Anatomical Body Systems PDF - University of Central Lancashire

Anatomical Body Systems Overview of Body Systems Kris Phillips Lecturer in Anatomy [email protected] Where opportunity creates success  Part 1 – Overview Body Systems & Cavities Part 2 – MSK & Skin Skeletal System Muscular System Integumentary System...

Anatomical Body Systems Overview of Body Systems Kris Phillips Lecturer in Anatomy [email protected] Where opportunity creates success  Part 1 – Overview Body Systems & Cavities Part 2 – MSK & Skin Skeletal System Muscular System Integumentary System Today’s Part 3 – CVR & Lymphatics Cardiovascular System Session Respiratory System Lymphatic System Part 4 – GI Gastrointestinal System Part 5 – GU Urinary System Reproductive System Part 6 – Neuroendocrine Nervous System Endocrine System  Learning Outcomes: Learning M1.I.COR.ANA2 – Summarise the anatomy and function of each system of the body. Outcomes  Part 1 – Overview Body Systems & Cavities Body Systems: Overview The body can be organised into systems. Generally, there are 11 systems in total – though this can depend on who is counting. Structures aren’t always exclusive to one system, there is overlap. The 11 systems are: Skeletal system Muscular system Cardiovascular (circulatory) system Respiratory (pulmonary) system Digestive (gastrointestinal) system Urinary system Reproductive (sexual) system Nervous system Endocrine system Lymphatic system (sometimes grouped as Immune system) Integumentary/exocrine system Systems are the same in every human, with the exception of the reproductive system. Cavities: Overview The body is also compartmentalized into cavities where structures are located. These are actual divisions, with structures separating the cavities. The cavities are: Cranial cavity Extends into the vertebral cavity. Contains the brain and spinal cord. Thoracic cavity Contains the mediastinum (containing the heart and other structures) and lungs (pleural cavity). Separated from abdominal cavity by diaphragm. Abdominopelvic cavity Combination of abdominal cavity (containing most digestive organs and urinary system) and pelvic cavity (containing large bowel, urinary bladder, and reproductive organs). Abdominal cavity can be further divided by peritoneum. Structures that lie within peritoneum are intraperitoneal (most digestive organs), structures that lie behind are retroperitoneal (SADPUCKER). Thoracic and abdominopelvic cavities can be combined and are usually what is referred to by “trunk”. Surface Anatomy: Regions The skin of the body can also be divided into regions. This helps when referencing areas for surface anatomy. Part 2 – MSK & Skin Skeletal System Skeleton: Overview The skeletal system acts as the strut for the whole body, supports the structures and acting as attachment points for muscles. It also protects vital organs Contains reservoirs of calcium and phosphorus Involved in blood production. It can be divided into an axial skeleton and appendicular skeleton. Axial skeleton Skull, vertebral column, ribs, and sternum. Appendicular skeleton Upper and lower limbs. Skeleton: Bones The skeleton is made up of around 206-213 bones as an adult, with an infant having around 270 bones. Again, depends on who’s counting and what they count. Bones are made up of two types of bone: Spongy bone Inner part of bone. Contains marrow – blood-forming cells. Also known as cancellous or trabecular bone. Compact bone Dense outer shell of bone. Also known as cortical bone.  Skeleton: Cartilage Semirigid, avascular form of connective tissue that forms part of the skeleton where more flexibility is required. Their functions include – Support soft tissues – Provide a smooth, gliding surface for bone articulations at joints – Enable the development and growth of long bones There are three types – hyaline, elastic and fibrocartilage Adapted from slides by Izu Obazie Skeleton: Bone Classification Bones can also be sorted into classifications: Long bones Long bones are tubular shaped bones defined as being longer than they are wide, often found in the limbs. Short bones Short bones are cuboidal (as wide as they are long). Their primary function is stability, with hardly any movement, if any. Flat bones Flat bones are flat and broad plates of bone, usually used for muscle attachment and protection. Irregular bones Irregular bones have no defined form but exist as