maintain a stable, relatively constant internal moved away from the set point or has left the normal range. environment. The body maintains homeostasis for many factors, such as temperature, the concentration of various ◦ Sensor or Receptors monitors the values of the variable and ions in your blood, pH and the concentration of glucose. If sends data on it to the control center. They detect changes in these values get too high or low, one can end up getting the environment very sick. ◦ Control center matches the data with normal values. If the Homeostasis is maintained at many levels, not just the value is not at the set point or is outside the normal range, the level of the whole body as it is for temperature. control center sends a signal to the effector. It analyzes the Homeostasis depends on the body's ceaselessly carrying information it receives and determines the appropriate response on many activities. Its ma jor activities or functions are of course of action. For instance the Hypothalamus in our responding to changes in the body's environment, brains processes signals from central and peripheral thermoreceptors before signaling effectors to initiate a exchanging materials between the environment and cells, response. The control center usually determines our set point metabolizing foods, and integrating all of the body's and will signal effectors to compensate for any deviation from diverse activities. For example, the stomach maintains a pH this. that is different from that of the intestines, and each individual cell maintains ion concentrations different from ◦ Effector is an organ, gland, muscle, or other structure that those of the surrounding fluid. acts on the signal from the control center to move the variable back toward the set point. It is a component of the regulatory system that can adjust the body's internal environment. It is How is homeostasis maintained? used to restore the internal environment to the set point. Maintaining homeostasis at each level is key to maintaining the body's overall function. Keeping a stable internal Example: environment requires continuous monitoring of the internal 1. Stimulus - a slight decrease in body temperature resulting environment and constantly making adjustments to keep from a cooler external environment. 2. Receptors - nerve endings in the skin and hypothalamus can things in balance sense changes in temperature. Human body is constantly being pushed from its balanced 3. Control Centers - The hypothalamus normally works to points like other biological systems do. When a person maintain a set point core temperature of 37°C. exercise, his muscles increase heat production, increasing 4. Effectors - The effectors used in thermoregulation are the his body temperature. Similarly, when one drinks a glass of components of the system that can raise or lower our body temperature like our muscles that contract when we shiver. fruit juice or eat a piece of bread, the blood glucose 5. Response - The action of the effectors which is to adjust the elevates. Homeostasis depends on the ability of your body internal environment, usually restoring it to the set point. For to detect and oppose these changes. example, shivering generates heat and and can be used to raise our core body temperature back to a set point of approximately 37°C. Hypothalamus - a region of the brain that controls everything Negative Feedback: Homeostatic responses in from body temperature to heart rate, blood pressure, satiety temperature regulation (fullness), and circadian rhythms (sleep and wake cycles) Hypothalamus is the temperature regulation center of the brain which tells If it gets either too hot What are the two homeostatic Control Mechanisms? or too cold. If a person has been exercising hard, the Negative Feedback Mechanism. The effect of the body temperature can rise above its set point, and he response is to shut off the original stimuli or reduce its will need to activate mechanisms that will cool him intensity down, such as: Positive Feedback Mechanism. The effect of the response ▪ Blood vessels dilate is to increase the disturbance and push the variable ▪ Blood flow to the skin increases to speed up farther from its original value heat loss into the surroundings ▪ Sweating so the evaporation of sweat from the A. What is Negative Feedback Mechanism? skin can help him cool off. Maintenance of homeostasis usually involves negative ▪ Heavy breathing can also increase heat loss. feedback. This act to oppose the stimulus, or cue, that If a person sits in a cold room and is not dressed triggers them. For example, if your body temperature is too warmly, the temperature center in the brain will need high, a negative feedback loop will act to bring it back down to trigger responses that help warm him up, such as towards the set point, 37 degrees ▪ Blood vessels constrict ▪ Blood flow to the skin decreases ▪ Shivering so that the muscles generate more heat. ▪ Goose bumps—so that the hair on the body stands on end and traps a layer of air near the skin ▪ Increase the release of hormones that act to increase heat production. B. Positive Feedback Mechanism Most of our biological systems utilize negative feedback mechanisms. However, there are some that utilize positive feedback. Unlike negative feedback, positive feedback amplifies the starting signal. It serves to intensify a response until an endpoint is reached. Examples of processes controlled by positive feedback in the human body include blood clotting and childbirth. What happens if homeostasis fails? Compensatory mechanism - An action taken by the Homeostatic mechanisms should work continuously to body to continue physiological function despite an maintain stable conditions in the human body. Sometimes, alteration in natural function. however, the mechanisms fail resulting to homeostatic Two types of homeostatic control mechanisms: imbalance. Negative feedback mechanism - the effect of the response is to shut off the original stimuli or reduce Disease is any failure of normal physiological function that its intensity. leads to negative symptoms. While disease is often a result ex: of infection or injury, most diseases involve the disruption Body temp falls > blood vessel constrict (will of normal homeostasis. Anything that prevents positive or reduce in diameter) > sweat glands will not negative feedback from working correctly could lead to release fluid > shivering generates heat which disease if the mechanisms of disruption become strong warms