BIO 301 Lecture Notes - Lecture 1: Cremaster Muscle, Corpus Spongiosum Penis, Vas Deferens
Document Summary
Penis: organ of sexual intercourse, ejaculation, and excretion of urine: root: portion of the penis that extends internally into the pelvic cavity. Consist of 2 diverging crura: shaft: length of the penis between the glans and body, glans: head of the penis. Circumcision: surgically removing the foreskin the underside of the shaft. 2 corpora cavernosa: expandable spongy bodies, engorge with blood during arousal, contain the majority of sinusoids: collapsible tissue that engorges with blood during arousal. Corpus spongiosum: expandable spongy body that surrounds the urethra, and extends into the glans (lacks a capsule, spongy during an erection) Diameter ~1-1 flaccid, ~1 erect. Genes determine length and girth of the cavernosa tissue. Scrotum: sag of skin covering testicles (2 layers: skin and tunica dartos (smooth muscle) Tunica dartos: muscle in the middle layer of scrotum (contractions: cremaster muscle: (not part of the scrotum) smooth muscle that wraps.
