Human Biology Exam 3 - Ch 9

Aphasia

Loss of language to the broca or wernicke area.

Parts of the brain

• Cerebrum - largest portion

• Cerebellum - Posterior

• Brain stem - turns into spinal cord after passing through hole in the skull

White matter

Myelinated axons. Found deep in the brain

Grey matter

Unmyelinated axons. Found superficial in brain

Ventricles

Spaces in the brain that produce and contain CSF. All fluid is connected by the ventricles 

Two lateral ventricles 

One on each hemisphere of the cerebrum 

Third ventricle

Between hemispheres of cerebrum

Fourth ventricle

Between cerebellum and brain stem. Becomes central canal in spinal cord.

Production of CSF

Produced by ependymal cells that line the ventricles and by choroid plexuses (the blood capillaries in the ventricles)

Functions of CSF

Regulate environment in CNS, provided buoyancy to the brain, and cushions the brain and spinal cord. 

Blood brain barrier

Regulates what can pass from blood to nervous tissue. Formed by tight junctions between epithelial cells in the capillaries. 

Diencephalon

Contains thalamus, hypothalamus (maintain homeostasis) and pineal gland (helps aid sleep). Where nerves of the eyes cross

Midbrain

Contains bumps; the visual and auditory reflex

Pons

Responsible for keeping us conscious. Damage is almost always a coma.

Medulla oblongata

Controls heart, breathing, bp. Damage is almost always death.

Cerebellum

• 10% of brains mass but 50% of brains neurons. 

• Composed of left and right hemisphere and is connected by the vermis. 

• Functions - motor coordination, evaluating sensory input, planning movement, judging passage time. 

Hemispheres of cerebrum

The two hemispheres are connected by the corpus callosum (bridge) and separated by the longitudinal fissure.

Contain convolutions with gyri and sulci 

Convolutions with gyri and sulci

• Convolutions - Wrinkles

• Gyri - Hills 

• Sulci - Valleys 

Frontal Lobe

What makes you, you. Contains memory, mood, decision making and primary motor cortex (coordinates and causes involuntary and voluntary muscle movement and where info crosses)

Parietal Lobe

Contains taste, language processing, and primary somatosensory cortex (primary response for sense of touch) 

Occipital Lobe

Contains vision (seeing things and processing what they are)

Temporal Lobe

Contains hearing, smell, emotions, and memory

Insula (Lobe)

Deep in the brain. Don’t know much about it because it is hard to get to. Contains taste, pain, and visceral sensation. 

Special senses

Vision, hearing, equilibrium, taste, and smell. Found in special sense organs in the head 

General senses

Touch, signals go to the somatosensory cortex. 

Wernicke area 

Understanding what we see and hear in the left hemisphere 

Broca area

Creating the muscle movements to speak in the left hemisphere.

Cerebral Lateralization

Both hemispheres carry out different functions; one thing happens in one hemisphere, and another thing happens in the other hemisphere. 

Sensory nerve 

Carries sensory information 

Motor nerve

Carries motor information

Mixed nerve

Carries both sensory and motor information

Sympathetic division

AKA fight or flight. Adapts the body for physical pain. Increases alertness, HR, BP, blood glucose, and respiration. Active when aroused, stressed, in danger, angry, or fearful. Blood goes more to muscles and less to digestive system. 

Parasympathetic division

AKA rest and digest. Calms the body. Decreases expenditure, carries out normal bodily functions. Blood goes less to muscles and more to digestive system. 

Does the sympathetic and parasympathetic nervous system work together?

Yes! They work together at the same time and shift depending on the situation.