they cannot be categorised into the other groupings. They usually have unusual shapes. They serve many functions individually such as protection, muscle attachment and support of tissues. Sesamoid bones Sesamoid bones are found within tendons or muscle, primarily functioning to aid in movement. They do not form any direct joints with other bones. Skeleton: Clinical Joints: Overview When two (or more) bones come together they form a joint. Joints allow movement, driven by muscle and gravity. They can be divided into: Synovial joints Skeletal elements are separated by a cavity Also known as diarthroses (freely moveable). Solid joints Skeletal elements are held together by connective tissue, with no cavity present. Also known as either synarthroses (immovable) or amphiarthroses (slightly moveable). Synovial joints make up a large majority of joints and allow for greater movement than solid joints (which have very little movement). Other classification systems do exist, which you will go into later on. Joints: Classifications Synovial joints can be further classified as: Plane/gliding joints Plane/gliding joints allow sliding or gliding movement when one bone moves across another. Their articular surfaces are usually flat and have limited movement. Pivot joints Pivot joints allow movement on once axis, usually permitting rotation. Hinge joints Hinge joints allow movement on one axis, usually permitting only flexion and extension. Bones usually seem moulded to the shape of the joint. Saddle joints Saddle joints allow movement on two axes that are at a right angle to each other. Their articular surfaces are saddle shaped, usually permitting flexion, extension, abduction, adduction, and circumduction. Ball and socket joints Ball and socket joint allow movement in multiple axes, usually permitting a full range of movements including flexion, extension, abduction, adduction, circumduction, and rotation. Ellipsoid/Condyloid/Bicondylar joint These joints allow movement in one axis, sometimes with limited rotation in a second axis. They are sometimes formed by two convex condyles that articulate with concave or flat surfaces. Some joints may also fall into more than one category - their definitions may vary. Joints: Classifications Examples Plane/gliding: Acromioclavicular, areas of wrist and ankle, 2nd-7th sternocostal Pivot: Radioulnar, Atlanto-axial Hinge: Elbow, ankle, knee, interphalangeal of foot and hand Saddle: Thumb, sternoclavicular, middle ear, certain heel joints (calcaneocuboid) Ball & socket: Hip, shoulder Ellipsoid/condyloid/bicondylar: Wrist, metacarpophalangeal, metatarsophalangeal, Atlanto-occipital, knee Part 2 – MSK & Skin Muscular System Muscle: Types Skeletal muscle consists of parallel bundles of long, multinucleated fibers with transverse stripes. Cardiac muscle is striated muscle found only in the walls of the heart (myocardium) and in some of the large vessels close to where they join the heart. Smooth muscle (absence of stripes) consists of elongated or spindle- shaped fibers capable of slow and sustained contractions. Most muscles are named based on their: Function or the bones to which they are attached to (e.g. abductor digiti minimi) Shape (e.g., rhomboid major muscle) Attachments (e.g., sternohyoid, Sternocleidomastoid muscle) Position (e.g., palmar interosseous muscle) Fiber orientation (e.g., external oblique muscle). Adapted from slides by Izu Obazie Muscle: Skeletal Muscle Shapes Flat Muscles – have parallel fibers e.g., sartorius and external oblique Pennate muscles – featherlike – Unipennate – muscle fibers slope into one side of the tendon - extensor digitorium longus – Bipennate – muscle fibers slope into two sides of a central tenson - rectus femoris – Multipennate – multiple bipennate muscles - deltoid Fusiform muscles – spindle shaped e.g., biceps brachii Convergent muscles – arise from a broad area and converge to form a single tendon e.g., pectoralis major Quadrate muscles – four equal sides e.g., rectus abdominus, pronator quadratus Circular or sphincteral muscles – surround a body opening or orifice e.g., orbicularis oculi & oris Multi-headed and multi-bellied muscles – have more than one head of attachment or more than one contractile belly e.g., biceps brachii & triceps (multiple heads), digastric and gastrocnemius (multiple bellies) Adapted from slides by Izu Obazie  Part 2 – MSK & Skin Integumentary System Skin: Overview The integumentary system (L. integumentum, covering, or cutaneous layer) is an organ system consisting of the skin, hair, nails, and glands. Commonly just called ‘skin’ It is the largest organ in the body and accounts for ~15% of total body weight. Readily accessible, so is a very good indicator of general health. Lots of health issues can present in a variety of ways and influence the integumentary system. Skin renews itself every month. This renewal does not compromise the skin barrier. Cuts, grazes etc. act as entry points for potential bacteria/infections into the body. Adapted from slides by Dr Anthony Adefolaju Skin: Layers Adapted from slides by Dr Anthony Adefolaju Skin: Functions The skin provides: Protection Heat regulation Sensation - superficial nerves and their sensory endings. Endocrine (e.g. Synthesis and storage of vitamin D) Immunological functions Homeostasis Excretion Adapted from slides by Dr Anthony Adefolaju Part 3 – CVR & Lymphatics Cardiovascular System Location: Chest Wall The heart is one of the primary organs of the body. Its function is to supply blood to all tissues of the body, including itself. It is located usually between rib 2 and the 5th intercostal space. It extends from the right medial border of the sternum to having its apex at the midclavicular line on the left. This can change due to cardiomegaly or it can be displaced by mediastinal or lung conditions. The heart is usually between vertebral levels T4-T9. Location: Mediastinum It is located within the pericardium in the middle mediastinum. Bordered anteriorly by the anterior mediastinum. Bordered posteriorly by the posterior mediastinum. Bordered laterally by the pleura of each lung. Bordered superiorly by the sternal angle and superior mediastinum Bordered inferiorly by the diaphragm. Heart: Overview The heart is essentially a 4 chambered structure, divided in half by a septum. One half (the right side) takes in deoxygenated blood from the body and sends it to the lungs to be oxygenated. This is known as the pulmonary circuit. The other half (the left side) takes in newly oxygenated blood from the lungs and sends it to the rest of the body. This is known as the systemic circuit. Valves exist between each chamber and major onward vessel to control the flow of blood between them. Heart: Chambers The 4 chambers of the heart are: Right atrium Right ventricle Left atrium Left ventricle The atria collect blood from either the venous circulation or the pulmonary veins. The atria then contract to pass the blood through atrioventricular valves to the ventricles. The ventricles then contract to send the blood onwards to either the lungs (right) or the rest of the body (left). Heading towards their destination the blood passes through the semilunar valves at the entrance to the pulmonary trunk (right) and ascending aorta (left). As the ventricles contract, the atria fill, and as the atria contract, the ventricles fill. This provides a continuous flow of blood. Pericardium: Overview The heart and the roots of the great vessels are contained within the middle mediastinum in a specialised fibroserous sac called the pericardium. The pericardium can be divided into: Fibrous pericardium Serous pericardium Further divided into: Parietal layer Pericardial cavity (between layers) Visceral layer The pericardial cavity that lies between the parietal and visceral layer usually has about 15-50ml of pericardial fluid in. This acts as lubrication so the heart can move without friction. It is also important clinically as there can be too much fluid in this cavity. Surface Anatomy: Auscultation It is important to know at what areas you can hear structures associated with the heart. The most common structures you will listen for are heart valves – or more precisely the blood flow associated with them. Heart valves are generally auscultated close to their location, though depending on the type of pathology present it may be before or after the valve. The pericardium can also be heard if there is certain pathologies associated with it. Circulatory System: Overview Circulatory System: Structure Heart > Aorta > Artery > Arteriole > Capillary > Venule > Vein > Vena Cava > Heart Three layers (tunica): Intima, media, and adventitia. Different thickness of layers in vessels, most distinct in arteries. Veins all similar – different sizes. Arteries – muscular/elasticity specialisations. Generally, goes from oxygenated blood to deoxygenated blood. Capillaries are the site of gas and nutrient exchange. Only fit 1 blood cell at a time. Circulation: Great Vessels Great vessels are blood vessels that either originate from or flow to the heart. Most are at the superior aspect of the heart, from right to left: Superior vena cava – Drains deoxygenated blood from the thorax, upper limbs, head, neck, and brain. Aortic arch (or Arch of Aorta) – originates as the ascending aorta as it leaves the heart, becomes the aortic arch and goes on to supply the entire body with oxygenated blood. Pulmonary trunk – Takes deoxygenated blood from the heart to the lungs to be oxygenated. Posteriorly there is also the pulmonary veins – They leave the lungs carrying oxygenated blood and deliver it to the heart ready to be circulated round the body. Inferiorly there is the inferior vena cava – Drains deoxygenated blood from all of the abdomen and lower limbs. Circulation: Coronary Circulation As with all areas of the body, the heart needs oxygenated blood to function. It receives this from the coronary circulation. Two coronary arteries supply the heart and arise from the proximal part of the ascending aorta. Left coronary artery Right coronary artery These arteries circle the heart in the coronary sulcus. They give off multiple branches in and around the interventricular sulci that converge towards the apex of the heart. These all drain through cardiac veins, mostly emptying in the coronary sinus. The coronary sinus lies on the posterior aspect of the heart in the coronary sulcus. It drains into the right atrium. Conduction: Overview The heart receives signals towards the SA node in the right atrium which begin the cardiac cycle. The SA node sends impulses to: Internodal tracts – Stimulate contraction of the right atrium. Bachmann’s bundle – Stimulate contraction of the left atrium. AV node – Passing signals to it for the ventricles. The AV node is then stimulated and passes signals down into the bundle of His. This then splits into the right and left bundle branches. Signals continue either side to the Purkinje fibres that stimulate the cardiac muscle to contract. Part 3 – CVR & Lymphatics Respiratory System Thorax: Divisions Thorax can be divided into: Right pleural cavity Left pleural cavity Mediastinum Mediastinal pleura encapsulates most of the mediastinum. Blends with the parietal pleura of the lungs laterally. Blends with the pericardium internally. Pleura: Overview Each lung is encapsulated within a pleural cavity. The pleura fills the remaining space in the thorax not taken up by the mediastinum. Each pleura is distinct from the other – there is no connection between them. Respiratory System: Overview Upper Respiratory Tract: Overview  Lower Respiratory Tract: Overview TRACHEA LEFT MAIN BRONCHUS RIGHT MAIN BRONCHUS SECONDARY (LOBAR) BRONCHI X2 SECONDARY (LOBAR) BRONCHI X3 TERTIARY (SEGMENTAL) BRONCHI X10 TERTIARY (SEGMENTAL) BRONCHI X10 TERMINAL BRONCHIOLES - MANY TERMINAL BRONCHIOLES - MANY RESPIRATORY BRONCHIOLES - MANY RESPIRATORY BRONCHIOLES - MANY ENDS IN ACINUS OF ALVEOLI ENDS IN ACINUS OF ALVEOLI Lower Respiratory Tract: Trachea Trachea is a flexible, hollow tube that extends from about C6 to T4/T5. Starting after the cricoid cartilage, it is surrounded by C- shaped cartilaginous rings The open part of the C always faces posteriorly. Why a C shape? Lungs: Overview Right lung: Left lung: 3 lobes – Superior, middle, and inferior 2 lobes – Superior and inferior Divided by oblique and horizontal fissures Divided by oblique fissure Shorter and wider than the left lung Has distinct cardiac notch and lingula. Both lungs have an apex which projects above rib 1 and into the neck. They both have a base which sits on the diaphragm. Lungs: Hilum Structures from the mediastinum enter and leave the lungs at the hilum. These include: pulmonary artery (usually 1), pulmonary veins (usually 1), main bronchus, bronchial vessels, nerves, and lymphatics. The structures of the hilum also help anchor the lung in the mediastinum and give it support. Lungs: Bronchopulmonary Segments Each lung can be dived into 10 functionally independent segments. This means each segment has its own air, blood, and nerve supply – independent from adjacent segments – how can this be