Anatomy Lecture Exam 2 Study

Name the cerebral arteries

Posterior cerebral artery

Middle cerebral artery

Anterior cerebral artery

Where do each of the cerebral arteries supply blood to the brain?

Posterior: Temporal and occipital

Middle: Frontal, parietal, temporal

Anterior: Frontal, parietal, and occipital lobes

Describe the Pineal body

• Produces melatonin

• Helps maintain the circadian rhythm

• When the environment is dark, more melatonin is produced; when its light less melatonin is produced.

• The cycle can be disrupted by too much light at night, too little in the day.

Describe the Medulla

• Inferior portion of the brain stem.

• Contains the cardiac, respiratory, and vasomotor centers.

• Autonomic functions of maintenance of heart rate, breathing, and blood pressure.

Describe the Pituitary gland

• Known as the “master gland.”

• Smaller than most glands that regulate hormones.

• Produces hormones that influence the thyroid gland, the adrenal gland, and the gonads (thyroid stimulating hormone, adrenocorticotropic, and gonadotropic hormone).

What does the pituitary gland produce?

Hormones: thyroid stimulating hormone, adrenocorticotropic, and gonadotropic hormone

Describe Stroke Traits as opposed to brain tumors

• Lack of blood, lack of oxygen to brain tissue; possible death of brain tissue.

• Four arteries supply all blood to the brain - vertebrals and internal carotids.

• Rapid onset.

• Implies death of brain tissue due to lack of oxygen.

Describe Brain tumors traits as opposed to strokes

• Slower onset (weeks or months).

• Implies brain compression by a “space occupying lesion.”

Why might a partially occluded vertebral artery cause fainting?

The vertebral artery is partially confined by neck (cervical) vertebrae, and twisting these vertebrae may cause distortion and further occlusion of the vertebral artery. Which means lack of blood flow, which means lack of oxygen.

Transient Ischemic Attack (TIA)

• Some call it a mini-stroke

• Usually passes quickly with little residual defect.

• Can be a sign of an increased risk of stroke

Give an Example of Functional deficits

Posterior cerebral arterial occlusion could result in oxygen deprivation of the occipital area, resulting in a stroke and possible blindness

What is Anastomosis

• The joining of two arteries.

• Communication between blood vessels by means of collateral channels, especially when usual routes are obstructed

Advantage of the circle of willis

Availability of blood from the unblocked side being reverted to the blocked site; creates redundancies and helps to avoid symptoms of ischemia

Bell’s Palsy

• Sudden weakness in muscles on one side of the face.

• Temporary weakness.

• ½ of face appears to droop.

• Smiles are one sided.

• Eye on affected side resists closing.

• Significantly improves over weeks.

• Some may have bell’s palsy for life (rare)

• Exact cause is unknown - May be due to a viral infection.

Know Cranial Nerves of the Eye

Superior oblique: trochlear nerve (CN4)

Lateral Rectus: Abducens (CN6)

All the rest (Superior Rectus, medial rectus, inferior rectus, inferior oblique): oculomotor (CN3)

Medial rectus action and innervation

innervated by CN lll, rotates eye inward

Lateral rectus

Innervated by CN VI, rotates eye outward

Superior rectus

innervated by CN III, rotates eye upward and inward

Inferior rectus

innervated by CN III, rotates eye downward and inward

Superior oblique

innervated by CN IV, rotates eye “down and out”

Inferior oblique

innervated by CN III, rotates eye upward and outward

Trigeminal Dermatomes

V1: Ophthalmic Division

V2: Maxillary Division

V3: Mandibular Division

V1: Ophthalmic Division

Sensory to skin of forehead, nose, nasal mucous membranes, cornea of eye, other structures.

V2: Maxillary Division

• Passes into foramen rotundum.

• Main branch exits through the infraorbital foramen. Sensory to skin of cheek, lower eyelid, upper jaw, teeth, maxillary sinus, and adjacent structures.

V3: Mandibular Division

• Passes through the foramen ovale.

• Sensory to skin of lower jaw, teeth, and gums, external ear, temporomandibular joint.

• A motor division of this nerve passes along with V3 to innervate muscles of mastication (chewing), namely the masseter muscle and temporalis muscle.

