Directional terms and anatomy

Introduction and Cortical Control

• Correct anatomical terms are important in locating body regions and components, as well as describing body movements.

Directional Terms

• Superior/inferior refers to the axial skeleton; superior means higher or cranial, and inferior means lower or caudal.
• Proximal/distal refers to locations on the appendicular skeleton; proximal means closer, and distal means furthest.
• Medial means closer to the midline, and lateral means further from the midline.
• Anterior means front or ventral, and posterior means back or dorsal.
• Superficial means close to the surface, and deep means away from the surface.
• Supine means face up, and prone means face down.

Take Home Messages

• The anatomical position has the person standing upright with arms by their side, palms facing forward.
• The body has three main viewable planes, which are frontal, sagittal, and transverse.
• Directional terms help to describe and localize injuries on the body.
• Superior/inferior only refer to locations on the axial skeleton.
• Proximal/distal only refer to locations on the appendicular skeleton.
• Body regions receive their names from nearby anatomical structures, which allows for damage to be precisely described.

Cerebrum Structure

• The cerebrum comprises gray matter on the surface and white matter inside, along with basal nuclei in the center.
• Gyri (hills) and sulci (valleys) are surface features, including the central and lateral sulci.
• The lobes include frontal, parietal, temporal, occipital, and insula.

Cerebrum Functions

• Gray matter is where the thinking takes place, composed of cell bodies.
• White matter acts as the communication side of the brain, consisting of myelinated axons.
• Basal nuclei help coordinate and generate smooth movement, and are essentially islands of gray matter.
• Cerebral hemispheres have contralateral control where the right side of the brain controls the left side of the body, and vice versa.
• The cortex has different areas specialized for different tasks, including the location of the conscious mind.
• The cortex handles conscious thought processes, intellectual functions, memory, sensory input localization, and skeletal muscle activity regulation.
• Sensory, association, and motor areas are the 3 functional areas of the cerebral hemisphere's cortex.
• Each hemisphere's cortex processes sensory and motor functions for the opposite side of the body.

Surfaces of the Brain

• Sulci are the 'grooves' while gyri are the raised portions of the brain.
• Gray matter contains neuron dendrites and somas – the site for signal processing.
• White matter contains axons, sending signals from one place to another.
• The cerebrum consists of frontal, parietal, temporal, occipital, and insula lobes.
• Each brain hemisphere controls the contralateral side of the body.

Sensory Areas

• General senses involve somatosensory stimuli like pain, touch, and temperature, providing sensory input from all over the body.
• Special senses include vision, hearing, taste, smell, and balance.
• The primary somatosensory cortex is a general sensory area located in the post-central gyrus of the parietal lobes.
• The primary somatosensory cortex receives somatosensory information (pain, touch, temperature, pressure, vibration) and information about body position from general sensory receptors and proprioceptors.
• Somatotopic organization indicates that stimulus destination matches the origin site.
• The amount of sensory cortex for a body region relates to sensitivity, needing more area to analyze incoming information.
• The somatosensory association cortex interprets sensory information by comparing it to memories, and it is located posterior to the primary somatosensory cortex in the parietal lobe.
• Damage to the somatosensory association cortex causes loss of ability to identify objects by touch alone.
• Visual areas are located in the occipital lobes; the primary visual cortex receives impulses from the retinas (photoreceptors).
• Damage to the visual cortex causes functional blindness, while damage to the visual association areas results in failure to recognize objects.
• Primary auditory cortex and auditory association areas are located in the temporal lobes.
• The primary auditory cortex receives impulses from the inner ear; damage causes deafness.
• Auditory association areas interprets auditory stimuli, and damage causes inability to recognize sounds.
• The temporal lobe contains the olfactory cortex; damage impairs conscious awareness of odor.
• The insula has he gustatory and visceral cortices; gustatory cortex perceives taste, while the visceral cortex perceives visceral sensations (e.g., upset stomach, full bladder).
• The vestibular or equilibrium cortex lies within the insula, creating awareness of balance.

General Interpretive Area

• The general interpretive area/Wernicke's area integrates sensory, visual, and auditory information for recognition and understanding.
• Damage results in aphasia, impairing language understanding typically found in the left temporal lobe, linked to Broca's area.