the body. > heat is retained > normal enough. This lack of homeostasis increases the risk for body temp illness and is responsible for the physical changes ex: associated with aging. Heart failure is the result of body temp rises > blood vessel dilate resulting in negative feedback mechanisms that become overwhelmed, heat loss > sweat glands secrete fluid, as the allowing destructive positive feedback mechanisms to sweat evaporates heat is loss > heat lost to the compensate for the failed feedback mechanisms. This envi > normal leads to high blood pressure and enlargement of the heart, which eventually becomes too stiff to pump blood body temp effectively, resulting in heart failure. Severe heart failure constriction: lumilit ang diameter can be fatal. dilation: lumalaki ang diameter Positive Feedback Mechanism: the effect of the Consequences of homeostatic imbalance: response is to increase the disturbance and push ◦ cells may not get everything they need the variable farther from its original value. ◦ toxic wastes may accumulate in the body. ◦ If it is not restored, it may lead to disease or even ex: death. Oxytocin stimulates uterine contractions and For example: pushes the baby towards the cervix > head of ◦ Diabetes is an example of a disease caused by the baby pushes against the cervix > nerve homeostatic imbalance. Blood glucose levels are no longer impulses from cervix transmitted to brain > brain regulated and may be dangerously high. Medical stimulates pituitary gland to secrete oxytocin > intervention can help restore homeostasis and possibly oxytocin carried in bloodstream to uterus. prevent permanent damage to the organism.  Module 2: Lesson 5 TISSUES, GLANDS, AND MEMBRANE Tissue Is a group of cells with similar structure and function. Contributes to the functioning of the organs in which it is found. HISTOLOGY : microscopic study of tissue appearance, organization and function. 4 major groups of tissues: epithelial, connective, muscle and nerve tissue Epithelial Tissue Refers to the sheets of cells that cover exterior surfaces of the body, lines internal cavities and passageways and forms certain glands. Functions: Protecting underlying structure ( provide the body’s first line of protection from physical, chemical and biological wear and tear) Acting as barrier ( skin ) Permitting passage of substances (lungs and kidneys) Secretion of substances ( pancreas ) Absorption ( stomach and small intestine ) Simple Squamous Epithelium Single layer of flat cells; scaly appearance Important physical characteristics very thin and very smooth. EX : 1| Endothelium : The alveoli (air sacs) of the lungs: the thinness of the cells permits the diffusion of gases between the air and blood; Capillaries: permits the exchange of gases, nutrients and waste products between the blood and tissue fluid. 2| Mesothelium : forms the surface layer of the serous membrane that lines body cavities and internal organ. Simple Cuboidal Epithelium Active in the secretion and absorption of molecules Served in the : Lining of the kidney tubules, in the ducts of glands : thyroid gland and salivary glands. Simple Columar Epithelium Forms the lining of some sections of the digestive system and parts of the female reproductive tract. Ciliated columnar epithelium: lining of the fallow tubes, parts of the respiratory system. Stratified Squamous Epithelium Mostly common type of stratified epithelium Many layers of mostly flat cells, although lower cells are rounded Mitosis takes place in the lowest layer to continually produce new cells to replace those worn off the surface makes up the epidermis of the skin, where it is called “keratinizing” because the protein keratin is produced, surface cells are dead Non-keratinizing type lines the oral cavity and the esophagus Stratified Cuboidal and Columnar Epithelium Can also be found in certain glands and ducts, but are uncommon i n the human body Transitional Epithelium Found only in the urinary system Appears thicker and more multi-layered when the bladder is empty, and more stretched out and less stratified when the bladders is full and distended Connective Tissue They support and connect other tissues Other Functions: Protection Defend the body from microorganisms that enter the body Transport and fluid, nutrients, waste and chemical messengers Thermal insulation Muscle Tissues Specialized for contraction. Skeletal muscle Smooth Muscle // Synapse Cardiac Muscle Skeletal Muscle Also called striated muscle or voluntary muscle Makes up the muscles that are attached to bones The striations are the result of the precise arrangement of the contracting proteins within the cell Produce a significant amount of heat, which is important to help maintains the body’s constant temperature Smooth Muscle Involuntary muscle or viceral muscle Cells of smooth muscle have tapered ends, a single nucleus and no striations Functions of smooth muscle are actually functions of the organs in which the muscle is found EX : Stomach and Intestines ( Peristalsis ), in arteries and veins to maintain normal blood pressure, Iris of the Eye Cardiac Muscle Enables the heart to beat in a very precise wave of contraction from the upper chambers to the lower chambers MYOCARDIUM Have the ability to contract by themselves = heart maintains its own beat Nervous Tissue Consists of nerve cells called neurons GLANDS Are cells or organs that secrete something They produce a substance that has a function either or that site or at a more distant site | Endocrine Gland : A ductless gland that releases secretions directly into surrounding tissues and fluids (end = “inside”) Secretions are called hormones Is part of a major regulatory system coordinating the regulation and integration of body responses EX : Anterior Pituitary, Thymus, Adrenal Cortex and Gonads | Exocrine Gland : Secretions leave through a duct that opera directly, or indirectly, to the external environment (exo- = “outside) Release their contents through a duct that leads the epithelial surface Mucous, Sweat, Saliva and Breast Milk Body Membrane Sheets of tissue that cover or lines surfaces or that separate organs or parts (lobes) of organs from one another 2 major categories of membranes: *epithelial membranes and connective tissue membranes Epithelial Membranes: Serous Membrane Peritoneum is the serous membrane that lines the cavity * Mesentery, or visceral peritoneum: is folded over and covers the abdominal organs * Serous Fluid prevents friction as the stomach and intestines