• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
CNS (Central Nervous System)
 

CNS (Central Nervous System)

on

  • 1,133 views

ZOO211 Anatomy & Physiology Finals Coverage under Sr. Salazar

ZOO211 Anatomy & Physiology Finals Coverage under Sr. Salazar

Statistics

Views

Total Views
1,133
Views on SlideShare
1,133
Embed Views
0

Actions

Likes
1
Downloads
101
Comments
0

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    CNS (Central Nervous System) CNS (Central Nervous System) Presentation Transcript

    • MAJOR DIVISIONS OF THE NERVOUS SYSTEM
    • FUNCTION
      • Functions of the Nervous System
      • Control and communication system
      • Monitors Changes inside and outside the
      • body (sensory input)
      • Processes and interprets sensory input and
      • makes decisions (integration)
      • Affects a response (motor output) by affecting
      • glands, muscles etc.
      • Works closely in conjunction with the endocrine system
    • NEURONS
      • Nerve Transmission
      • Neurons - Basic anatomic and functional unit of the nervous system
      • Respond to sensory and chemical stimuli,
      • conduct impulses and release specific chemical regulators
      • A nerve impulse is a wave of electrical charge sweeping from neuron to neuron
      • The gap lying between one neuron and the next is the synapse
      • Neurotransmitters move across the synapse
      • where they excite, inhibit or modify
    • MENINGES
      • 3 layers that lay directly on the surface of the brain tissue (parenchyma) and spinal cord. Offer a cushioning effect.
      • • Dura Mater - outer most layer that is thick and fibrous, that lines
      • the interior of the skull.
      • • Arachnoid - middle layer, is extremely thin and loosely encloses
      • the brain
      • • Pia Mater - inner most, mesh like and very vascular. It follows the convolutions of the brain
      • Meninges
      • • Spaces of the meninges - extradural, subdural and subarachnoid
    • VENTRICULAR SYSTEM
      • Produces (~ 500mL/day) and circulates (~ 150mL) CSF.
      • • CSF is usually a clear colourless fluid that acts as a shock absorber
      • • The ventricular system is connected to the subarachnoid space (SAS)
      • • 3 main compartments - 2 lateral ventricles, 1 third ventricle and
      • 1 fourth ventricle
      • • CSF is produced by the choroid plexus in each ventricle
      • • CSF is reabsorbed into the venous blood flow via the arachnoid villi
      • • Arachnoid villi are small granulations that project from the SAS into the venous outlets of the brain.
    • What are the major parts of the nervous system?
      • The major divisions of the nervous system include:
      • Central Nervous System (CNS)
      • Peripheral Nervous System (PNS)
      • Autonomic Nervous System (ANS)
      • a. sympathetic nervous system
      • b. parasympathetic nervous system
    • What are the major parts of the nervous system?
      • 1. Central Nervous System
      • consists of the brain and the spinal cord
      • functions as a switchboard that controls and coordinates the activities of the whole nervous system
    • What are the major parts of the nervous system?
      • 2. Peripheral Nervous System
      • carries all the messages sent between the central nervous system and the rest of the body
    • What are the major parts of the nervous system?
      • 3. Autonomic nervous system
      • controls involuntary activity such as the action of the heart and glands, breathing, digestive processes, and reflex actions
    • What are the major parts of the nervous system?
      • 3. Autonomic nervous system
      • a. sympathetic system
      • responds to the body’s needs during increased activity and in emergencies.
      • controls heartbeat, blood circulation, respiration and other unconscious activities.
    • What are the major parts of the nervous system?
      • 3. Autonomic nervous system
      • b.parasympathetic system
      • opposes the actions of the sympathetic system.
      • slows down heartbeat, diverts blood circulation, etc.
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • organ of thought and feeling
      • responsible for issuing nerve impulses, processing data, and the master control center over the body
      • divided into cerebrum, cerebellum and the brainstem
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • Cerebrum
      • forms the bulk of the brain
      • responsible for the higher thought processes such as memory, judgment and reason
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • a.1Parts of the Cerebrum
      • Frontal lobe
      • planning, consciousness, speech, memory, and reasoning
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • a.1Parts of the Cerebrum
      • Parietal lobe
      • houses the control centers for processing impulses related to the sense of touch; temperature, texture, size, shape and weight
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • a.1Parts of the Cerebrum
      • Occipital lobe
      • contains the centers responsible for sight.
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • a.1Parts of the Cerebrum
      • Temporal lobe
      • houses centers for the processing and correlation of the auditory (hearing) and olfactory (smell) senses.
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • b. Cerebellum
      • responsible for body balance, posture and the coordination of movement
      • receives, coordinates and modifies orders from the cerebrum
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • c. Brain stem
      • connects the cerebrum with the spinal cord
      • consists of the midbrain, pons, and medulla oblongata
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • Brain stem
