Lab 3 reflexes and peripheral nerves

Dura Mater

_ most superficial layer of brain

Arachnoid

• Middle layer (Between dura and pia)

Pia Mater

• Deepest meningeal layer

Longitudinal fissure

• Separates the left and right hemispheres

Convulsions

• Gyri (ridges) of brain

• Sulci (grooves) of brain

Cerebrum

• Large front portion of the brain

• Responsible for higher brain functions EX: Thought, Action, and sensory processing

Cerebral hemispheres

• Left and right hemispheres

Cerebellum

• Inferior to cerebrum, behind the brainstem

• Coordination, balance, and fine motor control

Superior Corpora Quadrigemina

• -       Involved in visual processing and reflexes

  -       Help coordinate head and eye movements in response to visual stimuli

Inferior corpora quadrigemina

-       Involved in auditory processing

-       Relay auditory information from the ear to the thalamus and help with reflexive responses to sound

Olfactory Bulbs (1)

• Involve sense of smell (Sensory)

Optic Nerves (II)

• Sense of vision (Sensory)

Oculomotor (III)

• Eye Movement

• Eye dilation/Tracking (parasympathetic)

Trochlear nerve (IV)

• Eye Movement Up/Down (Motor)

• Adduction/Abduction of Eye

Trigeminal (V)

• Sensation of the face (sensory)

• Chewing muscles (Motor)

Abducens nerve (VI)

• Adduct/ Abduct eye

Facial Nerve

• Controls facial expression (Motor)

• Salivary glands

Vestibulocochlear nerve (VIII)

• Hearing and Balance (Sensory)

Glossopharyngeal (IX)

• Sense of taste (Sensory)

• Muscles that help swallow (motor)

Vagus (X)

• Innervates all internal organs

Accessory Nerve (XI)

• Controls neck muscles (sternocleidomastoid/trapezius)

Hypoglossal Nerve (XII)

• Tongue Movement

Corpus Callosum

• Location: Deep within the brain, connecting the left and right cerebral hemispheres.

• Function: Facilitates communication between the two hemispheres, integrating motor, sensory, and cognitive performances.

Lateral ventricle

• Location: C-shaped cavities located within each cerebral hemisphere.

• Function: Contain cerebrospinal fluid (CSF) that cushions the brain and removes waste.

Fornix

• Location: beneath the corpus callosum.

• Function: Connects the hippocampus to other brain regions, playing a role in memory formation.

Third Ventricle

• Location: A narrow cavity located in the midline between the two halves of the thalamus.

• Function: Circulates CSF and connects the lateral ventricles to the fourth ventricle via the cerebral aqueduct.

Thalamus

• Location: Situated above the brainstem, between the cerebral cortex and midbrain.

• Function: Acts as a relay station, transmitting sensory and motor signals to the cerebral cortex.​

Hypothalamus

• Location: Below the thalamus, forming the floor of the third ventricle.

• Function: Regulates vital bodily functions, including temperature, hunger, thirst, and hormone production.

Pineal Body

• Location: Near the center of the brain, between the two hemispheres, in a groove where the two halves of the thalamus join.

• Function: Secretes melatonin, regulating sleep-wake cycles.

Midbrain

• Location: Upper part of the brainstem, connecting the forebrain to the hindbrain.

• Function: Involved in vision, hearing, motor control, sleep/wake, arousal, and temperature regulation.

Cerebral aqueduct

• Location: A narrow channel running through the midbrain.

• Function: Connects the third and fourth ventricles, allowing CSF to flow between them.

Fourth ventricle

• Location: Located between the pons and the cerebellum.

• Function: Continues the flow of CSF from the cerebral aqueduct to the central canal of the spinal cord.

Cerebral peduncles

• Location: Structures on the front of the midbrain.

• Function: Contain motor tracts that convey information from the cerebral cortex to the brainstem and spinal cord.

Pons

• Location: Part of the brainstem, situated above the medulla oblongata and below the midbrain.

• Function: Relays signals between the forebrain and the cerebellum; involved in sleep, respiration, swallowing, and facial expressions.

Medulla Oblongata

• Location: Lowest part of the brainstem, connecting the brain to the spinal cord.

• Function: Controls autonomic functions such as breathing, heart rate, and blood pressure.

Cerebellum

• Location: Located at the back of the brain, beneath the occipital lobes.

• Function: Coordinates voluntary movements, balance, and posture.

Musculotaneous nerve

• Motor Function: Innervates the anterior compartment of the arm: biceps brachii, brachialis, and coracobrachialis.

• Sensory Function: Provides sensation to the lateral forearm via the lateral cutaneous nerve of the forearm.

Radial Nerve

• Motor Function: Supplies the posterior compartments of the arm and forearm, including triceps brachii, extensor muscles of the wrist and fingers.

• Sensory Function: Innervates the posterior arm, forearm, and dorsolateral hand.

Median Nerve

• Motor Function: Innervates most of the anterior forearm muscles (except flexor carpi ulnaris and part of flexor digitorum profundus) and thenar muscles in the hand.

• Sensory Function: Provides sensation to the lateral palm and the palmar side of the thumb, index, middle, and half of the ring finger.

Ulnar Nerve

• Motor Function: Supplies flexor carpi ulnaris, the medial part of flexor digitorum profundus, and most intrinsic hand muscles.

• Sensory Function: Innervates the medial one and a half fingers on both palmar and dorsal sides.

Femoral Nerve

• Motor Function: Innervates the anterior thigh muscles, including quadriceps femoris, sartorius, and pectineus.

• Sensory Function: Provides sensation to the anterior thigh and medial leg via the saphenous nerve.

Sciatic Nerve

• Motor Function: Innervates the posterior thigh muscles (hamstrings) and all muscles of the leg and foot via its branches.

• Sensory Function: Provides sensation to the lateral leg and foot through its branches.

Tibial Nerve

• Motor Function: Supplies the posterior compartment of the leg and the plantar muscles of the foot.

• Sensory Function: Innervates the sole of the foot.

Common fibular nerve

• Motor Function: Divides into:

  • Superficial Peroneal Nerve: Innervates the lateral compartment of the leg (fibularis longus and brevis).

  • Deep Peroneal Nerve: Supplies the anterior compartment of the leg (tibialis anterior, extensor muscles).