contract and slide against other organs. Mucous Membranes In the respiratory, digestive, urinary and reproductive tracts. Epithelium of a mucous membrane (mucosa) Mucus secreted by these membranes keeps the lining epithelial cells wet = WHY? In the respiratory tract. traps dust and bacteria, which are then swept to the pharynx by ciliated epithelium Module 2 Lesson 6 Integumentary System —> Skin and Skin Derivatives —> Sweat Glands, Nails, and Hair. Skin is the largest organ (15% of body weight) Functions of the Skin - Protection of the underlying structure/s - Regulation of Body Temperature - Sensation - Storage - Immune Function - Excretion - Absorption - Dermis (Collagen, - Maintenance of Body 1| Thick layer of skin located beneath - Non-Verbal Communication the epidermis (the outermost layer). - Synthesize of Vitamins 2| The dermis can be divided into two D3 = Metabolism/Breakdown of Calcium layers: the papillary dermis (the upper layer with thin collagen fibers and blood 3 layers of the skin: vessels) and the reticular dermis (the Epidermis, Dermis & Subcutaneous Tissue thicker, deeper layer with denser connective tissue). Overall, the dermis is Types of Tissue essential for providing structure, Epidermis (Keratinization) support, and sensation to the skin. 1| Protection - Epidermis acts as a barrier, protecting underlying tissues from physical - Hypodermis “Adipose Tissue" damage, pathogens, chemicals and UV Radiation. 1| Known as the subcutaneous layer, is 2| Water Resistance - Keratin and Lipids produced the innermost layer of skin that lies in the epidermis help prevent excessive water loss and dehydration. beneath the dermis. *Inshort - The epidermis is a vital component of 2| The composition of the hypodermis the skin that plays essential roles in protection, can vary significantly based on sensation, and water regulation. Its structure, individual body composition and comprising multiple layers and specialized cells, location on the body, with some areas enables it to effectively guard against having more adipose tissue than others. environmental threats while facilitating various Overall, the hypodermis plays a critical bodily functions. role in the overall health and function of the skin.  Epidermis The epidermis is the outermost layer of the skin, serving as a protective barrier between the body and the external environment. It is composed primarily of keratinized stratified squamous epithelium and is significantly thinner than the underlying dermis. - 2nd major layer of the skin - Thickest layer of the skin - A vascular layer Michanoreceptors “touch" - Papilary Layer and Reticular Layer - Rete Ridges Mechanoreceptors are sensory receptors that respond to mechanical stimuli, such as 3 Phases of Growth pressure, vibration, stretching, and touch. Anagen They are essential for several sensory Anagen is the active growth phase of the hair modalities associated with touch and cycle, during which hair follicles produce new proprioception. hair. It is one of the three main phases of the hair growth cycle, the others being catagen (the 1| Merkel Discs: Detect light touch and transitional phase) and telogen (the resting texture. phase). The active growth phase, lasting several 2| Meissner’s Corpuscles: Sensitive to light years (typically 2 to 7 years). touch and vibration; located in hairless skin. 3| Pacinian Corpuscles: Respond to deep Catagen pressure and vibration; found in deeper skin The catagen phase is one of the three primary layers and other tissues. stages of the hair growth cycle. It follows the anagen phase (the active growth phase) and 4| Ruffini Endings: Sense skin stretching and precedes the telogen phase (the resting phase). sustained pressure; found in the dermis. Nociceptors are specialized sensory Telogen receptors responsible for detecting pain, Understanding the telogen phase and the which is a crucial component of the body’s overall hair growth cycle is essential in protective mechanisms. When activated, dermatology and trichology, especially in nociceptors transmit signals to the brain diagnosing and treating hair loss conditions and implementing effective hair care practices. that result in the perception of pain, promoting protective. Hair Growth 6| Hypopigmentation (Lightened Skin Patches) Alopecia and Hirutism Causes: Vitiligo, albinism, certain skin infections, or What do they sense? post-inflammatory hypopigmentation. Vibration - deep touch or pressure Indications: Lighter areas on the skin due to loss Skin color: Factors affecting the skin, Pigment, Blood of melanin. circulation through the skin and thickness and stratum. 7| Tanning (Bronzed Skin) Causes: Prolonged sun exposure or artificial Abnormal Skin Colors: tanning methods. 1| Pallor (Pale Skin) Indications: Darkening of the skin as a response to Causes: Anemia (low red blood cell count), shock, UV radiation. cold temperatures, or certain hormonal disorders. Indications: Reduced blood flow or low oxygen 8| Chloasma (Mask of Pregnancy) levels. Causes: Hormonal changes during pregnancy, typically resulting in dark patches on the face. 2| Cyanosis (Blue or Purple Skin) Indications: Brown or gray-brown patches, Causes: Lack of oxygen in the blood, respiratory primarily on the forehead, cheeks, or above the issues, heart problems, or poor circulation. upper lip. Indications: Areas may appear bluish, particularly around the lips, fingers, or toes. 9| Ashen or Gray Skin Causes: Severe illness, respiratory failure, or 3| Jaundice (Yellow Skin and Eyes) chronic kidney disease. Causes: Liver disease (such as hepatitis or cirrhosis), Indications: A grayish hue may appear, often bile duct obstruction, or hemolysis (rapid associated with systemic illness. breakdown of red blood cells). Indications: Yellowing of the skin and sclera (the 10| Rash Colors white part of the eyes). Red: Can indicate allergic reactions, infections, or 4| Erythema (Red Skin) inflammatory conditions. Causes: Inflammation, allergic reactions, infections, White: May suggest vitiligo or a fungal infection or conditions such as rosacea. (such as tinea versicolor). Indications: Redness may appear in localized areas Purple: Can indicate conditions such as bruising, or broadly over the skin. vasculitis, or certain skin cancers. 