Neuroscience and Reproductive Anatomy Quiz

Term 1 Revision - Human Bioscience 2

• This revision is for the entire term, not just a common test.
• Students need to revise lecture content and McGraw Hill textbooks (2 ebooks).
• Avoid memorizing slides, focus on understanding concepts.
• Worksheets and post-lecture quizzes should be practiced for optimal preparation.
• Summary slides are available for practical class review.

Structure & Function of a Neuron

• Dendrites: Receive signals
• Cell body (soma): Contains the nucleus and organelles
• Axon: Carries signals to the next cell
• Myelin sheath: Insulates the axon, increasing speed of transmission
• Synapse (Axon terminal): Bulb-shaped endings that form a synapse with the next cell
• Neuroglia: Protects, supports, and regulates the environment
• Neuron: Transmits nerve impulses

Classification of Neurons

• Classified based on structure (unipolar/pseudounipolar, bipolar, and multipolar)
• Classified based on function (sensory, interneuron, and motor/efferent).
• Multipolar Neuron: Most common in the CNS and efferent neurons. It has two or more dendrites and one axon.
• Found in the sensory division.*
• Unipolar Neuron or pseudounipolar Neuron: Only one process emerging from the cell body; found in special sensory, olfactory epithelium etc.
• Bipolar neuron: Two processes extend from the cell body: one is an axon and one is a dendrite.

Information of Transmission in a Neuron

• Depolarization: Sodium channels open, sodium ions move into the cell, and membrane potential rises to +30 mV.
• Repolarization: Sodium channels close, voltage-gated potassium channels open, and potassium ions move out of the cell. Repolarization begins.
• Refractory Period: During this period, the membrane cannot respond to further stimulation.
• Action Potential: Process conducted along the axon length.
• Electrolytes (Na+, K+, CI-), and protein.

The Structure of a Typical Synapse

• Presynaptic neuron: Axon bulbs form synapses with a postsynaptic neuron.
• Synaptic cleft: Separates the presynaptic and postsynaptic neurons.
• Mitochondria: Provide energy.
• Synaptic vesicles: Contain neurotransmitters
• Postsynaptic neuron: Dendrite, cell body.
• Presynaptic membrane: The membrane of the axon bulb that releases neurotransmitter
• Postsynaptic membrane: The membrane of the dendrite or cell body that receives the neurotransmitter.
• Neurotransmitters: Chemical messengers released across the cleft to signal the next cell.

The Central Nervous System (CNS)

• Cerebrum (divided into lobes):

  • Frontal lobe: primary motor area, problem solving, conscious thoughts, higher-order functions.
  • Parietal lobe: Primary somatosensory area, processing sensory information.
  • Temporal lobe: primary auditory, memory and language comprehension area (Wernicke's area).
  • Occipital lobe: Primary visual area.

• Cerebellum

  • Coordination of voluntary movements; balance.

• Brain Stem

  • Midbrain: auditory and visual information relay station.
  • Pons: connects the cerebral cortex to cerebellum.
  • Medulla oblongata: vital autonomic functions (heart rate, breathing, blood pressure).

• Spinal Cord: Connects brain to body; involved in reflex actions; carries sensory and motor signals.

Protections of the CNS

• Bones: Skull and vertebral bones protect the brain and spinal cord; from mechanical damage.
• Meninges: Three layers (dura mater, arachnoid mater, pia mater) surround the CNS and protect it.
• Cerebrospinal fluid (CSF): A protective fluid that bathes the brain and spinal cord, filling the spaces.
• Blood-brain barrier: Regulates the passage of substances into the brain.

Clinical Notes

• Meningitis:

Inflammation of the meninges, predominantly caused by infections in cerebrospinal fluid. Diagnosis is through lumbar puncture (spinal tap).

• Stroke(CVA):

Cerebrovascular accident caused by blood flow blockage (ischemic) or rupture (hemorrhagic) in the brain, leading to oxygen deprivation.

• Aphasia:

Language disorder affecting communication, including difficulty with articulation and comprehension. Broca's and Wernicke's areas are implicated.

• Head Injury/Intracranial hemorrhage:

Severe head injuries can damage cerebral blood vessels, causing epidural, subdural, or subarachnoid hemorrhages.

Clinical Notes: Eye

• Cataract:

Opacity of the lens

• Conjunctivitis:

Irritation or damage to the conjunctiva

• Sty:

Infected sebaceous glands in the eyelid.

• Glaucoma:

Increased pressure inside the eyeball.

• Retinal Detachment:

Separation of the retina from the choroid layer.

• Diabetic & Hypertensive retinopathy:

Complications frequently requiring yearly eye checks for control.