helpful? In the left lung this are often fused – sometimes only referred to as having 8 or 9 segments. Diaphragm: Movement Effects Respiration: Muscles Auscultation: Anterior Auscultation: Posterior Surface Anatomy: Lateral Part 3 – CVR & Lymphatics Lymphatic System Lymphatic System: Overview A series of organs, vessels and nodes that collect and filter excess tissue fluid (lymph), before returning it to the venous circulation. Function: To drain excess interstitial fluid from tissues into the venous system To produce and transport immune cells (lymphocytes) To mount an immune response against pathogens To transport dietary lipids from the GI tract into the blood Structures include: Organs: Spleen, thymus Bones: Specifically, bone marrow Tonsils Lymph nodes Lymphatic System: The Spleen Essentially acts as a large lymph node (becomes larger during infections) Can include: Lymphocyte proliferation Immune surveillance and response Blood filtration Destruction of old or damaged red blood cells Recycling iron and globin Providing a reservoir for blood Providing a source of red blood cells in early fetal life Lymphatic System: Drainage Lymph drains back into venous circulation near the heart. However, the duct via which it drains depends on where in the body the lymph is from. Thoracic duct: Collects lymph from left head, neck, thorax and upper limb, & lower half of body 40cm long Right lymphatic duct: Collects lymph from right head, neck, thorax and upper limb. 1cm long  Part 4 – GI Gastrointestinal System GI: Overview The GI/digestive system is composed of the gastrointestinal tract (GIT), also known as the alimentary canal, and accessory organs/structures. Gastrointestinal tract– mouth, pharynx, oesophagus, stomach, small intestine, and large intestine. Accessory digestive organs/structure – teeth, tongue, salivary glands, gallbladder, liver, and pancreas. Its functions include: Ingestion – Taking food into the digestive tract. Digestion Mechanical, chewing, mixing, and churning food. Chemical, catabolic breakdown of food. Absorption – Taking up the soluble digestion products into the body's cells Defecation – Elimination of indigestible material Adapted from slides by Dr Rehab Eltarhoni GI: Organisation Gastrointestinal (GI) tract commences at the buccal cavity of the mouth and terminates at the anus. It can be divided into: Upper GI tract Upper GI tract Mouth/Oral Cavity Pharynx Oesophagus Lower GI tract Stomach Small intestines (duodenum) Lower GI tract Small intestines (jejunum, ileum) Large intestines Rectum Anal canal It can also be divided according to its embryological origins: Foregut Distal oesophagus, stomach, duodenum Midgut Duodenum, jejunum, ileum, ascending colon, transverse colon Hindgut Transverse colon, descending colon, sigmoid colon, rectum Adapted from slides by Dr Rehab Eltarhoni Surface Anatomy: Quadrants Surface Anatomy: 9 Regions GI: Mouth The mouth functions to break down food into smaller parts. Chemical digestion Mechanically digestion The main structures of the mouth include: Tongue Salivary glands The process of chemical digestion through the secretion of several enzymes Teeth Mechanically break food down into smaller particles for easier swallowing and ingestion Adapted from slides by Dr Rehab Eltarhoni GI: Pharynx & Oesophagus The pharynx, also known as the throat. A tube extends behind the nasal and oral cavities, then gives a branch to the larynx (voice box) and carries on to the oesophagus. Oesophagus: A long fibromuscular tube extending from the pharynx to the stomach. It consists of muscles that run both longitudinally and circularly. Transports food and liquids from the mouth down to the stomach. This is accomplished by periodic contractions (peristalsis) Adapted from slides by Dr Rehab Eltarhoni GI: Stomach J- or C shaped muscular sac Located between the oesophagus and the duodenum. The main parts of the stomach. Cardiac notch Fundus Body Pyloric part Greater and lesser curvatures Adapted from slides by Dr Rehab Eltarhoni GI: Small Intestine The small intestine extends from the pylorus to the ileocecal valve. The small intestine is composed of the duodenum, jejunum, and ileum. The primary function of the small intestine is the absorption of vitamins and nutrients, including electrolytes, iron, carbohydrates, proteins, and fats. Adapted from slides by Dr Rehab Eltarhoni GI: Large Intestine