5| Hyperpigmentation (Darkened Skin Regions) Sebaceous (Oil) Glands Causes: Sun exposure, hormonal changes (e.g., Occur over entire body, except palms and soles melasma), medications, or certain skin conditions. Produce only secretion (sebum) Indications: Overproduction of melanin results in Sebun (collect dist, soften and lubricate hair and skin) dark patches on the skin. Sudoriferous (Sweat) Glands Other Integumentary Glands: - widely distributed on the body & provide sweat 1| Sebaceous Glands Sudoriferous glands, commonly known as sweat These are holocrine glands that secrete an oily glands, are specialized exocrine glands found in the substance called sebum. Found all over the body skin that are responsible for producing sweat. They except for the palms and soles. They are most play a crucial role in regulating body temperature and abundant on the scalp, face, and upper back. maintaining homeostasis. There are two primary Function: Sebum helps to lubricate and types of sudoriferous glands: eccrine glands and waterproof the skin and hair. It has antimicrobial apocrine glands. properties that help prevent infections. Sebaceous glands usually open into hair follicles. Merocrine glands are essential for various 2| Mammary Glands physiological processes, including perspiration, Specialized sweat glands that produce milk in digestion, and lubrication. Their method of secretion mammals. Found in the breasts of females. allows them to continuously produce and release Function: The primary function is lactation, their substances without disrupting the integrity of the glandular cells. providing nourishment to infants. Milk secretion involves both apocrine and merocrine Apocrine glands and apoeccrine glands are both types mechanisms. of sweat glands that contribute to the secretion of 3| Ceruminous Glands sweat, but they have distinct characteristics and Modified apocrine glands that secrete cerumen, or functions. earwax. Found in the external auditory canal of These glands are larger than eccrine (or merocrine) the ear. glands and are associated with hair follicles. Their Function:Cerumen protects the ear by trapping ducts open into the hair follicle rather than directly debris and preventing the entry of foreign onto the skin surface. materials. Function: While once thought to have a limited It also has antimicrobial properties to help function in thermoregulation, apocrine glands are prevent infections. now believed to be more closely associated with scent 4| Pilosebaceous Units and pheromonal signaling in some mammals. Not a gland per se, but a structure that includes a hair follicle along with its associated sebaceous Apoeccrine glands are a hybrid type of sweat gland gland. that exhibit characteristics of both apocrine and Function: The unit participates in hair growth and eccrine glands. They are sometimes referred to as provides lubrication to the hair through sebum. "apocrine-like eccrine glands." 5| Factor Glands (Not Truly Integumentary) Function: The precise role of apoeccrine glands is still not entirely understood. They may contribute to While not strictly part of the integumentary thermoregulation and emotional sweating, similar to system, factors such as the thyroid gland and eccrine glands, but can also be involved in the body's adrenal glands can influence skin physiology response to stress. through hormone production. Mammary Glands 3 Types of Body Hair Mammary glands are specialized exocrine glands 1| Lanugo: responsible for the production of milk in mammals. ◦ Description: Lanugo is the fine, soft hair that covers They play a crucial role in lactation, providing the body of a fetus during late gestation. It usually nutritional support to infants. appears in the womb around 20 weeks and helps to provide insulation and protection. Epidermal derivatives, including hair, sebaceous ◦ Characteristics: This hair is typically very thin, glands, sweat glands, and nails, arise from the unpigmented, and is usually shed before or shortly epidermis and play important roles in the after birth, often replaced by vellus hair. integumentary system. 2| Vellus Hair: Functions of Hair ◦ Description: Vellus hair is the short, fine, and lightly 1| Protection: pigmented hair that covers most of the human body, except for the palms of the hands and soles of the feet. Hair on the head protects the scalp from UV radiation ◦ Characteristics: It is often referred to as "peach and physical injuries. fuzz" and is usually less than 2 mm in length. Vellus hair Eyelashes and eyebrows protect the eyes from debris helps with thermoregulation and provides some and sweat. sensory function. 2| Insulation: Hair helps to trap air and retain heat, contributing to 3| Terminal Hair: body temperature regulation. ◦ Description: Terminal hair is thicker, longer, and 3| Sensation: more pigmented than lanugo and vellus hair. It Hair follicles are surrounded by nerve endings, develops in specific areas of the body during puberty, allowing the sensation of touch and pressure. such as the scalp, face (facial hair), armpits, and genital 4| Social and Sexual Signals: region. Hair can serve as a social signal, contributing to ◦ Characteristics: Terminal hair is coarser and can personal identity, attractiveness, and social status. vary in color and texture. It is influenced by hormones, 5| Pheromonal Signaling: particularly androgens, and plays a role in social and 6| In some mammals, hair can play a role in the sexual signaling. dispersal of pheromones, which are chemical signals that can attract mates. Hair is a complex epidermal derivative with essential functions relating to protection, insulation, and sensory perception. Its growth and characteristics can vary greatly among individuals and are influenced by genetics, hormones, and environmental factors. 3 Major Types of Skin Cancer: 1| Basal Cell Carcinoma (BCC): ◦ Description: Basal cell carcinoma is the most common type of skin cancer and arises from the basal cells, which are located in the lowest layer of the epidermis. ◦ Characteristics: BCCs typically appear as small, pearly nodules, flat, scar-like lesions, or open sores that do not heal. They often occur in areas exposed to the sun, such as the face, neck, and ears. ◦ Prognosis: BCC is usually slow-growing and rarely metastasizes (spreads to other parts of the body), making it the least aggressive form of skin cancer. However, if left untreated, it can cause local damage to surrounding tissues. 