Multimodal Association Areas

• The prefrontal cortex holds multimodal association areas where the most complicated information from all association areas is located.
• Involved in intellect, complex learning abilities, recall, and personality.
• Working memory involves abstract ideas, judgement, reasoning, and planning.
• Maturation is connected to environmental interaction over time.

Sensory Areas

• General senses possess receptors all over the body and are processed in somatosensory areas.
• Special senses possess a specific structure for their detection (e.g., eyes for vision) with their own brain areas for information processing.
• Primary areas detect the sensation while the association areas handle the processing and recognition.
• Wernicke's area is specific to language understanding.

Primary Motor Cortex

• The pre-central gyrus of the frontal lobe includes the primary motor cortex, which plans and initiates voluntary motor activity.
• It contains cell bodies of upper motor neurons of somatic motor pathways, which direct skeletal muscle movement.
• The somatic motor pathways control the contralateral side of the body, with the right primary motor cortex controlling skeletal muscles on the left, and vice versa.
• Specific areas are dedicated to controlling specific body parts with somatotopic organization.
• An area's complexity and precision determine the amount of motor cortex devoted.

Other Motor Areas

• The premotor area (motor association area) coordinates muscles involved in learned motor activity, like typing.
• Broca's area oversees speech generation, only in one hemisphere.
• The frontal eye field directs muscles for eye movements.
• Each of these three areas contains memory banks for complex motor activities, coordinates the movement of several muscle groups, and acts through the primary motor cortex.
• Damage to the primary motor cortex paralyzes skeletal muscles, blocking voluntary but not reflexive movement.
• Damage to the premotor cortex results in loss of programmed motor skills, but discrete movements remain unhindered.

The Cerebellum

• The cerebellum shares many structural and functional similarities with the cerebrum.
• The cerebellum features two hemispheres, each with lobes (anterior and posterior) with a superficial cortex of gray matter containing sensory and motor maps.
• Deep white matter branches like a tree (arbor vitae) is found in the cerebellum with peduncles that include paired fiber tracts.

Cerebellar Function

• The cerebellum coordinates motor activities started by the primary motor cortex, as the motor cortex informs the cerebellum of its plans.
• Proprioceptors throughout the body, along with visual and equilibrium pathways supply the cerebellum with sensory information that evaluates body position and movement.
• The cerebellum compares plans with actions and adjusts the output of the primary motor cortex, so muscle actions are balanced, smooth, and coordinated.
• Posture and balance are maintained by monitoring and adjusting muscle tone and body position.
• The cerebellum does not control the PMC but helps to check motor plans from the PMC against inputs, then adjusts as needed.

Take Home Messages

• The primary motor cortex is responsible for initiating voluntary contralateral muscle control
• There is a somatotopic organisation in the primary motor area
• There are additional motor areas that work in concert with the primary motor area to allow for memory banks and co-ordination of movement

Diencephalon Components

• The thalamus, hypothalamus, and epithalamus comprise the diencephalon.
• The thalamus is a bilateral, egg-shaped collection of nuclei that acts as a "gateway to the cerebral cortex," relaying sensory information.

Thalamic Function

• The thalamus sorts and edits sensory information before sending it to the cerebral cortex, such as somatosensory information.
• The thalamus conducts impulses between the cerebral motor areas and cerebellum.
• The thalamus is involved in cortical arousal (alertness), learning, and memory processing.
• The hypothalamus is located below the thalamus, holding many nuclei and vital functions in a small structure.
• As the chief integration center of the ANS, it regulates by controlling brain stem and spinal cord centers (cardiac and regulatory functions).
• The hypothalamus is a center for emotional responses as part of the limbic system.
• The hypothalamus monitors and regulates body temperature as the thermoregulatory center.
• Appetite and satiety are regulated with its control of food intake.
• It regulates water balance by monitoring plasma Na+ concentration and triggering ADH release and promoting thirst to reduce urine output.
• The hypothalamus controls sleep-wake cycles (biological clock) and controls endocrine system functioning (primarily via the pituitary gland).
• The epithalamus is the most posterior portion of the diencephalon.
• The pineal gland incorporates the epithalamus, producing melatonin to induce sleep.
• It helps the hypothalamus regulate sleep-wake cycles.
• Thalamus directs incoming information where it is needed acting as a relay station.
• Hypothalamus has a major role in the autonomic nervous system's control, a big part of the endocrine system, and regulating body homeostasis.
• Epithalamus (particular the pineal gland) helps to regulate your sleep-wake cycle.