Trigeminal Neuralgia

• Nerve damage, inflammation of the trigeminal nerve.

• Sudden, intense pain on one side of the face; pain can feel like an electric shock.

• Cause is not clear.

Mumps

• Communicable viral disease.

• Parotid (salivary) gland (inflammation and swelling).

• Pain with chewing, swallowing, fever, muscle aches, fatigue.

• Can cause deafness, inflammation of testes, sterility.

Why does a scalp bleed heavily when cut?

Scalp has lots of blood vessels - vascular

Which arteries must not be injected by a dentist

Inferior alveolar

• injectate usually contains epinephrine (a vasoconstrictor) which then remains in area of termination of the artery, resulting in poor arterial perfusion of the area, possible death of tissue

Function of tonsils?

Tonsils are part of the lymphatic system. Defends the body from infection; tonsils contain a lot of white blood cells, which kill germs.

Apparent function of palate in mammals.

Suckling

Function of Eustachian (auditory) tube.

Protects the tympanic membrane (eardrum). Equalize pressure in the middle ear, drains middle ear.

Do all sinuses connect with atmosphere (can drain fluid)?

Yes

Why do vertebrates have sinuses?

Deal with pressure change, reduce weight, shock absorption, resonance.

Which bone normally breaks when a human is strangled?

Hyoid bone

Where could an emergency cricothyroidotomy be performed?

Cricothyroid membrane

Thyroid gland Features

• Butterfly shaped

• Two lobes

• Produces calcitonin

Parathyroid gland features

• Two pairs small, oval-shaped glands

• Produces parathyroid hormone that regulates blood calcium level

Hyperthyroidism (Graves)

• Overactive thyroid,thyroid gland produces to much of the hormone thyroxine

• Can accelerate body’s metabolism causing unintentional weight loss.

• Rapid, or irregular heartbeat.

• Bulging eyes

Hypothyroidism (Hashimotos)

• Underactive thyroid.

• Can cause obesity.

• Hair loss

• Joint pain, infertility, heart disease, fatigue

Which joint allows nodding?

Atlas, Atlanto-occipital.

What Joint allows Shaking head (no)?

Axis, Atlanto-axial

Define scoliosis.

Curvature of the spine, curve goes off to the side.

Describe lordosis. (Swayback)

Abnormally increased curvature of cervical and lumbar spine.

Describe kyphosis.

Curvature thoracic.

Hunchback (hyperkyphosis): worsens with age and osteoporosis; more common in women

Heart failure commonly swells which neck vein?

External jugular vein

Define stenosis

Narrowing or stricture of a anatomical tube

Where are the baroreceptors found (bp receptors)?

Located at the bifurcation of the carotid. Sends messages via CN IX (glossopharyngeal) to hypothalamus which sends autonomic response to heart to adjust and correct the potential problem.

What is a carotid body?

A group of cells near carotid bifurcation which are “chemoreceptors,” sensing the concentration of oxygen and carbon dioxide in the blood, also the pH, then sends messages via CN IX (glossopharyngeal) to hypothalamus which sends autonomic message to the medulla to change the respiratory rate appropriately.

Define a Goiter

Swelling of the thyroid gland.

What is the brachial plexus?

Network of nerves; landmark for anterior and posterior scalenes.

If you contract your right sternocleidomastoid muscle how will your head tilt?

Up and left.

Describe a pulled elbow

injury to annular ligament

Define joint capsule

thin, fibrosis sac containing fluid enclosed in a joint.

Define bursa

Closed sac of serous membrane which contains a thin layer of lubricating fluid secreted by the membrane

Define tendon sheath

A layer of membrane around a tendon

Define luxation

Dislocation of a joint.

Define subluxation

joint “out of place” but partially functional.

Partial dislocation

Describe what “double jointed” actually means

Hypermobility

Define flexion

decrease an angle of a joint.

Define extension

Increasing angle of a joint.

Define adduct

Moving toward medial plane

Define abduction

Moving away from the medial plane

What are the three joint types?

1. Fibrous

2. Cartilaginous

3. Synovial

Types of Cartilage

1. Hyaline

2. Elastic

3. Fibrous

Hyaline Cartilage Feature

Hyaline cartilage lines joints. It has little ducts that secrete synovial fluid to lubricate the joint to allow it to move freely.