2| Squamous Cell Carcinoma (SCC): ◦ Description: Squamous cell carcinoma arises from the squamous cells located in the outer layer of the skin (epidermis). It is the second most common type of skin cancer. ◦ Characteristics: SCCs may appear as firm, red nodules, flat sores that crust or bleed, or scaly patches that can develop into open sores. Like BCC, they commonly occur in sun-exposed areas. ◦ Prognosis: SCC can be more aggressive than BCC and has the potential to metastasize if not treated promptly, especially if they arise on the lips or ears. 3| Melanoma: ◦ Description: Melanoma is the least common but most aggressive type of skin cancer. It originates in the melanocytes, the cells that produce the pigment melanin. ◦ Characteristics: Melanoma can develop from existing moles or appear suddenly as a new, unusual-looking mole or spot. Common features include asymmetry, irregular borders, multiple colors, and a diameter larger than 6 mm (often described by the ABCDE rule: Asymmetry, Border irregularity, Color variation, Diameter, Evolving). ◦ Prognosis: Melanoma has a higher risk of metastasis than BCC or SCC, making early detection and treatment crucial. If caught early, it can often be treated successfully, but advanced melanoma can be life-threatening. Module 3: INTRODUCTION OF THE MUSCULAR SYSTEM Interactions of Skeletal Muscles in the Body Oxygen and Muscle (similar to hemoglobin) 1| Muscles can only pull as they contract-not push binds to and stores oxygen Supplies O, needed to make ATP for contraction. 2| In general, groups of muscles that produce - Prolonged, moderate exercise opposite actions in lie on opposite sides of a joint - ATP supplied through cellular respiration A. PRIME MOVER: - Once glycogen stores are depleted in muscle, muscle with the major responsibility for a certain glucose and fatty acid deliveries from blood movement. are used as fuel source. B. ANATOGONIST: Key Terms: 1| Origin: attached to the immovable or less muscle that oppose or reverse a prime mover movable bone C. SYNERGIST: muscle that aids a prime mover in a movement or 2| Insertion: attached to the movable bone, and reduces undesirable movements when the muscle contracts, the insertion moves D. FIXATOR: toward the origin. specialized synergists that hold a bone still stabilize the origin of a prime mover 3| Flexion: decrease the angle of the joint and brings 2 bones closer together. Naming Skeletal Muscles Muscles are named on the basis of several criteria 4| Extension: opposite of flexion, a movement that - by direction of muscle fibers increases the angle, or the distance. Example/s: Rectus (straight) 5| Rotation: movement of a bone around a - by relative size of the muscle longitudinal axis; it is a common movement of Example/s: Temporalis (temporal bone) ball and socket joints. - by number of origins Example/s: Triceps (3 heads) 6| Adduction: opposite of the abduction, movement of a limb toward the body’s midline. Axial (muscles of the trunk and head) Appendicular (muscles of the arms and legs) 7| Circumduction: combination of flexion, extension, abduction, and adduction commonly seen in ball Anesthesia and socket joints; the proximal end is stationary, and its distal and moves in a circle. Muscles of the Anterior Neck Special Movements - categorized according to their position relative 1| Dorsiflexion and plantar flexion to the hyoid bone. 2| Inversion and eversion - facilitate swallowing and speech. 3| Supination and pronation Muscles that move the head Module 3: Skeletal System - BONES (OSSEOUS TISSUE, is a hard, dense connective tissue) JOINTS (where 2 or more bones meet to create mobility) TENDONS (muscle bone) LIGAMENT (bone-bone) CARTILAGE (semi-rigid connective tissue, provides flexibility) FUNCTIONS OF THE SKELETAL SYSTEM SUPPORT, PROTECTION, STORAGE OF MINERAL, HELPING IN MOVEMENT, CHEMICAL ENERGY STORAGE AND PRODUCTIONS OF RED BLOOD CELL Compact Bone denser, stronger of the 2 types found under the periosteum and in the diaphyses of long bones microscopic structural unit; osteon/haversian system Veins - Blue deoxygenated Arteries - Red because they have oxygen. Lamella - “Trabeculae” No distinct circle Spongy (Cancellous Bone) has open spaces and supports shifts in weight distribution. consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavitiest hat contain red bone narrow. Osteacytes - in between osteacytes there is lacuna/lacume Spongy (Cancellous) Bone ◦ Spongy (cancellous) bone is lighter and less dense than compact bone. The canaliculi of spongy bone connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply. Spongy bone consists of: ▪ Trabeculae (plates) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. ▪ Canaliculi that connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply. ▪ It may appear that the trabeculae are arranged in a haphazard manner, but they are organized to provide maximum strength similar to braces that are used to support a building. BONE TYPES Sesamoid bone The bones of the body come in a variety of sizes and Calcification of sesamoid bone is one of the shapes. The four principal types of bones are long, important features of pubertal growth spurt, which short, flat and irregular. is earlier in females than in males. Sesamoid bone 1. Flat Bones are somewhat flattened, and can is a small nodular bone most often present provide protection, like a shield; flat bones can also embedded in tendons. Absence of sesamoid bone provide large areas of attachment for muscles. Most indicates delay in reaching puberty. Sesamoids of the bones of the cranium are flat bones. act like pulleys, providing a smooth surface for tendons to slide over, increasing the tendon's 2. Long bones are longer than they are wide and ability to transmit muscular forces. Sesamoid function to support the weight of the body and bones form directly from the connective tissue facilitate movement. They consist of a long shaft found in tendons and ligaments. with two bulky ends or extremities. They are primarily compact bone but may have a large Sesamoiditis of the foot simply means amount of spongy bone at the ends or extremities. inflammation of the sesamoids and is normally Long bones include bones of the thigh, leg, arm, and caused by increased pressure or loading on the forearm. sesamoid bones and associated tendons. In the normal foot, each sesamoid bone is a pea-shaped 3. Short Bones are cube- shape about as long as bone located on the underside of the forefoot just they are wide provide stability and some movement. back from the big toe joint. They’re located on the They consist primarily of spongy bone, which is inside edge of the ball of the foot as marked in the covered by a thin layer of compact bone. Short image below. It’s just one cause of pain in the ball bones include the bones of the wrist