The large intestine extends from the terminal ileum at the ileocecal valve to the rectum. At the terminal ileum, the large intestine becomes the ascending colon, the transverse colon, and then the descending colon. Following the descending colon is the sigmoid colon and the rectum. The main functions of the large intestine are: Water absorption, Producing and absorbing vitamins Forming and propelling feces toward the rectum for elimination. Adapted from slides by Dr Rehab Eltarhoni GI: Accessory Organ – Liver The largest internal organ. Multiple metabolic activities Storage of glycogen Secretion of bile Lies in the right hypochondrium and epigastric regions and extend into left hypochondrium. Adapted from slides by Dr Rehab Eltarhoni GI: Accessory Organ – Gallbladder The gallbladder is a pear‐shaped, attached to the liver that serves as a storage facility for bile. When a large or fatty meal is consumed, nerve and chemical signals cause the gallbladder to contract. This contraction releases bile into the digestive system. The biliary tree comprises The common hepatic duct The cystic duct The common bile duct Adapted from slides by Dr Rehab Eltarhoni GI: Accessory Organ – Pancreas The pancreas is a gland has head, neck, body, tail and uncinate process. The functions include the production of: Insulin Glucagon Hormones Somatostatin Trypsin Lipase Enzymes Amylase These enzymes help digest carbohydrates, proteins, and fats. Adapted from slides by Dr Rehab Eltarhoni  Part 5 – GU Urinary System Urinary System: Overview The urinary system can be divided into: Upper Urinary Tract: Kidneys and ureters Lower Urinary Tract: Bladder and urethra The urinary system functions to produce and remove waste products from the body as urine. It also aids in regulating the body’s water content. All production of urine and osmoregulation happens in the kidneys. The ureters, bladder, and urethra are part of the removal of urine. The ureters extend from each kidney towards the bladder. The bladder is essentially a large muscular bag that can inflate when filled with urine and deflates when expelling urine into the urethra. The urethra transports urine from the bladder to outside the body. Length varies between sexes. Kidneys: Structure Within the kidney is where urine production occurs. The functional units are known as a nephrons. This is where filtration and urine production occurs. They mostly lie within the renal cortex. The degree at which they extend into the medulla can vary. The renal cortex surrounds the kidney and extends inwards at points to form the renal columns within the renal medulla. These columns divide the renal medulla into triangular-shaped tissues known as renal pyramids. The renal medullas collect urine and transfer them into the minor calyces and onto the major calyces. These drain into the widened area of the kidney known as the renal pelvis. The renal pelvis leaves the kidney at the hilum and thins to continue as the ureter. Urinary System: Relationships Kidneys lie in the retroperitoneal space of the abdomen, pressed against the posterior abdominal wall. They are protected by the lower ribs and surrounding musculature and viscera. The ureters travel retroperitoneally towards the bladder. Due to the anatomy around them they are sometimes narrower at specific points – important clinically. The bladder lies in the pelvis: In males it is directly anterior to the rectum. In females it is directly anterior to the vagina and uterus. Urethra: Males vs. Females Structure of kidneys, ureters, and bladder remain largely the same between males and females. Female urethra is shorter than male urethra. Urethra has some adaptations/changes: In males, the urethra is surrounded by the prostate is present before passing through the pelvic floor to the penis externally. In females, the urethra passes though the pelvic floor. Urethra has two (directly) associated muscles: Internal sphincter Keeps bladder neck and urethra free of urine until pressure builds in the bladder. Involuntary smooth muscle. External sphincter Controls release of urine from the urethra. Voluntary skeletal muscle – can prevent urination even when involuntary controls are trying to empty the bladder.  