The Brain Flashcards
Protection of CNS
Bone- skull and vertebrae surround the brain and spinal cord.
Meninges - 3 protective layers that hold cerebrospinal fluid
-Dura Matter: hardest layer, outermost layer
-Arachnoid: “spider web” middle layer
-Pia Matter: “soft”, deepest layer
Cerebrospinal Fluid- bathes brain tissue (between arachnoid and pia layer) and is in the central canal of the spinal cord called “ventricles”
-provides nutrients to brain, eliminates waste
-shock absorber
Ganglion
bundle of nerves
Dorsal root ganglion
brings sensory info into the spinal cord
Ventral root ganglion
carries motor info from spinal cord to effectors
Hindbrain Consists of:
- Medulla Oblongata
- The Pons
- The Cerebellum
Medulla oblongata
posterior portion of hindbrain and joins with the swollen extension of spinal cord
acts as site of connection between CNS and PNS
-regulates breathing, vomiting, circulatory roles, other involuntary muscle actions
-major site of coordination for autonomic NS
The Pons
means “bridge”
Located between midbrain and medulla
-acts as relay center between 2 sections of the cerebellum and between the cerebellum and medulla
Cerebellum
located beneath 2 hemispheres.
- largest section of hindbrain
- aka “little brain”
- receives sensory info from eyes, ears and info about position of limbs
- coordinates fine motor skills and muscular movement
- controls balance, coordination, posture and muscle tone
Midbrain
- consists of 4 spheres of grey matter
- acts as relay center for eye and ear reflexes
- sensory inputs (vision, smell, hearing, …)
Forebrain (7 Parts)
- Cerebrum
- Cerebral Cortex
- Limbic System
- Thalamus
- Hypothalamus
- Olfactory bulbs
- Pituitary Gland
Cerebrum
- Largest part of forebrain
- has LEFT and RIGHT hemispheres
- controls personality, complex thinking, languages, sense, speech, memory
- initiates voluntary movement
LEFT= logical/linear side RIGHT= creative/emotional
Cerebral Cortex
outer layer which surrounds cerebrum
- composed of grey matter
- has deep folds called FISSURES to increase surface area
Limbic System
Hippocampus: effects learning and memory
Amygdala: effects anger, avoidance, defensiveness, and fear.
together supports emotion, behaviour, long-term memory and olfaction
Thalamus
Located below cerebrum
-acts as relay center for sensory input, sorts and ships to appropriate part of cerebrum for interpretation
Very important in voluntary motor control
Hypothalamus
Below thalamus
-in charge of maintaining body’s internal equilibrium
-unites nervous system to endocrine
controls hunger, thirst, uterine contraction and milk ejection