and ankle. of the foot sometimes broadly termed Metatarsalgia. Sesamoiditis is especially common 4. Irregular Bones vary in shape and structure and among certain types of athletes and dancers. It’s therefore do not fit into any other category (flat, also more common with particular foot types short, nor long). They often have a fairly complex which display more rigid and pronounced anatomy shape, which helps protect internal organs. They are in the region of the sesamoid bones. The condition primarily spongy bone that is covered with a thin usually stems from straining or overworking the layer of compact bone. The vertebrae and some of tendons associated with these particular bones. the bones in the skull are irregular bones. All bones have surface markings and characteristics that make a specific bone unique. There are holes, depressions, smooth facets, lines, projections and other markings. These usually represent passageways for vessels and nerves, points of articulation with other bones or points of attachment for tendons and ligaments. Types of Bones according to shape: long bone irregular bone flat bone short bone - carpal (wrist) bones. tarsal (ankle) bones Lacrimation - tearing up (luha) Epiphyseal plate - (growth plate) layer of hyaline (transparent) cartilage in a growing bone = when the bone stops growing in early adulthood (approximate). Medullary Cavity - has a delicate membranous lining called the endosteum (end = inside, oste = bone), where bone growth, repair and remodeling occur. ◦ Epiphysis is the wider section at each end of the - bonefilled with spongy bone. ▪ Red marrow fills the spaces in the spongy bone. ▪ Each epiphysis meets the diaphysis at the metaphysis, the narrow area that contains the epiphyseal plate Other structures of a long bone ◦ Epiphyseal plate (growth plate) is a layer of hyaline (transparent) cartilage in a growing bone. When the bone stops growing in early adulthood (approximately 18–21 years), the cartilage is replaced by osseous tissue and the epiphyseal plate becomes an epiphyseal line. ◦ Endosteum is a membranous lining of the medullary cavity, where bone growth, repair, and remodeling occur. ◦ Periosteum is a fibrous membrane covering the entire outer surface of the bone except where the epiphyses meet other bones to form joints. It contains blood vessels, nerves, and lymphatic vessels that nourish compact bone. Bone Cells ◦ Articular cartilage is a thin layer of cartilage covering Osteogenic Cells / Osteoprogenitor: called stem the epiphyses that reduces friction and acts as a shock absorber. cells Osteoblast: forms bone matrix, bone forming BONE MARKINGS cells (for ossification) Articulation - where 2 bone surfaces come together Osteocyte: maintains bone tissue. mature bone (articulus = “joint”) cells Projection - area of a bone that projects above the surface Osteoclast: resorbs bone. resorption = of the bone destruction. Hale - opening or groove in the bone that allows blood Hematopoietic: found in bone marrow. function vessels and nerves. is to make red blood cells, WBC and platelets. Tuberosity: large rounded projection, may be roughed - palpable Bone Development and Growth: Crest: narrow ridge of bone usually prominent - palpable Ossification - process of bone formation Trochanter: very large, blunt irregular shaped process - Bone Resorption - process of bone palpable destruction Line: narrow ridge of bone, less prominent Head: bony expansion carried on a narrow neck - not 1| Intramembranous = cells = flat bones = palpable face + clavicle Faucet: smooth nearly flat articular surface - not 2| Endochondral = inside the cartilage. for long palpable bones  Figure 3. There are three bone cells involved in homeostasis: osteocytes, osteoclast and osteoblast. Types of Bone Tissues. There are two types of bone tissue: compact and spongy. The names imply that the two types differ in density, or how tightly the tissues are packed together. Compact Bone Compact bone consists of closely packed osteons or Haversian systems to form a solid mass. Components of the Haversian system: ▪ Haverisan canal - central canal, which is surrounded by concentric rings (lamellae) of matrix ▪ Lacunae - spaces in between the ring of matrix that contain the osteocytes ▪ Canaliculi - small channels that radiate from the lacunae to the osteonic (haversian) canal to provide passageways through the hard matrix. Figure 4. The Haversian system consists of Haversian canal, lacunae, canaliculi and osteocytes Bone development and Ossification Process Endochondral Ossification. This is the process is The skeleton begins to form early in fetal development as followed by long bones and occurs in two a flexible skeleton made of hyaline cartilage and dense ossification centers irregular fibrous connective tissue. These tissues act as a ▪ Primary Ossification Center (happens in the soft, growing framework and placeholder for the bony diaphysis) skeleton that will replace them. As development progresses, ▪ The cartilage in the center of the diaphysis blood vessels begin to grow into the soft fetal skeleton, begins to disintegrate. Osteoblasts penetrate the bringing stem cells and nutrients for bone growth. Osseous disintegrating cartilage and replace it with spongy tissue slowly replaces the cartilage and fibrous tissue in a bone. After spongy bone is formed in the diaphysis, process called calcification. The calcified areas spread out osteoclasts break down the newly formed bone to from their blood vessels replacing the old tissues until they open up the medullary cavity. reach the border of another bony area. ▪ Secondary Ossification (happens in the At birth, the skeleton of a newborn has more than 300 epiphysis) bones; as a person ages, these bones grow together and ▪ The cartilage in the epiphyses continues to fuse into larger bones, leaving adults with only 206 bones. grow so the developing bone increases in length. Ossification in the epiphyses is similar to that in the Ossification or Osteogenesis is the process of bone diaphysis except that the spongy bone is retained formation. Osteocytes, Osteoclasts and osteoblast and cells instead of being broken down to form a medullary involved in the development, growth and remodeling of bones. cavity. Two types of ossification processes: intramembranous and ▪ When secondary ossification is complete, the endochondral. hyaline cartilage is totally replaced by bone except in two areas. A region of hyaline cartilage remains over ▪ Intramembranous Ossification which