Part 5 – GU Reproductive System Male and Female: Use of binary terms in anatomy and physiology ▪ Terms “Male” and “Female” are used to ▪ The gender of an individual is not always describe the anatomical structures and related to either their genetic or hormone profiles usually associated with reproductive phenotype. individuals with an XX or YY background ▪ I.e. biological sex ▪ Language in teaching will be binary and used to describe biological sex rather than ▪ This biological sex is usually assigned at gender. birth on the basis of external genitalia ▪ Where appropriate, gender-neutral rather than genetic testing. language will be used, introduced and ▪ Genetic, anatomical, and hormonal discussed differences do occur, and will affect individuals. Adapted from slides by Dr Allyson Clelland Males: Overview Male Reproductive System composed of a variety of structures: Testis (plural: Testes) – Paired – External The region of sperm production. Scrotum – External Contains the testes and associated structures. Aids in temperature regulation of the testes. Epididymis – Paired – External Stores mature spermatozoa Ductus deferens – Paired – External → Internal Transports the sperm towards the ejaculatory duct during ejaculation. Seminal Vesicles – Paired – Internal Accessory glands that contributes fluid to the ejaculate. Ejaculatory ducts – Paired – Internal Fusion of a ductus deferens and a seminal vesicle to transmit ejaculate to the urethra. Prostate – Internal Accessory gland that contributes fluid to the ejaculate. Urethra – Internal → External Collects formed ejaculate and transmits it along the penis to exit at the urethral orifice. Also transmits urine from the bladder (outside of sexual stimulation). Bulbo-urethral glands – Paired – Internal Accessory glands that lubricate the urethra during sexual stimulation before ejaculation. Penis – External (roots Internal) External genitalia of the male reproductive system formed by erectile tissues. Directs semen our of the urethra and into the vagina during copulation. Directs urine out of the urethra. Males: Surface Anatomy Females: Overview Composed of a variety of structures: Ovary – Paired – Internal Site of egg production. Ovulates mature eggs towards the uterine tubes. Uterine tube – Paired – Internal ‘Catch’ ovulated eggs. Transports eggs/zygote to the uterus. Fertilisation usually occurs within these tubes. Uterus – Internal Muscular organ that can expand during pregnancy. Where implantation of the zygote should occur and the foetus grows. Cervix – Internal Inferior aspect of the uterus and boundary between uterus and vagina. Important clinically. Vagina – Internal Copulatory organ for sperm to be directed to and enter the uterus. Vulva – External External genitalia composed of clitoris, labia minora, and labia majora. Has underlying erectile tissue in the form of the bulbs of the vestibule. Clitoris – External External genitalia of the female reproductive system composed of erectile tissues. Greater vestibular glands – Paired – Internal Accessory glands located at the inferior pole of the bulbs of the vestibule. Provides lubrication to the vestibule of the vagina during sexual stimulation. Females: Surface Anatomy True Pelvis: Pelvic Cavity Pelvic Floor: Overview Pelvic floor (also known as pelvic diaphragm) is composed of muscles and fascia. Supports pelvic and abdominal contents. Important in biological processes such as defecation, micturition, and childbirth – Has clinical significance. Has openings to allow the passage of structures from the pelvic cavity to the perineum and external orifices. These include the urogenital hiatus (urethra and vagina in females, urethra in males) and rectal hiatus (for rectum in both sexes). Inferiorly it is supported by the perineum and its associated structures. Perineum: Overview Perineum is located inferior to the pelvic floor (levator ani and coccygeus muscles), between the thighs. Perineum inferior border is the pelvic outlet, but divided into two triangles by an imaginary line from each ischial tuberosity: Urogenital triangle – Located anteriorly, orientated inferiorly and anteriorly. Anal triangle – Located posteriorly, orientated inferiorly and posteriorly at ~120° angle against the urogenital triangle. Important to support the pelvic floor integrity and also allows for attachment of the external genitalia and other clinical significance. Part 6 – Neuroendocrine Nervous System Nervous: Overview The nervous system can be divided either: Structurally into the: Central nervous