Identifying the Brain Stem

• The brain stem includes the midbrain (mesencephalon), pons, and medulla oblongata
• The midbrain, also known as the mesencephalon, has visual and auditory reflex centers coordinating head and eye movements while the substantia nigra contains neurons that produce dopamine, which controls the cerebral basal nuclei.
• The substantia nigra degenerates in Parkinson's disease, and connects cranial nerves involved in eye movements.

Functions of the Pons

• The pons functions as a 'bridge,' containing fiber tracts, that relay sensory information from the thalamus to the cerebellum, and the motor cortex to the cerebellum.
• The pons contains somatic and visceral motor nuclei for sleep, hearing, taste, eye movement, facial expression and sensation, respiratory rhythms, swallowing, bladder control and posture.

Medulla Oblongata

• The medulla oblongata is the inferior part of the brainstem that blends into the spinal cord.
• The medulla oblongata has conducting pathways between the brain and spinal cord, relaying sensory information to the thalamus, other portions of the brain stem, and the cerebellum.
• Medulla oblongata has autonomic reflex centers essential for survival, including cardiovascular and respiratory centers.
• The cardiovascular center controls rate and force of hear contraction; the vasomotor center adjusts blood vessel diameter.
• Medulla oblongata controls rate and depth of breathing in the respiratory center; vomitting, hiccupping, swallowing, salivation, coughing, sneezing, speech and GI secretion from centers regulating visceral functions.
• Mid-brain is involved in reflexive response to visual and auditory cues.
• The pons acts as a relay with nuclei involved in somatic and visceral processes.
• The hypothalamus contains the cardiovascular and respiratory centres controlling heart rate and breathing.

Limbic System and Reticular Formation

• The limbic system is 'emotional brain' whereas the reticular formation allows for 'consciousness'/awareness; damage to reticular formation results in coma.
• The limbic system structures include the cerebral and hypothalamic nuclei with the hippocampus, which is linked by the fornix.

Limbic Functions

• It facilitates memory storage and retrieval via the hippocampus as the emotional brain forms.
• It enables "conscious awareness of emotional states" connecting the prefrontal cortex with the hypothalamus. - Logic and reasoning helps to consciously be aware of the emotions.
• It enables physical response to emotional states, which elicits fear response via hypothalamus and ANS.
• The reticular formation extends through the central core of the brain stem with projection fibers to the cerebral cortex, thalamus, and more of the brain as a sensory filter, cutting 99% of sensory input.
• It filters out repetitive, familiar, or weak signals.
• It allows strong or unusual stimuli to reach the cerebral cortex and allows the consciousness of stimuli.
• The reticular activating system maintains cortical alertness (consciousness by regulating sensory input to the cerebrum, which is inhibited by sleep centers in the hypothalamus and depressed by alcohol.
• Damage to the reticular formation can result in a coma.
• The limbic system results in a relationship between feelings and thoughts.
• The reticular formation works as a filter, allowing pertinent information to be focused on.

Brain Dysfunction

• Brain dysfunctions are disorders affecting the appropriate functioning of the brain.
• Neurodegenerative including Alzheimer and Parkinson diseases may come from genetic or enviromental factors that cause abnormal portein buildup. Progressively cause memory loss, decline in cognition, impairement in movement, and changes in mood or behavior.
• A traumatic brain injury due to accidents, falls, or violence could result in cognitive deficits, memory loss, emotional instablility, physical impairements, and can be fatal.
• A stroke due to deprivation of oxygen caused by ruptures within the blood vessels can cause paraylsis, language difficulties, and memory problems.
• Brain injuries from genetics, infection, or abormalities. Can cause seizures, cognitive decline, and/or physical harm.
• Genetics, imbalances in brain chemistry, environmental stressors, and trauma can be the causes of mental health including schizophrenia, bipolar disorder, and depression. These result in thoughts, moods, and behaviors that can disrupt daily life.
• Bacterial, viral and fungal infections can cause encephatilis and meningitis including fever, seziures, and cognitive impairment.
• ADHD and learning disablities may come from genetic factors, developmental issues, and or environmental influences. Can cause academic difficulties, and poor attention.