involves the replacement of sheet-like connective tissue membranes with the surface of the epiphysis as the articular bony tissue. Flat bones and some irregular bones follow the cartilage and the epiphyseal plate or growth region process of intramembranous ossification where the young ▪ As we grow through childhood, the growth bones grow from a primary ossification center in fibrous plates grow under the influence of growth and sex membranes and leave a small region of fibrous tissue in hormones, slowly separating the bones. At the same between each other. In the skull these soft spots are known time the bones grow larger by growing back into the as fontanels, and give the skull flexibility and room for the growth plates. This process continues until the end bones to grow. Bone slowly replaces the fontanels until the of puberty, when the growth plate stops growing individual bones of the skull fuse together to form a rigid and the bones fuse permanently into a single bone. adult skull. The vast difference in height and limb length Supplementary Video: Please watch this video to learn between birth and adulthood are mainly the result of more about intramembranous ossification process: endochondral ossification in the long bones.  Division of the Skeletal System The adult human skeleton usually consists of 206 named bones. These bones can be grouped in two divisions: axial skeletonand appendicular skeleton. The 80 bones of the axial skeleton form the vertical axis of the body. They include the bones of the head, vertebral column, ribs and breastbone or sternum. The appendicular skeleton consists of 126 bones and includes the free appendages and their attachments to the axial skeleton. The free appendages are the upper and lower extremities, or limbs, and their attachments which are called girdles. Figure 1. Axial and Appendicular Skeleton. The axial skeleton supports the head, neck, back, and chest and thus forms the vertical axis of the body. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The appendicular skeleton is made up of all bones of the upper and lower limbs. (image from: opentextbc.ca) 1. Axial Skeleton It forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back It protects the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs. Human Axial Skeleton: ◦ The axial skeleton of the human adult consists of 80 bones, including the skull, the vertebral column, and the thoracic cage. ◦ The skull is formed by 22 bones and additional seven bones, including the hyoid bone and the ear ossicles ◦ The vertebral column consists of 24 bones, each called a vertebra, plus the sacrum and coccyx. ◦ The thoracic cage includes the 12 pairs of ribs, and the sternum, the flattened bone of the anterior chest.  Figure 2. Human Axial Skeleton consists of skull, vertebrae and the thoracic cage 2. Appendicular skeleton It is consists of the 126 bones which are attached to the axial skeleton are the limbs These bones are divided into two groups: the limbs and the girdle bones ◦ Pectoral Girdle -the bones of the shoulder region which anchors the upper limb to the thoracic cage of the axial skeleton. ◦ Pelvic Girdle - the bones of the hip region which attaches the lower limb to the vertebral column. Human Appendicular Skeleton: ◦ Because of our upright stance, different functional demands are placed upon the upper and lower limbs. ▪ Lower limbs are adapted for weight-bearing support and stability, as well as for body locomotion via walking or running. ▪ Upper limbs are not required for these functions. Instead, our upper limbs are highly mobile and can be utilized for a wide variety of activities. ▪ The large range of upper limb movements, coupled with the ability to easily manipulate objects with our hands and opposable thumbs, has allowed humans to construct the modern world in which we live. Vertebral Bones Cervical: axis - c1 & atlas - c2 Thoracic Lumbar Sacrum Coccyx transverse foramen V Transverse Foramen : Body Thoracic Cage: - Xiphoid process - Rib- hes intercostal spaces - False Ribs -> 7 to 10 - Floating Ribs - 11 to 12 - True Ribs -> 1 to 6 directly attach to sternum Appendicular: Clavicle - Scapula Figure 3. The Appendicular Skeleton is made up of the upper and the lower limbs, the pectoral and pelvic girdles (image from: - Head of humerus Lumen Learning) NERVOUS SYSTEM - A system that controls all of the activities of the body Functions: Monitoring Changes: - Stimuli - Sensory Input Interpretation of sensory input Effects responses: motor output Mental Activity: consciousness, thinking, and memory Homeostasis The Brain weighs about 3.3 lbs. (1.5kg), about 2% of a human body weight. contains about 86 billion nerve cells (neurons) - the “gray matter” contains billions of nerve fibers (axons and dendrites) - the “white matter” command center: receives Information through the senses assembles the message in a way that has meaning for us , and can store that information in our memory. controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body. Like all vertebrate brains, the human brain develops from three sections: 1. Forebrain: a develop into cerebrum and underlying structures. 2. Midbrain: becomes part of the brainstem 3. Hindbrain: gives rise to regions the brainstem and the cerebellum  - Like all vertebrate brains, the human brain develops from three sections: ▪ Forebrain – develops into cerebrum and underlying structures ▪ Midbrain – becomes part of the Brainstem ▪ Hindbrain - gives rise to regions of the brainstem and the cerebellum CENTRAL NERVOUS SYSTEM ❖ act as the integrating and command centers Cerebum largest part of the brain composed of right and left hemisphere performs higher functions like interpreting, touch, vision, and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement. Carpus Callosum bundle of fibers that joins the right and left hemisphere of cerebrum transmit messages from one side to the other each hemisphere controls the opposite side of the body if a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed Gyrus —> Gyri Sulcus —> Suki (Shallow growes) Cerebellum: coordinate muscle movements, maintain posture, and balance Brainstem: “relay center” connecting the cerebrum and cerebellum to spinal cord automatic functions: breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting and swallowing. Frontal Lobe: Primary motor area Personality, behavior, emotions Judgement, planning, problem solving speech: speaking and writing (Broca’s Area) Body movement (motor strip) Intelligence, concentration, self-awareness