system (CNS) – Consisting of the brain and spinal cord Peripheral nervous system (PNS) – The remainder of the nervous system outside of the CNS. Functionally into the: Somatic nervous system (SNS) and Autonomic nervous system (ANS). The CNS acts as the control centre, sending and receiving information to and from muscles, glands, organs and other systems in the body through the Peripheral Nervous System Adapted from slides by Dr Anthony Adefolaju Nervous: Divisions Major divisions: Forebrain [prosencephalon] Midbrain [mesencephalon] Hindbrain [rhombencephalon] The forebrain comprises of the: Cerebrum – Executive decisions, intellectual functions, memory storage and processing, and initiation and coordination of movement Diencephalon – Composed of the thalamus, hypothalamus, pituitary gland and others Thalamus – Relay and processing centre for sensory data Hypothalamus – Controls emotions and the production of hormones The midbrain is an important relay centre in the auditory and visual pathways and serves important functions in motor movement, particularly control of eye movements. The hindbrain includes the: Cerebellum – Helps maintain posture, balance, and equilibrium Pons and Medulla oblongata – Both an important relay centre for information travelling between the spinal cord and the cerebrum and cerebellum and contain autonomic centres for the regulation of visceral functions Adapted from slides by Dr Anthony Adefolaju Nervous: Structure Adapted from slides by Dr Anthony Adefolaju Nervous: Terminology A collection of neuron cell bodies in the CNS = nucleus A collection of nerve cell bodies in the PNS are ganglia (e.g. dorsal root ganglia and autonomic ganglia) A bundle of nerve fibres (axons) within the CNS connecting neighbouring or distant nuclei of the cerebral cortex is a tract. A bundle of nerve fibres (axons) within the PNS is a Nerve. Nervous: Nerves 12 pairs of cranial nerves: 1. I – Olfactory 2. II – Optic 3. III – Oculomotor 4. IV – Trochlear 5. V – Trigeminal 31 pairs of spinal nerves: 6. VI – Abducens 8 Cervical 7. VII – Facial 12 Thoracic 8. VIII – Vestibulocochlear 5 Lumbar 9. VIIII or IX – Glossopharyngeal 5 Sacral 10. X – Vagus 1 Coccygeal 11. XI – Accessory 12. XII – Hypoglossal Adapted from slides by Dr Anthony Adefolaju Nervous: ANS: P(S)NS vs. SNS Autonomic Nervous System operates without conscious control and is responsible for involuntary or unconscious activity such as: Heart rate, breathing, gland secretion, organ function, blood pressure, digestion, etc. Can be divided into: Parasympathetic Nervous System (PSNS/PNS) Rest and Digest. Concerned with conserving energy. Sympathetic Nervous System (SNS) Fight, flight or Fright. Activated during exercise, excitement, and emergencies. Adapted from slides by Dr Anthony Adefolaju Part 6 – Neuroendocrine Endocrine System Endocrine: Overview An endocrine gland is a gland which secretes hormones directly into the blood. An exocrine gland secretes substances through ducts onto external surfaces or internal passageways that connect to the exterior. E.g Sweat glands, Salivary glands, Mammary glands, Sebaceous glands The endocrine system is made up of glands that produce and secrete hormones. Hormones are chemical substances produced in the body to regulate the activity of cells or organs. These hormones regulate the body's growth, metabolism (the numerous physical and chemical processes of the body), and sexual development and function. Function similar to nervous system in that they are both messengers. Endocrine glands/organs include: The Hypothalamus – In Brain Pituitary gland – In Brain Pineal gland – In Brain Thyroid gland – In neck Parathyroid glands – In neck Adrenal glands – In abdomen, above kidneys Thymus – Only usually in children, gone by adulthood Placenta – During pregnancy The gonads (testes/ovaries) – Reproductive system Pancreas – GI system Adapted from slides by Rachel Jones  Part 1 – Overview Body Systems & Cavities Part 2 – MSK & Skin Skeletal System Muscular System Integumentary System Learning Part 3 – CVR & Lymphatics Cardiovascular System Outcomes Respiratory System Lymphatic System Part 4 – GI Gastrointestinal System Part 5 – GU Urinary System Reproductive System Part 6 – Neuroendocrine Nervous System Endocrine System  Learning Outcomes: Learning M1.I.COR.ANA2 – Summarise the anatomy and function of each system of the body. Outcomes