Anatomy & Physiology of the Ear

• External Ear: Outer structures include the pinna and auditory canal.
  • The pinna is lined with hairs and modified sweat glands.
• Middle Ear: Three small bones (ossicles); auditory tube, equalizes air pressure across the tympanic membrane.
• Inner Ear: Semicircular canals; vestibular apparatus; cochlea where sound is transmitted.

Receptors

• Chemoreceptors: Respond to chemical stimulation (e.g., blood pH).
• Photoreceptors: Respond to light.
• Thermoreceptors: Respond to temperature changes.
• Mechanoreceptors: Respond to pressure, touch, and position (e.g., tactile receptors, proprioceptors).
• Nociceptors: Respond to pain.

Case Discussion

• Patients may have issues related to brain injuries, cranial nerves, facial muscle weakness or other underlying issues.
• Doctors need to determine causes, clinical features to formulate diagnosis and treatment plans and provide prognosis.

The Autonomic Nervous system

• Regulates involuntary processes, like heart rate and digestive processes.
• Parasympathetic and sympathetic branches, counteracting each other in coordinating functions within the body.

The Cranial Nerves

• 12 pairs of nerves attached to the brain, providing sensory and motor function to parts of the head, neck, and facial regions. The use of roman numerals and specific names differentiate between these nerves.

The Pituitary Gland

• Hormones produced by the anterior and posterior pituitary glands.
• Anterior pituitary: Thyroid-stimulating hormone (TSH); Adrenocorticotropic hormone (ACTH); Gonadotropic hormones; Prolactin.
• Posterior pituitary: Antidiuretic hormone (ADH); Oxytocin.

Hormones Regulating Blood Glucose:

• Insulin: Decreases blood sugar.
• Glucagon: Increases blood sugar, along with growth hormone, glucocorticoids, and norepinephrine.
• Hormones outside of the pancreas contribute during stress.

The Adrenal Glands

• Adrenal medulla: Short-term stress response; epinephrine (adrenaline) and norepinephrine.
• Adrenal cortex: Long-term stress response; glucocorticoids and mineralocorticoids.

The Pancreas & Endocrine Pancreatic Tissue (Islets of Langerhans)

• Endocrine pancreatic tissue is called pancreatic islets, containing A cells (secrete glucagon) and B cells (secrete insulin).

The Female Reproductive Tract:

• Gonads: Ovaries
• Ducts: Fallopian tubes, Uterus, and External genitalia.
• Secretion of female sex hormones: Estrogen and Progesterone

The Uterine Wall

• Endometrium: Functional layer for implantation, shed during menstruation. The basal layer under the functional layer regenerates.
• Myometrium: Middle muscle layer involved in contractions during labor.
• Perimetrium: Outer serous layer.

The Ovarian Cycle

• Cyclical process of egg maturation.
• Hormonal regulation.

The Male Reproductive Structures:

• Testes: Produce sperm, and sex hormones.
• Epididymis: Stores sperm.
• Vas Deferens: Conducts the sperm.
• Seminal Vesicles: Provides fluid to the semen.
• Prostate glands: Secrete fluid to semen.
• Bulbourethral glands: Contribute mucus-containing fluid to semen.
• Penis: Organ of Sexual Intercourse.

Clinical Notes Male Reproductive Health:

• Undescended Testicle: A testicle that hasn't descended into the scrotum before birth, increasing the risk of fertility issues and testicular carcinoma.
• Benign Prostatic Hyperplasia (BPH): Enlargement of the prostate gland in older men, potentially resulting in urinary obstruction.

Vitamin D3 synthesis

• Exposure to sunlight triggers synthesis in cholesterol in the epidermis.
• Vitamin D3 (inactive) gets activated in liver and kidneys to become calcitriol.
• Increased absorption of Calcium in the intestine.

###Why does exposure to sunlight darken skin?

• The skin will produce melanin to absorb ultraviolet radiation and protect the deeper layers of skin.

Skin Color Changes - Role of Dermal Circulation

• Flushed skin: High oxygenation creates a red appearance.
• Paling skin: Blood vessel constriction reduces blood flow.
• Anaemia: Decreased RBC production or blood loss.
• Cyanosis: Blue discoloration from insufficient blood oxygen.
• Jaundice: Yellow discoloration from bilirubin accumulation in the liver or RBC destruction.
• Orange hue: Too much carotene.

Five General Functions of the Integument

• Protection: Skin acts as a barrier.
• Temperature maintenance: Temperature regulation.
• Synthesis & storage of nutrients: Vitamin D3 synthesis.
• Sensory reception: Pain, pressure, touch, and temperature.
• Excretion & secretion: Excretion of waste; milk production

Test your knowledge on key concepts related to neuroscience and reproductive anatomy. This quiz covers topics such as cerebrospinal fluid acquisition, types of hemorrhages, aphasia characteristics, and the role of hormones in reproduction. Perfect for students studying biology or medicine.