      • pons – located between the midbrain and the medulla oblangata; connects the cerebellum and the cerebrum
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • Brain stem
      • medulla oblangata – lowest part of the brain stem; controls involuntary processes such as the heartbeat, breathing, digestion and body temperature regulation.
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Brain
      • Brain stem
      • Mid brain – the middle part of the three main divisions of the brain; helps control the movement of the eyes and the size of the pupils
    • PARTS OF THE CENTRAL NERVOUS SYSTEM AND THEIR FUNCTIONS
      • Spinal cord
      • allows signals to be sent from the brain to the parts of the body
      • receives messages from the parts of the body to the brain
      • acts as a coordinating center responsible for some simple reflexes
    • CRANIAL NERVES
    • CRANIAL NERVES
    • BLOOD SUPPLY
    • BRAIN BLOOD SUPPLY
      • INTERNAL CAROTID ARTERY
      • • Not all ICA occlusions become symptomatic. It depends on the
      • amount of collateral blood supply primarily from the C of W
      • • The degree of deficits vary, from asymptomatic to a catastrophic
      • infarction (similar to MCA
      • MIDDLE CEREBRAL ARTERY
      • • MCA is the largest branch that comes off the ICA
      • • It has deep branches that supply part of the internal capsule and
      • basal ganglia (putamen, caudate nucleus and globus pallidus)
      • • It passes out to the lateral surface of the cerebral hemisphere where
      • it supplies blood to the cortical areas of the temporal, frontal and
      • parietal lobes
    • The Endocrine System
      • Controls many body functions
        • exerts control by releasing special chemical substances into the blood called hormones
        • Hormones affect other endocrine glands or body systems
      • Derives its name from the fact that various glands release hormones directly into the blood, which in turn transports the hormones to target tissues via ducts.
    • The Endocrine System
      • Exocrine glands - transport their hormones to target tissues via ducts.
      • Endocrine Emergencies:
        • from common:
          • Diabetes
          • to the unusual:
            • Thyrotoxicosis
    • The Endocrine System
      • Consists of several glands located in various parts of the body.
      • Pituitary gland : a small gland located on a stalk hanging from the base of the brain - AKA
      • “ The Master Gland”
        • Primary function is to control other glands.
        • Produces many hormones.
        • Secretion is controlled by the hypothalamus in the base of the brain.
    • The Endocrine System
      • The Pituitary Gland is divided into 2 areas, which differ
        • structurally and functionally
        • each area has separate types of hormone production.
      • The two segments are:
        • Posterior Pituitary:
          • produces oxytocin and antidiuretic hormone ( ADH )
        • Anterior Pituitary:
          • produces thyroid-stimulating hormone ( TSH )
          • growth hormone ( GH )
          • adrenocorticotropin ( ACTH )
          • follicle-stimulating hormone ( FSH )
    • The Endocrine System
      • And even more…
        • luteinizing hormone ( LH )
        • prolactin
      • Let’s go over these one at a time...
      • Posterior Pituitary
        • Oxytocin (the natural form of pitocin)
          • stimulates gravid uterus
          • causes “let down” of milk from the breast.
        • ADH (vasopressin) causes the kidney to retain water.
    • The Endocrine System
      • Anterior Pituitary
        • Primarily regulates other endocrine glands
        • rarely a factor in endocrinological emergencies
        • TSH stimulates the thyroid gland to release its hormones, thus  metabolic rate
      • Anterior Pituitary…
        • Growth hormone ( GH )
          •  glucose usage
          •  consumption of fats as an energy source
        • ACTH stimulates the adrenal cortex to release its hormones
        • FSH & LH stimulates maturation & release of eggs from ovary.
    • The Endocrine System
      • The Thyroid Gland
        • lies in the anterior neck just below the larynyx.
        • Two lobes, located on either side of the trachea, connected by a narrow band of tissue called the isthmus .
        • Sacs inside the gland contain colloid
      • Within the colloid are the thyroid hormones:
        • thyroxine ( T4 )
        • triiodothyronine ( T3 )
          • When stimulated (by TSH or by cold), these are released into the circulatory system and  the metabolic rate.
        • “ C” cells within the thyroid produce the hormone calcitonin .
    • The Endocrine System
      • Calcitonin , when released, lowers the amount of calcium in the blood.
      • Inadequate levels of thyroid hormones = hypothyroidism, or Myxedema.
      • Myxedema symptoms:
        • Facial bloating
        • weakness
        • cold intolerance
        • lethargy
        • altered mental status
        • oily skin and hair
        • TX: replacement of thyroid hormone.
    • The Endocrine System
      • Increased thyroid hormone release causes hyperthyroidism, commonly called Graves’ disease.
        • Signs and symptoms:
          • insomnia, fatigue
          • tachycardia
          • hypertension
          • heat intolerance
          • weight loss
        • Long term hyperthyroidism:
          • Exopthalmos
            • bulging of the eyeballs (picture Barbara Bush)
          • In severe cases - a medical emergency called thyrotoxicosis can result.
    • The Endocrine System
      • Parathyroid Glands
        • small, pea-shaped glands, located in the neck near the thyroid