Parietal lobe: primary somatosensory area - interprets language, words sense of touch, pain, temperature (sensory strip) interprets signals from vision, hearing, motor, sensory and memory spatial and visual perception Occipital Lobe interprets vision (color, light, and movement) Temporal Lobe Understanding language (Wernicke’s area) Memory Hearing Sequencing and organization Cerebral Cortex "Gray Matter - the gray-brown layer containing the nerve cell bodies /substantia grisea White Matter - lies beneath the gray matter containing long nerve fibers (axons) that connect brain areas to each other (substantia alba) Gyrus - fold on the surface Sulcus - the groove between folds The folding of the cortex increases the brain's surface area allowing more neurons to fit inside the skull and enabling higher functions. grey matter white matter Messages can travel from one gyrus to another, from one lobe to another, from one side of the brain to the other, and to structures deep in the brain Hypothalamus: “is located in the floor of the third ventricle master control of the autonomic system" hunger, thirst, sleep, and sexual response It also regulates body temperature, blood pressure, emotions, and secretion of hormones  PART OF HEMISPHERE Aphasia ▪ a disturbance of language affecting speech production, comprehension, reading or writing, due to brain injury – most commonly from stroke or trauma ▪ The type of aphasia depends on the brain area damaged Broca’s Aphasia: (lies in the left frontal lobe) ▪ difficulty moving the tongue or facial muscles to produce the sounds of speech ▪ The person can still read and understand spoken language but has difficulty in speaking and writing (i.e. forming letters and words, doesn't write within lines) Wernicke's aphasia: (lies in the left temporal lobe) ▪ The individual may speak in long sentences that have no meaning, add unnecessary words, and even create new words. ▪ They can make speech sounds, however they have difficulty understanding speech and are therefore unaware of their mistakes. Pituitary gland: - lies in a small pocket of bone at the skull base called the sella turcica "Known as the "master gland" It controls other endocrine glands in the body It secretes hormones that control sexual development, promote bone and muscle growth, and respond to stress EEPER STRUCTURES OF THE BRAIN Pineal gland: It is located behind the third ventricle It helps regulate the body's internal clock and circadian rhythms by secreting melatonin It has some role in sexual development Thalamus: serves as a relay station for almost all information that comes and goes to the cortex pain sensation, attention, alertness and memory Basal ganglia: includes the caudate, putamen and globus pallidus These nuclei work with the cerebellum to coordinate fine motions, such as fingertip movements Limbic system: enter of emotions, learning, and nemory included in this system are the cingulate gyri, hypothalamus, amygdala (emotional reactions) and hippocampus (memory) Prefrontal cortex holds short-term memory Hippocampus encodes long-term memory MEMORY CEREBELLUM (the green) A complex process that includes 3 phases: Encoding (deciding what information is important) Storing Recalling Short-term memory (working memory) occurs in the prefrontal cortex stores information for about 1min and its capacity is limited to about 7 items Long-term memory occurs in hippocampus activated when you want to memorize something for a longer time = has unlimited content and duration capacity it contains personal memories as well as facts and figures Skill memory processed in the cerebellum stores automatic learned memories like tying a shoe, plating an instrument, or riding a bike Cerebellum = “little brain" coordinates movements controls posture, balance and fine motor movement involved in motor learning Brain Stem the lowest part of the brain controls the flow of messages between the brain and the rest of the body Ventricles and the CSF - Ventricles hollow fluid-filled cavities in the brain Choroid Plexus a ribbon-like structure that makes a clear colorless fluid Cerebrospinal Fluid (CSF) flows within and around the brain and spinal cord to help cushion it from injury Common Sites of Obstruction Foramen of Monro Aqueduct of Sylvius Obex Glial Cells Oligodendroglia Cells provide neurons with nourishment, protection and create a fatty substance called myelin that insulates structural support axons-allowing electrical messages to travel faster Astroglia or Astrocytes Ependymal Cells “the caretakers" line the ventricles and secrete cerebrospinal fluid (CSF) regulate the blood brain barriers, allowing nutrients and molecules to interact with neurons  Neurons ▪ nerve cells ▪ carryelectrical impulses from one place to another Nerve ▪ is a bundle of neurons parts of neurons Myelin sheath Dendrons A fatty sheath that Insulates are tiny branches at the end of a the axon; increases the speed of the nerve impulses along the neuron neuron, which branch even further into dendrites  Neurotransmitters - molecules cross the synapse and fit into special receptors on the receiving nerve cell, which stimulates that cell to pass on the message A layer of tissue that covers and protects the brain and spinal cord Pia mater: Arachnoid mater: hugs the surface of the brain following its folds is a thin, web-like membrane that covers the and grooves entire brain made of elastic tissue has many blood vessels that reach deep into the brain Subarachnoid Space space between the arachnoid and pia Dura mater: where the cerebrospinal fluid bathes and is a strong, thick membrane that closely lines the cushions the brain inside of the skull creates little folds or compartments Subdural space space between the dura and arachnoid The Spinal Chord membranes approximately 17 inches (42 cm) long provides a two-way conduction pathway to and from the brain, and it is a major reflex center 31 pairs of spinal nerves Communication of Neurons at Synapses Arrival: The action potential arrives at the axon terminal Fusion: The vesicle fuses with plasma It membrane Release: Neurotransmitter is released into synaptic cleft Binding: Neurotransmitter bin receptor on receiving neurons Opening: The ion channel opens Closing: Once the neurotransmitter is broken down and released, the ion channel close SOMATIC NERVOUS SYSTEM * SOMATIC SENSORY FIBERS * SOMATIC MOTOR FIBERS * VOLUNTARY ACTIONS AUTONOMIC NERVOUS SYSTEM * INVOLUNTARY FUNCTIONS * VISCERAL MOTOR * VISCERAL SENSORY