Defense of the Brain

• The combination of structures that work together protect the brain.
• The meninges, cerebrospinal fluid (CSF), and the blood-brain barrier.

Meninges

• Meninges are three layers of connective tissue membranes that surround the brain and spinal cord.
• Outer layer is the dura mater for support and protection.
• Middle is the arachnoid mater for cushioning.
• Innermost layer is the Pia mater for the delivery of nutrients and adherence to the brain.
• The spaces are defined as: epidural space between skull and dura mater, subdural space between the dura mater and the arachnoid mater, subarachnoid space between the arachnoid mater and the pia mater.

Cerebrospinal Fluid (CSF)

• Clear fluid that surrounds and cushions brain and spinal cord while playing key roles in defending the brain.
• CSF helps to prevent injury from trauma, provides buoyancy, waste removal and maintains chemical stability.

Blood-Brain Barrier (BBB)

• Barrier formed by tightly packed endothelial cells in the blood vessels of the brain.
• Prevents harmful substances from entering while ensuring the necessary nutrients and gases are available.
• Selective transport and is used homeostatically.
• Safeguard the brain from physical damage, infections, toxins, and other harmful elements, ensuring its proper function and overall health.
• Cerebrospinal fluid (CSF) is produced by the choroid plexus located within the brain's ventricles.
• Four ventricles, 2 lateral, a 3rd, and 4th, act as a communication system.
• The flow moves from the lateral ventricles through the interventricular foramina to the third ventricle, travels to the cerebral aqueduct to the fourth ventricle, which drains into the subarachnoid space through the median aperture and lateral apertures
• CSF is absorbed in the arachnoid.
• Ventricles are in the lateral hemispheres (deep), is in the diencephalon (midline, 3rd), and the 4th, being in the brainstem (posterior).

Brain Arteries

• The vertebral arteries and carotid arteries supply blood and oxygen to the brain
• Internal carotid arteries branch into the skull and circulate blood to the front of the brain.
• The vertebral arteries spinal collumn flows to where they join and create the brain which supplies the brain with blood to the rear portions.
• A circle of Willis allows blood to come from the front and connect through major arteries by communicating with one another as a loop of blood vessels.
• Venous drainage drains to sigmodal sin and to the internal jugular vein.

Circle of Willis

• The cerebral arterial circle (circle of Willis) acts a safety net and is a collateral for blood flow, and is a ringlike network.

Head Injury

• Raised intracranial pressure from increased components of solid matter can damange blood vessels, and or cause a space filling lesion.
• Damage of tissue because compresses neural tissue and blood pressure, as well as cause inflammation.
• Bleeding may cause a re-bleed - Venous would increase bleeding may week after.
• Brains can be complient, and some amount of CSF can rise befroe ICP increases.
• Consciousness decreases.

Stroke

• A stroke stems from blood flow interruption, due to blockage or hemorragic.
• Hemorragic strokes may lead to death more likley, cause parts deprivation and hypoxia, and edema permanently may affect other areas.
• Strokes caused by infarctions happen when areas undergo liquifactinvercosis.
• Ischemia happens when blood restores.
• Stroke can also happen in Evolution where it turns into a stroke, with or without warnings.

Haemorrhagic Stroke

• Hemorrhagic strikes happens in 10-15% of all strokes.
• Bleeding can occur within the brain of or meningial places surrounding it.
• Hard to differentaite between the other stroke.
• Look mostly ill wit includde features.

Ischemic Strokes

• Common in hemorrhagic strokes.
• Main symptom is irritation from the menigeal place and stiff neck after hemorrhagif stroke.
• Common pattern from left side: anasia, impairede speech, impairent and decreased movement and sesnory loss.

Topic 3 - Bones and Joints

• Bones are involved in movement, blood cell production and storage of minerals, provide the support and protection.
• Bones, Joints, ligaments, and cartilage are apart of the skeletal system.
• Fibrous collagent tissue to help connect bones.
• Three types of cartilage include elastic with flexibility, fibrocartilage with shock absorbtion, and hyaline with smooth movement.