        • usually 4 - number can vary
        • regulate the level of calcium in the body
        • produce parathyroid hormone -  level of calcium in blood
        • Hypocalcemia can result if parathyroids are removed or destroyed.
    • The Endocrine System
      • Pancreas
        • a key gland located in the folds of the duodenum
        • has both endocrine and exocrine functions
        • secretes several key digestive enzymes
      • Islets of Langerhans
        • specialized tissues in which the endocrine functions of the pancreas occurs
        • include 3 types of cells:
          • alpha (  )
          • beta (  )
          • delta (  )
        • each secretes an important hormone.
    • The Endocrine System
      • Alpha (  ) cells release glucagon , essential for controlling blood glucose levels.
      • When blood glucose levels fall,  cells  the amount of glucagon in the blood .
      • The surge of glucagon stimulates the liver to release glucose stores (from glycogen and additional storage sites).
      • Also, glucagon stimulates the liver to manufacture glucose -
      • gluconeogenesis.
    • The Endocrine System
      • Beta Cells (  ) release insulin (antagonistic to glucagon).
      • Insulin  the rate at which various body cells take up glucose. Thus, insulin lowers the blood glucose level.
      • Insulin is rapidly broken down by the liver and must be secreted constantly.
      • Delta Cells (  ) produce somatostatin, which inhibits both glucagon and insulin.
    • The Endocrine System
      • Adrenal Glands
        • 2 small glands that sit atop both kidneys.
        • Each has 2 divisions, each with different functions.
      • the Adrenal Medulla secretes the catecholamine hormones norepinephrine and epinephrine (closely related to the sympathetic component of the autonomic nervous system).
    • The Endocrine System
      • The Adrenal Cortex secretes 3 classes of hormones, all steroid hormones:
        • gluticocorticoids mineralocorticoids
        • androgenic hormones
      • One at a time…
        • gluticocorticoids:
        • accounts for 95% of adrenal cortex hormone production
        •  the level of glucose in the blood
        • Released in response to stress, injury, or serious infection - like the hormones from the adrenal medulla.
    • The Endocrine System
      • Mineralocorticoids:
        • work to regulate the concentration of potassium and sodium in the body.
      • Prolonged  in adrenal cortex hormone results in Cushing’s Disease.
      • Signs & Symptoms of Cushing’s Disease:
        •   in blood sugar levels
        • unusual body fat distribution
        • rapid mood swings
    • The Endocrine System
      • And - if there is an  in mineralocorticoids as well
        • A serious electolyte imbalance will occur due to the  potassium excretion by the kidney, which results in hypokalemia.
      • Sodium can also be retained by the kidney, resulting in hyponatremia.
        • Causes:
          • dysrhythmias
          • coma
          • death
        • usually results from a tumor - TX? Removal of tumor.
    • The Endocrine System
      • Gonads and Ovaries :
        • the endocrine glands associated with human reproduction.
        • Female ovaries produce eggs
        • Male gonads produce sperm
      • both have endocrine functions.
      • Ovaries:
        • located in the abdominal cavity adjacent to the uterus.
        • Under the control of LH and FSH from the anterior pituitary they manufacture
          • estrogen
          • protesterone
    • The Endocrine System
      • Estrogen and Progesterone have several functions, including sexual development and preparation of the uterus for implantation of the egg.
      • Testes:
        • located in the scrotum
        • produce sperm for reproduction
        • manufacture testosterone -
          • promotes male growth and masculinization
        • Controlled by anterior pituitary hormones FSH and LH.
    • The Endocrine System
      • Endocrine Emergencies:
      • Diabetes Mellitus
        • one of the most common diseases in North America.
        •  insulin secretion by the Beta (  ) cells of the islets of Langerhans in the pancreas.
      • Complications of Diabetes:
        • contributes to heart disease
        • stroke
        • kidney disease
        • blindness
    • The Endocrine System
      • Pathophysiology of Diabetes:
      • Glucose Metabolism
        • Glucose (dextrose) is a simple sugar required by the body to produce energy.
        • Sugars, or carbohydrates, are 1 of 3 major food sources used by the body.
      • The other 2 major food sources are
        • proteins
        • fats
      • Most sugars in the human diet are complex and must be broken down into simple sugars: glucose, galactose and fructose - before use.
    • The Endocrine System
      • Breakdown of sugars is carried out by enzymes in the gastro intestinal system.
        • As simple sugars, these are absorbed from the GE system into the body.
        • More than 95% enter the body as glucose.
      • To be converted into energy, glucose must first be transmitted through the cell membrane. BUT - the glucose molecule is large and doesn’t readily diffuse through the cell membrane.
    • The Endocrine System
      • Glucose must pass into the cell by binding to a special carrier protein on the cell’s surface.
        • Facilitated diffusion - doesn’t use energy . The carrier protein binds with the glucose and carries it into the cell.
      • The rate at which glucose can enter the cell is dependent upon insulin levels.
        • Insulin serves as the messenger - travels via blood to target tissues.
        • Combines with specific insulin receptors on the surface of the cell membrane.