Classifying Bone Characteristics

• Bone has outer layer smooth as well as compact as well as inner layer.
• Outer layer has a periosteum that has nerves and blood vessels.
• Innermost has connective tissue membrane.
• Bone is made of osteons that are arranged with tissues, this is where blood, nerves and matrix circle.

Different Class of Bones

• Most compact, with a lot shaft and some spaces.
• Trabacula and are arranged with forces from transers and weight, made the spongy bone in light weights
• Long bones are longer than width, with short bones having similar width lengths.
• Flat bones have pelvises, skulls, and ribs while irregulate bones have vertebrae.
• The shaft diaphases with bone marrow inside, close to medials and distal. The bone marrow of yellow turns redder as we age.
• Each made to be spongey and strong with the forces of with stand it.

Remodelling

• Create, maintain and help to create bone matrix and tissue
• Periosteium membrane helps line it and to support the outside.

Factors Affecting Rate of Remodeling

• Calcum is added
• Collagen synthesis and stimulates osteoblast activity as well as with absorption.

Fractures

• When broken a fracture will happen, whether protrudes, comminuted or greenstick.
• It also will be treated accordingly in order to reduce pain, immbolize it and to rehabilitate.

Bone Repairs

• Bone repairs through hematomas, forms calluses, helps to create forms.
• Bones will then remodeled.

Joint Classifications

• The two bone come together.
• Classified according to ammount of movement and or movement and structurals
• Immovable - this is called a synarthrotic joint, and allows for no movement, such as that between the bones of the skull
• Semi-movable - this is called an amphiarthrotic joint, helps joint is between both immovable and freely movable and vertebrae joints.
• Fibrous and or with cartliage.
• Synovial are are more complicated that is seen with knees more often or with other parts.

Joints and Structues

• Additional structures with fibrocartilage and to absorb shock. Have fat tissues with synovial fluid to help smooth the joint.

Classing Synovial Joints

• Able to name, demonstrate and explain movement permitted by the six major synovial joints. include the kinds such as saddle and hingle.

Identifying Muscle Types

• Muscle tisue is speacilized for contraction with several main areas.
• Includes body movements, stabilizes joints, body position, and heat. The include several secondar functions and to control pupil size.
• Types of muscle include cardiac and sketeal.

Muscle Structure

• Complex and involves connective tissues with a lot of blood vesels.
• Includes bundles of fibers and sheathed
• muscle is able to stretch, contract and elasticity.
• The muscles are at micro level and are in rows such as sarcomere will be disucssed later within muscles. -There a connective tissur and fiber muscles being wrapped in this tissue,
• smallest has units and are wrapped in elasticity.

Neural Control and Junctions

• They work through and a set amount. With signals from and to muscles they reach the junctions.
  • Voltage gated movement is triggered here. It involves and potential triggers along the tubles and other stuff.
• arrival, a releas of neurotransmitter. -muscle action has the electrical to causte the release where its at. -thick with heads and are pulled and are active by sites. and -release at what starts. -the action is initiated and has ATP to break crosses.

Muscle Contraction

• It relies on clacium usage as well and has to grab the sites using the ATP at some places.
• Has to blend to pull more back around.

Rigor mortis

• Cross bridge detachement is requred and takes hours after death to to set into place and the is broken. Is in the release of calcium and where it goes.

Muscle Contraction Types

• They do so in groups to mazimize efficiency.
• These interact to form roles where they have a funtional group such as promoving.
• All helps for a part to help limb to move.
• May by istonic or dynamic to move a load with different positions.
  • Can do some dynamic movements for the muscles to lengthen as there is some heaviness.
  • All have static contracitons

Key Take-aways

• Mucles do so to move parts along. They then either get changed or not and have so.
• Each mucles either moves a section to give rise to movement through what is there.

Neurotransmitters

• Four types of include types in nerve control
• In cns are chemicals.
• Ach = Cholinergic
  • wide spread is PNS - central nervous center.
• Has lots to add

CNS Types

• Monoamindes are a class of chemicals with nero and many aspects.
• Diverse roles in all illness.
• Target in many places from imbalance effects
• Acid excitability also has a high range.

Normal vs Disease Progression + NT changes

• With things we have to see what we see there. Each area depends on areas.
• Brain to see if things can happen.